硬叶兜兰高产IAA菌株的筛选鉴定及其生物学特性研究  

Screening,identification and biological characteristics of high IAA-producing strains of Paphiopedilum micranthum

作　　者：任书娴 李宗艳[1] 胡梦露 冯尧 杨建伟 胡家雪 伍倩 REN Shuxian;LI Zongyan;HU Menglu;FENG Yao;YANG Jianwei;HU Jiaxue;WU Qian(School of Landscape Architecture and Horticulture Sciences,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学园林园艺学院,云南昆明650224

出　　处：《江西农业大学学报》2024年第4期902-913,共12页Acta Agriculturae Universitatis Jiangxiensis

基　　金：国家自然科学基金项目(32260414)。

摘　　要：【目的】筛选鉴定硬叶兜兰根、叶内高产IAA菌株并对其进行生物学特性研究。【方法】采用组织分离法从根、叶中分离内生真菌,结合形态学和rDNA-ITS分子生物学进行鉴定;并运用Salkowski比色法比较分离菌株分泌IAA的能力;同时采用单因素法探究YD-16菌株最适生长条件。【结果】分离出的33株真菌经鉴定为8属12种,所有菌株表现出不同程度分泌IAA的能力,其中YD-16(Nemania cyclobalanopsina)在所有菌株中分泌量最高,该菌株在添加和不添加L-色氨酸的培养基中IAA的产量分别为(59.29±0.46)μg/mL和(17.36±0.09)μg/mL;YD-16菌株在中性培养基25℃恒温黑暗条件下培养,且氮源为蛋白胨、碳源为蔗糖和淀粉时菌丝生长最好。【结论】分离鉴定的内生真菌有8属12种,优势种为炭垫菌属真菌。其中,双座炭壳菌属、间座壳属、炭团菌属、黑孢属和炭角菌属是首次从硬叶兜兰中分离的真菌。YD-16菌株具有较高的分泌IAA的能力,其氮源偏好为蛋白胨,碳源偏好为蔗糖和淀粉,研究结果可为后续开展硬叶兜兰养分生理和资源保护提供科学依据。[Objective]This study aims to screen and identify the high IAA-producing strains from the roots and leaves of Paphiopedilum micranthum and investigate the biological characteristics of the strains.[Method]The endophytic fungus was isolated from roots and leaves by using the tissue isolation method and identified based on their morphology and rDNA-ITS molecular biology.Moreover,the Salkowski colourimetric method was employed to screen the isolated strains with high IAA(indole-3-acetic aci)yield.Simultaneously,a single-factor experimental method was conducted to explore the optimal growth conditions for strain YD-16(Nemania cyclobalanopsina).[Result]The results indicated that thirty-three isolated strains were ultimately identified as 12 species belonging to 8 genera and they all differed in indole-3-acetic acid(IAA)production capability.The highest IAA yield was found in YD-16 strain.It could reach IAA level of(59.29±0.46)μg/mL and(17.36±0.09)μg/mL respectively when YD-16 strain was cultured in media with or without L-tryptophan.An optimal condition for the growth of YD-16 strain was in the neutral media with additives of protein peptone as nitrogen source,sucrose as carbon source under constant temperature of 25℃and dark condition.[Conclusion]Twelve species belonging to eight genera of endophytic fungus were identified from 33 strains obtained from leaves and roots of P.micranthum.Genus Biscogniauxia,Diaporthe,Hypoxylon,Nigrospora,and Xylaria were first reported to be isolated from P.micranthum.YD-16 strain had a high IAA production capacity.The nitrogen source preference was peptone,and the carbon source preference was sucrose and starch.The results lay a foundation for further study on nutrient physiological characteristics of YD-16 strain,its utilization and the conservation of P.micranthum.

关 键 词：硬叶兜兰 内生真菌 分泌IAA能力 最适生长条件 

分 类 号：Q948.122.3[生物学—植物学]