| Results The range of variability, heritability estimates and genetic advance for different characters are given in Table 1 and the correlations among different characters are given in Table 2. There were considerable differences among strains for 1000 kernel weight which varied from 22.10 to 54.20 gm with a mean of 39.10 gm. The heritability estimate for 1000 kernel weight was quite low (23.48) and its expected genetic advance was 10.69% of the mean. The specific gravity of the kernels differed markedly, the range being 1.04 to 1.73. The heritability estimate for this character was high (79.76). The expected genetic advance for specific gravity of the kernels was 20.75% of the mean. The hardness (breaking strength) of the kernels varied in different strains. The softest kernels had a breaking strength of 6.5 kg and the hardest had 14.4 kg. The heritability estimate and expected genetic advance for kernel hardness were found to be 84.5% and 24.65%, respectively. Grain yield was positively correlated with test weight whereas it had negative correlation with kernel hardness. The relationship of grain yield with specific gravity of the kernels was negative but non-significant. Kernel hardness was also negatively associated with specific gravity of the grains. The relationship of test weight, with grain hardness and specific gravity were very weak and insignificant. Discussion The present study reveals that among the kernel characters studies specific gravity and hardness of the kernels possessed high heritability with high expected genetic advance. Thus genetic improvement could be achieved with ease in these characters. Their negative correlation with each other indicated that with the increase in specific gravity, the hardness of the kernels would decrease. The test weight of the kernels was not associated with either the hardness of the kernels or their specific gravity. Therefore, this character is supposed to be inherited independent of the other two characters. A significant positive correlation between kernal weight and grain yield revealed the importance of the character in our breeding programme. SIKKA and JAIN (1958) and ANAND et al. (1969), also emphasized that kernel weight was an important factor contributing towards yield. Significant negative correlation between kernel hardness and grain yield indicated that the kernels of the higher yielding varieties were softer. Similar results were obtained by GUPTA and ATHWAL (1966) in Indian inbred lines of pearl millet. A non-significant relationship between specific gravity of the kernels and grain yield revealed that specific gravity had no bearing on yield. Summary Eighty strains from Wheat World Collection were tested for kernel weight, specific gravity and hardness of the kernels and grain yield. 1000 kernel weight had low heritability, whereas, kernel hardness and specific gravity had high heritability and high genetic advance. Test weight was positively correlated with grain yield whereas kernel hardness had negative relationship with grain yield. Specific gravity of the kernel had no association with grain yield. Kernel specific gravity and hardness were inversely related with each other. Literature Cited ANAND, S. C., B. S. GILL and Hardial SINGH 1969. The relative importance of yield components in three gene dwarf wheats. Proc. 8th All India Wheat Res. Workers Workshop. 1: 189-190. GUPTA, V. P. and D. S. ATHWAL 1966. Genetic variability, correlation and selection indecies of grain characters in pearl millet. J. Res. (P.A.U.) 3: 111-117. SIKKA. S. M. and K. B. L. JAIN 1958. Correlation studies and the application of discriminant functions in aestivum wheats for varietal selection under rainfed conditions. Ind. J. Gen. Pl. Breed. 18: 178-186. SHOLLENBERGER, J. H. and D. A. COLEMAN 1926. Relation of kernel texture to the physical characteristics, milling and baking qualities and chemical composition of wheat. USDA Bull. 420. (Received September 14, 1970) |
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