PYTHIUM SYLVATICUM鉴定及其专一性PCR引物

IDENTIFICATION OF PYTHIUM SYLVATICUM AND SPECIES-SPECIFIC PRIMERS

从杭州采集的水稻、棉花和大豆猝倒苗中分离到国内新记录腐霉种Pythium sylvaticum.该腐霉为异宗配合种,菌丝膨大体球形或柠檬形,雄器异丝生,藏卵器光滑,每个藏卵器上1～3个雄器,雄器常在接近藏卵器处形成二叉状分枝,卵孢子不满器.测定了该种4个菌株的核糖体内转录间隔区(ITS)的序列,根据与59种腐霉ITS序列的比较,设计了P. sylvaticum种专一性引物PSF1和PSR2.实际结果表明:该引物能从11种共14株腐霉DNA中特异性地扩增P.sylvaticum,从而与其它10种腐霉区分.

Pythium sylvaticum, a new record of Pythium in China, was isolated from damping-off seedlings of rice, cotton and soybean in Hangzhou region. Its a heterothallic species. This species is characterized by hyphal swellings frequent globose or limoniform, oogonia smooth, antheridia 1-3 per oogonia, diclinous, antheridial stalks branched, often bifurcate near the oogonium, oospores aplerotic. The study was conducted to sequence the rDNA internal transcribed spacer (ITS) region of P. sylvaticum, and to design species-specific primers for polymerase chain reaction (PCR), based on comparison of the sequence of the ITS region among 59 species of Pythium. Using PCR, the primer pair PSF1 + PSR2, amplified isolates of P. sylvaticum from 14 isolates of 11 Pythium species, but not isolates of 10 other Pythium species.