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Carrot root being used as vegetable and salad due to the nutritional value, hence consumers demanding carrot production. Thus, the production can be achieved by an understanding of the genetics of root traits namely root length, root weight, root diameter, core diameter, flesh thickness and root to top (shoot) ratio. Thus, the results assist in the development of carrot hybrids or varieties. Genetic analysis of economic traits of carrot was estimated through three cross combinations, and the results revealed the existence of additive [d], dominance [h], additive × additive [i], additive × dominance [j] and dominance × dominance [l] gene actions. The nature and magnitude of gene interaction and effects showed the importance of the inheritance modes, and the complimentary type of non-epistatic gene action of traits could be used for the exploitation of heterosis through favourable positive [h] and [l] gene interaction and effects. This information on root genetics aided to the adoption of suitable breeding method, handling and selection of segregates with desirable economic traits.

Pigeonpea is the second most important pulse legume crop for food and nutritional security of South Asia that requires accelerated breeding using high throughput genomic tools. Single nucleotide polymorphisms (SNPs) are highly suitable markers for this purpose because of their bi-allelic nature, reproducibility and high abundance in the genome. Here we report on development and use of a pigeonpea 62 K SNP chip array ‘CcSNPnks’ for Affymetrix GeneTitan® platform. The array was designed after filtering 645,662 genic-SNPs identified by re-sequencing of 45 diverse genotypes and has 62,053 SNPs from 9629 genes belonging to five different categories, including 4314 single-copy genes unique to pigeonpea, 4328 single-copy genes conserved between soybean and pigeonpea, 156 homologs of agronomically important cloned genes, 746 disease resistance and defense response genes and 85 multi-copy genes of pigeonpea. This fully genic chip has 28.94% exonic, 33.04% intronic, 27.56% 5′UTR and 10.46% 3′UTR SNPs and incorporates multiple SNPs per gene allowing gene haplotype network analysis. It was used successfully for the analysis of genetic diversity and population structure of 95 pigeonpea varieties and high resolution mapping of 11 yield related QTLs for number of branches, pod bearing length and number of seeds per pod in a biparental RIL population. As an accurate high-density genotyping tool, ‘CcSNPnks’ chip array will be useful for high resolution fingerprinting, QTL mapping and genome wide as well as gene-based association studies in pigeonpea.

Carrot has wide color range particularly purple, orange, red and yellow dependent upon anthocyanins, β-carotene, lycopene and lutein content. Due to recent awareness of nutritional health security, there is increasing consumption of carrot by consumers as well as nutraceutical based industry owing to huge bioavailability of dietary vitamins, phytonutrients and bioactive compounds of carrots. Though, breeding for multinutritional rich carrot varieties, there is need to study and understand the genetic mechanism of nutritional traits viz., moisture, total solids, total soluble solids, total carotenoids, β-carotene, lycopene and total anthocyanin content. Keeping these in view, the present investigation was designed to study the six genetic parameter in six generation of twelve cross combinations. The six digenic parameter model results clearly revealed that additive [d], dominance [h], additive × additive [i], additive × dominance [j] and dominance × dominance [l] interactions governed nutritional traits in the crosses studied. The positive sign of dominance [h] and dominance × dominance [l] resulted into complimentary epistatic interactions controlling moisture content and total solids, total soluble solids, total carotenoids and β-carotene, lycopene (in all crosses except PM × IPC-122) and total anthocyanin content. From the higher frequency of allele dispersal [a+i] between the parents, it is evident that the selection process should be delayed until homozygosity is attained in advance generation which can be obtained through inter-mating of parents followed by cyclic recurrent selection and mass selection for nutritional traits with consecutive cross combinations. This epistatic parameter of genetic analysis would be effectively utilized for breeding strategy for improvement of nutritional traits in carrot.

Determining moisture content correctly in different materials or grains is the need of various industries today. Various techniques are suggested in the literature for sensing moisture contents of different materials. Horn antenna and microstrip antenna are the most commonly used antennas for finding moisture content, because of the noncontact type of measurement of moisture present in the sample. The microwave measuring technique offers a very exact and reliable measurement of the concentration of moisture. In the proposed system microstrip patch antenna at 900 MHz resonant frequency is designed and different materials like sodium carbonate, borax, potassium chloride, and lactose are tested for moisture content. For the fixed quantity of the sample, water content is gradually increased and return loss is measured. It is observed that with the increase in moisture content, return loss decreases.

