新疆棉花枯萎病菌优势生理小种及其致病型研究

 1996~1998年,我们陆续从新疆各主要棉区采集和收集400余株病株样,共分离获得108株棉花枯萎病菌,对其中具有代表性菌株致病性和生理性状研究结果表明,新疆棉花枯萎病菌优势小种仍为7号生理小种,但其致病性较强,新疆棉花枯萎病菌致病型主要分为强、弱2种致病型,强致病型主要分布于南北疆棉区,弱致病型主要分布于东疆棉区。供试棉花枯萎病菌菌系在25℃培养7 d后,菌丝为白色,菌落皿底产生色素多为紫色或浅紫色,大分生孢子为10.4~44.2 μm×2.0~6.1μm,多为马特型,最适生长温度为25℃,除供试6个菌系能在35℃缓慢生长外,多数棉花枯萎病菌菌系30℃以上不易生长,吐鲁番菌系HAI-17在40℃仍能缓慢生长,新疆棉花枯萎病菌较耐高温,在40、45℃高温下并未致死。目前,尚未发现3号生理小种。

DOMINANT RACE AND PATHOGENICITY TYPE OF COTTON FUSARIUM WILT PATHOGENS IN XINJIANG

In 1996-1998, 400 isolates were collected from main cotton growing areas in Xinjiang Autonomous Region. 108 strains of fusarium wilt were isolated and purified. 45 representative strains were identified with 9 different hosts. The result showed that the dominant race of cotton fusarium wilt in Xinjiang was still race 7. It has stronger pathogenicity against cotton. The pathogenicity types of fusarium wilt in Xinjiang are mainly divided into strong and weak pathogenicity types. Strong pathogenicity type distributed in southern and northern cotton growing areas while the weak one distributed in eastern cotton growing area in Xinjiang. So far, race 3 has not been found in Xinjiang. Characters of macro conidia and temperature reaction of culture of 32 strains were assessed systemically.