金钗石斛IAA内生细菌筛选及对干旱胁迫下玉米种子萌发的影响  

Screening of IAA Producing Endophytic Bacteria in Dendrobium nobile Lindl and Effect on Zea mays Seed Germination Under Drought Stress

作　　者：高阳[1] 朱双丽 吴庆珊 雷珣[1] 安忠琦 王玉倩[1] 牛晓娟[1] 翁庆北[1] 

机构地区：[1]贵州师范大学生命科学学院,贵阳550001

出　　处：《种子》2017年第4期36-41,共6页Seed

基　　金：贵州省优秀科技教育人才省长专项资金([2011]47);贵州省大学生创新创业训练计划项目(201410663004)

摘　　要：从金钗石斛植株中分离并筛选产吲哚乙酸(IAA)的内生细菌,研究在不同浓度PEG-6000模拟的干旱胁迫条件下,产IAA内生菌发酵上清液浸种处理对玉米种子萌发的影响。从金钗石斛分离出645株内生细菌,通过salkowskis法筛选表明,63.4%的内生菌具有分泌IAA的能力,其中有9株菌分泌量较高,分泌量为12.8~34.5mg/L。基于16SrRNA基因序列分析,初步鉴定它们为芽孢杆菌属(Bacillus)和类芽孢杆菌属(Paenibacillus)细菌。将内生菌发酵上清液浸种处理玉米种子,在未加PEG以及5%、10%和15%PEG的干旱胁迫条件下,其种子萌发率与对照组的相当或降低。但部分产IAA内生菌浸种处理可缓解高度干旱胁迫作用:在20%PEG条件下,有7株内生菌浸种处理后玉米种子萌发率显著提高,较对照组提高了4.7%~13.3%;25%PEG条件下,内生菌LJYPD 10处理的玉米种子萌发率比对照组显著提高了5.3%。The indole-3-acetic acid （IAA） producing endophytic bacteria were isolated and screened from Dendrobiurn nobile Lindl.Under the condition of dought stress stimulated with different concentration of PEG- 6000,the maize seed germination were studied after treating with the IAA-producing strains. The results showed that a total of 645 strains endophytic bacteria were isolated from D.nobile Lindl.,and 63.4% of the strains have the ability to produce IAA, using with the salkowskis reagent method, 9 strains were screened, which produced 12.8-34.5 mg/L IAA and showed a higher ability of IAA production.Based on 16 S rRNA gene sequence analysis, these endophytic bacteria were identified as Bacillus sp. and Paenibacillus sp.. The IAA-produeing endophytic bacteria were fermentated and the supernatant were used to soak the maize seeds. Under the condition of absence PEG or drought stress of 5 %, 10 % and 15 % PEG, the germination rate of the seeds treated with the endophytic bacteria were less than or equal to the control ＇ s.Howerer, soaking with the IAA-producing endophytic bacteria could elliminate the high drought stress effect of the maize seeds. Under the condition of 20 % PEG, there are 7 strains can significantly promote the seed germination, the germination rate of endophytic bacteria soaking seeds were increased by 4.7 %- 13.3 % compared with the control. Under the condition of 25 %PEG, the germination rate of the seeds treated with the endophytic bacteria LJYPD 10 was increased by 5.3% than the control＇ s.

关 键 词：金钗石斛 内生细菌 IAA 玉米 种子萌发 干旱胁迫 

分 类 号：S513[农业科学—作物学]