离体条件下水稻种衣剂对串珠镰刀菌生长及形态毒理影响

 检测了黑龙江水稻主产区4个当地主栽品种的种子内部镰刀菌寄藏情况,测定了20%克福甲和20%克多甲种衣剂对种子带菌消毒处理效果及对水稻串珠镰刀菌(Fusarium moniliforme)的抑菌作用和联合毒力,并借助扫描电镜观察了上述2种混配种衣剂对串珠镰刀菌的形态毒理影响。结果表明,种子内部镰刀菌的分离频率高达56.7%~96.0%,其中串珠镰刀菌的分离频率为32.6%~48.2%,2种种衣剂对带菌种子具有显著的消毒处理效果。20%克福甲和20%克多甲种衣剂对镰刀菌F.moniliforme的毒力指数分别为457.11和802.04,增效倍数分别为6.53和0.13。20%克多甲种衣剂(多菌灵:甲基立枯磷为5:5,W/W)对串珠镰刀菌的抑菌作用优于20%克福甲种衣剂(福美双:甲基立枯磷为8:6,W/W),增效作用低于20%克福甲种衣剂。电镜观察表明,种衣剂低浓度至高浓度处理下均可引起串珠镰刀菌菌丝不同程度的异常生长,表现为主菌丝局部膨大或形成菌丝束,菌丝顶端异常膨大、缢缩或形成穗状和花絮状分枝。

EFFECT OF RICE SEED COATING CHEMICALS ON GROWTH AND MORPHOLOGY OF THE Fusarium moniliforme IN VITRO

Seed-borne Fusarium spp. ratio, disinfection effect and fungitoxicity of 20% carbofuran-thiram-rizolex (20% CTR), 20% carbofuran-carbendazim-rizolex (20% CCR) to Fusarium moniliforme from rice were determined by means of perti-dish testing.The results showed that Fusarium spp. were main seed borne pathogens inside of 4 major rice varieties from Heilongjiang Province and 20% CTR, 20% CCR provided good controls for seed-borne Fusarium spp. The toxicity index of 20% CTR containing thiram and rizolex (8:6, W/W) and 20% CCR containing carbendazim and rizolex (5:5, W/W) were 457.11 and 802.04, respectively. 20% CCR showed more effective toxicity to F.moniliforme than that of 20% CTR. Its synergized action to F.moniliforme was less effective than that of 20% CTR which synergized multiple was up to 6.53.The effect of above fungicides and their mixture on the morphological changes of F. moniliforme was studied with the use of SEM techniques. The hypha of F. moniliforme showed different types of malformed expansion and hyphal bunch, and the top of hyphae showed reduction, floral or spike expansion under the effect of fungicides.