植物叶际固氮菌研究进展

固氮菌广泛存在于植物叶际,能固定空气中的氮气,满足自身或植物的部分氮素需求。基于纯种分离和培养的传统生物学方法已经研究了部分叶际固氮菌的特性,但对叶际固氮菌的物种组成、群落结构及生态功能等方面的认识还非常有限。随着分子生物学技术的发展、微生物分子生态学研究方法的逐步成熟,人们对叶际微生物的多样性和生态功能的研究越来越深入。叶际固氮菌具有丰富的多样性,温度、湿度、光照等环境因素及植物种类和微生物互作均会影响叶际固氮菌的组成。不同于根际固氮菌,叶际固氮菌具有非专一性,且不易受化肥的影响,其在农业生产上已经表现出潜在的应用价值。为此,本文综述了农作物、森林、海域生态系统中叶际固氮菌的群落结构组成及生态功能,以及外界因素对叶际固氮系统的影响。

Nitrogen-fixing bacteria in the phyllosphere

Phyllosphere contains a wide distribution of nitrogen-fixing bacteria that fix nitrogen for bacterial and plant growth. The properties of nitrogen-fixing bacteria have been partially studied through traditional culture-dependent methods. However, knowledge on nitrogen-fixing bacteria diversity, community structure and function in phyllosphere remains limited. Recently, developments in molecular ecology techniques have led to the widespread use of culture-independent methods, enable researchers to understand phyllosphere microbial diversity and ecological function. Phyllosphere nitrogen-fixing bacteria exhibit abundant diversity that is mainly affected by environmental conditions (temperature, humidity and light), the host plant species and microorganism interactions. Unlike rhizosphere diazotrophs, phyllosphere nitrogen-fixing bacteria may not be affected by chemical fertilizers and could thus be potentially beneficial in agricultural applications. This review discusses the latest research on phyllosphere nitrogen-fixing bacteria diversity and ecological functions in agricultural, forest, and marine ecosystems, and on the factors influencing the nitrogen-fixing system, thus providing new insight into phyllosphere nitrogen-fixing bacteria.