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In the present study we evaluated a core set of 254 cowpea genotypes for seven pod physical traits and shattering score using a modified weighted average screening system based on random impact assessment. There was substantial variability in all the pod physical traits and shattering score in the cowpea core collection indicating significant diversity of the material in respect of pod traits. Shattering score had a mean value of 5.39 with a range of 0–10. Out of 254 genotypes, 34 were resistant, 83 were moderately resistant, 82 were moderately susceptible and 55 were highly susceptible. Shattering score had significant negative correlation with pod length followed by pod weight, pod breadth, seeds per pod, pod wall weight and pod thickness. PCA concentrated 69.60% variability in the first two principal components with Eigen value of 4.49 for PC1 and 1.07 for PC2, mainly contributed by pod weight, pod length, pod breadth, pod thickness and pod wall weight. The conventional screening methods are based on level of shattering and do not take into account various types of shattering such as fissured, split, twisted or abscised. The present was aimed at identification of shattering resistant genotypes using a modified screening method based on weighted level averages. The study identified several genotypes highly resistant to pod shattering that can be used to develop shattering resistant cowpea varieties for sustainable cowpea farming and highlights the effectiveness of proposed screening method. [ABSTRACT FROM AUTHOR]

Abstract Background Understanding the genetic control of pod shatter resistance and its association with pod length is crucial for breeding improved pod shatter resistance and reducing pre-harvest yield losses due to extensive shattering in cultivars of Brassica species. In this study, we evaluated a doubled haploid (DH) mapping population derived from an F1 cross between two Brassica carinata parental lines Y-BcDH64 and W-BcDH76 (YWDH), originating from Ethiopia and determined genetic bases of variation in pod length and pod shatter resistance, measured as rupture energy. The YWDH population, its parental lines and 11 controls were grown across three years for genetic analysis. Results By using three quantitative trait loci (QTL) analytic approaches, we identified nine genomic regions on B02, B03, B04, B06, B07 and C01 chromosomes for rupture energy that were repeatedly detected across three growing environments. One of the QTL on chromosome B07, flanked with DArTseq markers 100,046,735 and 100,022,658, accounted for up to 27.6% of genetic variance in rupture energy. We observed no relationship between pod length and rupture energy, suggesting that pod length does not contribute to variation in pod shatter resistance. Comparative mapping identified six candidate genes; SHP1 on B6, FUL and MAN on chromosomes B07, IND and NST2 on B08, and MAN7 on C07 that mapped within 0.2 Mb from the QTL for rupture energy. Conclusion The results suggest that favourable alleles of stable QTL on B06, B07, B08 and C01 for pod shatter resistance can be incorporated into the shatter-prone B. carinata and its related species to improve final seed yield at harvest.

Pod shattering is an undesirable process leading to loss of harvestable yields. In the present study, we sought to undertake the first comprehensive phenotyping in 254 bean (Phaseolus vulgaris L.) genotypes for pod shattering including various mechanistic aspects as well as assess natural variation in the germplasm set for 16 seed physical traits including shattering score. There was substantial variability in 16 pod physical traits in the material. Significant diversity of the material in respect of pod traits was indicated by the broad range and coefficient of variation (CV) values. Using Random Impact Assessment (RIA), we found substantial variability in pod shattering score in common bean genotypes indicating significant diversity. Shattering score had a mean value of 6.098 with a range of 1.07 to 9.13. Highest shattering score was recorded in WB-6, WB-20-247, and N-7 while the lowest value for shattering score was recorded in WB-1129 and WB-216. Shattering score was negatively correlated with pod thickness (r = -0.698) followed by ventral/dorsal length ratio (r = -0.468) and positively correlated with breadth/thickness ratio (r = 0.599) and string % (r = 0.590). The principal component analysis (PCA) concentrated 86.91% variability in the first five principal components, and the first two PCs accounted for 55.62% of the total variation.

Background: Understanding the genetic control of pod shatter resistance and its association with pod length is crucial for breeding improved pod shatter resistance and reducing pre-harvest yield losses due to extensive shattering in cultivars of Brassica species. In this study, we evaluated a doubled haploid (DH) mapping population derived from an F1 cross between two Brassica carinata parental lines Y-BcDH64 and W-BcDH76 (YWDH), originating from Ethiopia and determined genetic bases of variation in pod length and pod shatter resistance, measured as rupture energy. The YWDH population, its parental lines and 11 controls were grown across three years for genetic analysis. Results: By using three quantitative trait loci (QTL) analytic approaches, we identified nine genomic regions on B02, B03, B04, B06, B07 and C01 chromosomes for rupture energy that were repeatedly detected across three growing environments. One of the QTL on chromosome B07, flanked with DArTseq markers 100,046,735 and 100,022,658, accounted for up to 27.6% of genetic variance in rupture energy. We observed no relationship between pod length and rupture energy, suggesting that pod length does not contribute to variation in pod shatter resistance. Comparative mapping identified six candidate genes; SHP1 on B6, FUL and MAN on chromosomes B07, IND and NST2 on B08, and MAN7 on C07 that mapped within 0.2 Mb from the QTL for rupture energy. Conclusion: The results suggest that favourable alleles of stable QTL on B06, B07, B08 and C01 for pod shatter resistance can be incorporated into the shatter-prone B. carinata and its related species to improve final seed yield at harvest. [ABSTRACT FROM AUTHOR]

Pod shattering is a major production constraint of soybean [Glycine max (L.)]. The objectives of this study were to (i) estimate heritability for pod shattering resistance, (ii) determine the frequency of the pod shattering resistance allele pdh1 in the International Institute for Tropical Agriculture (IITA) soybean germplasm and Zambian commercial varieties, and (iii) determine the effectiveness of the DNA marker for the pod shattering resistance allele pdh1. A total of 59 genotypes were evaluated for pod shattering in field trials conducted in Malawi and Zambia and genotyped with a marker for pdh1. TGx2002‐8FM and TGx2002‐9FM were the most resistant among genotypes in early and medium maturity classes and can be used for genetic enhancement of pod shattering resistance in these specific maturity classes. Narrow sense heritability estimates for pod shattering ranged from 0.27 to 0.80. Of the 59 genotypes, 57 (96.6%) carried the resistance allele pdh1 while only two genotypes (3.6%) carried the susceptible allele, suggesting near‐fixation of the resistance allele pdh1 in the IITA germplasm. The marker for pdh1 was highly effective in selecting resistant genotypes. [ABSTRACT FROM AUTHOR]

The ever-increasing impact of global climate change has profoundly affected crop growth, physiology, and yield characteristics, making them an economic hazard. Canola, a vital crop, is particularly susceptible to environmental challenges at any stage of development, which can have a negative impact on its growth, physiology, and pod formation, ultimately resulting in pod shattering and reduced yield. Canola's rate of return is decreased by mechanical harvesting, which results in pod shattering. The establishment of an abscission layer, triggered by enzymatic and hormonal disruptions, and accompanied by a decline in cell wall stickiness, exacerbates pod shattering. In this context, the potential roles of Paclobutrazol and silver nanoparticles in reinforcing pod strength to withstand shattering. The specific doses of both AgNPs and Paclobutrazol could be done on the aerial parts of plant. These elements facilitate the physiological growth of crops by mitigating the adverse effects of stress on canola, thereby reducing pod shattering and enhancing yield output. This critical review aims to comprehensively explore the physiological, enzymatic, and hormonal-based factors contributing to pod shattering under environmental stresses, while also highlighting the potential mitigation techniques employing Paclobutrazol and silver nanoparticles, to elevate canola yield production. Based on this comprehensive review, it is recommended to organize research experiment to explore the potential of AgNPs and Paclobutrazol in mitigating the pod shattering based yield losses in canola. [ABSTRACT FROM AUTHOR]

Abstract Pod shattering is a major production constraint of soybean [Glycine max (L.)]. The objectives of this study were to (i) estimate heritability for pod shattering resistance, (ii) determine the frequency of the pod shattering resistance allele pdh1 in the International Institute for Tropical Agriculture (IITA) soybean germplasm and Zambian commercial varieties, and (iii) determine the effectiveness of the DNA marker for the pod shattering resistance allele pdh1. A total of 59 genotypes were evaluated for pod shattering in field trials conducted in Malawi and Zambia and genotyped with a marker for pdh1. TGx2002‐8FM and TGx2002‐9FM were the most resistant among genotypes in early and medium maturity classes and can be used for genetic enhancement of pod shattering resistance in these specific maturity classes. Narrow sense heritability estimates for pod shattering ranged from 0.27 to 0.80. Of the 59 genotypes, 57 (96.6%) carried the resistance allele pdh1 while only two genotypes (3.6%) carried the susceptible allele, suggesting near‐fixation of the resistance allele pdh1 in the IITA germplasm. The marker for pdh1 was highly effective in selecting resistant genotypes.

