Biological control of the root-knot nematode Meloidogyne javanica by Trichoderma harzianum
Biological control of the root-knot nematode Meloidogyne javanica by Trichoderma harzianum
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DOI：
10.1094/phyto.2001.91.7.687
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发表时间：
2001-07-01
期刊：
影响因子：
3.2
通讯作者：
Spiegel, Y
中科院分区：
文献类型：
--
作者：
Sharon, E;Bar-Eyal, M;Spiegel, Y
本文研究了生防真菌哈茨木霉对爪哇根结线虫的防治效果。在温室实验中，根瘿减少，顶部鲜重增加线虫感染的番茄土壤预处理木霉泥炭麸皮制剂，使用的蛋白酶Prb 1转化线（P-2），其中包含多个拷贝的该基因提高了生物防治活性在温室实验中相比，非转化的野生型菌株（WT）。所有的木霉菌株表现出定殖M，爪哇分离的鸡蛋和第二阶段的青少年（J2）在无菌的体外测定的能力，而P-2也穿透卵块。这种蛋白酶转化的线提出了相同的杀线虫和整体蛋白水解活性的WT在体外试验中，其中从木霉处理的土壤中的浓缩土壤提取物固定的感染J2。然而，P-2和WT的J2固定化和蛋白水解活性均高于菌株T-203的J2固定化和蛋白水解活性。所有木霉菌株土壤提取物对J2的活性表征表明，它是耐热的，并仅限于低分子量部分（小于3 kDa）。这表明，提高拮抗剂的蛋白水解活性可能是重要的生物防治线虫。
The fungal biocontrol agent, Trichoderma harzianum, was evaluated for its potential to control the root-knot nematode Meloidogyne javanica. In greenhouse experiments, root galling was reduced and top fresh weight increased in nematode-infected tomatoes following soil pretreatment with Trichoderma peat-bran preparations, The use of a proteinase Prb1-transformed line (P-2) that contains multiple copies of this gene improved biocontrol activity in the greenhouse experiments compared with the nontransformed wild-type strain (WT). AH the Trichoderma strains showed the ability to colonize M, javanica-separated eggs and second-stage juveniles (J2) in sterile in vitro assays, whereas P-2 also penetrated the egg masses. This protease-transformed line presented the same nematicidal and overall proteolytic activity as the WT in in vitro tests in which concentrated soil extracts from Trichoderma-treated soils immobilized the infective J2. However, the J2 immobilization and proteolytic activities of both P-2 and the WT were higher than those obtained with strain T-203. Characterization of the activity of all Trichoderma strains soil extracts on J2 showed that it was heat resistant and restricted to the low-molecular-weight fraction (less than 3 kDa). It is suggested that improved proteolytic activity of the antagonist may be important for the biological control of the nematodes.