Heterotic Effects in Spring Wheat (Triticum aestivum L.) Under Saline Conditions
Heterotic effects in spring wheat was investigated using the six basic generations (P1, P2, F1, F2 and back crosses, BC1 and BC2) of cross between Alexandria (salt sensitive) and KRL1-4 (salt tolerant) varieties. Heterotic effects were greatly pronounced as F1, means fall outside the parental range for all physiological and most of the agronomic traits except number of spikes per plant and average grain weight. The significantly different estimates of the dominance components in F2 for Na+, K+, K+/Na+ ratio, number grains per spikes and grain weight per spike than that obtained from F1 indicate spurious overdominance exhibited by the F1 generation for these traits. Gene dispersion or non-allelic interaction or involvement of modifier are suggested from the transgressive segregation in the F2 population. It is also suggested from the F2 population frequency distributions for all traits that they were quantitatively inherited.
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