| 摘要: |
| 分离纯化青藏高原横断山区（四川甘孜藏族自治州和阿坝藏族羌族自治州）原生野生饲用黄芪根瘤菌，为优良菌株的筛选提供种质资源。采用纯培养法从该地区部分饲用黄芪植物根瘤中分离纯化根瘤菌；通过16S rDNA序列同源性分析确定菌株的系统发育地位；通过测定菌株的耐盐性、初始pH生长范围及生长温度范围来分析饲用黄芪根瘤菌的抗逆性。从青藏高原横断山区7个县15个采样点获得10种饲用黄芪植物的根瘤，共分离纯化出36个根瘤菌菌株。16S rDNA序列同源性系统发育分析表明，36个菌株分别为根瘤菌属-土壤杆菌属（Rhizobium-Agrobacterium）30株、苍白杆菌属（Ochrobactrum）5株、中慢生根瘤菌属（Mesorhizobium）1株，共3个群。生理性状测定试验表明，36个根瘤菌菌株中20株能在4~45 ℃的恒温条件下生长，15株能在4~50 ℃的恒温条件下生长，仅供试菌株SCAU509的最高耐受温度不能超过37 ℃，所有菌株能在经过60 ℃处理10 min后置28 ℃恒温条件下生长；除SCAU495只能在pH 6~8的培养基上生长，SCAU509只能在pH 5~8的范围内正常生长外，其余34株均能在pH 4~10的培养基上生长；SCAU509只能在1%NaCl以下的YMA培养基上生长外，其余供试菌株中最高能耐受1%、2%、3%、4%、5%、6%NaCl的数量分别为2、7、6、10、8和2株。本研究表明，青藏高原横断山区（四川甘孜藏族自治州和阿坝藏族羌族自治州）饲用黄芪根瘤菌中多数菌株对高盐、高温、低温及过酸过碱环境均具有较强的耐受能力。 |
| 关键词: 饲用黄芪 根瘤菌 抗逆性 系统发育 青藏高原横断山区 |
| DOI：10.14188/j.ajsh.2022.01.011 |
| 分类号:S182 |
| 基金项目: |
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| Stress resistance and phylogenetic analysis of rhizobia from fodder plant Astragalus in Hengduan Mountain area of Qinghai Tibet Plateau |
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Jiang Huaming1,2, Peng Wanren1, Li Renquan1
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1.Sichuan Vocational and Technical College， Suining 629000， Sichuan， China;2.College of Resources， Sichuan Agricultural University， Chengdu 611130， Sichuan， China
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| Abstract: |
| Stress resistance and phylogeny of the rhizobia from fodder plant Astragalus in high elevation area of western Sichuan were studied. Pure culture method was used for isolating the rhizobial strains from Astragalus nodules，16S rDNA sequencing was used for determining the phylogenetic status of the strain. The growth performance in different salt content， pH and temperature was tested. 36 strains were isolated from fodder plant Astragalus from 15 sampling site in 7 counties in the western Sichuan. Phylegenetic tree analysis showed that 30 strains were closely related to Rhizobium-Agrobacterium， 5 strains were Ochrobactrum， and 1 strain was Mesorhizobium. 20 strains isolates perfomed good growth in the temperature range of 4 °C to 45 °C， 15 strains in 4 °C to 50 ℃， and only SCAU509 in 4 °C to 37 ℃. All of 36 strains could grow at 28 °C after the treatment of 60 °C for 10 minutes. 34 strains strains could grow in the pH range of 4.0 to 10， while SCAU509 could only grow in pH 5 to 8， and SCAU495 could only grow in pH 6 to pH 8. SCAU509 could only grow below 1% NaCl concentraion， and other strains could grow in the range of 1% to 6% NaCl concentration. This study reveals that the most of these strains of rhizobia from fodder plant Astragalus have strong tolerance to high salt， high and low temperatures， over acid and over alkali environments. |
| Key words: fodder plant Astragalus rhizobium stress resistance phylogeny Hengduan Mountain area of Qinghai-Tibet Plateau |
