Genetic Studies of Crown Depth and Subcrown Intenode Length in Winter Wheat1
- Jean M. Poulos and
- R. E. Allan2
Crown depth (CD) and subcrown internode length (SIL) affect coldhardiness of winter wheat (Triticum aestivum L.). Information on their inheritance and comparative value as selection criteria is limited. This study measured the heritability and predicted selection gain for CD and SIL in crosses involving a common parent and three semidwarf cultivars differing for CD and SIL. The semidwarfs were ‘Daws’ (DA), ‘Nugaines’ (NU), and ‘Stephens’ (ST), which deep vs. short, intermediate vs. intermediate, and shallow vs. long CD and SIL phenotypes, respectively. The common non-semidwarf parent was ‘Cappelle Desprez’ (CA), which has shallow CD and long SIL. A greenhouse procedure was devised and compared to field tests. The relationships of CD and SIL to seed depth (SD), coleoptile length (CL), and plant height were determined. In the greenhouse, progeny of most populations segregated for CL, SIL, and CD. In the field, all except the CA/ST progeny segregated for CD, but none segregated for SIL. Genotype by environment interactions were not significant (P > 0.05) for SIL and CD, except for CD of the CA/ NU population. Seed depth had a greater effect on SIL than on CD, and, accordingly, SIL had less utility as a selection criterion than CD. In the greenhouse, parent-progeny heritability estimates ranged from 0.32 to 0.42 for CD and 0.29 to 0.48 for SIL. Heritability estimates ranged from 0.00 to 0.37 for CD and 0.03 to 0.24 for SIL, when F4 field data were regressed on F3 greenhouse data. Dominance or overdominance occurred for shallow CD and long SIL. Most segregating generations showed nearly continuous variation and trangressive segregation for CD and SIL. At a 10% selection intensity, the average expected gain from selection was 2.9 mm for CD and 3.3 mm for SIL.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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