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Excessive oxidative stress and inflammatory responses are associated with the development of various diseases, including cancer. Glucosinolates (GSLs) are phytochemicals known for their antioxidant properties, and doubled haploid lines (DHLs) of Brassica rapa with high GSL contents (HGSL) were intentionally developed from two edible subspecies of Brassica rapa: B. rapa subsp. trilocularis and B. rapa subsp. chinensis. The purpose of the present study is to assess the capacity of HGSL DHLs to mitigate oxidative stress and inflammation in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, compared to pak choi as a parental control. Our findings demonstrate that HGSL DH lines effectively suppressed the expression of inducible nitric oxide synthase, leading to the reduced levels of nitric oxide at non-toxic concentrations. Additionally, these lines exhibited scavenging activity against reactive oxygen species and free radicals. The enhanced antioxidant capacity of HGSL DHLs was mechanistically attributed to the upregulation of antioxidant enzymes, such as NADPH quinone oxidoreductase 1 (NQO1), the glutamate–cysteine ligase catalytic subunit (GCLC), and heme oxygenase-1 (HMOX1). Furthermore, we confirmed that these effects were mediated through the nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway via p38 phosphorylation. Moreover, HGSL DHLs demonstrated inhibitory effects on pro-inflammatory cytokines and signal transducers and activators of transcription 3 (STAT3) phosphorylation. Collectively, our results indicate that HGSL DHLs possess better antioxidant and anti-inflammatory properties compared to the parental control pak choi in LPS-stimulated RAW264.7 cells, suggesting that HGSL DHLs of Brassica rapa could be considered as a beneficial daily vegetable for reducing the risk of inflammation-associated diseases. [ABSTRACT FROM AUTHOR]

One of the biotic constraints in rice production worldwide is blast disease which can control by planting resistant varieties. To find out effective resistance, blast resistance quantitative trait loci (QTL) were mapped against 20 and 3 virulent isolates for leaf blast and neck blast, respectively, using 111 doubled haploid lines from the cross of IR64 and Azucena. QTLs associated with leaf blast were found on chromosomes 1, 2, 4, 7, 8, 10, 11, and 12 (%R2 = 3.6 – 64.3), while neck blast linked QTLs were identified on chromosomes 1, 6, 10, and 12 (%R2 = 6.4 – 22.6). The new QTLs were identified on chromosome 1; however, most QTLs were mapped in the vicinity of resistance genes in previous references. The genetic relationship of leaf and neck blast was explained by the coincidence of detected QTLs and positive value of pathogenicity correlation (r = 4.5 – 4.7). This study provides reliable QTLs locations that will benefit rice breeding programs to develop new cultivars containing durable and broad-spectrum resistance to leaf and neck blast disease. [ABSTRACT FROM AUTHOR]

This paper proposes the use of weighted multiple linear regression to estimate the triple3interaction (additive×additive×additive) of quantitative trait loci (QTLs) effects. The use of unweighted regression yielded an improvement (in absolute value) in the QTL×QTL×QTL interaction effects compared to assessment based on phenotypes alone in three cases (severe drought in 2010, control in 2012 and severe drought in 2012). In contrast, weighted regression yielded an improvement (in absolute value) in the evaluation of the aaagw parameter compared to aaap in five cases, with the exception of severe drought in 2012. The results show that by using weighted regression on marker observations, the obtained estimates are closer to the ones obtained by the phenotypic method. The coefficients of determination for the weighted regression model were significantly higher than for the unweighted regression and ranged from 46.2% (control in 2010) to 95.0% (control in 2011). Considering this, it is clear that a three-way interaction had a significant effect on the expression of quantitative traits. [ABSTRACT FROM AUTHOR]

Curly kale (Brassica oleracea L. convar. acephala var. sabellica), the most common type of edible kale, characterized by providing rich nutrition and health care functions, is sought after and has been listed as top of the healthiest vegetables in recent trends, and has aroused the interest of breeders in cultivating new varieties. However, it usually takes more than six years to obtain a homozygous kale inbred line for commercial seed production through conventional breeding procedures due to its long growth and development period. The isolated microspore culture (IMC) technique could be a time-saving alternative method for producing doubled haploid (DH) lines that are genetically homozygous. In this study, we successfully utilize the efficient cytokinin thidiazuron (TDZ) to promote microspore embryogenesis and plant regeneration in two curly kale cultivars ('Winterbor F2' and 'Starbor F2'). Compared with the control (0 mg/L TDZ), all tested TDZ concentrations (0.1, 0.2, 0.3, 0.4 mg/L) had no adverse effects on embryogenesis, and 0.2 mg/L TDZ had an optimal effect on embryo survival and plant regeneration of the two genotypes. For 'Starbor F2', 0.2 mg/L TDZ treatment achieved the highest embryogenesis rate (1.83-fold higher than the control group) and direct seeding rate (1.61-fold increase), and the lowest mortality rate. Likewise, 0.2 mg/L TDZ increased the embryogenesis rate of 'Winterbor F2' by 1.62 times, the direct seeding rate by 1.61 times, and the mortality rate fell to the lowest. A 1/2 Murashige and Skoog (MS) medium with 0.2 mg/L 1-Naphthaleneacetic acid (NAA) can significantly promote the rooting of the regenerated seedlings. These results provide new insights into the practical application of the IMC technique in shortening the breeding cycle of kale. [ABSTRACT FROM AUTHOR]

