宁夏白芨滩自然保护区苦豆子内生真菌的区系组成及其抑菌活性

Diversity and antimicrobial activity of endophytic fungi in Sophora alopecuroides L. from Baijitan National Nature Reserve of Ningxia

【目的】探索宁夏干旱荒漠区苦豆子内生真菌的区系组成及特点,为苦豆子内生真菌的合理开发和利用提供理论依据。【方法】从宁夏白芨滩国家级自然保护区植被、土壤类型等不同的5个样区采集苦豆子样品25份,分离苦豆子内生真菌,并根据培养性状、菌落、孢子等形态特征对其进行鉴定;根据苦豆子的侵入率、分离率、物种多样性指数和相似性系数,分析其区系组成特点;采用琼脂移块法,检测所分离的内生真菌对番茄早疫病菌(Alterna-ria solani)、小麦赤霉病菌(Fusarium graminearum)、番茄灰霉病菌(Botrytis cinerea)、黄瓜枯萎病菌(Fusarium oxys-porum)、马铃薯干腐病菌(Fusarium sulphureum)、辣椒炭疽病菌(Colletotrichum capsici)等6株植物病原菌的的抑菌活性。【结果】从25份苦豆子样品中,共分离到214株内生真菌。同一植株不同组织中的内生真菌数量以种子最多,叶部最少;植被类型中,沙生植被草原比荒漠草原分离的苦豆子内生真菌多。经鉴定,从各样区分离的苦豆子内生真菌分属22个属,其中卵形孢霉属(Oospora)和头孢霉属(Cephalosporium)为样区共有属。样区Ⅰ与样区Ⅲ及样区Ⅳ与样区Ⅴ的内生真菌群落有密切的亲缘关系,相似性较高。214株内生真菌中有167株(78.0%)有抑菌活性,不同属内生真菌的抑菌率差异较大。【结论】宁夏干旱荒漠区苦豆子内生真菌具有丰富的多样性和较高的抑菌生物活性。

[Objective] The composition, diversity and antimicrobial activity of endophytic fungi from Sophora alopecuroides L. in arid and desolate areas of Ningxia were analyzed,which could also provide research methods and theory on rational development and use of endophytic fungi from S. alopecuroides L. [Method] The endophytic fungi were separated and cultivated from 25 samples of healthy seeds and plants of S. alopecuroides L. in five sample plots were sampled from different vegetations and soil types in Baijitan National Nature Reserve of Ningxia. Endophytic fungi were classified according to their cultural and morphological characteristics. Colonization rate,isolation rate, Shannon-Wiener index and Sorenson＇s similarity coefficient were calculated. A variety of antimicrobial activities of endophytic fungi were analyzed by agar block shift methods to 6 pathogenic fungus strains. [Result] 214 endophytic fungi were separated and cultivated from 25 samples of S. alopecuroides L. quantities of endophytic fungi from different parts of S. alopecuroides L. varied. The endophytic fungi from seeds were the most in its all parts and that of leaves for the same plant was the least. In different vegetations types,quantities of endophytic fungi were significantly more in the sandy weeds than in other desert steppes. These isolates 199 were sporulated and identified into 22 taxa by cultural and morphological characteristics. Oospora and Cephalosporium were the common taxas in the five sample plots. The endophytic fungi groups of sample plot I , IV were related more closely to that of sample plot III, V. Antimicrobial ratio was different among 214 endophytic fungi from S. alopecuroides L. which tested different genera. And 167 （78.0K） endophytic fungi had antimicrobial activities. [Conclusion] There was rich diversity and bioactivity of endophytie fungi from S. alopecuroides L. in arid and desolate areas of Ningxia.