海南西瓜蔓枯病病原菌的鉴定及8种杀菌剂对其室内毒力测定

Pathogen Identification of Gummy Stem Blight on Watermelon in Hainan and Determination of Laboratory Toxicities of Eight Fungicides

对海南西瓜蔓枯病病原菌进行了分离鉴定及室内杀菌剂筛选,为西瓜蔓枯病的防控提供参考依据。采用PDA培养基,对西瓜病株病原菌进行分离、培养,经致病性测定,形态学分析及rDNA-ITS测序,鉴定其致病菌为Stagonosporopsis cucurbitacearum。选用8种不同类型杀菌剂对西瓜蔓枯病菌进行室内毒力测定,结果表明,8种杀菌剂均对西瓜蔓枯病菌有一定的抑制作用,其中24%双胍·吡唑酯可湿性粉剂(WP)和11%精甲·咯·嘧菌悬浮种衣剂(FSC)的毒力较强,EC50值分别为0.1017、0.3911 mg/L,均小于1 mg/L;其次是10%苯醚甲环唑水分散粒剂(WDG)和18.7%丙环·嘧菌酯悬浮剂(SC),EC50值分别为1.3933、3.0376 mg/L;27%春雷·溴菌腈WP和22.5%啶氧菌酯SC毒力一般,EC50值分别为10.7530、20.9826 mg/L;毒力效果较差的是46%氢氧化铜WDG和50%多菌灵WP,EC50值分别为60.7039、151.4770 mg/L。

In order to provide references for the prevention and control of gummy stem blight on watermelon,we isolated and identified the pathogen of watermelon gummy stem blight in Hainan province,and screen out the fungicides in laboratory.The pathogen of watermelon disease was isolated and cultured in PDA medium.Making using of pathogenicity test,morphology and r DNA-ITS sequencing,the pathogen was identified as Stagonosporsis cucurbitacearum.Then the laboratory toxicities of 8 fungicides against S.cucurbitacearum were tested.The results showed all the 8 fungicides had somecertain inhibitory effects on S.cucurbitacearum,among them,the toxicities of 24%biguanide trioctylbenzene sulfonate·pyraclostrobin wettable powder(WP)and 11%methomyl·cymoxanil·pyrimethanil suspension seed coat(FSC)were higher than other fungicides,with the EC50 values of 0.1017,0.3911 mg/L,respectively,which were less than1 mg/L.The EC50 values of 10%phenoxymethoxazole water dispersible granules(WDG)and 18.7%propiconazol·azoxystrobin suspending agent(SC)were 1.3933,3.0376 mg/L,respectively.The toxicities of 27%kasugamycin·bromothalonil WP and 22.5%picoxystrobin SC were general,with the EC50 values of 10.7530,20.9826 mg/L,respectively.The toxicities of 46%copper hydroxide WDG and 50%carbendazim WP were lower than those of other fungicides,with the EC50 values of 60.7039,151.477 mg/L,respectively.