Among all the abiotic stresses, cold is one of the important factor limiting crop productivity. Medium and late maturing varieties cover most of the cultivated area of pigeonpea and therefore the chances of facing cold/frost are prominently high. Northern parts of the country are witnessing very low temperature during the last fort night of December and first fortnight of January, which is conducive for frost injury and the susceptible lines exhibit frost symptoms. Screening of 302 germplasm/lines of pigeonpea comprising of varieties and advance materials against frost injury during the years 2016-2018 facilitated to identify tolerant and susceptible lines. One hundred and forty one lines did not show any injury symptom, whereas 120 were classified under score 1 and 17 lines showed moderate symptoms to frost injury. A highly frost tolerant (insensitive) line ICP 10509 was crossed to susceptible (sensitive) line ICP 11182 to study the nature of frost injury and mode of inheritance. The F1 hybrid showed tolerance to frost injury with 1-2 leaves showing little symptom (score 0-1) indicating dominance of the trait. The F2 population segregated into tolerant (216 plants) and susceptible individuals (91 plants) fit well into expected ratio of 3(T): 1(S) (P value = 0.06027) signifying that frost tolerance (insensitivity) is controlled by a single dominant gene. The proposed hypothesis was verified by backcross populations; B1 (F1 x ICP 11182) segregating into 1(T):1(S) ratio (P value = 0.1237), whereas, all the plants in B2 (F1 x ICP 10509) generation exhibited tolerance to frost injury. The identification of a single gene exhibiting tolerance to frost injury may be useful for developing frost tolerant genotypes.

Chickpea is predominantly an indeterminate (IDT) plant due to which high fertility and irrigation have adverse effect on seed yield. The semi-determinate (SDT) types are relatively early, lodging resistant and found to be similar in their yield potential to that of IDT genotypes. However, the inheritance of SDT stem type is not well understood in chickpea. The present investigation was aimed at studying the genetics of SDT stem type and identifying molecular marker linked to Dt1 locus through Bulked Segregant Analysis (BSA). The genetics of semi-determinacy was studied in BGD 72 (IDT) x BG 3078-1(SDT) cross in which the genetic constitution of BGD 72 was already known as Dt1Dt1Dt2Dt2 based on the previous study. The F1 was IDT indicating the dominance of indeterminacy over semideterminacy. The segregation in F2 and F3 revealed that SDT stem growth in the new-found genotype BG3078-1 was governed by a single dominant gene Dt2 and its genotype designated as dt1dt1Dt2Dt2. The study of polymorphic survey between BGD-72(IDT) and BG 3078- 1(SDT) using 581 SSR markers found 50 markers polymorphic. The BSA using 50 polymorphic markers has identified TA42 and TR29 as polymorphic between IDT and SDT parents as well as IDT and SDT bulks and hence considered putatively linked to Dt1 locus governing IDT stem growth in chickpea. The two linked markers were validated in 15 IDT and 15 SDT F2 plants individually. These two markers were also validated in 3 IDT, 8SDT and 3 DT genotypes. This is the first report on the identification of a molecular marker associated with stem growth habit in chickpea.

Soil salinity is a major constraint that limits legume productivity. The present study evaluates the physiological and biochemical basis of radiation affect on salt tolerance response of pigeonpea. Seed gamma irradiation, in general, at 1.92 (control), 5.86 (80 mM) and 8.02 dSm−1 (100 mM) soil electrical conductivity (NaCl stress), enhanced seedling establishment, plant growth, carbon metabolism and gas exchange characteristics such as net photosynthesis, stomatal conductance and transpiration rate. Further, an improvement in salt tolerance response of gamma irradiated (

Pigeonpea [Cajanus cajan (L.) Millspaugh] is an important food legume of the semi-arid tropics (SAT) sustaining livelihood of millions of people. Stagnant and unstable yield per hectare all over the world is the characteristic feature of this crop. This is primarily ascribed to its susceptibility/sensitivity to a number of biotic and abiotic factors. Among biotic factors, insects such as pod borer (Helicoverpa armigera), pod fly (Melanoagromyza obtusa) and spotted borer (Maruca vitrata) substantially damage the crop and result in significant economic losses. Management of these insects by genetic means has always been considered environment friendly approach. However, genetic improvement has always been impeded by limited genetic variability in the primary gene pool of pigeonpea. Wild species present in the secondary and tertiary gene pools have been reported to carry resistance for such insects. However, transfer of resistance through conventional backcrossing has not been much successful. It calls for gene introgression through marker assisted backcrossing (MABC) or advanced backcross breeding (AB breeding). In this review, we have attempted to assess the progress made through conventional and molecular breeding and suggested the ways to move further towards genetic enhancement for insects resistance in pigeonpea

