The variability for protein concentration in a composite cultivar named "Rattan" was studied using half sib and full sib progenies developed by following nested mating design (Design-1 of Comstock and Robinson, Biometrics 4:254-266, 1948). Sixty-four plants were selected at random and each as a male was crossed to four randomly taken plants used as females, making 64 half sibs and 256 full sibs. These were grown in two agro-climatically different locations in an incomplete block design with two replications.
Table 1. The estimates of various variance components along with standard
|Variance components||Pooled||Location I||Location II|
|Additive genetic||0.01 ± 0.12||-0.19 ± 0.17||-0.71 ± 0.32|
|Dominance||-0.03± 0.33||1.86 ± 0.44**||4.53 ± 0.94**|
|Additive x environment||-0.40± 2.40||-||-|
|Dominance x environment||3.80 ± 0.96**||-||-|
Perusal of Table 1 indicates that only dominance variance component was significant in the individual locations analysis. However, in the pooled analysis the only component that was significant was due to dominance x environment interaction. Negative estimates were also obtained contrary to the theoretical expectations. The results indicated that the population is not suited for protein improvement through intra-population selection. It may be added that remarkable progress has been made in the manipulation of protein concentration in "Burr White" in a classical long-term selection experiment at Illinois (Dudley, pp. 459-473, in Proc. Internat. Conf. Quant. Genetics, Pollak et al., eds., Iowa State Univ. Press, Ames, 1977).
S. S. Pal, A. S. Khehra, B. S. Dhillon and K. S. Sekhon
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