Genetic analysis of self-compatibility in a near-inbred of a wild potato species and construction of a genetic map

点击翻译按钮获取中文摘要

A self-compatible (SC) variant of a wild diploid potato species Solanum chacoense, which is normally self-incompatible (SI), was investigated for self-compatibility. It was crossed with a SI cultivated diploid potato species S.phureja. The F_1 progenies segregated to be SC vs.SI and diallele crosses were made among them. Self-compatibility was tested in a selfed family of a parental SC variant and in sib-mated and selfed families of F_1 progenies. All the data suggest that there is a single dominant gene (Sli gene) inhibiting S gene expression in the pollens. Plants having a Sli gene produced pollens which are compatible to both its own parent and the others. The Sli gene has been maintained as a heterozygous condition through 8 times of selfed generations implying that homozygotes might be associated with lethality.One of the F_1 progenies was crossed as a male parent with one of selective clones from a S.stenotomum-S.phureja population, resulting in a segregating population consisted with 116 hybrid plants. Self-compatibility was assessed by selfing each of the hybrids. Sixty-six of them were SC,while 35 were SI,showing a significant distortion from an expected Mendelian ratio of 1 : 1. A genetic linkage map was constructed using DNA markers to localize the Sli gene. A total of 38 RAPD and 35 RFLP markers identified 52 loci on 11 linkage groups, among which the Sli gene was mapped at a distal end of chromosome 12. As A locus has been localized on chromosome 1 on the potato RFLP map, it is confirmed that the Sli gene is independent to S locus.