Authors: Wataru Takahashi Yuichi Miura Tohru Sasaki Tadashi Takamizo
Publish Date: 2009/10/21
Volume: 126, Issue: 3, Pages: 333-342
Abstract
Epidemics of blast disease also called grey leaf spot GLS in ryegrass species have recently become a serious problem in Japan and the USA GLS causes serial growth inhibition and the abnormal morphology of withering in ryegrass seedlings If the lesions expand they can completely destroy the plant at several growth stages We attempted to construct a partial genetic linkage map around the LmPi1 locus which confers resistance to GLS and is located on linkage group LG 5 of Italian ryegrass by using synteny with rice Because LG5 of Italian ryegrass is syntenic with rice chromosome Chr 9 we designed intronscanning primers with alignment between the rice genome sequence and expressed sequence tag EST information on rice Chr 9 These primers were used to genotype an F1 mapping population which had been used for detection of the LmPi1 locus by detecting singlestrand conformation polymorphisms SSCPs We successfully constructed a partial genetic linkage map around the LmPi1 locus spanning 663 cM A comparative genomic analysis between the partial genetic linkage map and the rice Chr 9 genetic linkage map revealed that the LmPi1 locus was a candidate for orthology to the Pi5 locus or Pi15 locus both of which are colocated in a resistance gene cluster on rice Chr 9 and are associated with broadspectrum resistance to rice blastWe thank Ms K Akimoto Japan Grassland Agriculture and Forage Seed Association for her superior assistance throughout this study This work was funded by a research grant from the Japan Racing Association JRA and supported by National Agriculture and Food Research Organisation NARO Japan
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