P113 FINE MAPPING OF ZUCCHINI YELLOW MOSAIC VIRUS RESISTANCE GENE IN CUCUMBER Masashi Amano1, Akira Mochizuki1, Yumi Kawagoe2, Keisuke Iwahori2, Kaori Niwa2, Jiri Svoboda3, Takanori Maeda2, Yoshiyuki Imura2 1Saitama Gensyu Ikuseikai Co, Ltd. 2Dep. Plant Sci. and Res., Nihon Univ. 3Crop Res. Inst.,Czech Rep. The cucumber (Cucumis sativas L.) gene zym is a recessive resistance allele against Zucchini Yellow Mosaic Virus (ZYMV). Resistant to ZYMV has been evaluated in F2 or BC1 cucumber families from a cross between susceptible ‘CS-PMR1’ and resistant ‘A192-18’ (Japanese type) cucumber inbred lines, we confirmed that ZYMV resistance was conferred by a single recessive locus (zymA192-18). The linkage map included 125 simple sequence repeat (SSR) markers that segregated into 7 chromosomes. The zymA192-18 locus was mapped on chromosome 6 at genetic distances from 2 closely linked SSR markers of 0.9 and 1.3 cM. For fine genetic mapping, we identified new molecular markers cosegregating with the zymA192-18 locus by using cucumber genomic and molecular marker resources in the F2:3 population. Screening of a mapping population of 2,429 F2 plants allowed us to narrow down the zymA192-18 locus to a <50 kb genomic region flanked by two SSR markers, which included six predicted genes. Semi-quantitative RT-PCR analysis revealed no differences in expression of these genes between A192-18 and CS-PMR1. Sequence analysis of the candidate genes’ coding regions revealed that the vacuolar protein sorting-associated protein 4-like (VPS4-like) gene had two SNPs between the parental lines. These results suggest that the gene encoding VPS4-like protein is a candidate for the zymA192-18 locus in cucumber.
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