施钾调控烟草根系酚酸的释放及其防控青枯病的研究

Analysis on the Release of Phenolic Acids from Tobacco and Control of Tobacco Bacterial Wilt by Potassium Fertilizer

针对贵州烟草产区青枯病发病普遍和防治此病害研究不够深入的现状,本文通过田间试验研究了施用不同量的钾肥对烟草青枯病的防控效果,同时测定根系分泌物中的酚酸种类和含量,及其对烟草青枯病病原菌(Ralstonia solanacearum)的抑制作用,为农业措施上防控病害提供科学依据。结果表明,当田间施用150 kg/hm^2的钾肥时,烟草青枯病发病率和病情指数最低,根际土壤中青枯病原菌的数量最少,为5.6 log cfu/g,而无钾肥处理的发病程度最高。同时,测定烟草根系分泌物中的酚酸发现,150 kg/hm^2处理的肉桂酸、水杨酸和苯丙酸释放量最高。外源添加酚酸对青枯病病原菌的生长结果表明,低浓度促进了菌丝的生长,当浓度达到600 mg/L时表现为抑制的作用。此外,在田间中施钾肥显著提高了烟草的生物量、钾浓度和总酚含量。本研究结果表明,施用150 kg/hm^2的钾肥时,能在生产上有效的防控烟草青枯病,其根系分泌物中的酚酸能显著抑制致病菌的生长。

According to the situation of prevalence of tobacco bacterial wilt and its disease had not enough studied, the effect of different amount of potassium （K） fertilizer on tobacco bacterial wilt was studied by field experiment, the inhibitory effect of the potassium （K） fertilizer on Ralstonia solanacearum was determined, the content and varieties of phenolic acids were measured in order to provide reference for the control of tobacco bacterial wilt. The results showed that when the application amount of K fertilizer was 150 kg/hm2, the incidence and index of tobacco bacterial wilt were the lowest, the number of Ralstonia solanaeearum in the rhizosphere soil was the least, which was 5.6 log cfu/g. The incidence of tobacco bacterial wilt was the highest without potassium （K） fertilizer. The amount of release of ciunamic acid, salicylic acid and phenylpropionic acid from 150 kg/hm2 were the highest. The growth effect of Exogenous phenolic acids on the Ralstonia solanacearum showed that low concentration promoted the growth, the inhibitory effect was achieved when the concentration reached 600 mg/L. In addition, K application significantly increased the tobacco biornass, K concentration and total phenol content in the field. The results showed that the application of 150 kg/hm2 of K fertilizer could effectively control tobacco bacterial wilt, the phenolic acids from root exudates could significantly inhibit the growth of Ralstonia solanacearum.