Chemoprevention is a method of health control in modern industrialized societies. Traditional breeding (hybridization) has been widely used to produce new (sub)species with beneficial phenotypes. Previously, we produced a number of doubled haploid (DH) lines of Brassica rapa with a high glucosinolate (GSL) content. In this study, we evaluated the anticancer activities of extracts from three selected high-GSL (HGSL)-containing DH lines (DHLs) of Brassica rapa in human colorectal cancer (CRC) cells. The three HGSL DHL extracts showed anti-proliferative activities in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assay and pro-apoptotic activities in the cell cycle or annexin V analysis with the induction of pro-apoptotic protein expression in CRC cells. Mechanistically, HGSL DHL extracts inhibited the NF-κB and ERK pathways, leading to a reduction in the nuclear localization of NF-κB p65. In addition, reactive oxygen species were induced by HGSL DHL extract treatment in CRC cells. In conclusion, our data suggest that the newly developed HGSL DHLs possess enhanced anticancer activities and are potentially helpful as a daily vegetable supplement with chemopreventive activities. [ABSTRACT FROM AUTHOR]

Excessive oxidative stress and inflammatory responses are associated with the development of various diseases, including cancer. Glucosinolates (GSLs) are phytochemicals known for their antioxidant properties, and doubled haploid lines (DHLs) of Brassica rapa with high GSL contents (HGSL) were intentionally developed from two edible subspecies of Brassica rapa: B. rapa subsp. trilocularis and B. rapa subsp. chinensis. The purpose of the present study is to assess the capacity of HGSL DHLs to mitigate oxidative stress and inflammation in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, compared to pak choi as a parental control. Our findings demonstrate that HGSL DH lines effectively suppressed the expression of inducible nitric oxide synthase, leading to the reduced levels of nitric oxide at non-toxic concentrations. Additionally, these lines exhibited scavenging activity against reactive oxygen species and free radicals. The enhanced antioxidant capacity of HGSL DHLs was mechanistically attributed to the upregulation of antioxidant enzymes, such as NADPH quinone oxidoreductase 1 (NQO1), the glutamate–cysteine ligase catalytic subunit (GCLC), and heme oxygenase-1 (HMOX1). Furthermore, we confirmed that these effects were mediated through the nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway via p38 phosphorylation. Moreover, HGSL DHLs demonstrated inhibitory effects on pro-inflammatory cytokines and signal transducers and activators of transcription 3 (STAT3) phosphorylation. Collectively, our results indicate that HGSL DHLs possess better antioxidant and anti-inflammatory properties compared to the parental control pak choi in LPS-stimulated RAW264.7 cells, suggesting that HGSL DHLs of Brassica rapa could be considered as a beneficial daily vegetable for reducing the risk of inflammation-associated diseases.

In cereals, resistance and tolerance to salinity are qualities that allow their cultivation in arid and semi-arid regions. Hence, we sought to select salt stress-resistant barley genotypes by applying sub-lethal NaCl concentrations and observing their effect on germination. This work was carried out using parent spring barley genotype (Hordeum vulagre L.) namely Tamelalt, and its doubled haploids progeny. Salt stress resistance was tested on seeds germination in Petri dishes provided with filter paper containing increasing concentrations of salt (0, 5, 10, and 15 g.L-1) for 10 days at 25°C. The doubled haploids progeny derived from Tamelalt showed to be the most tolerant to salt stress with a germination rate under the most severe salt stress conditions (NaCl 15 g.L-1), while the parent genotype Tamelalt was the least tolerant with a germination rate of only 26.67% under the same stress. Principal component analysis and hierarchical cluster analysis allowed the separation of DH lines and parent genotype. Two groups were identified. The DH lines were completely different from the parent genotype. [ABSTRACT FROM AUTHOR]

Single nucleotide polymorphism (SNP) arrays, also named « SNP chips », enable very large numbers of individuals to be genotyped at a targeted set of thousands of genome-wide identified markers. We used preexisting variant datasets from USDA, a French commercial line and 30X-coverage whole genome sequencing of INRAE isogenic lines to develop an Affymetrix 665 K SNP array (HD chip) for rainbow trout. In total, we identified 32,372,492 SNPs that were polymorphic in the USDA or INRAE databases. A subset of identified SNPs were selected for inclusion on the chip, prioritizing SNPs whose flanking sequence uniquely aligned to the Swanson reference genome, with homogenous repartition over the genome and the highest Minimum Allele Frequency in both USDA and French databases. Of the 664,531 SNPs which passed the Affymetrix quality filters and were manufactured on the HD chip, 65.3% and 60.9% passed filtering metrics and were polymorphic in two other distinct French commercial populations in which, respectively, 288 and 175 sampled fish were genotyped. Only 576,118 SNPs mapped uniquely on both Swanson and Arlee reference genomes, and 12,071 SNPs did not map at all on the Arlee reference genome. Among those 576,118 SNPs, 38,948 SNPs were kept from the commercially available medium-density 57 K SNP chip. We demonstrate the utility of the HD chip by describing the high rates of linkage disequilibrium at 2–10 kb in the rainbow trout genome in comparison to the linkage disequilibrium observed at 50–100 kb which are usual distances between markers of the medium-density chip. [ABSTRACT FROM AUTHOR]

