3 research outputs found
Genome-Wide DArTSeq Genotyping and Phenotypic Based Assessment of Within and Among Accessions Diversity and Effective Sample Size in the Diverse Sorghum, Pearl Millet, and Pigeonpea Landraces
Germplasm should be conserved in such a way that the genetic integrity of a given
accession is maintained. In most genebanks, landraces constitute a major portion of
collections, wherein the extent of genetic diversity within and among landraces of crops
vary depending on the extent of outcrossing and selection intensity infused by farmers.
In this study, we assessed the level of diversity within and among 108 diverse landraces
and wild accessions using both phenotypic and genotypic characterization. This included
36 accessions in each of sorghum, pearl millet, and pigeonpea, conserved at ICRISAT
genebank. We genotyped about 15 to 25 individuals within each accession, totaling
1,980 individuals using the DArTSeq approach. This resulted in 45,249, 19,052, and
8,211 high-quality single nucleotide polymorphisms (SNPs) in pearl millet, sorghum,
and pigeonpea, respectively. Sorghum had the lowest average phenotypic (0.090) and
genotypic (0.135) within accession distances, while pearl millet had the highest average
phenotypic (0.227) and genotypic (0.245) distances. Pigeonpea had an average of
0.203 phenotypic and 0.168 genotypic within accession distances. Analysis of molecular
variance also confirms the lowest variability within accessions of sorghum (26.3%)
and the highest of 80.2% in pearl millet, while an intermediate in pigeonpea (57.0%).
The effective sample size required to capture maximum variability and to retain rare
alleles while regeneration ranged from 47 to 101 for sorghum, 155 to 203 for pearl
millet, and 77 to 89 for pigeonpea accessions. This study will support genebank
curators, in understanding the dynamics of population within and among accessions,
in devising appropriate germplasm conservation strategies, and aid in their utilization for
crop improvement
Calcium-Rich Pigeonpea Seed Coat: A Potential Byproduct for Food and Pharmaceutical Industries
Pigeonpea is a protein-rich legume which is consumed worldwide in a variety of forms (whole seed, dhal, and as a green vegetable). In India, pigeonpea is milled to yield dhal (cotyledon) and this process generates 25–35% waste byproducts. The hull (seed coat) which accounts for 10% of the byproduct is disposed of either as waste or low-cost cattle feed. To recycle the waste byproducts into the food value chain, this study was conducted with the objectives: (i) to estimate nutrient accumulation in the major seed fractions (cotyledon and seed coat), (ii) to estimate the percentage of nutrient contribution by major seed fractions, (iii) to assess the percentage of nutrient loss due to dehulling, and (iv) to determine the scope of seed coat in nutritional value addition. For this, a subset of 60 diverse pigeonpea accessions selected from 600 pigeonpea accessions raised during the 2019 and 2020 rainy seasons at ICRISAT, Patancheru, India, was subjected to a cotyledon and seed coat nutrient analysis. The three-way analysis of variance revealed the significant influence of cropping years, seed fractions, genotypes, and their interactions on nutrient accumulation. The nutrients, namely protein (32.28 ± 2.29%), P (476.51 ± 39.05 mg/100 g), K (1557.73 ± 66.82 mg/100 g), Fe (4.42 ± 0.41 mg/100 g), Zn (2.25 ± 0.21 mg/100 g), and Cu (0.95 ± 0.07 mg/100 g) were enriched in cotyledon. Mn was equally enriched in both the cotyledon and seed coat (1.02 ± 0.12 mg/100 g and 0.97 ± 0.34 mg/100 g, respectively). The seed coat had a high concentration of Ca (652.02 ± 114.82 mg/100 g), and Mg (249.19 ± 34.12 mg/100 g) with wide variability for Fe (2.74–5.61 mg/100 g), Zn (0.88–3.95 mg/100 g), Cu (0.38–1.44 mg/100 g), and Mn (0.58–2.18 mg/100 g). It is noteworthy that the protein and P contents in the cotyledon were 7 and 18 times higher than that in the seed coat, respectively, and the Ca content in the seed coat was 12 times higher than that in the cotyledon. A correlation study revealed that for overall nutrient improvement in dhal, selection for a small seed size was desirable. On an average, the percentage of nutrient contribution by major seed fractions revealed that the cotyledon portion contributed around 95% protein and P; 90% K and Zn; 85% Fe, Cu, and Mn; and 75% Mg, while the seed coat portion contributed nearly 65% Ca to the whole grain. The findings of high Fe and protein concentrations in the cotyledon and high Ca accumulation in the seed coat can serve as a new guide for improved technological fractionation of these components to serve as a novel functional food ingredient and as a dietary supplement that can address malnutrition
Grain Nutrients Variability in Pigeonpea Genebank Collection and Its Potential for Promoting Nutritional Security in Dryland Ecologies
Pigeonpea, a climate-resilient legume, is nutritionally rich and of great value in Asia, Africa, and Caribbean regions to alleviate malnutrition. Assessing the grain nutrient variability in genebank collections can identify potential sources for biofortification. This study aimed to assess the genetic variability for grain nutrients in a set of 600 pigeonpea germplasms conserved at the RS Paroda Genebank, ICRISAT, India. The field trials conducted during the 2019 and 2020 rainy seasons in augmented design with four checks revealed significant differences among genotypes for all the agronomic traits and grain nutrients studied. The germplasm had a wider variation for agronomic traits like days to 50% flowering (67-166 days), days to maturity (112-213 days), 100-seed weight (1.69-22.17 g), and grain yield per plant (16.54-57.93 g). A good variability was observed for grain nutrients, namely, protein (23.35-29.50%), P (0.36-0.50%), K (1.43-1.63%), Ca (1,042.36-2,099.76 mg/kg), Mg (1,311.01-1,865.65 mg/kg), Fe (29.23-40.98 mg/kg), Zn (24.14-35.68 mg/kg), Mn (8.56-14.01 mg/kg), and Cu (7.72-14.20 mg/kg). The germplasm from the Asian region varied widely for grain nutrients, and the ones from African region had high nutrient density. The significant genotype x environment interaction for most of the grain nutrients (except for P, K, and Ca) indicated the sensitivity of nutrient accumulation to the environment. Days to 50% flowering and days to maturity had significant negative correlation with most of the grain nutrients, while grain yield per plant had significant positive correlation with protein and magnesium, which can benefit simultaneous improvement of agronomic traits with grain nutrients. Clustering of germplasms based on Ward.D2 clustering algorithm revealed the co-clustering of germplasm from different regions. The identified top 10 nutrient-specific and 15 multi-nutrient dense landraces can serve as promising sources for the development of biofortified lines in a superior agronomic background with a broad genetic base to fit the drylands. Furthermore, the large phenotypic data generated in this study can serve as a raw material for conducting SNP/haplotype-based GWAS to identify genetic variants that can accelerate genetic gains in grain nutrient improvement