| 摘要: |
| 西南岩溶石漠化山区水土流失严重、养分贫瘠,导致植被恢复困难。为探究固氮菌对岩溶石漠化地区造林苗木的生长促进效应,该文以广西石漠化地区常见造林树种香樟、任豆、喜树和台湾相思苗木为材料,利用平板稀释法从石漠化乡土植物根际土壤筛选固氮菌,通过测定固氮酶活性及鉴定固氮菌菌种,选择固氮酶活性较高的菌种制成复合菌剂接种到试验苗木进行盆栽试验。结果表明:共筛选得到6株具有固氮能力的根际促生菌,分别属于根瘤菌属(Rhizobium)、中华根瘤菌属(Sinorhizobium)和黄杆菌属(Flavobacterium),其中归类为根瘤菌属的3株固氮菌酶活性较高。复合菌剂接种试验表明接种固氮菌对造林苗木的生长具有明显促进作用。与未接种处理相比,接种处理苗木的株高、叶面积、生物量以及叶绿素含量均显著增长; 同时苗木的氮、磷、钾含量也有不同程度的增加。其中,香樟、任豆、喜树和台湾相思的氮含量分别提高了28.9%、53.1%、37.0%和31.6%; 香樟、台湾相思的磷含量分别增加了25.6%和42.5%; 任豆、台湾相思的钾含量分别增加了57.5%和49.7%。接种石漠化乡土固氮菌能够显著促进造林苗木生长和养分含量,在石漠化植被修复中具有较好的应用前景。 |
| 关键词: 石漠化, 固氮菌, 造林苗木, 促生效应, 植被修复 |
| DOI：10.11931/guihaia.gxzw201911003 |
| 分类号:Q948.12 |
| 文章编号:1000-3142(2021)05-0738-08 |
| Fund project:国家自然科学基金(31960272); 广西重点研发计划(桂科AB18126065); 广西科技公关计划(桂科攻1598016-12); 广西喀斯特植物保育与恢复生态学重点实验室基金(19-185-7,17-259-23); 广西植物研究所基本业务费项目(21010)[Supported by the National Natural Science Foundation of China(31960272); Key Science and Technology Program of Guangxi(AB18126065); Science and Technology Program of Guangxi(1598016-12); Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain(19-185-7, 17-259-23); Fundamental Research Fund of Guangxi Institute of Botany(21010)]。 |
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| Growth promoting effect of plant growth-promoting rhizobacteria on tree seedlings suitable for afforestation in rocky desertified region |
|
CAO Yanqiang1, ZHANG Zhongfeng1*, JIANG Shisong2, TANG Jinrong3,
ZHOU Longwu1, TENG Qiumei1, XU Guangping1
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1. Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain, Guangxi Institute of Botany, Guangxi Zhuang Autonomous
Region and Chinese Academy of Sciences, Guilin 541006, Guangxi, China;2. Quanzhou County Institute of Scientific and Technological Information,
Quanzhou 541500, Guangxi, China;3. Agricultural Technology Extension Station of Jiantang Town, Quanzhou 541518, Guangxi, China
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| Abstract: |
| Extensive soil erosion and vegetation degradation are common in karst rocky desertified area, and presenting a serious challenge of restoration of degraded habitats. In order to explore the promoting effect of PGPR(plant growth promoting rhizobacteria)on the growth of afforestation seedlings, seedlings of Cinnamomum camphora, Zenia insignis, Camptotheca acuminata and Acacia confusa which are common in Guangxi rocky desertified region were used as experimental materials. The plate dilution method was used to screen nitrogen-fixing bacteria from rhizosphere soil of rocky desertification native plants. The strains with higher nitrogenase activities were selected and inoculated into experimental seedlings for pot experiment. The results were as follows: Six strains of nitrogen-fixing bacteria from rhizosphere soil were obtained, and the 16S rDNA sequence analysis showed that the tested strains belong to Rhizobium, Sinorhizobium and Flavobacterium. Among them, the nitrogenase activity of three strains of Rhizobium was the highest. Pot experiment showed that inoculating nitrogen fixing bacteria could promote the growth of afforestation seedlings. Plant height, leaf area, leaf dry weight and chlorophyll content increased significantly compared to control. Nitrogen content of Cinnamomum camphora, Zenia insignis, Camptotheca acuminate and Acacia confusa seedlings significantly increased by 28.9%, 53.1%, 37.0% and 31.6%, respectively. Phosphorus contents of Cinnamomum camphora and Acacia confusa was increased significantly by 25.6% and 42.5%, respectively, while the potassium contents of Zenia insignis and Acacia confusa was increased significantly by 57.5% and 49.7%, respectively. The nitrogen-fixing bacterial strains of karst rocky decertified areas in Guangxi have growth promoting effect on local tree seedings used for afforestation. They provide a strong potential for forest restoration through seedling inoculation. |
| Key words: rocky desertification, nitrogen-fixing bacteria, afforestation seedlings, growth promotion, vegetation restoration |
