白及锈病的病原鉴定及其田间防治药剂筛选

Pathogen identification and field control agents screening of leaf rust of Bletilla striata

随着对白及需求的增加,其人工种植规模不断扩大,病害也逐年加重。白及锈病常年在种植区发生,传播能力强,是生产上危害严重的病害之一。本文对采集自湖北恩施来凤县的白及锈病材料进行显微观察,发现了该病原菌的夏孢子和冬孢子,并进行了详尽的形态描述,同时基于夏孢子的ITS和LSU基因序列构建了系统发育树。结果表明,该病原为Coleosporium bletiae。此外,选择5种常见药剂对该病进行田间防效试验,结果表明,250 g/L吡唑醚菌酯EC和12%萎锈灵WP的防效最佳,第2次施药后14 d,其防效分别可达(90.01±0.64)%和(87.80±0.61)%。本研究结果为白及锈病病原学及其田间防治提供了重要的理论依据。

With the increasing demand for Bletilla striata,the scale of its artificial planting is expanding.However,the occurrence of diseases is also increasing year by year.Leaf rust with strong reinfecting ability,occurs perennially in the cultivating areas of B.striata all the year round,so it is one of the most harmful diseases in production.In this study,the B.striata materials infected by rust were collected from Laifeng town of Enshi,Hubei,and the morphological characteristics of the pathogen were observed under microscope.The urediospores and teliospores of the pathogen were found,and detailed morphological descriptions were performed.Meanwhile,ITS and LSU gene sequences of the urediospores were amplified to construct a phylogenetic tree.And the pathogen was identified as Coleosporium bletiae.Five fungicides were used for field control test.The results showed that pyraclostrobin 250 g/L EC and carboxin 12%WP had the best control effect,with the control efficacies of(90.01±0.64)%and(87.80±0.61)%,respectively,14 days after second application.The above results provide an important theoretical basis for the etiology and field control of leaf rust of B.striata.