Pigeonpea is an important tropical grain legume widely cultivated in South and South-East Asia for versatile end usage as food, feed, fodder and fuel. Recent publication of draft genome sequence of pigeonpea (‘Arhar’) has allowed mining of large numbers of genomic simple sequence repeat (SSR) markers most of which are either not validated or show very little polymorphism in simple agarose gel–based assays. Here, we describe a special category of 370 validated highly variable ‘Arhar’ genomic SSR (HASSR) markers, which provide much higher level of polymorphism than a random set of SSR markers. These markers were validated for consistent amplification in a set of eight pigeonpea varieties and 152 of these (41%) showed allelic polymorphism on agarose gel electrophoresis. Twenty-four highest polymorphic HASSR markers were used on a larger set of forty pigeonpea varieties and eight wild Cajanus species for the analysis of genetic diversity and phylogenetic relationship. Genomic HASSR markers described here are highly suitable for genetic diversity and phylogenic studies in pigeonpea.

With 5 figures and 6 tables Abstract An understanding of the inheritance of aluminium (Al) tolerance is important to breed for Al-tolerant genotypes of chickpea (Cicer arietinum L.). Therefore, a study was undertaken to infer genes governing Al tolerance in chickpea. Tolerant lines ‘ICC14880’ and ‘IPC92-39’ were crossed with sensitive lines ‘IPCK96-3’ and ‘IPC99-4’. Parental, F1, F2, F3 and backcross generations were evaluated in a nutrient solution containing 20 ppm Al for haematoxylin staining and root re-growth and classified for tolerance by staining of root tips and root re-growth. The F1 hybrids responded similarly to the tolerant parents indicating dominance of Al tolerance over sensitivity. Segregation for tolerance vs. sensitivity in F2 fitted well with the 3 : 1 ratio expected for a single gene. The backcross and F3 data confirmed the presence of single dominant gene common in tolerant parents. Experimental findings showed that Al tolerance is a monogenic dominant trait that can be easily transferred to high yielding lines through a backcross breeding.

Pigeonpea (Cajanus cajan (L.) Millsp.) is a major food legume cultivated in semi-arid tropical regions including the Indian subcontinent, Africa, and Southeast Asia. It is an important source of protein, minerals, and vitamins for nearly 20% of the world population. Due to high carbon sequestration and drought tolerance, pigeonpea is an important crop for the development of climate resilient agriculture and nutritional security. However, pigeonpea productivity has remained low for decades because of limited genetic and genomic resources, and sparse utilization of landraces and wild pigeonpea germplasm. Here, we present a dense intraspecific linkage map of pigeonpea comprising 932 markers that span a total adjusted map length of 1,411.83 cM. The consensus map is based on three different linkage maps that incorporate a large number of single nucleotide polymorphism (SNP) markers derived from next generation sequencing data, using Illumina GoldenGate bead arrays, and genotyping with restriction site associated DNA (RAD) sequencing. The genotyping-by-sequencing enhanced the marker density but was met with limited success due to lack of common markers across the genotypes of mapping population. The integrated map has 547 bead-array SNP, 319 RAD-SNP, and 65 simple sequence repeat (SSR) marker loci. We also show here correspondence between our linkage map and published genome pseudomolecules of pigeonpea. The availability of a high-density linkage map will help improve the anchoring of the pigeonpea genome to its chromosomes and the mapping of genes and quantitative trait loci associated with useful agronomic traits.

Information on the genetic basis of root yield and quality of different coloured carrot genotypes is essential for planning the breeding strategies for genetic improvement. The objective of this study was carried out during winter and spring-summer season of 2011–15 to determine the gene action involved in the inheritance of economic traits of three carrot hybrids by using six generation mean analysis (P1, P2, F1, F2, B1 and B2). Three crosses of carrot were analyzed to study the gene actions involved in the inheritance of economic traits, viz., root length, root weight, shoulder diameter, root diameter, flesh thickness, core diameter and root to top ratio. The genetics of root weight, root to top ratio and root diameter in the all White Pale crosses were complementary type of gene interaction, which shows the genetic improvement of carrot tropical with respect to these traits can improved through biparental matting followed by mass and cyclic recurrent selection in advanced generation.