Relevance. Broccoli cabbage (Brassica oleracea L. convar. botrytis (L.) Alef. var. cymosa Duch.) is widely spread around the world due to its dietetic attribute, preventive and healing effect, cooking simplicity. F1 hybrids production is the main stream in modern crop breeding as they surpass varieties in evenness and yield quality. However, it takes up to 6 years of inbreeding to obtain pure parent lines capable for hybrid creation. Thus biotechnological methods, especially doubled haploids production technology shell be implemented in selection process. 100% homozygous line can be worked out in one generation by this technology. Nevertheless earlier researches revealed such plants low seed set that hinder their application in mass production. Therefore after pollination seed set level identification is an important step in applying lines gained via in vitro process.Materials and methods. Broccoli cabbage regenerated plants produced by isolated microspore in vitro culture method were used as raw material in our study. Flower and bud pollination was held in climate cells.Results. Study of 11 broccoli cabbage DH-lines disclosed genotype influence the ability to set seeds after bud pollination. 93.3% genotype A and 95.5% A1.3 pods were seedless in our experiments. Most genotypes demonstrated 50.3-85.7% seed set level. Low and middle ability to form seeds prevailed mainly. This peculiarity should be considered while dealing with regenerated plants by raising the number of crossings for successful breeding.

This paper proposes the use of weighted multiple linear regression to estimate the triple3interaction (additive×additive×additive) of quantitative trait loci (QTLs) effects. The use of unweighted regression yielded an improvement (in absolute value) in the QTL×QTL×QTL interaction effects compared to assessment based on phenotypes alone in three cases (severe drought in 2010, control in 2012 and severe drought in 2012). In contrast, weighted regression yielded an improvement (in absolute value) in the evaluation of the aaagw parameter compared to aaap in five cases, with the exception of severe drought in 2012. The results show that by using weighted regression on marker observations, the obtained estimates are closer to the ones obtained by the phenotypic method. The coefficients of determination for the weighted regression model were significantly higher than for the unweighted regression and ranged from 46.2% (control in 2010) to 95.0% (control in 2011). Considering this, it is clear that a three-way interaction had a significant effect on the expression of quantitative traits.

Curly kale (Brassica oleracea L. convar. acephala var. sabellica), the most common type of edible kale, characterized by providing rich nutrition and health care functions, is sought after and has been listed as top of the healthiest vegetables in recent trends, and has aroused the interest of breeders in cultivating new varieties. However, it usually takes more than six years to obtain a homozygous kale inbred line for commercial seed production through conventional breeding procedures due to its long growth and development period. The isolated microspore culture (IMC) technique could be a time-saving alternative method for producing doubled haploid (DH) lines that are genetically homozygous. In this study, we successfully utilize the efficient cytokinin thidiazuron (TDZ) to promote microspore embryogenesis and plant regeneration in two curly kale cultivars (‘Winterbor F2’ and ‘Starbor F2’). Compared with the control (0 mg/L TDZ), all tested TDZ concentrations (0.1, 0.2, 0.3, 0.4 mg/L) had no adverse effects on embryogenesis, and 0.2 mg/L TDZ had an optimal effect on embryo survival and plant regeneration of the two genotypes. For ‘Starbor F2’, 0.2 mg/L TDZ treatment achieved the highest embryogenesis rate (1.83-fold higher than the control group) and direct seeding rate (1.61-fold increase), and the lowest mortality rate. Likewise, 0.2 mg/L TDZ increased the embryogenesis rate of ‘Winterbor F2’ by 1.62 times, the direct seeding rate by 1.61 times, and the mortality rate fell to the lowest. A 1/2 Murashige and Skoog (MS) medium with 0.2 mg/L 1-Naphthaleneacetic acid (NAA) can significantly promote the rooting of the regenerated seedlings. These results provide new insights into the practical application of the IMC technique in shortening the breeding cycle of kale.

Chemoprevention is a method of health control in modern industrialized societies. Traditional breeding (hybridization) has been widely used to produce new (sub)species with beneficial phenotypes. Previously, we produced a number of doubled haploid (DH) lines of Brassica rapa with a high glucosinolate (GSL) content. In this study, we evaluated the anticancer activities of extracts from three selected high-GSL (HGSL)-containing DH lines (DHLs) of Brassica rapa in human colorectal cancer (CRC) cells. The three HGSL DHL extracts showed anti-proliferative activities in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assay and pro-apoptotic activities in the cell cycle or annexin V analysis with the induction of pro-apoptotic protein expression in CRC cells. Mechanistically, HGSL DHL extracts inhibited the NF-κB and ERK pathways, leading to a reduction in the nuclear localization of NF-κB p65. In addition, reactive oxygen species were induced by HGSL DHL extract treatment in CRC cells. In conclusion, our data suggest that the newly developed HGSL DHLs possess enhanced anticancer activities and are potentially helpful as a daily vegetable supplement with chemopreventive activities.

