Characterization of core collection of lentil germplasm for phenology, morphology, seed and straw yields
Increasing and maintaining crop residues in predominantly cereal-based rotations of the US Pacific Northwest is critical to controlling soil erosion. The core collection of lentil (Lens culinaris Medik.) germplasm comprising 287 accessions was evaluated for variation in phenological, morphological and growth parameters including seed yields and residue amounts over a two-year period under conventional tillage and no-till conditions. The objectives of this study were (i) assess lentil genetic variation in germplasm for variation in biomass production and seed yield, (ii) assess the relationship of phenological and morphological traits with biomass and seed yield and (iii) identify high biomass producing germplasm for use as parents in the breeding program. Days to flowering and days to maturity ranged from 31 to 78 and from 71 to 106 days, respectively. Time to flowering in terms of cumulative heat units was a more efficient measurement than days to flowering. Plant height and plant canopy width had a significant association with total biomass, seed yield and residue amounts. Total biomass ranged from 788–6389 kg ha−1 under conventional tillage, while the range under no-till conditions was 1045–6195 kg ha−1. Most of the lines with higher biomass also produced the highest seed yields and residue amounts. Overall, only one accession produced more residue than `Laird'. In the more favorable environment of 1997, six accessions exceeded the control cultivars, `Laird' and `Indianhead', for residue amounts, and seven and twenty-four accessions exceeded control cultivars, `Pardina' and `Brewer', for seed yield. Results indicated that plant height, canopy width at maturity and seed yield explained most of the variation in biomass and residue production. Large seeded germplasm consistently had a longer reproductive growth period than small seeded accessions and had 17%, 7% and 21% more biomass, seed yield and residue, respectively. Our data indicated significant variation in lentil germplasm for biomass, seed yield and residue amounts to warrant their use in the breeding program.
Effect of High Temperature Stress During the Reproductive Stage on Grain Yield and Nutritional Quality of Lentil (Lens culinaris Medikus)
High temperature during the reproductive stage limits the growth and development of lentil (Lens culinaris Medikus). The reproductive and seed filling periods are the most sensitive to heat stress, resulting in limited yield and nutritional quality. Climate change causes frequent incidents of heat stress for global food crop production. This study aimed to assess the impact of high temperature during the reproductive stage of lentil on grain yield, nutritional value, and cooking quality. Thirty-six lentil genotypes were evaluated under controlled conditions for their high temperature response. Genotypic variation was significant (p < 0.001) for all the traits under study. High temperature-induced conditions reduced protein, iron (Fe) and zinc (Zn) concentrations in lentils. Under heat stress conditions, mineral concentrations among lentil genotypes varied from 6.0 to 8.8 mg/100 g for Fe and from 4.9 to 6.6 mg/100 g for Zn. Protein ranged from 21.9 to 24.3 g/100 g. Cooking time was significantly reduced due to high temperature treatment; the range was 3–11 min, while under no stress conditions, cooking time variation was from 5 to 14 min. Phytic acid variation was 0.5–1.2 g/100 g under no stress conditions, while under heat stress conditions, phytic acid ranged from 0.4 to 1.4 g/100 g. All genotypes had highly significant bioavailable Fe and moderately bioavailable Zn under no stress conditions. Whereas under heat stress conditions, Fe and Zn bioavailability was reduced due to increased phytic acid levels. Our results will greatly benefit the development of biofortified lentil cultivars for global breeding programs to generate promising genotypes with low phytic acid and phytic acid/micronutrient ratio to combat micronutrient malnutrition.
The Physiological Basis for Yield Differences between Four Genotypes of Groundnut (Arachis hypogaea) in Response to Drought. II. Solar Radiation Interception and Leaf Movement
SUMMARY Four genotypes of groundnut grown with limited irrigation during the post-rainy season in Central India produced similar amounts of dry matter per unit of intercepted solar radiation (e) before pod-filling, although different e values were observed during pod-filling. The relation between cumulative transpiration and intercepted radiation was similar for all genotypes. When drought became severe, fractional radiation interception (f) was reduced by folding of leaves, with little decrease in leaf area (L). The ratio f/√L was used as an index of the degree of leaf folding and was correlated with leaf water potential. The degree of folding varied with genotype and may have contributed to the observed differences in e and the dry matter:water ratio (q). The genotype EC76446(292) had the smallest q and largest f/√L ratio (the poorest radiation avoidance), while Kadiri 3 had the largest q and smallest value of f/√L.