Leaf Pubescence in Common Wheat, <i>Triticum aestivum</i> L., and Resistance to the Cereal Leaf Beetle, <i>Oulema melanopus</i> (L.)¹

Abstract

Plant materials were derived from crosses between glabrous and pubescent wheat varieties. A technique for evaluating pubescence density on photomicrographs of cleared leaf samples was developed. Individual plants from parental and segregating populations were evaluated for leaf pubescencea nd tested for resistance by a larval feeding test. Correlation coefficients between larval weight and pubescence density were highly significant with highpubescence, density associated with resistance. The original data for both larval weight and pubescence density were transformed to square roots to make variances independent of the means. The square root transformation also made the frequency distributions for segregating populations more normal. Analyses of the pubescence data of F 1 , F 2 , and BC progenies from crosses between glabrous and pubescent varieties show this character to be quantitatively inherited. The gene action estimated on the square root scale is mainly additive. Partition of variance shows only additivity, but analysis of population means reveals a partial dominance for pubescence density. Heritability in the F 2 was approximatdy 50%.