Background:
To meet the growing demand of edible oil in the country the government is spending a large amount of foreign exchange on import. As expanding the area for cultivation of this crop is not feasible, it is imperative to breed lines with potential for higher productivity, which is currently stagnated at ~17 quintals per hectare. The current breeding methods in use for Indian mustard improvement include selection, recombination breeding through intervarietal and inter-specific hybridization, backcross breeding and recurrent selection. However, these methods now seem to be ineffective in pursuing quantum jump in productivity to the desired level. Production of hybrid mustard provides an important alternative for realizing higher yields. However, development of hybrid varieties will essentially require a cost-effective pollination control system in mustard. Hybrid breeding could not be undertaken in Indian mustard due to the non-availability of pollination control system. Five pollination control systems viz. cytoplasmic male sterility system (CMS), genetic male sterility (GMS), self-incompatibility, use of chemical hybridizing agents (gametocides) and genetically engineered male sterility systems have been suggested for hybrid seed production in mustard. Of these, CMS system, which is widely used for commercial hybrid seed production in a number of crop species, is regarded as the most feasible and costeffective from practical viewpoint. CMS is governed by the mitochondrial genome. Attempts to generate novel CMS lines through mutation breeding have not been successful due to large number of the copies of mitochondrial genome in each mitochondrion.:
Technology Details:
ICAR-NIPB has developed CMS system in Brassica juncea by using alloplasmic lines derived from interspecific hybridization between Moricandia arvensis and Brassica juncea. Subsequently, the male fertility restorer gene for this CMS was introgressed into B. juncea from M. arvensis and has been tagged with a dominant SCAR marker. The M. arvensis based CMS and Fertility Restorer system are useful to breed hybrid B. juncea varieties. This Moricandia cytoplasm based CMS system can be transferred to any desirable germplasm of B. juncea by traditional backcrossing. Similarly, the restorer gene can be transferred to any desired background with or without marker assisted breeding.