Genetic progress in wheat grain yield and its relationship

Abstract

The genetic diversity and the variability of morpho-physiological traits associated with grain yield potential of eleven brazilian wheats were examined during two years, under two fertilizer and fungicide levels. The results from two experiments carried out in 1983 and 1984 were not consistent due to the genotype x environment interaction. On the other hand, the results indicated that recent genotypes demonstrated higher yield than the old ones. The increase of the yield capacity appears to be due to a progressive improvement in the potential yield of varieties, kernels/spike number and increase green flag leaf area duration. Furthermore, the relative coefficient (r) suggests that a limited basic number of parents utilized on the different crosses may have contributed for a smaller genetic base on the crop.