Abstract

Brassica carinata (BBCC, 2n = 34) has still to emerge as a major oilseed crop owing to poor agronomic attributes like long stature, long maturity duration and low seed yield. The restricted amount of genetic variability available in natural B. carinata necessitates utilization of new sources of variability for broadening the genetic base of the source population. Interspecific hybridization followed by selection in selfed and back-cross progenies was employed to generate useful variability into B. carinata (BBCC) cv PC5 from two related digenomics namely Brassica napus (AACC) and Brassica juncea (AABB). The morphological evaluation of 24 stable introgressed progenies revealed a wide range of variability for key economic traits. The progenies with mean maturity duration of 161±2.1 days, short stature of 139.5±6.5 cm and seed yield per plant of 18.6±2.0 g in comparison to the corresponding figures of 168±4.6 days, 230.6±12.7 cm and12.0±2.4 g in PC5 (recurrent parent) were recovered. Diversity analysis at morphological level revealed that, out of 24 stable introgressed progenies, 22 were grouped with B. carinata var.PC5 at average taxonomic distance of 1.19. The diversity at molecular level using 25 polymorphic and reproducible RAPD primers revealed that, 19 out of 21 introgressed progenies grouped with B. carinata cv. PC5 at a similarity coefficient of 0.68. The clusters in general represented a wide range of genetic diversity, generated in the back cross lines of B. carinata as a result of introgression of genes from elite lines of B. napus and B. juncea parents.

Key words: B. carinata, interspecific hybridization, gene introgression, variability, genetic relatedness.