Pod shattering is an undesirable process leading to loss of harvestable yields. In the present study, we sought to undertake the first comprehensive phenotyping in 254 bean (Phaseolus vulgaris L.) genotypes for pod shattering including various mechanistic aspects as well as assess natural variation in the germplasm set for 16 seed physical traits including shattering score. There was substantial variability in 16 pod physical traits in the material. Significant diversity of the material in respect of pod traits was indicated by the broad range and coefficient of variation (CV) values. Using Random Impact Assessment (RIA), we found substantial variability in pod shattering score in common bean genotypes indicating significant diversity. Shattering score had a mean value of 6.098 with a range of 1.07 to 9.13. Highest shattering score was recorded in WB-6, WB-20-247, and N-7 while the lowest value for shattering score was recorded in WB-1129 and WB-216. Shattering score was negatively correlated with pod thickness (r = -0.698) followed by ventral/dorsal length ratio (r = -0.468) and positively correlated with breadth/thickness ratio (r = 0.599) and string % (r = 0.590). The principal component analysis (PCA) concentrated 86.91% variability in the first five principal components, and the first two PCs accounted for 55.62% of the total variation. [ABSTRACT FROM AUTHOR]

Context: Agronomical traits like loss of seed dispersal targeted by ancient human selection are an important milestone of crop domestication. Evolution in plant species is a result of natural and human selection at the time of domestication. Evolution leads to continued improvement of adaptive traits in almost all plant species. Aims: Pod shattering, one of the examples of convergent evolution, is defined as breaking up of the pod shell enabling the successful dispersal of seeds mainly in wild species. Since the available climate change models predict an increase in aridity, it is expected that the losses on account of shattering will be aggravated, especially in dry areas. Methods: Histological studies and biochemical parameters are increasingly used as surrogates for pod shattering response as they provide key inputs for selecting contrasting genotypes based on differential lignification, role of pectin, fibre, cellulose and total carbohydrate content as well as enzymes such as endopolygalacturonase and β-glucanase and hormones. Key results: There is diversity for level of shattering, with race Nueva Granada showing higher rates of pod shattering as compared to the Durango and Jalisco races. Genomics has helped identify several genes or quantitative trait loci (QTL) such as PDH-1, St-1, SHAT-1, WRKY1 and MYB26 that are implicated in various traits related to pod shattering. Conclusions: Plant breeders need to introgress shattering resistance into commercial varieties to mitigate the imminent yield losses. Implications: This requires an in-depth knowledge of mechanistic, physiological, biochemical and the underlying genetic basis of pod shattering resistance. Common bean is an important legume crop that has long been used as a staple food. Pod shattering is an important early trait to be selected against in crop domestication. Introgression of shattering resistance into commercial varieties could mitigate the imminent yield losses. [ABSTRACT FROM AUTHOR]

Abstract Background The pod shattering (PS) trait negatively affects the crop yield in rapeseed especially under dry conditions. To better understand the trait and cultivate higher resistance varieties, it’s necessary to identify key genes and unravel the PS mechanism thoroughly. Results In this study, we conducted a comparative transcriptome analysis between two materials significantly different in silique shatter resistance lignin deposition and polygalacturonase (PG) activity. Here, we identified 10,973 differentially expressed genes at six pod developmental stages. We found that the late pod development stages might be crucial in preparing the pods for upcoming shattering events. GO enrichment results from K-means clustering and weighed gene correlation network analysis (WGCNA) both revealed senescence-associated genes play an important role in PS. Two hub genes Bna.A05ABI5 and Bna.C03ERF/AP2-3 were selected from the MEyellow module, which possibly regulate the PS through senescence-related mechanisms. Further investigation found that senescence-associated transcription factor Bna.A05ABI5 upregulated the expression of SAG2 and ERF/AP2 to control the shattering process. In addition, the upregulation of Bna.C03ERF/AP2-3 is possibly involved in the transcription of downstream SHP1/2 and LEA proteins to trigger the shattering mechanism. We also analyzed the PS marker genes and found Bna.C07SHP1/2 and Bna.PG1/2 were significantly upregulated in susceptible accession. Furthermore, the role of auxin transport by Bna.WAG2 was also observed, which could reduce the PG activity to enhance the PS resistance through the cell wall loosening process. Conclusion Based on comparative transcriptome evaluation, this study delivers insights into the regulatory mechanism primarily underlying the variation of PS in rapeseed. Taken together, these results provide a better understanding to increase the yield of rapeseed by reducing the PS through better engineered crops.

Pod shatter is a trait of agricultural relevance that ensures plants dehisce seeds in their native environment and has been subjected to domestication and selection for non-shattering types in several broadacre crops. However, pod shattering causes a significant yield reduction in canola (Brassica napus L.) crops. An interspecific breeding line BC95042 derived from a B. rapa/B. napus cross showed improved pod shatter resistance (up to 12-fold than a shatter-prone B. napus variety). To uncover the genetic basis and improve pod shatter resistance in new varieties, we analysed F2 and F2:3 derived populations from the cross between BC95042 and an advanced breeding line, BC95041, and genotyped with 15,498 DArTseq markers. Through genome scan, interval and inclusive composite interval mapping analyses, we identified seven quantitative trait loci (QTLs) associated with pod rupture energy, a measure for pod shatter resistance or pod strength, and they locate on A02, A03, A05, A09 and C01 chromosomes. Both parental lines contributed alleles for pod shatter resistance. We identified five pairs of significant epistatic QTLs for additive x additive, additive dominance and dominance x dominance interactions between A01/C01, A03/A07, A07/C03, A03/C03, and C01/C02 chromosomes for rupture energy. QTL effects on A03/ A07 and A01/C01 were in the repulsion phase. Comparative mapping identified several candidate genes (AG, ABI3, ARF3, BP1, CEL6, FIL, FUL, GA2OX2, IND, LATE, LEUNIG, MAGL15, RPL, QRT2, RGA, SPTand TCP10) underlying main QTL and epistatic QTL interactions for pod shatter resistance. Three QTLs detected on A02, A03, and A09 were near the FUL (FRUITFULL) homologues BnaA03g39820D and BnaA09g05500D. Focusing on the FUL, we investigated putative motifs, sequence variants and the evolutionary rate of its homologues in 373 resequenced B. napus accessions of interest. BnaA09g05500D is subjected to purifying selection as it had a low Ka/Ks ratio compared to other FUL homologues in B. napus. This study provides a valuable resource for genetic improvement for yield through an understanding of the genetic mechanism controlling pod shatter resistance in Brassica species. [ABSTRACT FROM AUTHOR]

Pod coloration is a domestication-related trait in soybean, with modern cultivars typically displaying brown or tan pods, while their wild relative, Glycine soja , possesses black pods. However, the factors regulating this color variation remain unknown. In this study, we cloned and characterized L1 , the classical locus responsible for black pods in soybean. By using map-based cloning and genetic analyses, we identified the causal gene of L1 and revealed that it encodes a hydroxymethylglutaryl-coenzyme A (CoA) lyase-like (HMGL-like) domain protein. Biochemical assays showed that L1 functions as a eucomic acid synthase and facilitates the synthesis of eucomic acid and piscidic acid, both of which contribute to coloration of pods and seed coats in soybean. Interestingly, we found that L1 plants are more prone to pod shattering under light exposure than l1 null mutants because dark pigmentation increases photothermal efficiency. Hence, pleiotropic effects of L1 on pod color and shattering, as well as seed pigmentation, likely contributed to the preference for l1 alleles during soybean domestication and improvement. Collectively, our study provides new insights into the mechanism of pod coloration and identifies a new target for future de novo domestication of legume crops. This study characterizes the domestication-associated L1 gene and demonstrates that it encodes an HMGL-like domain protein that functions as a eucomic acid synthaseand facilitates the synthesis of eucomic acid and piscidic acid, both of which contribute to the black color of soybean pods. Black-podded L1 plants are more susceptible to pod shattering due to the higher photothermal efficiency of dark pigmentation, potentially contributing to selection of l1 alleles with lighter pod color during domestication and improvement of soybeans. [ABSTRACT FROM AUTHOR]

