多功能植病生防木霉的分离筛选与鉴定

Isolation,Screening and Identification of Multifunctional Trichoderma spp. with Antipathogenic Biocontrol Capacity

从采集的120份土壤样品中分离获得木霉244株。对峙培养发现其中对棉花立枯丝核菌(Rhizoctonia solani)具有拮抗能力的有114株;固体培养检测木霉的解磷和固氮能力,发现所有菌株都能够水解植酸钙,有74株能够水解磷酸钙,未发现具有固氮能力的菌株。对抑菌圈和解磷圈最大的19株木霉在液体培养条件下检测了解磷和解钾能力,其中菌株T13-8(1.792μg/mL)、T23(1.652μg/mL)显示出较高的解磷能力,部分菌株在液体培养条件下不能解磷;部分菌株在液体培养下显示出解钾功能,其中菌株T47-4(20.585μg/mL)显示出较高的解钾能力。上述19个菌株的形态学和ITS序列分析鉴定表明,其中9个菌株为Trichoderma longibrachiatum,8个菌株为T. harzianum,另外2个菌株分别为T. virens和T. citrinoviride。

We isolated 244 Trichoderma from 120 soil samples. All strains were dually cultured with Rhizoctonia solani which is pathogenic on cotton, 114 isolates showing inhibition to Rhizoctonia solani and 19 isolates showing higher inhibitory ability than others. We employed solid plate culture method to detect phosphorus-releasing, potassium-releasing and nitrogen-fixing potential of all strains. Results show that 74 isolates can hydrolyze Ca3（P04）2, of which 19 isolates having better bacteriostatie ability also show the best hydrolyzing ability. No isolates can grow in nitrogen-free medium. We detected the phosphorus-releasing and potassium-releasing ability of the 19 isolates in a liquid culture. Results indicate that some strains do not show phosphorus-releasing ability, whereas strains T13-8 （ 1. 792 μg/mL） and T23 （ 1. 652 μg/mL） show stronger phosphorus-releasing ability and strain T47-4 （ KC1 content 20. 585 μg/mL） stronger potassium-releasing ability. We also detected the phytase activity of the 19 strains in a solid culture and identified 19 Trichoderma by morphological and molecular methods. Results demonstrate that these strains respectively belong to Trichoderma Longibrachiatum , Trichoderm Harzianum , Trichoderma Virens and Trichoderma citrinoviride.