Early Generation Selection for Grain-Filling Period in Wheat
Grain-filling period (GFP) may be a useful physiological selection trait that could influence grain yield of cereals. This study was conducted to estimate heritability of GFP and to determine the response to selection for long and short GFP in six genetically diverse populations of spring wheat (Triticum aestivum L. emend. Thell.). Selections were made in the F2 generation and selected progenies were evaluated in replicated field tests in the F3 generation. The tests were seeded under normal and late conditions at Rampur, Nepal, in 1990. Date of seeding had a significant effect on GFP, grain and biomass yield, harvest index, and hundred kernel weight. Selection in the F2 for long and short GFP was effective in identifying F3 lines with long and short GFP, respectively. Also, selection for long GFP usually resulted in higher grain and biomass yield. Average harvest index and hundred kernel weight of the long GFP lines were higher than those of the short GFP fines. Realized heritability estimates for GFP were intermediate to high in magnitude (0.52–0.86). Duration of GFP had a high positive genotypic correlation with grain yield (0.52–0.79), harvest index (0.50–0.80), and hundred kernel weight (0.53–0.72). Results indicated that selection for long GFP in early segregating generations should bring about positive improvements in these yield components.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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