Background Pigeonpea is an important grain legume of the semi-arid tropics and sub-tropical regions where it plays a crucial role in the food and nutritional security of the people. The average productivity of pigeonpea has remained very low and stagnant for over five decades due to lack of genomic information and intensive breeding efforts. Previous SSR-based linkage maps of pigeonpea used inter-specific crosses due to low inter-varietal polymorphism. Here our aim was to construct a high density intra-specific linkage map using genic-SNP markers for mapping of major quantitative trait loci (QTLs) for key agronomic traits, including plant height, number of primary and secondary branches, number of pods, days to flowering and days to maturity in pigeonpea. Results A population of 186 F2:3 lines derived from an intra-specific cross between inbred lines ‘Pusa Dwarf’ and ‘HDM04-1’ was used to construct a dense molecular linkage map of 296 genic SNP and SSR markers covering a total adjusted map length of 1520.22 cM for the 11 chromosomes of the pigeonpea genome. This is the first dense intra-specific linkage map of pigeonpea with the highest genome length coverage. Phenotypic data from the F2:3 families were used to identify thirteen QTLs for the six agronomic traits. The proportion of phenotypic variance explained by the individual QTLs ranged from 3.18% to 51.4%. Ten of these QTLs were clustered in just two genomic regions, indicating pleiotropic effects or close genetic linkage. In addition to the main effects, significant epistatic interaction effects were detected between the QTLs for number of pods per plant. Conclusions A large amount of information on transcript sequences, SSR markers and draft genome sequence is now available for pigeonpea. However, there is need to develop high density linkage maps and identify genes/QTLs for important agronomic traits for practical breeding applications. This is the first report on identification of QTLs for plant type and maturity traits in pigeonpea. The QTLs identified in this study provide a strong foundation for further validation and fine mapping for utilization in the pigeonpea improvement.

Contributions made through conventional breeding have been of great significance in the development of pigeon varieties for diverse agro ecological regions in the country. The available genetic variability has been exploited to its full potential for enhancing trait based genetic improvement. However, the on farm productivity and production has remained low due to several constraints including the plant architecture, early maturity, disease and insect pest resistance. Hence, to breed cultivars having high agronomic performance with broad genetic base for specific regions, new sources of genetic variability need to be tapped. Wild species of Cajanus present a vast reservoir of useful genes for pigeonpea improvement. Heterosis breeding has enormous scope to break the yield barrier and enhancing potential but there is great need to identify heterotic parents to be used as MS lines and their respective restorers. However the major challenges are still being faced to answer genetic solutions for achieving yield potential through early maturity restructuring the plant type and resistance breeding to pave the way for sustainability in pigeon pea production.

Pigeonpea [Cajanus cajan (L.) Millsp.] is a protein-rich pulse crop which can grow well under soil moisture limited environments. The crop can play a significant role in meeting the challenges of global food security under the looming threats of climate change, soil degradation and rising production costs. This would be possible through fasttrack breeding of new cultivars with high and stable performances. This paper reviews the achievements of pigeonpea breeding research and suggests the growth trajectory for future programmes related to breeding of high yielding pure line and hybrid cultivars. In the past few decades, three pigeonpea breeding milestones have made their mark. These include development of (i) medium maturing disease resistant pigeonpea cultivars for greater yield and stability, (ii) high yielding early maturing pigeonpea cultivars for area expansion involving new production niches, and (iii) a trend setting hybrid breeding technology for breaking the decades-old low yield plateau. These innovations are showing their positive impact on pigeonpea production and productivity and hold promise for achieving nutritional security of masses in the country.

In the present study, genetic diversity among 73 genotypes comprising of cultivars and stable inter-specific derivatives from pigeonpea (Cajanus cajan x C. scarabaeoides) was assessed based on thirteen agro-morphological and quality traits and 42 genic microsatellite markers. Cluster analysis based on Tocher's methods of pooled fielddata of agromorphological traits from all three environment and two locations grouped pigeonpea genotypes into nine clusters. Genetic divergence was mainly contributed by days to 50% flowering (30.14%) followed by 100 seed weight (20.78%) and protein content (12.56%). The range of polymorphic information content (PIC) for microsatellites was 0.055–0.695. A total of 104 alleles were amplified with 42 SSR markers with an average of 2.48 alleles per locus. Ten alleles were unique to inter-specific derivatives. Based on Shannon's information index (I), ASSR 17 was the most informative locus for all the genotypes. Two loci, ASSR114 and ASSR317 were polymorphic only among the interspecific derivatives. Cophenetic correlations were statistically significant for phenograms based on Euclidean distances and average Manhattan distance analysis. The first three principal coordinates explained 60.17% and 57.22% of the accumulated variation in case of agromorphological traits and microsatellite data respectively. The information accrued is potential for broadening the genetic base in pigeonpea.

