|Hosaka, Kazuyoshi - KOBE UNIV HYOGO JAPAN|
|Hanneman Jr, Robert|
Submitted to: Journal of Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 1999
Publication Date: N/A
Interpretive Summary: Most wild species of potato are prevented from being able to set seed when pollinated with their own pollen because of a genetic system which inhibits their own pollen from effecting fertilization by preventing its growth in the pistil (tube leading to the ovary). A self compatible form of Solanum chacoense, a wild potato species from Argentina, was found in earlier studies. The genetic nature of its self-compatibility was found to be due to a major gene that controlled the gene preventing selfing. This study has shown that this gene is located at the end of chromosome 12, which is a completely different chromosome than the one the self-incompatibility gene is located on. Since this gene is a dominant controlling gene, it should be able to be easily passed on to other self-incompatible potato species. It will make genetics much simpler when working with other traits because of selfing and may have application to other plants through cloning and transformation. It brings new opportunities for potato breeding strategies since selfing is now possible.
Technical Abstract: A self-compatible (SC) hybrid plant F1-1 was obtained from a cross between a SC variant of a wild diploid potato species, Solanum chacoense, and a self-incompatible (SI) cultivated diploid species, S. phureja. The clone F1-1 has previously been proposed to have a dominant S locus inhibitor gene (Sli gene) in a heterozygous condition. It was crossed as a male parent with a selected clone from a S. stenotomum-S. phureja population, resulting in a segregating population consisted of 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 mapping positions on 11 linkage groups. The Sli gene was mapped at a distal end of chromosome 12. Since the S locus has been localized on chromosome 1 on the potato RFLP map, it is confirmed that the Sli gene is independent of the S locus.