Self-incompatibility in Brassica napus: seed set on crossing 19 self-incompatible lines

Abstract

Seed set after self-pollination confirmed that 19 lines of Brassica napus were self-incompatible . Eight lines, H, J, Q, W, X, K, P and Z, were fully cross-compatible . Line R was cross-compatible with these lines but often had a low seed set as female parent . These results are consistent with the activity of nine distinct S-alleles . Line S was cross-incompatible with K, as was V with P, and F with Z . With each of the lines A, E, B, 0, G, L and M at least one reciprocal difference was found so that the number of additional distinct S-alleles could not be inferred, but there must be a minimum of seven .Pollen tube counts of intra-and inter-line pollinations using M, B and X confirmed the homozygosity of these lines with respect to self-incompatibility status and the presence of non-reciprocal compatibility between M and B .The results are interpreted in terms of the activity of both B. oleracea and B . campestris S-loci and the implications for hybrid breeding are discussed .

Resynthesis of Brassica napus L. for self‐incompatibility: self‐incompatibility reaction, inheritance and breeding potential

“…Hodgkin (1986) and Gemmell et al (1989) also reported non-reciprocal compatibility in their resynthesized B. napus. The resynthesized B. napus self-incompatible lines developed in this research project can be used in combination with selfcompatible lines for developing single-cross F 1 hybrids of forage and swede rape, where vegetative and root parts, respectively, are the main product.…”

Expression of self-incompatibility and fertility of Brassica napus L. resynthesized by interspecific somatic hybridization

“…Natural B. napus is generally considered to be SC, despite the presence of two SI loci derived from its diploid progenitor species (Mackay, 1977). Several of the effective S-alleles found in B. napus are derived from artificially (via sexual hybridization) synthesized lines (Gemmell et al, 1989) or via introgression from B. rapa (Mackay, 1977). In our previous study (Ozminkowski & Jourdan, 1993a) sexual interspecific hybrids were attempted from the same parent plants used to produce the somatic hybrids discussed here.…”

“…and B. rapa (Schenck & R6bbelen, 1982;Sundberg & Glimelius, 1986;Robertson et al, 1987;Sundberg et al, 1987;Rosdn et al,, 1988;Jourdan et al, 1989;Yamashita et al, 1989). While sporophytic self-incompatibility (SI) is common within the diploid species and is often used in the commercial production of hybrid cultivars (Dickson & Wallace, 1986), most natural B. napus is self-compatible (SC), with some exceptions (Gemmell et al, 1989;Gowers, 1989). Several previous studies in the somatic resynthesis of B. napus have emphasized cytoplasmic male sterility for use in commercial hybrid production in canola (Sundberg & Glimelius, 1986;Robertson et al, 1987;Sundberg et al, 1987;Ros6n et al, 1988;Jourdan et al, 1989), yet none have explored the interaction among S-alleles in somatic hybrids of the two closely-related diploid species.…”

Heterosis and Its Utilization

“…A new scheme was proposed (Gowers 1980) to overcome cross-incompatibility controlled by two S genes by the use of modified double-cross using self-incompatible and self-compatible isogenic lines. In B. napus, 19 lines were proved to be selfincompatible, having nine different S alleles (Gemmell et al 1989). The background genotype could modify the strength of the self-incompatibility reaction (Gowers 1989).…”