The resistance to pod shattering is an important trait of the soybean crop, which helps to preserve the yield. This characteristic can be influenced by genotype, as well as by many environmental factors. The careful selection of cultivars resistant to pod shattering, combined with good practices during harvest, can greatly help to reduce the seed losses. The aim of the present study was to evaluate a part of the Bulgarian soybean (Glycine max L.) collection, stored in the National gene bank, for its resistance to pod shattering under different humidity conditions. The energy consumed to shattering a single pod and the proportion of pod shattering as a function of the moisture content, were also the subjects of the current study. The highest energy of pod shattering was reported for sample BGR3171, followed by BGR1827, BGR4177 and two Bulgarian varieties (Avigeya and Mira). The lowest energy was found for sample BGR37971. In a moisture range of 12% to 16%, about 60% of the studied soybean samples showed pod shattering. At humidity w < 8%, the proportion of pod shattering reached to 100%. As a result of the study, it was found that the soybean collection has a rich genetic potential for future breeding work in terms of pod shattering resistance. [ABSTRACT FROM AUTHOR]

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Plant domestication has strongly modified crop morphology and development. Nevertheless, many crops continue to display atavistic characteristics that were advantageous to their wild ancestors but are deleterious under cultivation, such as pod dehiscence (PD). Here, we provide the first comprehensive assessment of the inheritance of PD in the common bean (Phaseolus vulgaris), a major domesticated grain legume. Using three methods to evaluate the PD phenotype, we identified multiple, unlinked genetic regions controlling PD in a biparental population and two diversity panels. Subsequently, we assessed patterns of orthology among these loci and those controlling the trait in other species. Our results show that different genes were selected in each domestication and ecogeographic race. A chromosome Pv03 dirigent-like gene, involved in lignin biosynthesis, showed a base-pair substitution that is associated with decreased PD. This haplotype may underlie the expansion of Mesoamerican domesticates into northern Mexico, where arid conditions promote PD. The rise in frequency of the decreased-PD haplotype may be a consequence of the markedly different fitness landscape imposed by domestication. Environmental dependency and genetic redundancy can explain the maintenance of atavistic traits under domestication.

Pod shatter is a trait of agricultural relevance that ensures plants dehisce seeds in their native environment and has been subjected to domestication and selection for non-shattering types in several broadacre crops. However, pod shattering causes a significant yield reduction in canola (Brassica napus L.) crops. An interspecific breeding line BC95042 derived from a B. rapa/B. napus cross showed improved pod shatter resistance (up to 12-fold than a shatter-prone B. napus variety). To uncover the genetic basis and improve pod shatter resistance in new varieties, we analysed F2 and F2:3 derived populations from the cross between BC95042 and an advanced breeding line, BC95041, and genotyped with 15,498 DArTseq markers. Through genome scan, interval and inclusive composite interval mapping analyses, we identified seven quantitative trait loci (QTLs) associated with pod rupture energy, a measure for pod shatter resistance or pod strength, and they locate on A02, A03, A05, A09 and C01 chromosomes. Both parental lines contributed alleles for pod shatter resistance. We identified five pairs of significant epistatic QTLs for additive x additive, additive dominance and dominance x dominance interactions between A01/C01, A03/A07, A07/C03, A03/C03, and C01/C02 chromosomes for rupture energy. QTL effects on A03/A07 and A01/C01 were in the repulsion phase. Comparative mapping identified several candidate genes (AG, ABI3, ARF3, BP1, CEL6, FIL, FUL, GA2OX2, IND, LATE, LEUNIG, MAGL15, RPL, QRT2, RGA, SPT and TCP10) underlying main QTL and epistatic QTL interactions for pod shatter resistance. Three QTLs detected on A02, A03, and A09 were near the FUL (FRUITFULL) homologues BnaA03g39820D and BnaA09g05500D. Focusing on the FUL, we investigated putative motifs, sequence variants and the evolutionary rate of its homologues in 373 resequenced B. napus accessions of interest. BnaA09g05500D is subjected to purifying selection as it had a low Ka/Ks ratio compared to other FUL homologues in B. napus. This study provides a valuable resource for genetic improvement for yield through an understanding of the genetic mechanism controlling pod shatter resistance in Brassica species.

Background: The pod shattering (PS) trait negatively affects the crop yield in rapeseed especially under dry conditions. To better understand the trait and cultivate higher resistance varieties, it's necessary to identify key genes and unravel the PS mechanism thoroughly. Results: In this study, we conducted a comparative transcriptome analysis between two materials significantly different in silique shatter resistance lignin deposition and polygalacturonase (PG) activity. Here, we identified 10,973 differentially expressed genes at six pod developmental stages. We found that the late pod development stages might be crucial in preparing the pods for upcoming shattering events. GO enrichment results from K-means clustering and weighed gene correlation network analysis (WGCNA) both revealed senescence-associated genes play an important role in PS. Two hub genes Bna.A05ABI5 and Bna.C03ERF/AP2-3 were selected from the MEyellow module, which possibly regulate the PS through senescence-related mechanisms. Further investigation found that senescence-associated transcription factor Bna.A05ABI5 upregulated the expression of SAG2 and ERF/AP2 to control the shattering process. In addition, the upregulation of Bna.C03ERF/AP2-3 is possibly involved in the transcription of downstream SHP1/2 and LEA proteins to trigger the shattering mechanism. We also analyzed the PS marker genes and found Bna.C07SHP1/2 and Bna.PG1/2 were significantly upregulated in susceptible accession. Furthermore, the role of auxin transport by Bna.WAG2 was also observed, which could reduce the PG activity to enhance the PS resistance through the cell wall loosening process. Conclusion: Based on comparative transcriptome evaluation, this study delivers insights into the regulatory mechanism primarily underlying the variation of PS in rapeseed. Taken together, these results provide a better understanding to increase the yield of rapeseed by reducing the PS through better engineered crops. [ABSTRACT FROM AUTHOR]

Pod shattering is an important domesticated trait which can cause great economic loss of crop yield in cultivated soybean. In this study, we utilized two recombinant inbred line populations (RILs, CY, Huachun 2×Wayao; GB, Guizao 1× B13) to identify quantitative trait loci (QTLs) associated with pod shattering in soybean across multiple environments. A total of 14 QTLs for pod shattering were identified in the two RIL populations, which had LOD scores ranging from 2.64 to 44.33 with phenotypic variance explanation (PVE) ranging from 1.33 to 50.85%. One QTL qPS16-1, located on chromosome 16, included a well-known functional gene Poddehiscence1 (Pdh1) that was reported previously. Ten new putative QTLs were validated in two RIL populations, and their LOD scores were between 2.55 and 4.24, explaining 1.33 to 2.60% of the phenotypic variation. Of which four novel QTLs (qPS01-1, qPS03-2, qPS05-1, and qPS07-1) could be detected in two environments where nine genes had specific changes in gene expression. Although the nine genes may have significant effects on pod shattering of soybean, their detailed functions still need to be further explored in the future. The results of this study will facilitate a better understanding of the genetic basis of the pod shattering-resistant trait and benefit soybean molecular breeding for improving pod shattering resistance.

