ISHS Acta Horticulturae 459: International Symposium Brassica 97, Xth Crucifer Genetics Workshop
ATTEMPTS TO DEVELOP FERTILITY RESTORERS FOR OXY CMS IN CROP BRASSICAS |
| Authors: | Shashi K. Banga, S.S. Banga |
| Keywords: | Rapeseed-mustard, Brassica oxyrrhina, B. napus, B. juncea, addition line, CMS, hybrid |
| Abstract:
Oxy CMS, inspite of several advantages, has not been commercialized so far due to lack of fertility restoring genotypes. All test germplasm accessions (298) of B. juncea, B. napus, B. campestris, B. nigra and B. tournefortii acted as maintainers of sterility. To introgress fertility restorer gene(s) from B. oxyrrhina, synthetic alloploid between B. oxyrrhina x B. campestris (2n=38; OOAA) was repeatedly backcrossed as female with B. campestris (2n=20; AA). BC3 yielded one campestris type (2n=20 + II) partially pollen fertile plant. This plant was subsequently hybridized with B. nigra and B. oleracea followed by chromosome doubling to synthesize alloplasmic B. juncea and B. napus respectively. Cytological screening, only of fertile progeny, helped in identifying juncea type (2n=37) and napus type (2n=40) plants. These were crossed as female with respective euplasmic parents. Selfing of the resultant F1 progeny of B. napus produced F2 which segregated for male fertility. Cytological analysis of some of the fertile plants revealed normal chromosome number of 2n=38. The fertility restoration was, however, partial. Partial fertility restoration appeared to be under the control of a single dominant gene. | |
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