Increasing Yield of Spring Oilseed Rape Hybrids through Introgression of Winter Germplasm
1999
Butruille, D.V. | Guries, R.P. | Osborn, T.C.
Yields of spring oilseed rape (Brassica napus L.) hybrids are generally higher if derived from crosses of more distantly related spring cultivars. Winter cultivars are genetically very distinct from spring cultivars; however, it is not practical to use them directly as parents with spring cultivars for F₁ hybrids because of their noncoincident flowering times, and the excessively delayed maturity of the F₁ Thus, we tested whether the introgression of winter germplasm into spring-type oilseed rape could further increase the yields of spring hybrids. Nineteen doubled-haploid lines, derived from a cross between a spring canola (`Stellar') and a winter rapeseed (`Major') cultivar, were selected based on early-flowering phenology and having a range of germplasm from Major estimated to be 21 to 74% by screening with 480 molecular marker loci. These lines were test-crossed to two spring cultivars and evaluated for yield in 1994, 1995, and 1996 in Madison or Arlington, WI. The mean yield of the experimental hybrids was higher than the yields of cultivars, inbreds, and spring by spring hybrids in every year. The oil content was similar in all categories of germplasm. A slight delay in maturity may have contributed to the yield advantage of the experimental hybrids; however, there was no significant correlation between flowering time and yield among these hybrids. This study indicates that winter rapeseed may be a valuable source of germplasm for spring hybrid breeding.
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