IS MICRO-ENVIRONMENT A HURDLE IN GENETIC ENHANCEMENT OF YIELD IN PIGEONPEA?

Abstract

Yield stagnation in pigeonpea remains a serious concern. Since most cultivars in the past were bread using pedigree method, it seems that this method was ineffective in increasing the crop productivity. To get insight into this failure, 10 highly inbred parents and their F2 bulks were examined by comparing their single plant yield variances. Surprisingly, the inbred parents exhibited high inter-plant variability; and their F2s were less variable than their one or both the parents. These unusual observations were attributed to the interaction of individual plants with unspecied micro-environmental factors prevailing in their vicinity, both below and above the ground. Under such circumstances, the selections had low heritability and unpredictable performance in the subsequent generation. Since these factors cannot be targeted through breeding, it is suggested that the breeders should try other breeding approaches such as bulk, composites, and single pod descent. The pedigree method of breeding, however, will continue to have its utility in the genetic enhancement of qualitative traits like yield.Yield stagnation in pigeonpea remains a serious concern. Since most cultivars in the past were bread using pedigree method, it seems that this method was ineffective in increasing the crop productivity. To get insight into this failure, 10 highly inbred parents and their F2 bulks were examined by comparing their single plant yield variances. Surprisingly, the inbred parents exhibited high inter-plant variability; and their F2s were less variable than their one or both the parents. These unusual observations were attributed to the interaction of individual plants with unspecied micro-environmental factors prevailing in their vicinity, both below and above the ground. Under such circumstances, the selections had low heritability and unpredictable performance in the subsequent generation. Since these factors cannot be targeted through breeding, it is suggested that the breeders should try other breeding approaches such as bulk, composites, and single pod descent. The pedigree method of breeding, however, will continue to have its utility in the genetic enhancement of qualitative traits like yield.