北京地区主栽西瓜品种种子携带真菌检测及鉴定

用离体平皿法对北京西瓜产区主栽的11个西瓜品种进行种子带菌检测、分离纯化和形态学、ITS序列比对,确定其属或种地位。结果表明:不同品种所带真菌种类有差异,种子表面携带的优势菌群主要为曲霉属Aspergillus spp.、青霉属Penicilliumspp.、链格孢属Alternariaspp.和镰刀菌属Fusariumspp.;种子内部寄藏真菌主要为青霉属、根霉属Rhizopus spp.和曲霉属。种子外部检出的主要病原菌有镰刀菌属的F.verticillioides,F.proliferatum及茎点霉Phomasp.;种子内部检出的病原菌有F.verticillioides和F.oxysporum。不同品种间种子表面携带真菌量与种子内部携带真菌率差异显著,但种子外部带菌量和内部种仁带菌率之间无显著相关性。本研究对开展西瓜种子处理研究有借鉴意义。

Detection and identification of seedborn fungi of main watermelon varieties in Beijing area

Seedborn fungi of 11 main watermelon varieties sold in Beijing were detected by culture test, and further purified and identified by morphology and ITS sequencing. The results indicated that seedborn fungi were different among varieties. The dominant seedborne fungi on the seed surface were Aspergillus spp., Penicillium spp., Alternaria spp. and Fusarium spp.. The genus of Penicillium spp., Rhizopus spp. and Aspergillus spp. were the main internal seedborn fungi. Fusarium verticillioides, F. proliferatum and Phoma sp. were isolated from external seed, and F. oxysporum and F.verticillioides were isolated from internal seed. Both the amounts of fungi on seed surface and infection rate of internal seeds were significantly different among varieties. However, there was no correlation between the amount of fungi from seed surface and the infection rate from internal seeds. The result of this study will be helpful for development of seed treatment in watermelon production.