Estimation of genetic architecture of biochemical traits in mid–late cauliflower (Brassica oleracea L. var. botrytis) under sub-temperate conditions of north western Himalayas

Understanding the genetic basis of biochemical traits of different cauliflower genotypes is essential for planning the effective breeding strategies in genetic improvement. To determine the mode of inheritance of dry matter content and biochemical traits, we made crosses using four genotypes of cauliflower, and obtained F1, F2, BC1 and BC2 populations. The six generations obtained were replicated thrice and evaluated in a randomized block design. The generation mean analysis of data showed the presence of duplicate epistasis in dry matter content which suggested the adoption of reciprocal recurrent selection and biparental mating for the improvement of the trait. However, in case of vitamin C, complementary type of epistasis was reported in three crosses, which indicated the exploitation of heterosis breeding of enhancing vitamin C. It can be concluded that the role of gene action was in general more complex for the traits studied. The nature and magnitude of gene effects varies character-wise as well as cross-wise. Hence, for the improvement of dry matter content and biochemical traits in a particular cross, a specific breeding strategy has to be implemented.

Morphological and Biochemical Traits Associated with Resistance to POD Fly, Melanagromyza Obtusa (Malloch) in Pigeonpea.

Pod fly, Melanagromyza obtusa is an important emerging pest and a major constraint to increase the production and productivity of pigeonpea. The concealed mode of life of pod fly within the pod makes it difficult to control. Hence, host plant resistance is an important tool for the management of this pest. Therefore, a set of forty genotypes were screened for resistance to pod fly under field conditions and characterized for morphological and biochemical traits in the pods. The correlation studies revealed that, among morphological and biochemical constituents of pigeonpea, pod length (r=0.389*), pod width (r=0.380*), protein content (r=0.857**), total carbohydrates (r=0.782**), reducing sugars (r=0.848**) and total free amino acids (r=0.832**) in the pod walls were positively correlated with per cent pod damage, whereas pod wall thickness (r= -0.762**), trichome density (r= -0.745**) and phenol content (r= -0.871**) had significant negative correlation with pod fly damage. Therefore, these traits can be used as phenotypic and biochemical markers to identify pigeonpea genotypes with resistance to M. obtusa, and use in pod fly resistance breeding program.