松材线虫对黑松、湿地松幼苗活性氧代谢的影响

以2月龄黑松（Pinus thunbergii)、湿地松（P.elliottii)幼苗为材料，研究松材线虫（Bursaphelenchus xylophilus)感染对松幼苗活性氧代谢的影响。在接种松材线虫后，黑松较湿地松发病快且重，黑松内超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性逐渐降低；湿地松内SOD和CAT在接种早期活性增加，随后下降。两种幼苗接种后，过氧化物酶（POD）活性、H2O2和丙二醛（MDA）含量不断增加。H2O2和MDA的积累与植株发病速度呈明显正相关。因此，松材线虫病的发生和发展与寄主植物组织的膜脂过氧化作用有关。

Effects of Pine Wood Nematode Infection on Metabolism of Active Oxygen in Japanese Black Pine and Slash Pine Seedlings

Inoculated 2 month old Japanese black pine( Pinus thunbergii )and slash pine( P.elliottii )seedling with pine wood nematode( Bursaphelenchus xylophilus PWN),the experiment studied changes of active oxygen metabolism in the pine seedlings and the relations between the changes and disease development.Activities of superoxide dismutase(SOD)and catalase(CAT)reduced gradually in Japanese black pine seedlings after infection by PWN,and increased in infected slash pine seedlings at the early stage,but decreased at the later stage.Activity of peroxidase(POD),contents of H 2O 2 and malondialdehyde(MDA)increased progressively in the seedlings.The rising of contents of H 2O 2 and MDA were coincident with the speeds of seedling wilting.The results showed that the balance of the host's active oxygen metabolism was disturbed,the rapid death of the seedlings was associated with active oxygen accumulation in the seedling tissues after infection by PWN.The increase of the speed of membrane lipid peroxidation might be the major factor accelerating the death of the host's cells and stimulates the development of the disease.