Relevance One of the basic directions of the cabbage crop breeding is the creation of F1 hybrids with a complex of economically valuable traits. This process is difficult and time-consuming as to get pure lines must be within 6-12 years hold inbreeding. Herewith not every line gives the desired heterotic effect that also requires additional verification. Methods Biotechnological method culture of isolated microspores in vitro, which allows in the first generation to receive a line with 100% homozygosity, was used to speed up the breeding process. Combination ability were performed in complete diallel cross on the basic morphological signs. Results Culture medium for cultivation of isolated microspores in vitro was optimized for each genotype of cabbage for the best embryoids regeneration. Maximum amount of embryoids was received on medium with pH 6.2 using ampicillin 100 mg/l and zeatin 1 mg/l: 466.7 ± 153.2 PCs/100 buds. A new source material for breeding – doubled haploid lines of cabbage was received. Lines – the best parents for F1 hybrids with high yield, compact rosette of leaves, with optimum inside and short outside cabbage stump was created. Studies have shown that optimization of breeding process in case of creation of pure lines of cabbage in 3 years with microspore culture requires to reduce the breeding process in 2 times.

The in vivo haploid induction has been widely applied to the maize breeding in recent decades, but it has not been used in the breeding programs in the Republic of Croatia by now. This study's objectives were to examine the haploid induction rates in the Croatian germplasm and to evaluate the properties of the D0 haploids, which are essential for a successful implementation of this method in breeding. The in vivo haploid induction was performed on 11 single-cross hybrids using the Zarodyshevy Marker Krasnodarsky (ZMK) inducer, and colchicine was used as a chromosome doubling agent. Emergence, misclassification rate, colchicine treatment survival, chromosome doubling rate and self-pollination success were examined in the D0 generation. The haploid induction rates ranged from 6.9 to 15.8%, which is consistent with the average induction rates characteristic of the ZMK inducer and the other modern ones. Significant differences were found among the populations of D0 haploids for all tested properties, except for self-pollination success. On average, the misclassification rates were lower, and the seedling survival rates were higher than those reported in other studies, indicating a possibility of a successful application of the doubled haploid method in maize breeding.

Fusarium stalk rot disease (FSR) of maize caused by Fusarium verticillioides (Sacc.) Nirenberg is becoming an important biotic production constraint in many of the major maize growing areas causing substantial yield losses. Inbreds are preferred as parents in hybrid development owing to homozygous nature and high heterotic ability. Double haploid (DH) technology has emerged as a significant milestone. A total of 339 DH lines were generated from two inbred lines, VL1043 (susceptible) and CM212 (resistant), through in vivo haploid induction method. The 339 DH lines along with parents were phenotyped for their response to the FSR at the College of Agriculture, V. C. Farm, Mandya, India during summer, kharif and rabi seasons of the 2019–2020. Best linear unbiased predictors (BLUPs) were estimated for the FSR disease scores over three seasons. A wide range of BLUP scores of three to nine indicated the presence of higher variation for response of DH lines to FSR disease. The higher estimates of standardized range (1.31) and phenotypic coefficient of variation (19.80) also displayed higher variability. Nine lines were moderately resistant and 188 exhibited moderately susceptible reaction. The distribution of DH lines was positively skewed (1.34) and platykurtic (2.31) which suggested complementary epistasis and involvement of large number of genes in the disease expression. [ABSTRACT FROM AUTHOR]

The dynamics of changing climatic factors and the study of the impact they have on cultivated crops is an area that needs to be carefully and thoroughly researched in order to adequately address the future challenges of human nutrition. The present study concerned the influence of major environmental factors on some morphological and economic characteristics of sunflower (Helianthus annuus L.), which is a main oil crop in Bulgaria. Development and selection of parental lines with stabilized morphological and economic parameters is a main point of the heterosis breeding in sunflower. This study was carried out during 2009-2011 at Dobrudzha Agricultural Institute - General Toshevo. The three years of the investigation differed by the sum of vegetative rainfalls. The investigation involved 10 doubled haploid fertility restorer lines. The analysis of the results showed that the year conditions and the genotype of the investigated lines had a significant effect (p=0.001) on the studied morphological traits and on the oil content in seeds. The combined influence of these two factors was not significant on plant height and oil content. The head diameter was influenced to a much higher degree by the year conditions than the plant height. The oil content in seed was the trait with lowest variation during the period of investigation in comparison to the two morphological traits. The highest values of the morphological traits and the content of oil in seed were determined in the warm and humid year 2010. [ABSTRACT FROM AUTHOR]