Phaseolus vulgaris L., known as common bean, is one of the most important grain legumes cultivated around the world for its immature pods and dry seeds, which are rich in protein and micronutrients. Common bean offers a cheap food and protein sources to ameliorate food shortage and malnutrition around the world. However, the genetic basis of most important traits in common bean remains unknown. This study aimed at identifying QTL and candidate gene models underlying twenty-six agronomically important traits in common bean. For this, we assembled and phenotyped a diversity panel of 200 P. vulgaris genotypes in the greenhouse, comprising determinate bushy, determinate climbing and indeterminate climbing beans. The panel included dry beans and snap beans from different breeding programmes, elite lines and landraces from around the world with a major focus on accessions of African, European and South American origin. The panel was genotyped using a cost-conscious targeted genotyping-by-sequencing (GBS) platform to take advantage of highly polymorphic SNPs detected in previous studies and in diverse germplasm. The detected single nucleotide polymorphisms (SNPs) were applied in marker-trait analysis and revealed sixty-two quantitative trait loci (QTL) significantly associated with sixteen traits. Gene model identification via a similarity-based approach implicated major candidate gene models underlying the QTL associated with ten traits including, flowering, yield, seed quality, pod and seed characteristics. Our study revealed six QTL for pod shattering including three new QTL potentially useful for breeding. However, the panel was evaluated in a single greenhouse environment and the findings should be corroborated by evaluations across different field environments. Some of the detected QTL and a number of candidate gene models only elucidate the understanding of the genetic nature of these traits and provide the basis for further studies. Finally, the study showed the possibility of using a limited number of SNPs in performing marker-trait association in common bean by applying a highly scalable targeted GBS approach. This targeted GBS approach is a cost-efficient strategy for assessment of the genetic basis of complex traits and can enable geneticists and breeders to identify novel loci and targets for marker-assisted breeding more efficiently. [ABSTRACT FROM AUTHOR]

Western Himalayan region is a rich repository of common bean genetic resources evolved over generations of farmer selection. The bean variability encompasses various use categories such as dry, snap and shelled beans. The present study aimed to characterize 40 small-seeded red common bean genotypes collected from different districts of Kashmir valley as well as Poonch, Rajouri and Bhaderwah areas of Jammu which are world famous for their beans. Based on 5-year evaluation, there was substantial variability for various qualitative traits as well as quantitative traits. Among variability parameters, higher PCV and GCV values were recorded for plant height, seed yield per plant and number of pods per plant and low for days to maturity, seed length and pod length. High heritability was recorded for all the traits ranging from 78.72 to 94.87%. There was substantial variability in root traits scored in laboratory and greenhouse as well as canopy temperature depression and relative water content. Various genotypes were found resistant to bean common mosaic virus (WB-N-1, WB-N-11, WB-1318, WB-401, WB-451, WB-1634); anthracnose (WB-1634 WB-83, WB-258, WB-1282, WB-1304); angular leaf spot (WB-6, WB-1634, WB-258, WB-451, N-1 and N-10); Fusarium wilt (WB-341, WB-451, WB-N-1 and WB-1587) and Ascochyta blight (WB-6). Similarly WB-92 was highly resistant to shattering. The genotypes WB-341, WB-1634, WB-N-1 performed better under water stress, WB-N-1 and WB-1634 were resistant to multiple diseases and WB-1634 had better cooking quality. The genotypes identified can be used in bean improvement programmes and have also been submitted to NBPGR for long-term storage. [ABSTRACT FROM AUTHOR]

Phaseolus vulgaris L., known as common bean, is one of the most important grain legumes cultivated around the world for its immature pods and dry seeds, which are rich in protein and micronutrients. Common bean offers a cheap food and protein sources to ameliorate food shortage and malnutrition around the world. However, the genetic basis of most important traits in common bean remains unknown. This study aimed at identifying QTL and candidate gene models underlying twenty-six agronomically important traits in common bean. For this, we assembled and phenotyped a diversity panel of 200 P. vulgaris genotypes in the greenhouse, comprising determinate bushy, determinate climbing and indeterminate climbing beans. The panel included dry beans and snap beans from different breeding programmes, elite lines and landraces from around the world with a major focus on accessions of African, European and South American origin. The panel was genotyped using a cost-conscious targeted genotyping-by-sequencing (GBS) platform to take advantage of highly polymorphic SNPs detected in previous studies and in diverse germplasm. The detected single nucleotide polymorphisms (SNPs) were applied in marker-trait analysis and revealed sixty-two quantitative trait loci (QTL) significantly associated with sixteen traits. Gene model identification via a similarity-based approach implicated major candidate gene models underlying the QTL associated with ten traits including, flowering, yield, seed quality, pod and seed characteristics. Our study revealed six QTL for pod shattering including three new QTL potentially useful for breeding. However, the panel was evaluated in a single greenhouse environment and the findings should be corroborated by evaluations across different field environments. Some of the detected QTL and a number of candidate gene models only elucidate the understanding of the genetic nature of these traits and provide the basis for further studies. Finally, the study showed the possibility of using a limited number of SNPs in performing marker-trait association in common bean by applying a highly scalable targeted GBS approach. This targeted GBS approach is a cost-efficient strategy for assessment of the genetic basis of complex traits and can enable geneticists and breeders to identify novel loci and targets for marker-assisted breeding more efficiently.

Soybean is one of the most valuable commercial crops because of its high protein, carbohydrate, and oil content. The land area cultivated with soybean in subtropical regions, such as Brazil, is continuously expanding, in some instances at the expense of carbon storing natural habitats. Strategies to decrease yield/seed losses and increase production efficiency are urgently required to meet global demand for soybean in a sustainable manner. Here, we evaluated the effectiveness of an Ascophyllum nodosum extract (ANE), SealicitTM, in increasing yields of different soybean varieties, in two geographical regions (Canada and Brazil). In addition, we investigated the potential of SealicitTM to reduce pod shattering at the trials in Brazil. Three different concentrations of SealicitTM were applied to pod shatter-susceptible (SS) UFUS 6901 and shatter-resistant (SR) UFUS 7415 varieties to assess their impact on pod firmness. SS variety demonstrated a significant decrease in pod shattering, which coincided with deregulation of GmPDH1.1 and GmSHAT1–5 expression, genes that determine pod dehiscence, and higher seed weight per pod. SealicitTM application to the SR variety did not significantly alter its inherent pod shatter resistance, but provided higher increases in seed yield at harvest. This yield increase maybe associated with to other yield components stimulated by the biostimulant. This work demonstrates that SealicitTM, which has previously been shown to improve pod firmness in Arabidopsis and selected commercial oilseed rape varieties through IND gene down-regulation, also has the potential to improve pod resistance and seed productivity in soybean, a member of the legume family sharing a similar strategy for seed dispersal.

Abstract Background The changing climate and the desire to use renewable oil sources necessitate the development of new oilseed crops. Field cress (Lepidium campestre) is a species in the Brassicaceae family that has been targeted for domestication not only as an oilseed crop that produces seeds with a desirable industrial oil quality but also as a cover/catch crop that provides valuable ecosystem services. Lepidium is closely related to Arabidopsis and display significant proportions of syntenic regions in their genomes. Arabidopsis genes are among the most characterized genes in the plant kingdom and, hence, comparative genomics of Lepidium-Arabidopsis would facilitate the identification of Lepidium candidate genes regulating various desirable traits. Results Homologues of 30 genes known to regulate vernalization, flowering time, pod shattering, oil content and quality in Arabidopsis were identified and partially characterized in Lepidium. Alignments of sequences representing field cress and two of its closely related perennial relatives: L. heterophyllum and L. hirtum revealed 243 polymorphic sites across the partial sequences of the 30 genes, of which 95 were within the predicted coding regions and 40 led to a change in amino acids of the target proteins. Within field cress, 34 polymorphic sites including nine non-synonymous substitutions were identified. The phylogenetic analysis of the data revealed that field cress is more closely related to L. heterophyllum than to L. hirtum. Conclusions There is significant variation within and among Lepidium species within partial sequences of the 30 genes known to regulate traits targeted in the present study. The variation within these genes are potentially useful to speed-up the process of domesticating field cress as future oil crop. The phylogenetic relationship between the Lepidium species revealed in this study does not only shed some light on Lepidium genome evolution but also provides important information to develop efficient schemes for interspecific hybridization between different Lepidium species as part of the domestication efforts.

