Marker-assisted selection of self-incompatible oilseed rape plants

摘要

Self-incompatibility (SI) could be used as a pollination control system for Brassica napus, ifa sufficient number of S-alleles is available in this species. Unlike self-incompatible (SI) Brassica rapa and Brassica oleracea, two ancestor species, Brassica napus is naturally self-compatible (SC). However, occasionally SI also occurs in rapeseed cultivars. SI oilseed rape plants selection was performed with doublehaploids derived from crosses between lines with recessive self-incompatibility and self-compatible donors of quality. SI in Brassicaceae plants is sporophytically controlled by a single multi-allelic locus (S-locus),which contains at least three highly polymorphic genes expressed in the stigma (SLG and SRK) and in the pollen (SCR or SP11).We have used two S-genes, SLG gene class Ⅰ and SCR gene class Ⅱ, as molecular markers in order to screen segregating doublehaploid population for SI plants. A molecular marker on the basis of SCR class Ⅱ gene was designed to determine specific SCR Ⅱ allele connected with self-incompatibility. This marker specifically determines SI lines derived from line 'Tandem' only. In contrast to SCR Ⅱ marker gene, universal SLG Ⅰ marker gene enables to detect SC plants in all SI lines. Theoretically expected segregation ratio 1:1 (SI:SC) of doublehaploids derived from the SI line and the SC quality donor was confimed by molecular analysis in two model populations. Both marker genes determined the same SI/SC phenotype.