2010 年 44 巻 2 号 p. 127-131
Gamma irradiation was used to induce mutations affecting self-incompatibility (SI) in diploid Ipomoea trifida. Plants (S1 homozygote) with developing flower buds were exposed with gamma rays of 10 and 20 Gy. Mature pollen from the irradiated plants was used for crosses with S3 and S10 homozygotes. By pollination test and Southern blot analysis of the M1 progenies, we screened 2 mutant plants carrying a deletion of the S locus derived from irradiated pollen, designated ΔS1. In both mutant alleles, the deleted region was found to exceed a genetic distance of 12 cM around the S locus. Progeny test of both mutant plants showed that neither female nor male gametes carrying the ΔS1 allele were fertile probably due to the lethal effect of the chromosomal deletion spanning the S locus.