Summary: Shifting from a livestock‐based protein diet to a plant‐based protein diet has been proposed as an essential requirement to maintain global food sustainability, which requires the increased production of protein‐rich crops for direct human consumption. Meanwhile, the lack of sufficient genetic diversity in crop varieties is an increasing concern for sustainable food supplies. Countering this concern requires a clear understanding of the domestication process and dynamics. Narrow‐leafed lupin (Lupinus angustifolius L.) has experienced rapid domestication and has become a new legume crop over the past century, with the potential to provide protein‐rich seeds. Here, using long‐read whole‐genome sequencing, we assembled the third‐generation reference genome for the narrow‐leafed lupin cultivar Tanjil, comprising 20 chromosomes with a total genome size of 615.8 Mb and contig N50 = 5.65 Mb. We characterized the original mutation and putative biological pathway resulting in low seed alkaloid level that initiated the recent domestication of narrow‐leafed lupin. We identified a 1133‐bp insertion in the cis‐regulatory region of a putative gene that may be associated with reduced pod shattering (lentus). A comparative analysis of genomic diversity in cultivars and wild types identified an apparent domestication bottleneck, as precisely predicted by the original model of the bottleneck effect on genetic variability in populations. Our results identify the key domestication genetic loci and provide direct genomic evidence for a domestication bottleneck, and open up the possibility of knowledge‐driven de novo domestication of wild plants as an avenue to broaden crop plant diversity to enhance food security and sustainable low‐carbon emission agriculture. Significance Statement: Narrow‐leafed lupin Lupinus angustifolius L. was rapidly transformed from a wild species to a cultivated crop in less than 50 years to become an important source of plant‐based protein. Using a long‐read whole‐genome sequencing and meta‐assembly approach, we assembled a chromosome‐level narrow‐leafed lupin reference genome, and traced down the critical mutation, resulting in a low level of seed alkaloid that was essentially the first step in the domestication of narrow‐leafed lupin since 1929. We demonstrated an apparent domestication bottleneck, as precisely predicted in the original model of the genetic effect of population bottleneck. Our work provides valuable genomic resources for further genetic improvement of the narrow‐leafed lupin and de novo domestication of other Lupinus species as new high‐protein crops. [ABSTRACT FROM AUTHOR]

In legumes, pod shattering occurs when mature pods dehisce along the sutures, and detachment of the valves promotes seed dispersal. In Phaseolus vulgaris (L). the major locus qPD5.1-Pv for pod indehiscence was identified recently. We developed a BC4/F4 introgression line population and narrowed the major locus down to a 22.5 kb region. Here, gene expression and a parallel histological analysis of dehiscent and indehiscent pods identified an AtMYB26 orthologue as the best candidate for loss of pod shattering, on a genomic region ~11 kb downstream of the highest associated peak. Based on mapping and expression data, we propose early and fine up-regulation of PvMYB26 in dehiscent pods. Detailed histological analysis establishes that pod indehiscence is associated with the lack of a functional abscission layer in the ventral sheath, and that the key anatomical modifications associated with pod shattering in common bean occur early during pod development. We finally propose that loss of pod shattering in legumes resulted from histological convergent evolution and that it is the result of selection at orthologous loci. [ABSTRACT FROM AUTHOR]

Soybean is one of the most valuable commercial crops because of its high protein, carbohydrate, and oil content. The land area cultivated with soybean in subtropical regions, such as Brazil, is continuously expanding, in some instances at the expense of carbon storing natural habitats. Strategies to decrease yield/seed losses and increase production efficiency are urgently required to meet global demand for soybean in a sustainable manner. Here, we evaluated the effectiveness of an Ascophyllum nodosum extract (ANE), SealicitTM, in increasing yields of different soybean varieties, in two geographical regions (Canada and Brazil). In addition, we investigated the potential of SealicitTM to reduce pod shattering at the trials in Brazil. Three different concentrations of SealicitTM were applied to pod shatter-susceptible (SS) UFUS 6901 and shatter-resistant (SR) UFUS 7415 varieties to assess their impact on pod firmness. SS variety demonstrated a significant decrease in pod shattering, which coincided with deregulation of GmPDH1.1 and GmSHAT1–5 expression, genes that determine pod dehiscence, and higher seed weight per pod. SealicitTM application to the SR variety did not significantly alter its inherent pod shatter resistance, but provided higher increases in seed yield at harvest. This yield increase maybe associated with to other yield components stimulated by the biostimulant. This work demonstrates that SealicitTM, which has previously been shown to improve pod firmness in Arabidopsis and selected commercial oilseed rape varieties through IND gene down-regulation, also has the potential to improve pod resistance and seed productivity in soybean, a member of the legume family sharing a similar strategy for seed dispersal. [ABSTRACT FROM AUTHOR]

Significant yield losses are caused by pod shattering during the harvest of domesticated crop plants. The phenotype evaluation of pod shattering requires fully grown plants, and it is a labor-intensive and time-consuming procedure. The purpose of this study was to test the applicability of previously identified KSS-SNP5 SNP marker on chromosome 16 in the marker assisted selection (MAS) system for pod shattering in soybean breeding programs. For this research, TaqMan SNP assay was successfully developed to detect the A/G allele of the KSS-SNP5 marker in the breeding materials, including two breeding stages, F2:3 populations, and yield trial stage breeding lines. The MAS prediction accuracy was calculated by comparing the genotyping data from the TaqMan assay with the phenotype data from the dry-oven method. The total MAS prediction accuracy was 92.5% and 96.2% in two F2:3 populations and breeding lines, respectively and 85% and 96% accuracy were shown in severe conditions. In this study, we confirmed that the KSS-SNP5 TaqMan probe tightly linked to pod shattering is effective to select a resistant line. Based on these results, we propose that the marker tightly linked to pod shattering can be of valuable use in soybean breeding program for the development of pod shattering-resistant cultivars. [ABSTRACT FROM AUTHOR]

Seed loss resulting from pod shattering is a major constraint in production of oilseed rape (Brassica napus L.). However, the molecular mechanisms underlying pod shatter resistance are not well understood. Here, we show that the pod shatter resistance at quantitative trait locus qSRI.A9.1 is controlled by one of the B. napus SHATTERPROOF1 homologs, BnSHP1.A9 , in a doubled haploid population generated from parents designated R1 and R2 as well as in a diverse panel of oilseed rape. The R1 maternal parental line of the doubled haploid population carried the allele for shattering at qSRI.A9.1 , while the R2 parental line carried the allele for shattering resistance. Quantitative RT-PCR showed that BnSHP1.A9 was expressed specifically in flower buds, flowers, and developing siliques in R1, while it was not expressed in any tissue of R2. Transgenic plants constitutively expressing either of the BnSHP1.A9 alleles from the R1 and R2 parental lines showed that both alleles are responsible for pod shattering, via a mechanism that promotes lignification of the en b layer. These findings indicated that the allelic differences in the BnSHP1.A9 gene per se are not the causal factor for quantitative variation in shattering resistance at qSRI.A9.1. Instead, a highly methylated copia -like long terminal repeat retrotransposon insertion (4803 bp) in the promotor region of the R2 allele of BnSHP1.A9 repressed the expression of BnSHP1.A9 , and thus contributed to pod shatter resistance. Finally, we showed a copia -like retrotransposon-based marker, BnSHP1.A9 R2, can be used for marker-assisted breeding targeting the pod shatter resistance trait in oilseed rape. [ABSTRACT FROM AUTHOR]

Loss of pod shattering is one of the most important domestication-related traits in legume crops. The non-shattering phenotypes have been achieved either by disturbed formation of abscission layer between the valves, or by loss of helical tension in sclerenchyma of endocarp, that split open the pods to disperse the seeds. During domestication, azuki bean (Vigna angularis) and yard-long bean (Vigna unguiculata cv-gr. Sesquipedalis) have reduced or lost the sclerenchyma and thus the shattering behavior of seed pods. Here we performed fine-mapping with backcrossed populations and narrowed the candidate genomic region down to 4 kbp in azuki bean and 13 kbp in yard-long bean. Among the genes located in these regions, we found MYB26 genes encoded truncated proteins in azuki bean, yard-long bean, and even cowpea. As such, our findings indicate that independent domestication on the two legumes has selected the same locus for the same traits. We also argue that MYB26 could be a target gene for improving shattering phenotype in other legumes, such as soybean. [ABSTRACT FROM AUTHOR]