Validation of QTLs recently reported in pigeonpea for plant type and earliness traits viz., plant height, number of secondary branches, number of pods per plant, days to flowering and days to maturity was carried out using RILs derived from the cross Pusa Dwarf x H2001-4. RILs exhibited significant phenotypic variation for the all the traits. Using Interval mapping analysis QTLs for these traits except for plant height were successfully validated in the RILs in the marker interval ASSR100 and ASSR 206. Contribution of enhancing alleles by female parent Pusa Dwarf for the traits was also confirmed. QTLs for earliness traits qFL5.1 and qMT5.1 explained 15.3% and 11.6% phenotypic variation respectively while QTLs for plant type characteristics qSB5.1 and qPD5.1 exhibited phenotypic variation of 18.1% and 11.2% respectively.

Pigeon pea [Cajanus cajan] is an important grain legume of South-East Asia and East Africa. It is mainly grown as a kharif crop and is known to sustain prolonged drought and temperature stress. The Hsp 100family gene [ClpB] is one of the major and critical genes required for acquired thermo tolerance. The current study was taken up to identify and characterize the Hsp 100 family genes in pigeon pea since very little information is available for this thermo tolerant plant. In silico genome wide characterization was carried out and 5 Hsp100 like gene sequences were identified. Domains were predicted and three proteins were found to possess Class I type ClpB domains. Expression of these genes was observed at control 2, 6 and 24 h post heat stress conditions indicating their heat inducible nature. Out of the 5 genes predicted, two Clp genes show constant expression under heat stress and could be important components of the heat stress response in pigeon pea as they are targeted to the chloroplast. To identify additional members, candidate gene approach was taken up. Glycine max Hsp100 genes were downloaded and their expression studied under heat stress conditions in Asha, Pusa dwarf and C. platycarpus genotypes. Out of 23, 20 genes were expressed in pigeon pea indicating the presence of more Hsp100 family genes in the genome that need further investigation. This study would help in understanding the molecular components governing thermo tolerance in pigeon pea.

Aluminium toxicity is a major factor limiting plant growth in acid soil and more adequate genetic tolerance is needed to improve pigeonpea adaptation and production in affected areas. To study the inheritance, tolerant lines IPA7-10, T-7 were crossed with sensitive lines Pusa 9 and Bahar. The parents, F1, F2 and F3 generations were grown in a nutrient solution containing 30 ppm aluminium for hematoxylin staining and root re-growth measure and classified for tolerance by staining of root tips and root re-growth. The segregation ratios obtained for aluminium tolerance in the F2 and F3 generations were 15 : 1 and 7 : 8 : 1, respectively. These results indicated that aluminium tolerance is controlled by two dominant genes.

Background Pigeonpea [Cajanus cajan (L.) Millspaugh], one of the most important food legumes of semi-arid tropical and subtropical regions, has limited genomic resources, particularly expressed sequence based (genic) markers. We report a comprehensive set of validated genic simple sequence repeat (SSR) markers using deep transcriptome sequencing, and its application in genetic diversity analysis and mapping. Results In this study, 43,324 transcriptome shotgun assembly unigene contigs were assembled from 1.696 million 454 GS-FLX sequence reads of separate pooled cDNA libraries prepared from leaf, root, stem and immature seed of two pigeonpea varieties, Asha and UPAS 120. A total of 3,771 genic-SSR loci, excluding homopolymeric and compound repeats, were identified; of which 2,877 PCR primer pairs were designed for marker development. Dinucleotide was the most common repeat motif with a frequency of 60.41%, followed by tri- (34.52%), hexa- (2.62%), tetra- (1.67%) and pentanucleotide (0.76%) repeat motifs. Primers were synthesized and tested for 772 of these loci with repeat lengths of ≥18 bp. Of these, 550 markers were validated for consistent amplification in eight diverse pigeonpea varieties; 71 were found to be polymorphic on agarose gel electrophoresis. Genetic diversity analysis was done on 22 pigeonpea varieties and eight wild species using 20 highly polymorphic genic-SSR markers. The number of alleles at these loci ranged from 4-10 and the polymorphism information content values ranged from 0.46 to 0.72. Neighbor-joining dendrogram showed distinct separation of the different groups of pigeonpea cultivars and wild species. Deep transcriptome sequencing of the two parental lines helped in silico identification of polymorphic genic-SSR loci to facilitate the rapid development of an intra-species reference genetic map, a subset of which was validated for expected allelic segregation in the reference mapping population. Conclusion We developed 550 validated genic-SSR markers in pigeonpea using deep transcriptome sequencing. From these, 20 highly polymorphic markers were used to evaluate the genetic relationship among species of the genus Cajanus. A comprehensive set of genic-SSR markers was developed as an important genomic resource for diversity analysis and genetic mapping in pigeonpea.