水稻纹枯病菌菌核存活力及地下侵染的研究

不同生境下菌核萌发率和影响因子的作用，以及菌核的地下侵染试验结果表明：菌核的萌发率随温度升高而增加，分别组建了菌核萌发率与温度的定量关系式；菌核可多次萌发，室内保存１１年的浪渣菌核仍有１２％的萌发率。首次报道了不同生境下菌核能在土层下侵染水稻表现典型病斑。菌核多次萌发特性和地下侵染能力使防治增加困难。

化学药剂对水稻纹枯病菌的影响

研究了 11种杀菌剂对稻纹枯病菌菌核形成、萌发和菌丝生长的影响 ,测定了杀菌剂对稻纹枯病菌的毒力作用 ,结果表明 :三唑酮、980 2SC在质量浓度 10 μg/ml以上对菌核萌发有明显抑制作用 ;敌力脱、980 1SC、980 2SC在质量浓度 10 μg/ml以上能有效抑制菌核的形成 ;敌力脱 ;三唑酮、多菌灵、溴菌清、代森锰锌等杀菌剂对菌丝有明显抑制作用 ,井冈霉素和纹霉清在高浓度下对菌丝生长有抑制作用。其EC5 0 分别为 6.990 0、14.683 9、0 .6865、6.1465和 1.12 85 μg/ml ,复配剂 980 1EC、980 3WP和 980 4WP对菌丝生长有明显抑制作用 ,其EC5 0 分别为 1.0 60 0、4.2 480和 10 .1660 μg/ml,共毒系数 (CTC)分别为 90 0、2 10和 2 2 5 。

Investigation of Optimal Charcoal Concentration for Heterokaryon Formation of Rhizoctonia solani

Optimal charcoal concentrations were examined for tuff formation of SBIs （single-basidiospore isolates） obtained from Rhizoctonia solani AG-1 IC, AG-2-2 IV and AG-2-3, and SPIs （single-protoplast isolates） from AG-1 IA by using PDCA with different charcoal concentrations. The best charcoal concentration for SBIs from AG-1 IC was 0.5%, from AG-2-3 was 1%, and from AG-2-2 IV was 2%. The optimal concentration was 0% for SPIs from AG-1 IA. The optimal charcoal concentrations used for tuff formation between SBIs and between SPIs are quite varied, depending on the different AGs. The results of AFLP haplotypes suggest that tuff isolates formed between SBIs/SPIs are heterokaryon.