A yield loss caused by pod shattering is one of the obstacles to the improvement of soybean productivity in tropical areas. The aim of this study was to identify the resistance of soybean genotypes to pod shattering as affected by agronomical and morphological characters. The field study was conducted in Malang, Indonesia, using 150 soybean genotypes. Data were collected on agronomical traits, the percentage of pod shattering, and pod morphological traits. Identification for shattering resistance was done as per oven dry method. Percentage of pod shattering was ranged from 0 % up to 100 % shattering with a mean of 58.11 %. Pod shattering was found to be negatively correlated with a number of pod per plant, the thickness of the pod, and Y/Z (seed weight and pod weight ratio). The Identification obtained 66 very highly susceptible genotypes, 19 susceptible genotypes, 19 moderate genotypes, 38 resistant genotypes, and 8 very resistant genotypes. Two of eight very resistant genotypes (G511H/Anj//Anj///Anj////Anj-6-11 and G511H/Anj//Anj///Anj////Anj-5-4) have high yield, medium maturity day and large seed size. Those lines could be used as gene donor for soybean varietal improvement for shattering resistance, and recommended to propose as new improved soybean varieties resistant to pod shattering in Indonesia.

Field pea is used for human consumption or as livestock feed. The yield of pea seeds can be significantly decreased due to the genetically determined tendency of peas to pod shattering. This study aimed to evaluate the effect of pod sealant application on the quantitative and qualitative traits of the seed yield of two pea cultivars: Arwena and Tarchalska grown in south-western Poland in the years 2018–2019. Pod sealant application showed higher values of analysed quantitative and qualitative traits: number of pods per plant, number of seeds per plant, seed weight per pod, 1000-seed weight, seed yield, dry matter of seeds, protein content in seeds, and total protein productivity, except the number of seeds per pod. For both years (2018–2019), the interaction of cultivar and pod sealant application showed a significant effect on the number of seeds per plant, total protein content, total protein productivity, and seed weight per pod in 2019. Therefore, the pod sealant application can be a relatively simple way to improve the yielding of field peas.

Though crossing wild relatives to modern cultivars is a usual means to introduce alleles of stress tolerance, an alternative is de novo domesticating wild species that are already tolerant to various kinds of stresses. As a test case, we chose Vigna stipulacea Kuntze, which has fast growth, short vegetative stage, and broad resistance to pests and diseases. We developed an ethyl methanesulfonate–mutagenized population and obtained three mutants with reduced seed dormancy and one with reduced pod shattering. We crossed one of the mutants of less seed dormancy to the wild type and confirmed that the phenotype was inherited in a Mendelian manner. De novo assembly of V. stipulacea genome, and the following resequencing of the F2 progenies successfully identified a Single Nucleotide Polymorphism (SNP) associated with seed dormancy. By crossing and pyramiding the mutant phenotypes, we will be able to turn V. stipulacea into a crop which is yet primitive but can be cultivated without pesticides. [ABSTRACT FROM AUTHOR]

The moth bean (Vigna aconitifolia), possibly the most primitive crop of the genus Vigna, is a highly drought- and heat-resistant legume grown in arid areas. Moth bean domestication involved phenotypic changes, including reduction of seed dormancy and pod shattering, increased organ size, and earlier flowering and maturity. However, the genetics of the domestication process in moth bean is not known. In this study, we constructed a genetic linkage map for moth bean and used the map to identify quantitative trait loci (QTL) for domestication-related traits of an F2 population of 188 individuals produced from a cross of wild moth bean (TN67) and cultivated moth bean (ICPMO056). The genetic linkage map comprised 11 linkage groups (LG) of 172 simple sequence repeat markers and spanned a total length of 1016.8 centiMorgan (cM), with an average marker distance of 7.34 cM. A comparative genome analysis showed high genome synteny between moth bean and mungbean (Vigna radiata), adzuki bean (Vigna angularis), rice bean (Vigna umbellata), and yardlong bean (Vigna unguiculata). In total, 50 QTLs and 3 genes associated with 20 domestication-related traits were identified. Most of the QTLs belonged to five LGs (1, 2, 4, 7, and 10). Key traits related to domestication such as seed dormancy and pod shattering were controlled by large-effect QTLs (PVE > 20%) with one or two minor QTLs, whereas all other traits were controlled by one–seven minor QTLs, apart from seed weight, which was controlled by one major and seven minor QTLs. These results suggest that a small number of mutations with large phenotypic effects have contributed to the domestication of the moth bean. Comparative analysis of QTLs with related Vigna crops revealed that there are several domestication-related large-effect QTLs that had not been used in moth bean domestication. This study provides a basic genetic map and identified genome regions associated with domestication-related traits, which will be useful for the genetic improvement of the moth bean and related Vigna species. [ABSTRACT FROM AUTHOR]

Pod shattering is an important reproductive process in many wild species. However, pod shattering at the maturing stage can result in severe yield loss. The objectives of this study were to discover quantitative trait loci (QTLs) for pod shattering using two recombinant inbred line (RIL) populations derived from an elite cultivar having pod shattering tolerance, namely “Daewonkong”, and to predict novel candidate QTL/genes involved in pod shattering based on their allele patterns. We found several QTLs with more than 10% phenotypic variance explained (PVE) on seven different chromosomes and found a novel candidate QTL on chromosome 16 (qPS-DS16-1) from the allele patterns in the QTL region. Out of the 41 annotated genes in the QTL region, six were found to contain SNP (single-nucleotide polymorphism)/indel variations in the coding sequence of the parents compared to the soybean reference genome. Among the six potential candidate genes, Glyma.16g076600, one of the genes with known function, showed a highly differential expression levels between the tolerant and susceptible parents in the growth stages R3 to R6. Further, Glyma.16g076600 is a homolog of AT4G19230 in Arabidopsis, whose function is related to abscisic acid catabolism. The results provide useful information to understand the genetic mechanism of pod shattering and could be used for improving the efficiency of marker-assisted selection for developing varieties of soybeans tolerant to pod shattering.

