ibclogo XVI International Botanical Congess


Abstract Number: 4650
Session = 16.12.6


SPOROPHYTIC SELF-INCOMPATIBILITY IN IPOMOEA TRIFIDA.


Y. Kowyama, Mie University, Tsu 514-8507, Japan.


Ipomoea trifida (Convolvulaceae) is the diploid wild species closely related to the sweet potato, and has a sporopytic self-incompatibility (SSI) which is governed by a single S-locus with multiple alleles. SSI reaction of this plant occurs on the stigma surface after self-pollination, and results in complete arrest of pollen germination. We have identified S-locus-linked stigma proteins (SSPs) in an acidic region of about 70 kDa following two-dimensional gel electrophoresis of stigma extracts from defined S-homozygotes. From sequence analyses of cDNA clones encoding SSPs, a high sequence homology was found with members of short-chain alcohol dehydrogenase family. From RFLP analysis of S-allele-segregating population, we have mapped the SSP gene at a distance of 1.2 cM from the S-locus. The SSP gene, thus, could be used as an useful molecular marker to identify S-locus genes.


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