红树内生细菌RS261防治辣椒疫病机理的初步研究

 本研究从菌株内生定殖、促生、抑制和诱导防御酶活性4方面探讨了红树内生细菌RS261菌株防治辣椒疫病的机理。结果表明,该菌株能进入辣椒等多种陆生植物体内定殖,在辣椒体内的定殖时间达26d以上,且对辣椒生长表现有明显的促进作用;抑制作用测定发现,RS261能够分泌产生抗菌物质抑制辣椒疫霉菌丝的生长和游动孢子囊的形成;辣椒体内丙二醛(MDA)含量及防御性酶活测定结果显示,经过RS261培养液处理后,辣椒苗体内丙二醛(MDA)含量和超氧化歧化酶(SOD)、过氧化物酶(POD)以及过氧化氢酶(CAT)的活性等均较仅接种疫霉病菌的处理低,但可显著诱导辣椒体内苯丙氨酸解氨酶(PAL)的活性。

Mechanism of biological control of Phytophthora blight in pepper by mangrove endophytic bacterium strain RS261

The mechanism of biological control of Phytophthora blight by treatment with mangrove endophytic bacterium RS261 was studied.Tagged by the resistance to rifampicin(300 μg/ML),the strain RS261could colonize many plants,such as capsicum,tomato,eggplant,et al.An obvious promotion on pepper growth occurred after watering roots with strain RS261.The metabolites of strain RS261 showed strong inhibitory activity against mycelial growth and sporangia production of P.capsici.Inoculation with P.capsici considerably increased the content of MDA and the activities of SOD,CAT and POD in the capsicum.However,when co-inoculated with strain RS261 and P.capsici at the same time,the MDA content and SOD,POD and CAT activities were all lower than those inoculated with pathogen only.In addition.treatment by co-inoculation increased PAL activity.and the induced PAL activity might enhance ant-disease capability of the plants.