Summary: The complete or partial loss of shattering ability occurred independently during the domestication of several crops. Therefore, the study of this trait can provide an understanding of the link between phenotypic and molecular convergent evolution. The genetic dissection of 'pod shattering' in Phaseolus vulgaris is achieved here using a population of introgression lines and next‐generation sequencing techniques. The 'occurrence' of the indehiscent phenotype (indehiscent versus dehiscent) depends on a major locus on chromosome 5. Furthermore, at least two additional genes are associated with the 'level' of shattering (number of shattering pods per plant: low versus high) and the 'mode' of shattering (non‐twisting versus twisting pods), with all of these loci contributing to the phenotype by epistatic interactions. Comparative mapping indicates that the major gene identified on common bean chromosome 5 corresponds to one of the four quantitative trait loci for pod shattering in Vigna unguiculata. None of the loci identified comprised genes that are homologs of the known shattering genes in Glycine max. Therefore, although convergent domestication can be determined by mutations at orthologous loci, this was only partially true for P. vulgaris and V. unguiculata, which are two phylogenetically closely related crop species, and this was not the case for the more distant P. vulgaris and G. max. Conversely, comparative mapping suggests that the convergent evolution of the indehiscent phenotype arose through mutations in different genes from the same underlying gene networks that are involved in secondary cell‐wall biosynthesis and lignin deposition patterning at the pod level. Significance Statement: Genetic mapping of the genetic architecture of pod shattering in common bean, and comparisons with other crops, have allowed the genetic basis of phenotypic convergent evolution to be defined. This definition indicates that different genes can be responsible for the shattering phenotype in legumes. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Seed growth dynamics were followed across floral positions, cultivars and crop population plant densities. • Bi-linear functions provided good fits to seed dry weight/water concentration relationships. • Physiological maturity (PM) was reached at 45–46% seed water concentration (SWC). • The water concentration of whole pod was 70% at PM but decreased drastically before pod shattering. • At crop level, 46% SWC corresponded to 90% of the maximum simulated seed yield. Abstract Determining the optimum time for rapeseed harvest is challenging due to non-uniform seed maturity resulting from asynchronous flowering and pod dehiscence from sequential racemes. Identifying physiological maturity (PM) by visual methods is subjective and results can be affected by environmental conditions. PM can be determined using a quantitative model based on seed water concentration (SWC) as previously demonstrated for several other crops, although not yet developed for rapeseed crop. The objective of this work was to study the relationship between the dynamics of seed dry weight and water concentration in seven spring rapeseed cultivars grown at two contrasting densities (15 and 60 pl m−2) in three experiments at one location in Buenos Aires (Argentina). We evaluated the timing of PM on the basis of SWC in seeds located in the main raceme, second and fourth floral branches. The evolution of seed fresh and dry weight was followed bi-weekly from the beginning of flowering to harvest maturity. In Exp. 1, the grain-filling duration ranged from 39 to 57 days (700–1100 °C d) and the growth of seeds from floral branches finished 3–8 days later than those from the main raceme. Seed dry weight at PM ranged from 2.4 to 2.7 and from 3.0 to 3.2 mg for Lynx and Monty cultivars, respectively, without significant effects of floral position or plant density. Bi-linear functions were used to fit the relationship between relative seed dry weight (RSDW) and SWC relationships (R2 from 0.85 to 0.95). Across cultivars and floral positions, PM was attained when seeds exhibited 46.3 ± 0.7% SWC (R2 = 0.90, P < 0.001, n = 441). This model was validated against independent data from Exps. 2 and 3, successfully simulating the dynamics of relative seed dry weight based on fruit WC (r = 0.88; P < 0.001, n = 275). At PM, the water content (WC) of whole pod was about 70% and the pod shattering began after this point, when the WC of the pod dropped drastically. We conclude that under non-stressful conditions, PM in rapeseed occurs at 46% SWC. Swathing can be conducted from SWC < 46%, instead of the currently recommended 35%, advancing the harvest and leaving the land available for sowing the next crop, which would represent an advantage for double cropping in intensified agricultural systems. [ABSTRACT FROM AUTHOR]

Highlights • Pod dehiscence leads to remarkable yield losses in soybean. • Anatomy and morphology of pod tissues as well as moisture content and the ambient relative humidity relate to the dehiscence mechanism. • Fiber cap cells or mesocarp cell structure plays a role in preventing dehiscence. • Pod wall and extent of sclerenchymatous dorsal bundle caps might be a valuable indicator. • Factors other than forces may modify the pod shattering response. Abstract Pod dehiscence or pod shattering is one of the major factors leading to remarkable yield losses in soybean. The anatomical and morphological configuration of pod tissues is related to the dehiscence mechanism. Soybean pod forms abscission layers at the binding sites of its margins and accumulates the force to dehisce pod walls on drying during and after maturation. Pod opening is governed not only by a consequence of the weakening of the dorsal and ventral dehiscence zones but also by the tension in the cells of the inner sclerenchyma layer as a result of dehydration. The lignified fiber cap cells in the suture and the cell structure of the mesocarp play a role in preventing separation of the two halves. For separation to occur, physical forces have to trigger the detachment of cells at the separation layer, in an interplay that involves weakening of cell adhesion and tensions provided by the surrounding tissues or external agents. Pod dehiscence in soybean has a minimal relationship with the pod thickness-to-width ratio, while the thickness of the pod wall and extent of sclerenchymatous dorsal bundle caps might be appropriate indicators. There is also a critical pod moisture content for shattering. Moisture content of pods and environmental relative humidity are closely correlated with the degree of pod dehiscence. Intrinsic factors may modify the pod shattering response. Further analyses of pod tissues, particularly chemical structure and cell wall degrading enzymes of the pod wall will help to fully understand pod dehiscence in soybean. [ABSTRACT FROM AUTHOR]

Seed lost due to easy pod dehiscence at maturity (pod shatter) is a major problem in several members of Brassicaceae family. We investigated the level of pod shatter resistance in Ethiopian mustard (Brassica carinata) and identified quantitative trait loci (QTL) for targeted introgression of this trait in Ethiopian mustard and its close relatives of the genus Brassica. A set of 83 accessions of B. carinata, collected from the Australian Grains Genebank, was evaluated for pod shatter resistance based on pod rupture energy (RE). In comparison to B. napus (RE = 2.16 mJ), B. carinata accessions had higher RE values (2.53 to 20.82 mJ). A genetic linkage map of an F2 population from two contrasting B. carinata selections, BC73526 (shatter resistant with high RE) and BC73524 (shatter prone with low RE) comprising 300 individuals, was constructed using a set of 6,464 high quality DArTseq markers and subsequently used for QTL analysis. Genetic analysis of the F2 and F2:3 derived lines revealed five statistically significant QTL (LOD ≥ 3) that are linked with pod shatter resistance on chromosomes B1, B3, B8, and C5. Herein, we report for the first time, identification of genetic loci associated with pod shatter resistance in B. carinata. These characterized accessions would be useful in Brassica breeding programs for introgression of pod shatter resistance alleles in to elite breeding lines. Molecular markers would assist marker-assisted selection for tracing the introgression of resistant alleles. Our results suggest that the value of the germplasm collections can be harnessed through genetic and genomics tools.

The seed dispersion caused by pod shattering is a form of propagation used by many wild species. Loss of seeds from pod shattering is frequent in the common vetch (Vicia sativa L.), an important self-pollinating annual forage legume. However, pod shattering is one of the most important defects that limits the reproduction of the vetch in the field and the usage as a leguminous forage crop. To better understand the vetch pod shattering mechanism, we used high-throughput RNA sequencing to assess the global changes in the transcriptomes of the pod ventral sutures of shattering-susceptible and shattering-resistant vetch accessions screened from 541 vetch germplasms. A total of 1,285 significantly differentially expressed unigenes (DEGs) were detected, including 575 up-regulated unigenes and 710 down-regulated unigenes. Analyses of Gene Ontology and KEGG metabolic enrichment pathways of 1,285 DEGs indicated that 22 DEGs encoding cell wall modifications and hydrolases associated with pod shattering were highly expressed in shattering-susceptible accessions. These genes were mainly enriched in “hydrolase activity,” “cytoplasm,” and “carbohydrate metabolic process” systems. These cell wall modifications and hydrolases genes included β-glucosidase and endo-polygalacturonase, which work together to break down the glycosidic bonds of pectin and cellulose, and to promote the dissolution and disappearance of the cell wall in the ventral suture of the pod and make the pod more susceptible to shattering. We demonstrated the differences in gene transcription levels between the shattering-susceptible and shattering-resistant vetch accessions for the first time and our results provided valuable information for the identifying and characterizing of pod shattering regulation networks in vetch. This information may facilitate the future identification of pod shattering-related genes and their underlying molecular mechanisms in the common vetch.

Three parents viz., NRC7, EC 241780 and Kalitur were crossed in cyclic manner during Kharif 2012 with the objectives to study the inheritance of pod shattering in soybean. Among these NRC 7 and others were resistant and susceptible to pod shattering respectively. Six generations (P1, P2, F1, F2, B1 and B2) were obtained by inter-mating three diverse parents. Pod shattering screening was done as per oven dry method. Inheritance of pod shattering was found to be governed by partial dominance of susceptibility over the resistance. Two major genes with inhibitory epistasis were involved in inheritance of pod shattering in soybean as evidenced from F2 ratio (13:3) and confirmed by test cross ratio (3:1) in resistance x susceptible and susceptible x resistance crosses.