Speckled snow mold caused by Typhula ishikariensis is one of the most devastating diseases of winter wheat in Hokkaido, Japan and parts of the Pacific Northwest region of USA. Münstertaler is a winter wheat landrace from Switzerland that has very high resistance to snow mold and superior freezing tolerance. Quantitative trait loci (QTL) for resistance to speckled snow mold were identified in a doubled haploid population derived from a cross between Münstertaler and susceptible variety Ibis, both under field conditions and controlled environment tests. Composite interval mapping analysis revealed a major QTL on chromosome 5D from Münstertaler, and on chromosome 6B from Ibis. Flanking microsatellite marker cfd 29 for the QTL on chromosome 5D was about 5 cM distant from vernalization requirement gene Vrn-D1, suggesting that the QTL on chromosome 5D is located on a cold-stress-related gene cluster along with Vrn-D1 and freezing tolerance gene Fr-D1. The QTL on chromosome 6B from Ibis was located on the centromere region flanking QTn.mst-6B, which is reported to increase plant tiller number. [ABSTRACT FROM AUTHOR]

To study the relationships of grain yield and some of agro-morphological traits in 40 doubled haploid (DH) lines along with parental and three check genotypes in a randomized complete block design with two replications under two water regimes (normal and stress) were evaluated during 2011-2012 and 2012-2013 growing seasons. Combined analysis of variance showed significant difference for all the traits in terms of the year, water regimes, lines, and and line × year. Comparison of group means, between non-stress and stress conditions, showed that DH lines had the lowest reduction percentage for the number of grains per spike, thousand grain weight, grain yield and biological yield as opposed to check genotypes. The correlation between grain yield with biological yield, harvest index, thousand grain weight, and hectoliter of kernel weight in both conditions, were highly significant and positive. Based on stepwise regression the peduncle length, number of seeds per spike, thousand seed weight, and hectoliter of kernel weight had important effect on increasing seed yield. The result of path analysis showed that these traits had the highest direct effect on grain yield. Based on mean comparisons of morphological characters as well as STI and GMP indices it can be concluded that lines No.11, 13, 14, 24, 29, 30, 35 and 39 were distinguished to be desirable lines for grain yield and their related traits and also tolerant lines in terms of response to drought stress conditions.

Salinity majorly hinders horizontal and vertical expansion in worldwide wheat production. Productivity can be enhanced using salt-tolerant wheat genotypes. However, the assessment of salt tolerance potential in bread wheat doubled haploid lines (DHL) through agro-physiological traits and stress-related gene expression analysis could potentially minimize the cost of breeding programs and be a powerful way for the selection of the most salt-tolerant genotype. We used an extensive set of agro-physiologic parameters and salt-stress-related gene expressions. Multivariate analysis was used to detect phenotypic and genetic variations of wheat genotypes more closely under salinity stress, and we analyzed how these strategies effectively balance each other. Four doubled haploid lines (DHLs) and the check cultivar (Sakha93) were evaluated in two salinity levels (without and 150 mM NaCl) until harvest. The five genotypes showed reduced growth under 150 mM NaCl; however, the check cultivar (Sakha93) died at the beginning of the flowering stage. Salt stress induced reduction traits, except the canopy temperature and initial electrical conductivity, which was found in each of the five genotypes, with the greatest decline occurring in the check cultivar (Sakha-93) and the least decline in DHL2. The genotypes DHL21 and DHL5 exhibited increased expression rate of salt-stress-related genes (TaNHX1, TaHKT1, and TaCAT1) compared with DHL2 and Sakha93 under salt stress conditions. Principle component analysis detection of the first two components explains 70.78% of the overall variation of all traits (28 out of 32 traits). A multiple linear regression model and path coefficient analysis showed a coefficient of determination (R2) of 0.93. The models identified two interpretive variables, number of spikelets, and/or number of kernels, which can be unbiased traits for assessing wheat DHLs under salinity stress conditions, given their contribution and direct impact on the grain yield.

Salinity is a major obstacle to wheat production worldwide. Salt-affected soils could be used by improving salt-tolerant genotypes depending upon the genetic variation and salt stress response of adapted and donor wheat germplasm. We used a comprehensive set of morpho-physiological and biochemical parameters and simple sequence repeat (SSR) marker technique with multivariate analysis to accurately demonstrate the phenotypic and genetic variation of 18 wheat genotypes under salinity stress. All genotypes were evaluated without NaCl as a control and with 150 mM NaCl, until the onset of symptoms of death in the sensitive plant (after 43 days of salinity treatment). The results showed that the relative change of the genetic variation was high for all parameters, heritability (>60%), and genetic gain (>20%). Stepwise regression analysis, noting the importance of the root dry matter, relative turgidity, and their respective contributions to the shoot dry matter, indicated their relevance in improving and evaluating the salt-tolerant genotypes of breeding programs. The relative change of the genotypes in terms of the relative turgidity and shoot dry matter during salt stress was verified using clustering methods. For cluster analysis, the genotypes were classified into three groups: tolerant, intermediate, and sensitive, representing five, six, and seven genotypes, respectively. The morphological and genetic distances were significantly correlated based on the Mantel test. Of the 23 SSR markers that showed polymorphism, 17 were associated with almost all examined parameters. Therefore, based on the observed molecular marker-phenotypic trait association, the markers were highly useful in detecting tolerant and sensitive genotypes. Thus, it considers a helpful tool for salt tolerance through marker-assisted selection.

