【摘要】 将来自云南省20多个县市的水稻纹枯病标样130多份,选代表性的标样分离得到54个菌株。按菌丝融合测定法, 将54个菌株分为5个菌系:R.solani的AG-1 IA ,AG-1 IC,AG-6GW 以及双核丝核菌的AG-Bb, AG-I II。经致病性测定表明,该菌系对水稻、玉米、小麦的苗期及成株期的致病性有显著差异。其中AG-1 IA, AG-1 IC, AG-I II 的致病力最强, AG-6GW的最弱。对这些菌系的酯酶同工酶进行比较研究发现,不同菌系间均存在明显差异, 而同菌系不同菌株间却具一致性。由此说明,按菌丝融合与否区分丝核菌种群较之现行的其它分类法更能反映其遗传本质和亲缘关系。更多还原

【Abstract】 Fifty-four of isolates Rhizoctonia spp. were obtained from diseased tissues of sheath blight of rice more than 20 counties of Yunnan Province. They were divided into series of Rhizoctonia; multinucleate and binucleate series. According to the hyphal fusion with Ogoshi抯 anastomosis groups (AGs) of Rhizoctonia, the multinucleate and binucleate series belong to R.Solani AG-1 IA, AG-1 IC, AG-6GW and AG-Bb, AG-I II, respectively. The result of pathogenicity test on seedlings and full-grown plants of rice, corn and wheat indicated that the isolates of AG-1 IA, AG-1 IC and AG-I II had the strongest pathogenicity, and the isolates of AG-Bb were moderate, the isolates of AG-6GW had the least pathogenicity. Comparisons of esterase isoenzymes of the five groups of Rhizoctonia spp. were made. The result showed that they were different among various AGs but similar among the various isolates in the same AG.更多还原