Tournefortii male sterility system in Brassica napus. Identification, expression and genetic characterization of male fertility restorers
Pahwa, R.S.; Banga, S.K.; Gogna, K.P.S.; Banga, S.S.
Plant Breeding 123(5): 444-448
ISSN/ISBN: 0179-9541 DOI: 10.1111/j.1439-0523.2004.00960.x
A germplasm collection of 152 diverse rapeseed accessions from Canada, China, France, India, Poland and South Korea was assayed for identifying new fertility restorers and sterility maintainers for a Tournefortii (tour) cytoplasmic male sterility (CMS) system in rapeseed. Only 16 (10.5%) genotypes showed complete fertility restoration following hybridization with tour CMS line NE 409A. Notable among these were GSL 8851, GSL 8953, Mokpo # 9, Mali, Buk-wuk-13, Kuju-27 and Mokpo # 84. As many as 78 (51.3%) genotypes were perfect maintainers of sterility, the remaining 58 (38.2%) genotypes were classified as partial maintainers. To study the inheritance of fertility restoration, 20 CMS (tour) rapeseed lines were crossed with the four best fertility restorers, namely GSL 8851, GSL 8953, Kuju-27 and Mokpo # 9, to obtain F2 and test cross populations. Segregation data indicated that fertility restoration for tour CMS was governed by two genes, of which, one is stronger than the other (chi2(12:3:1)). Differences in gene interactions were also observed (chi2(9:3:4)) which could be explained on the basis of influence of female parent genotypes/or modified expression of the restorer gene(s) in different genetic backgrounds. Tests of allelism indicated that the restorer genes present in the four restorers evaluated were allelic.