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A mapping population of 95 doubled haploid lines of wheat Triticum aestivum L., raised by crosses between cultivar Chinese Spring (CS) and line SQ1, was grown in irrigated and rainfed conditions of South-East Kazakhstan (1998–2008 years), studied for grain quality traits, and characterized for Fe, Zn, and S content in grains. In addition to previous studies associated with grain productivity and drought stress torelance (Quarrie et al., 2005) and grain quality traits (Abugalieva et al., 2008), the range of variation in micronutrient contents in wheat grains of the CS × SQ1 doubled haploid population provides an excellent opportunity for identification of quantitative trait loci that control the amounts of Fe, Zn, and S in grains. Doubled haploid lines with stable high content of Fe and Zn grown in irrigated and rainfed conditions were obtained on the base of the referred work. The lines can be used in biofortification of spring wheat in Kazakhstan. The results reveal significant correlation indices between Zn and protein contents in grains. They may be important in local breeding programs for the improvement of productivity and grain quality.

Androgenesis has been studied in anther cultures of eight cultivars and one promising accession of spring common wheat raised in West Siberia (Siberian Research Institute of Agriculture, Omsk, Russia). The varieties are close in origin but vary in the presence or absence of wheat-alien translocations (wheat–rye 1RS.1BL and wheat–couch grass 7DL-7Ai). The promising accession L-311/00-22 bears the 1RS.1BL translocation and the cytoplasm of cultivated barley Hordeum vulgare L. The main task of the study is to assess the possibility of obtaining dihaploid lines in the genotypes examined bearing wheat-alien translocations. It has been found that different accessions respond differently to anther culture conditions depending on the concentration of 2,4-D in the initial medium. Accession L-311/00-22 is best for androgenesis experiments and raise of dihaploid lines. The dependence of the effect of the genotypic environment of wheat on the effect of wheat-alien translocation on androgenesis features, is discussed.

Improving salt tolerance of genotypes requires a source of genetic variation and multiple accurate selection criteria for discriminating their salt tolerance. A combination of morpho-physiological and biochemical parameters and multivariate analysis was used to detect salt tolerance variation in 15 wheat lines developed by doubled haploid (DHL) technique. They were then compared with the salt-tolerant check cultivar Sakha 93. Salinity stress was investigated at three salinity levels (0, 100, and 200 mM NaCl) for 25 days. Considerable genetic variation was observed for all traits, as was high heritability (>60%) and genetic gain (>20%). Principal component analysis indicated the ability of nine traits (root number, root length, root dry weight, shoot length, shoot dry weight, specific root length, relative water content, membrane stability index, and catalase) to identify differences in salinity tolerance among lines. Three traits (shoot length, shoot dry weight, and catalase) were indicative of salt-tolerance, indicating their importance in improving and evaluating salt tolerant genotypes for breeding programs. The salinity tolerance membership index based on these three traits classified one new line (DHL21) and the check cultivar (Sakha 93) as highly salt-tolerant, DHL25, DHL26, DHL2, DHL11, and DHL5 as tolerant, and DHL23 and DHL12 as intermediate. Discriminant function analysis and MANOVA suggested differences among the five groups of tolerance. Among the donor genotypes, Sakha 93 remained the donor of choice for improving salinity tolerance during the seedling stage. The tolerated lines (DHL21, DHL25, DHL26, DHL2, DHL11, and DHL5) could be also recommended as useful and novel genetic resources for improving salinity tolerance of wheat in breeding programs.

Development of cultivars better adapted to drought stress in the arid and semi arid climatic conditions is considered as a major breeding objective. Grain quality is a trait with physico-chemical complexity depending primarily on genotype, is strongly affected by environmental factors and their interactions. Effect of terminal drought stress on quality traits of 18 triticale lines, comprising of 9 doubled haploids (DH) and 9 F7-8 lines, and two bread wheat cultivars (Rowshan and Kavir), was investigated under two separate experiments (with/without drought stress) at the Research Farm of College of Agriculture, Isfahan University of Technology, Isfahan, Iran, during two growing seasons of 2007-2009. Plants were grown under full irrigation until the mid-jointing stage when drought stress was applied. In this experiment, amount of glutenin, gliadin, gliadin/glutenin ratio, dry gluten content, sediment volume SDS, crude protein, carbohydrate, ash, grain test weight and grain yield were evaluated. The results showed that triticale lines performed superior to wheat cultivars under drought stress conditions considering grain yield, but wheat cultivar possessed the highest values for majority of quality traits. Grain yield had negative and significant correlation (r = - 0.56**) with grain protein content under no-stress conditions, and with grain test weight (r = - 0.67**) under stress conditions. Accordingly, genotypes with more grain test weight and protein content under stress conditions were probably affected by drought stress. and this may be due to lower of plant performance under drought stress conditions than those under normal conditions. Grain yield produced under drought stress conditions negatively and significantly correlated with dry gluten and protein under non-stress conditions. Overall, based on the results of this research, it was concluded that under drought stress conditions at the reproductive stage, DH triticale line number 2 performed superior for grain quality and biochemical adaptation to drought stress.

