Genetic Variability Analysis of M4-M5 Mutants of Indian Mustard (Brassica juncea L.)

Abstract

Indian mustard [Brassica juncea (L.) Czern. & Coss.] is an important oilseed crop grown in India under diverse agro-ecological conditions in the temperate and subtropical regions during Rabi season. It fits well in the rainfed cropping system with low production cost and high potential to increase edible oil. Farmers in Assam grow rapeseed toria (Brassica rapa) due to its short duration but end up with low yield. Development of short-duration superior Indian mustard varieties is required to increase the average yield of rapeseed-mustard in Assam. Some Indian mustard genotypes were developed by induction of mutations at Assam Agricultural University, Jorhat. In the present study, 143 M4 lines from the parent variety NRCHB-101 of Indian mustard developed through mutation breeding using gamma rays, were evaluated during Rabi 2020-21 followed by 116 M5 selected lines during the Rabi 2021-22 to assess to genetic variability and interrelationships between yield component traits. Significant variation due to genotypes for the characters observed. Moderate genetic variation was observed for seed yield plant-1, number of primary and secondary branches plant-1. Moderate heritability coupled with high genetic advance was observed for number of siliquae in main shoot, number of primary branches, and number of secondary branches. The mutant lines JMM-NRCHB101-37, JMM-NRCHB101-57, JMM-NRCHB101-107 were found to be promising exhibiting superior performance for most of the yield attributing characters. The mutant line JMM-NRCHB101-86 and JMM-NRCHB101-95 also showed potentiality for early maturity with a high yield which could be exploited for the development of early maturing mustard varieties.