杜仲内生真菌DZJ07在小麦根际定殖及对根部酶活的影响

Rhizosphere Colonization and Effects of an Endophytic Fungus DZJ07 From Eucommia ulmoides on Enzyme Activities of Wheat Root

为了研究生防菌在植物根际定殖中的作用,本研究以一株对小麦纹枯病菌有较好抑菌活性的杜仲内生真菌DZJ07为试验菌株,通过浓度梯度法对其进行抗性标记,分析其在小麦根际的定殖特点;同时通过盆栽接种试验研究菌株抗性突变株DZJ07-2在小麦根际定殖对不同生育期的小麦植株根部中POD、PPO和PAL活性的影响。结果表明:筛选出的突变株菌株DZJ07-2能够耐受浓度为200μg·m L-1的80%多菌灵,具有较好的遗传稳定性;该突变株能成功在小麦根际定殖,接种第20天小麦根际土壤中DZJ07-2菌株数量达到最大值6.33×102cfu·g-1;菌株DZJ07-2在小麦根际的定殖能诱导小麦植株根部的PPO、POD和PAL3种防御酶活性的提高,在一定程度上增强了小麦对纹枯病的抗性,其苗期小麦纹枯病的发病率仅为13.36%,明显低于未经DZJ07-2处理的小麦纹枯病的发病率(90.25%)。本研究为揭示其生防机理及应用该菌提供了科学依据。

The colonization of antagonistic endophytes in the plants rhizosphere was a critical factor to prevent plant diseases biologically. In the study,the endophytic fungi DZJ07 showing strong activity against wheat Rhizoctonia cerealis was marked with carbendazim by the concentration gradient method,the colonization property of biocontrol strain DZJ07 in wheat rhizosphere was analysed,and the effect of colonization of mutant DZJ07-2 in the wheat rhizosphere on related enzyme activity of wheat roots in different growth stages was researched through pot experiments. The results indicated the mutant DZJ07-2 could tolerate 80% carbendazim at concentration of 200 μg · m L^-1and had the stabilities of heredity,the mutant strain successfully colonized in the wheat rhizosphere,and the population reached to the highest level after 20 days,with 6. 33 × 10^2cfu·g^-1in the soil. Then the activities of PPO,POD and PAL of wheat roots treated with of DZJ07-2 were significantly higher than that of normal control groups,and colonization of DZJ07-2 in the wheat rhizosphere could reduce significantly the incidence of wheat sharp eyespot,the incidence of wheat sharp eyespot by DZJ07-2 was 13. 36%,which was lower than that of the normal control groups. The results afforded scientific basis for its application and the further research on bio-controlling mechanism.