Qualitative determination of reaction norms in pea (Pisum sativum L.) mutant lines

Depending on the environmental conditions one genotype can express diverse phenotypes and conversely a particular phenotype can be produced by different genotypes. Reaction norm refers the response of a given phenotype to an array of environmental conditions. This might lead to a wider or smaller adaptability or to a shift of optimal adaptation to environmental conditions. The present experiment was conducted in order to determine the extent of reaction norm of a group of radiation-induced pea mutants grown under four environments (years). Plant height, plant height to first pod, total number of nodes, number of nodes to the first pod, number of pods, number of seeds, biological productivity, weight of pods, stem weight, seed weight per plant, vegetative productivity and follicle weight were analyzed. The differences in the performance behavior of distinct genotypes demonstrate the importance of studying their gene-ecological reaction under different environments. The importance of qualitative determination of reaction norm of the genotype is discussed.