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Seed lost due to easy pod dehiscence at maturity (pod shatter) is a major problem in several members of Brassicaceae family. We investigated the level of pod shatter resistance in Ethiopian mustard (Brassica carinata) and identified quantitative trait loci (QTL) for targeted introgression of this trait in Ethiopian mustard and its close relatives of the genus Brassica. A set of 83 accessions of B. carinata, collected from the Australian Grains Genebank, was evaluated for pod shatter resistance based on pod rupture energy (RE). In comparison to B. napus (RE = 2.16 mJ), B. carinata accessions had higher RE values (2.53 to 20.82 mJ). A genetic linkage map of an F2 population from two contrasting B. carinata selections, BC73526 (shatter resistant with high RE) and BC73524 (shatter prone with low RE) comprising 300 individuals, was constructed using a set of 6,464 high quality DArTseq markers and subsequently used for QTL analysis. Genetic analysis of the F2 and F2:3 derived lines revealed five statistically significant QTL (LOD ≥ 3) that are linked with pod shatter resistance on chromosomes B1, B3, B8, and C5. Herein, we report for the first time, identification of genetic loci associated with pod shatter resistance in B. carinata. These characterized accessions would be useful in Brassica breeding programs for introgression of pod shatter resistance alleles in to elite breeding lines. Molecular markers would assist marker-assisted selection for tracing the introgression of resistant alleles. Our results suggest that the value of the germplasm collections can be harnessed through genetic and genomics tools. [ABSTRACT FROM AUTHOR]

Mungbean, (Vigna radiata (L.) Wilczek) occupies a unique position in Indian agriculture and has been grown under various agro-ecological conditions. It is cultivated in 1.61mha with production of 3.38MT and productivity of 474kg/ha in India. Mungbean pods are thin and brittle when dry, so shattering is a major problem. The loss of seeds by pod dehiscence is one of the major reasons for low yield in mungbean; thus, reducing the frequency of pod dehiscence is an important objective in mungbean breeding. Induced mutations, have offered a single and short alternative to conventional breeding including isolation, screening, selection and testing generation after generation. In this study, variability was induced by gamma rays and Ethyl methane sulphonate (EMS) in two greengram genotypes viz., CO (Gg) 7 and NM 65. Screening for pod shattering was carried out in M2 and M3 populations of greengram. The scoring for shattering was recorded at physiological maturity of the pod. The shattering percentage ranged from 14.56 (400 Gy) to 93.45 per cent (20 mM). A total of 100 shattering tolerant mutants were selected from field based on visual observation. These mutants were again scored under laboratory condition as per IITA method. A total of 12 mutants of CO (Gg) 7 and 10 mutants of NM 65 which were tolerant to pod shattering were identified in M2 generation and forwarded to M3 generation. These mutants were scored for pod shattering under laboratory condition and nine mutants viz., M26, M44, M46, M58, M70, M71, M84, M92 and M98 were found to be tolerant in M3 generation. This study on identification and screening of the mutants tolerant to pod shattering with high yielding potential will help to increase the production of the pods to a greater extent. [ABSTRACT FROM AUTHOR]

A yield loss caused by pod shattering is one of the obstacles to the improvement of soybean productivity in tropical areas. The aim of this study was to identify the resistance of soybean genotypes to pod shattering as affected by agronomical and morphological characters. The field study was conducted in Malang, Indonesia, using 150 soybean genotypes. Data were collected on agronomical traits, the percentage of pod shattering and pod morphological traits. Identification for shattering resistance was done as per oven dry method. Percentage of pod shattering was ranged from 0 % up to 100 % shattering with a mean of 58.11 %. Pod shattering was found to be negatively correlated with a number of pod per plant, the thickness of the pod and Y/Z (seed weight and pod weight ratio). The Identification obtained 66 very highly susceptible genotypes, 19 susceptible genotypes, 19 moderate genotypes, 38 resistant genotypes and 8 very resistant genotypes. Two of eight very resistant genotypes (G511H/Anj//Anj///Anj////Anj-6-11 and G511H/Anj//Anj///Anj//// Anj-5-4) have high yield, medium maturity day and large seed size. Those lines could be used as gene donor for soybean varietal improvement for shattering resistance and recommended to propose as new improved soybean varieties resistant to pod shattering in Indonesia. [ABSTRACT FROM AUTHOR]

The seed dispersion caused by pod shattering is a form of propagation used by many wild species. Loss of seeds from pod shattering is frequent in the common vetch (Vicia sativa L.), an important self-pollinating annual forage legume. However, pod shattering is one of the most important defects that limits the reproduction of the vetch in the field and the usage as a leguminous forage crop. To better understand the vetch pod shattering mechanism, we used high-throughput RNA sequencing to assess the global changes in the transcriptomes of the pod ventral sutures of shattering-susceptible and shattering-resistant vetch accessions screened from 541 vetch germplasms. A total of 1,285 significantly differentially expressed unigenes (DEGs) were detected, including 575 up-regulated unigenes and 710 down-regulated unigenes. Analyses of Gene Ontology and KEGG metabolic enrichment pathways of 1,285 DEGs indicated that 22 DEGs encoding cell wall modifications and hydrolases associated with pod shattering were highly expressed in shattering-susceptible accessions. These genes were mainly enriched in "hydrolase activity," "cytoplasm," and "carbohydrate metabolic process" systems. These cell wall modifications and hydrolases genes included b-glucosidase and endo-polygalacturonase, which work together to break down the glycosidic bonds of pectin and cellulose, and to promote the dissolution and disappearance of the cell wall in the ventral suture of the pod and make the pod more susceptible to shattering. We demonstrated the differences in gene transcription levels between the shattering-susceptible and shattering-resistant vetch accessions for the first time and our results provided valuable information for the identifying and characterizing of pod shattering regulation networks in vetch. This information may facilitate the future identification of pod shattering-related genes and their underlying molecular mechanisms in the common vetch. [ABSTRACT FROM AUTHOR]

The pod shattering or dehiscence is essential for the propagation of pod-bearing plant species in the wild, but it causes significant yield losses during harvest of domesticated crop plants. Identifying novel molecular makers, which are linked to seed-shattering genes, is needed to employ the molecular marker-assisted selection for efficiently developing shattering-resistant soybean varieties. In this study, a genetic linkage map was constructed using 115 recombinant inbred lines (RILs) developed from crosses between the pod shattering susceptible variety, Keunol, and resistant variety, Sinpaldal. A 180 K Axiom® SoyaSNPs data and pod shattering data from two environments in 2001 and 2015 were used to identify quantitative trait loci (QTL) for pod shattering. A major QTL was identified between two flanking single nucleotide polymorphism (SNP) markers, AX-90320801 and AX-90306327 on chromosome 16 with 1.3 cM interval, 857 kb of physical range. In sequence, genotype distribution analysis was conducted using extreme phenotype RILs. This could narrow down the QTL down to 153 kb on the physical map and was designated as qPDH1-KS with 6 annotated gene models. All exons within qPDH1-KS were sequenced and the 6 polymorphic SNPs affecting the amino acid sequence were identified. To develop universally available molecular markers, 38 Korean soybean cultivars were investigated by the association study using the 6 identified SNPs. Only two SNPs were strongly associated with the pod shattering. These two identified SNPs will help to identify the pod shattering responsible gene and to develop pod shattering-resistant soybean plants using marker-assisted selection. [ABSTRACT FROM AUTHOR]

Birdsfoot trefoil (Lotus corniculatus L.) is a perennial species that is known for its outstanding characters as a crucial component of meadow and pasture vegetation and a highly successful fodder crop. However, its cultivation has been limited by the inability to control pod shattering. The anatomic and physiological bases of pod shattering are known and are considered to be controlled by more than one gene. This paper reviews the known causes of pod shattering and potential ways of overcoming pod indehiscence in L. corniculatus. Genetic transformation is possible in the genus Lotus; however, the useful genes determining the seed pod indehiscent character have not been identified yet. The only way of introducing pod indehiscence characters into L. corniculatus is by interspecific hybridization within the genus Lotus; embryo rescue and protoplast cultures are promising. To determine useful genotypes for crosses, investigations of pre- and post-fertilization barriers are necessary. To that end, we present here a convenient procedure for a whole-mount clearing treatment of immature seeds that leaves the cell walls of tissues intact. This is a useful technique for the study of post-fertilization barriers in Lotus.