分子检测土壤中南美大豆猝死综合症病菌和北美大豆猝死综合症病菌

对南美大豆猝死综合症病菌（Fusarium tucumaniae）和北美大豆猝死综合症病菌（Fusarium virguliforme）rDNA基因间间隔区（IGS）进行分析,设计并筛选出3对特异性引物FT1/FT6、FT1/FT9和FV1/FV1A。分别利用FT1/FT6、FT1/FT9进行PCR反应,对F.tucumaniae分别扩增出250bp、656bp的特异性片段,而F.virguliforme、F.brasiliense、F.cuneirostrum和F.phaseoli等近似种均无特异性PCR产物出现。利用FV1/FV1A进行PCR反应,F.virguliforme出现228bp特异性PCR产物,而F.tucumaniae、F.brasiliense、F.cuneirostrum和F.phaseoli等近似种无特异性PCR产物。引物FT1/FT6、FV1/FV1A检测F.tucumaniae和F.virguliforme的最低DNA含量为1pg/μL,利用FT1/FT6和FT1/FT9对土壤中的病菌进行巢式PCR,能检测到接种量为每g土壤含100个大分生孢子的F.tucumaniae,FV1/FV1A能检测到接种量为每g土壤含1000个大分生孢子的F.virguliforme。

Molecular detection of Fusarium tucumaniae and Fusarium virguliforme in soybean soil

Three pairs of specific primers of Fusarium tucumaniae and Fusarium virguliforme, the cause of soybean sudden death syndrome, were designed from rDNA intergenic spacer (IGS) regions. Using primers FT1/FT9 or FT1/FT6, Fusarium tucumaniae was amplified by PCR, produced PCR products of 655bp or 250bp respectively. Fusarium virguliforme was amplified by PCR using primers of FV1/FV1A, produced PCR products of 228bp.The sensitivity of primers FT1/FT6 and FV1/FV1A is 1pg/ul respectively when using total genomic DNA. Nested PCR by using primers FT1/FT9 in the first round and FT1/FT6 in the second round can detect 100 macroconidia /g soil of F. tucumaniae. Primers FV1/FV1A can detect 1000 macroconidia g soil of F. virguliforme by PCR.