淡紫拟青霉PL050705菌株的根际定殖及对根际真菌群落结构影响

Rhizosphere Colonization of Paecilomyces lilacinus Strain PL050705 and its Effects on Community of Rhizosphere Fungi

室内平板法测定了生防菌淡紫拟青霉(Paecilomyces lilacinus)PL050705菌株对柑橘慢衰病株根际主要真菌的拮抗能力,PL050705菌株对测试真菌均具有强的拮抗能力。田间试验的清水对照(CK)、PL050705+虾壳粉(p+p)、PL050705(p)、灭线磷(e)4个处理组中,p+p、p的处理组PL050705在柑橘根系周年均以保持高定殖量;p+p处理组PL050705菌株的B-P优势度指数周年保持较稳定高水平(0.444～0.526),p处理组PL050705菌株的B-P优势度指数周年呈下降状态(0.590～0.256);根际土壤真菌多样性指数(Shannon-Wienner指数)分别是p+p>p>CK>e。试验表明PL050705菌株具有良好拮抗与根际定殖能力,特别是与虾壳粉混合施用情况下,能周年保持种群优势度,并提高土壤真菌种群多样性。

The ability of Paecilomyces lilacinus strain PL050705 to compete with major fungi isolated from the rhizosphere of citrus with slow decline disease were determined in vitro. PL050705 have showed stronger antag-onistic effects on all the fungi. Four treatment groups including water control（CK）, PL050705＋prawn shell powder（p＋p）, PL050705 （p）, ethoprophos （e） were made in field experiment. P. lilacinus strain could colonized with high population in rhizosphere of citrus in treatment group of p＋p or p. Berger-Parker dominance index maintain higher lever （0.444-0.526） in treatment group of p ＋ p, but decreased （0.590-0.256） in treatment group with p ＋ p during the whole year. Shannon-Wiener diversity index of the fungi communities were in the order of p＋p〉p〉CK〉e. The results showed that PL050705 have antagonistic ability and good colonized ability in rhizosphere of citrus, could improved diversity of fungi communities especially treated with prawn shell powder.