Abstract:

To explore the physiological response of tobacco plant infected by Phytophthora to Trichoderma harzianum application sequence， the pot experiments were carried out with different treatments including inoculated with Phytophthora spore suspension （T1）， inoculated with T. harzianum spore suspension （T2）， inoculated with Phytophthora spore suspension first and then inoculated with T. harzianum spore suspension （T3）， inoculated with T.harzianum spore suspension first and then inoculated with Phytophthora spore suspension （T4）， inoculated with Phytophthora spore suspension and T. harzianum spore suspension at the same time （T5）， and clear water （CK） as controls. The effects of T. harzianum application sequence on biological characteristics， physiological characteristics and induced resistance of tobacco infected by Phytophthora were analyzed. The results showed that， in the growth of tobacco plants， the agronomic characters of tobacco plants with T4 treatment increased the most， and the dry and fresh weight of underground parts increased by 103.73% and 8.30% compared with CK. In the physiological characteristics of tobacco plants， T. harzianum could reduce the inhibition of Phytophthora on photosynthetic pigment accumulation and root activity of tobacco plants， and significantly increase both of them， and it could also strengthen the activities of enzymes related to carbon and nitrogen metabolism in tobacco plants. After transplanting 21 d， the activities of nitrate reductase and glutamine synthetase with T4 treatment increased by 13.14% and 6.40%， respectively. In the control effect， T4 treatment had the lowest incidence and disease index， which were 39.39% and 13.89%， and the highest antioxidant enzyme activity. In conclusion， there were significant differences in the physiological response of tobacco plants to the inoculation sequence of T. harzianum. In production， T. harzianum should be inoculated in advance to promote the growth and development of tobacco and inhibit the incidence of black shank disease. Above results laid a theoretical foundation for the regulation of tobacco growth and development and the comprehensive prevention and control of black shank.

Key words: Trichoderma harzianum, Phytophthora parasitica var., biological characters, physiological characteristics, induced resistance

摘要：

为探究疫霉侵染下烟草对哈茨木霉施用顺序的生理响应，采用盆栽试验方法，以接种清水为对照（CK），设置5个哈茨木霉处理，分别为接种疫霉孢子悬浮液（T1）；接种哈茨木霉孢子悬浮液（T2）；先接种疫霉孢子悬浮液，后接种哈茨木霉孢子悬浮液（T3）；先接种哈茨木霉孢子悬浮液，后接种疫霉孢子悬浮液（T4）；同时接种疫霉孢子悬浮液和哈茨木霉孢子悬浮液（T5），探究哈茨木霉接种顺序对疫霉侵染下烟草生物学性状、生理特性和诱导抗性的影响。结果表明，在烟株生长上，T4处理烟株的农艺性状较CK增幅最大，且地下部干、鲜重较CK分别增加103.73%、8.30%；在烟株生理特性上，哈茨木霉可缓解疫霉对烟株光合色素积累和根系活力的抑制作用，同时对二者有显著增益效果，还可增强烟株内碳氮代谢相关酶的活性。移栽后21 d，T4处理的硝酸还原酶和谷氨酰胺合成酶活性较CK分别提高13.14%和6.40%；在防治效果上，T4处理烟株黑胫病的发病率和病情指数最低，分别为39.39%和13.89%，且抗氧化酶活性最高。综上，烟株对哈茨木霉接种顺序的生理响应存在显著差异。在生产中，可提前接种哈茨木霉菌剂来促进烟草生长发育，抑制黑胫病的发病率。以上研究结果为调控烟草生长发育及黑胫病的综合防治奠定了理论基础。

关键词: 哈茨木霉, 疫霉, 生物学性状, 生理特性, 诱导抗性