Production of inbred progenies of diploid potatoes using anS-locus inhibitor (Sli) gene, and their characterization

Abstract

To develop inbred lines from self-incompatible, cultivated diploid potatoes, an S-locus inhibitor (Sli) gene derived from a self-compatible variant of a wild potato species, Solanum chacoense, was incorporated into various cultivated diploid potatoes. The progeny was selfed twice by the action of the Sli gene to obtain 74 S2 inbred clones belonging to 8 families. More than 40% of them were either non-flowering or pollen sterile. Among the pollen fertile clones, self-compatible clones occurred with a much lower frequency (20.9%) than expected (83.3%). The result demonstrated that self-compatibility was introduced and expressed in the gene pool of cultivated diploid potatoes by an action of the Sli gene, although serious inbreeding depression associated with selfing occurred. The genotypes of S2 inbreds were surveyed using 46 S. chacoense-specific RFLP (restriction fragment length polymorphism) markers covering the whole potato genome. More than half of the markers (67.4%) showed distorted segregation. Particularly, all markers on chromosome 12 were overrepresented in the S2 inbreds. This confirms our earlier finding that the Sli gene locates on chromosome 12 and the alleles linked with this gene are preferentially transmitted because of its essential requirement for selfing.

Cryptic improvement for fertility by continuous selfing of diploid potatoes using Sli gene

“…Recently, we found a dominant gene, named S-locus inhibitor gene (Sli), which is sporophytically expressed to inhibit a function of Sallele in pollen, and alters self-incompatible plants to self-compatible ones (Hosaka & Hanneman, 1998a). Birhman & Hosaka (2000) introduced the Sli gene by crossing into cultivated diploid potatoes and confirmed its expression in the genetic background of cultivated diploid potatoes. This facilitates to obtain selfed progeny of diploid potatoes, and continuous selfing may produce highly homozygous lines, which are attractive in genetic analyses, genetic fixation of traits, production of TPS (true potato seed) varieties with genetic uniformity, and heterosis breeding of the potato (Birhman & Hosaka, 2000).…”

Simple and Rapid Detection of Potato leafroll virus by Reverse Transcription Loop-mediated Isothermal Amplification

“…These characteristics have led to potato being a valuable cash crop for millions of farmers. However, in contrast to diploid wild species of potato (Birhman and Hosaka, 2000), most of the current potato cultivars are autotetraploid and encounter indreeding depression because of narrow genetic background, resulting in disease susceptibility (Bryan and Hein, 2008).…”

QTL mapping in diploid potato by using selfed progenies of the cross S. tuberosum × S. chacoense

“…The transition from self-incompatible to self-compatible in diploid potato can be done by the introgression of the S-locus inhibitor ( Sli ) gene (Hosaka and Hanneman 1998a, b). By repeated selfings of self-compatible diploid potatoes, more homozygous lines can be obtained (Birhman and Hosaka 2000; Phumichai et al 2005). These authors showed that the level of heterozygosity was decreasing and that no chromosomal regions could be identified that were exclusively heterozygous.…”