石榴枯萎病菌拮抗放线菌对南方根结线虫的毒力

从云南蒙自万亩石榴园、建水石榴园采集的土样中分离筛选得到对石榴枯萎病菌有较强拮抗活性的放线菌,其中菌株JS1对石榴枯萎病菌的室内抑菌半径为11mm。测定了菌株JS1发酵液对南方根结线虫的抑杀活性,结果表明,50%JS1菌株发酵液处理南方根结线虫卵6d,卵孵化率与对照相比降低了51.67%;50%JS1菌株发酵液处理南方根结线虫2龄幼虫72h,2龄幼虫的校正死亡率增加了88.10%;菌株JS1兼有拮抗石榴枯萎病菌及抑杀南方根结线虫的活性。结合菌株JS1在鉴定培养基上的培养特征、形态学观察及16SrDNA序列分析,将JS1初步鉴定为壮观链霉菌(Streptomyces spectabilis)。

Nematicidal activity of actinomycete antagonistic to pomegranate wilt pathogen

This study was conducted to separate actinomycetes with a strong antagonistic activity to pomegranate wilt pathogen from the soil collected from Mengzi megranate garden, Mengzi County and Jianshui Megranate Garden, Jianshui County in Yunnan Province. The indoor bacteriostatic radius of actinomycetes strains JS1 against pomegranate wilt pathogen was 11mm. Nematicidal activity of JS1 supernatant of fermented liquid to Meloidogyne incognita was measured. The results showed that, compared with the control, M. incognita egg hatching rate was lowered by 51.67% when treated for 6 d with 50% JS1 supernatant of the fermented liquid, and the corrected mortality rate of M. incognita second-stage juveniles was increased by 88.10% if treated for 72 h with 50% JS1 supernatant of the fermented liquid. The finding suggested that strain JS1 could inhibit pomegranate wilt pathogen and was toxic to M. incognita. Strain JS1 was identified as Streptomyces spectabilis based on its growth characteristics, morphological characteristics and analysis of 16S rDNA sequence