Epistasis, an additive-by-additive interaction between quantitative trait loci, has been defined as a deviation from the sum of independent effects of individual genes. Epistasis between QTLs assayed in populations segregating for an entire genome has been found at a frequency close to that expected by chance alone. Recently, epistatic effects have been considered by many researchers as important for complex traits. In order to understand the genetic control of complex traits, it is necessary to clarify additive-by-additive interactions among genes. Herein we compare estimates of a parameter connected with the additive gene action calculated on the basis of two models: a model excluding epistasis and a model with additive-by-additive interaction effects. In this paper two data sets were analysed: 1) 150 barley doubled haploid lines derived from the Steptoe x Morex cross, and 2) 145 DH lines of barley obtained from the Harrington x TR306 cross. The results showed that in cases when the effect of epistasis was different from zero, the coefficient of determination was larger for the model with epistasis than for the one excluding epistasis. These results indicate that epistatic interaction plays an important role in controlling the expression of complex traits.

Epistasis (additive × additive interaction) plays an important role in the genetic architecture of complex traits. This study presents analytical and numerical comparisons of two methods of estimation of additive × additive interaction of QTL effects. In the first method, we observed only the plant phenotype, while in the second method we have additional information from the molecular markers observations. In this study, two data sets were analyzed: i) 150 barley (Hordeum vulgare L.) doubled-haploid lines derived from the cross Steptoe × Morex and ii) 145 doubled-haploid lines of barley obtained from the cross Harrington × TR306. In total, 153 sets of observations were analyzed. The additive × additive interaction effect calculated on the basis of the marker observations is smaller than the total additive × additive interaction effect obtained from phenotypic observations only.

One of cereal diseases that has gained a greater importance for growers, processing industry as well as for breeders in many regions of the world is Fusarium head blight (FHB) caused by fungi of the Fusarium genus. The objectives of this study were to test diversity among spring barley breeding lines exhibiting various sensitivity to FHB and to find RAPD markers and AFLP markers that will distinguish between susceptible and resistant and/or moderately resistant genotypes. A test of a set of spring barley genotypes artificially infected by fusaria in field trials was carried out. Based on the results from field and laboratory evaluation and deoxynivalenol (DON) content assessment, barley genotypes with different responses to FHB were selected. The genotypes were hybridized and doubled haploid (DH) lines were derived in F1 generation using the in vitro androgenesis method. Initial parental components and derived DH lines were tested for FHB infection and DON content. A set of parental genotypes of spring barley was tested with 80 RAPD markers. A RAPD marker (H30) was detected which enabled to distinguish between very susceptible parental genotypes and other resistant or moderately resistant spring barley genotypes based on the fragment of about 1300 bp. This specific product was screened in 23 DH lines derived from crosses of parental genotypes of spring barley and detected in 10 DH lines. During the study, some DH lines were selected that exhibited improved resistance to Fusarium infection. A low infection level and low DON content was found in the line DH 4/2 derived from CI 4196 × Foster. The AFLP technique was used to analyse parental genotypes of spring barley. The detected markers can be further evaluated and employed to select breeding materials.

Epistasis, is the interaction between alleles from two or more loci determining complex traits, and thus plays an important role in the development of quantitative traits of crops. In mapping studies of inbreeding species epistasis is usually defined as the interactions between quantitative trait loci with significant additive gene effects. Indeed, in many studies, genes with small effects do not come into the final model and thus the total epistasis interaction effect is biased. Many loci may not have a significant direct effect on the trait under consideration, but they may still affect trait expression by interacting with other loci. In this paper the benefits of using all loci, not only the loci with significant main effects, for estimation of the epistatic effects are presented. The particular examples are with doubled haploids lines and so are restricted to homozygotes and thus additive genetic effects and additive × additive interactions. Numerical analyses were carried out on three populations of doubled haploid lines of barley ( Hordeum vulgare L.): 120 doubled haploid lines from the Clipper × Sahara 3771 cross, 145 doubled haploid lines from the Harrington × TR306 cross and 150 doubled haploid lines from the Steptoe × Morex cross. In total, 157 sets of observations were analyzed and altogether 728 pairs of loci were observed for the three datasets. [ABSTRACT FROM AUTHOR]

Doubled haploid (DH) lines are increasingly being used in commercial hybrid maize ( Zea mays L.) breeding. They allow for various quantitative genetic and logistic advantages provided that they are implemented in efficient and optimally allocated breeding procedures. In the present study, a new software was applied to optimize two recurrent selection (RS) schemes for hybrid maize breeding based on DH lines under a restricted annual budget and an upper limit for the relative annual loss of genetic variance. This software maximizes the expected gain from selection in general combining ability by means of quantitative genetic model calculations. Optimization results are compared for one, two, and three stages of testcross selection under different assumptions regarding the evaluation of lines per se and the annual budget. Results show that the optimum allocation of technical and budget resources to the individual steps of an RS program and the efficiency of alternative RS procedures are decisively determined by the number of selection stages. Under standard assumptions, one-stage selection was superior to two- and three-stage selection. Thus, shortening the length of an RS scheme considerably increases its efficiency. By intercrossing a reduced number of selected lines for starting a new RS cycle, the short-term response to selection may be increased, but the population size and, thus, the selection limits in the long run are diminished. Therefore, fair comparisons of alternative RS procedures require to define the intended time span for maximizing the genetic gain from RS and to restrict the relative annual loss of genetic variance accordingly. [ABSTRACT FROM AUTHOR]

Genetic analysis of resistance of pepper to bacterial wilt was performed in the doubled haploid progeny from a cross between a resistant parental line PM 687 and a susceptible cultivar Yolo Wonder. After artificial inoculation with a local isolate of Raistonia solanacearum, the progeny consisting of 90 lines was transplanted into a naturally infested field in Guadeloupe, Lesser Antilles. The 2 years of experimentation resulted in repeatable results, with a high heritability of the resistance, attesting the reliability of the evaluation procedure and the stability of the resistance over years. Two to five genes with additive effects were estimated to control the resistance, indicating an oligogenic control as observed in tomato sources of resistance. Relationships with resistance to other soilborne or tropical diseases were examined. Susceptibility to Tobacco mosaic virus (TMV) and to nematodes (Meloidogyne spp.) were significantly linked with resistance to bacterial wilt, whereas neither resistance to Phytophthora capsici nor to Leveillula taurica were linked. The similarity of the genetics of resistance to bacterial wilt in pepper and tomato and linkage with TMV resistance locus warrant the comparative mapping of the resistance quantitative trait loci in the genomes of the two species. [ABSTRACT FROM AUTHOR]

The resistance of rice to ozone (O3) is a quantitative trait controlled by nuclear genes. The identification of quantitative trait loci (QTL) and analysis of molecular markers of O3 resistance is important for increasing the resistance of rice to O3 stress. QTL associated with the O3 resistance of rice were mapped on chromosomes 1, 7 and 11 using 164 recombinant inbred (RI) lines from a cross between 'Milyang 23' and 'Gihobyeo'. The quantitative trait loci were tightly linked to the markers RC109, C507 and RG1094 and were detected in each of three replications. The association between these markers and O3 resistance in 26 rice cultivars and doubled haploid (DH) populations was analysed. The markers permit the screening of rice germplasm for O3 resistance and the introduction of resistance into elite lines in breeding programs. [ABSTRACT FROM AUTHOR]

A reproducible procedure for deriving highly regenerable cell suspensions that can readily and consistently regenerate green plantlets in wheat is described. Initiation and selection of the right type of callus from anther cultures, which consisted of friable early embryogenic portions that can easily disperse in liquid medium was important for the establishment of rapidly growing embryogenic suspensions. Using this type of inoculum no significant variation between three different independent replications was noted when cell suspensions from eleven specially recombined doubled haploid lines were maintained on General medium supplemented with dicamba and a predominance of amino acid nitrogen. This approach also enhanced a long-term embryogenic competence of the cell cultures, with some of the suspensions retaining their morphogenic capacity over a period of more than 15 months. Depending on the medium composition high frequencies of embryogenesis (over 70%) and green plantlet regeneration (repeatedly producing 90–100% of green regenerants) were obtained from the cell aggregates for most of the embryogenic cell lines. Potential advantages of anther culture-derived embryogenic cell suspensions for transformation purposes are the high number of cell lines which can be established routinely and the apparent maintenance of a stable haploid genome by the regenerants in culture. It is anticipated that an increased use of anther or microspore derived doubled haploid techniques in future wheat breeding programmes may favour selection in the breeding material of plant types generally responsive to such protocols. [ABSTRACT FROM AUTHOR]

The investigation was carried out at the Laboratory facilities of Dobrudzha Agricultural Institute (DAI), General Toshevo, Bulgaria during 2010 - 2012, and involved 15 doubled haploid fertility restorer sunflower lines (R-lines). The lines were obtained by the gamma-induced parthenogenesis method under greenhouse conditions in 2007 from three hybrid combinations developed at DAI. The resistance of the plants to downy mildew - one of the main pathogens on sunflower, and to the parasite broomrape was followed. The breeding materials were infected with downy mildew (Plasmopara halstedii), race 731, and broomrape (Orobanche cumana Wallr.) under greenhouse conditions. The evaluation for resistance was done according to a scale from 0 % (susceptible genotype) to 100 % (resistant genotype). To determine the resistance to downy mildew, standard methodology was applied, adapted for work under the specific conditions of DAI; the methodology of Panchenko (1975) was used to determine the resistance to broomrape. Four lines demonstrated complex resistance to downy mildew and broomrape. Among the other eleven lines, three lines showed 100 % resistance to downy mildew race 731, and five lines were resistant to Orobanche (races A-F). [ABSTRACT FROM AUTHOR]