Pisarska K, Adamski M, Pietr S J
Wrocław University of Environmental and Life Science, Faculty of Life Science and Technology, Dept. of Plant Protection, Division of Agriculture Microbiology, Grunwaldzka 53, PL-50-357 Wrocław, Poland.
Commun Agric Appl Biol Sci. 2011;76(4):699-704.
Presence of endophytic bacteria was reported in many crops including maize (Zea mays L.). Endophytes play a significant role in plant nutrient and pesticide uptake. Application of endophytic bacteria is a goal of sustainable agriculture. Occurrence of Azospirillum strains is often reported as tissue inhabiting bacteria of maize. The biological N2-fixation is one of most important processes assigned to this bacteria. The objective of this study was to examine the biodiversity of Azospirillum spp. isolated from the leaves of 6 cultivars of Zea mays L.. They were cultivated on two experimental fields at Smolice and Kobierzyce, (Poland). Strains of Azospirillum spp. were isolated on the solid RC medium. Forty four isolates grown as a small intensive red colonies were selected. To verify ability to N2-fixation isolates were analyzed based on nifH gene presence. Presence of nifH gene was tested using PCR method with PolF and PolR universal degenerate primers. The presence of nifH gene was found in 6 tested strains isolated from leaves of 3 cultivars (Cyrkon, Kosmo230, KB2704) from Smolice location, only. Our results suggest that selection of Azospirillum-like strains on RC solid medium based on appearance of colony is not correlated with theirs ability to nitrogen fixation or used degenerated primers (PolF, PolR) are not universal enough.
许多作物（包括玉米（Zea mays L.））中都报道了内生细菌的存在。内生菌在植物养分吸收和农药吸收方面发挥着重要作用。应用内生细菌是可持续农业的一个目标。固氮螺菌菌株的出现经常被报道为玉米的组织栖息细菌。生物固氮是赋予这种细菌的最重要过程之一。本研究的目的是检测从6个玉米品种叶片中分离出的固氮螺菌属的生物多样性。这些玉米品种种植于波兰斯莫利采和科比耶尔齐采的两个试验田。固氮螺菌属菌株在固体RC培养基上分离。挑选出44个长成小而密集红色菌落的分离株。为了验证固氮能力，基于nifH基因的存在对分离株进行分析。使用PolF和PolR通用简并引物通过PCR方法检测nifH基因的存在。仅在从斯莫利采地区3个品种（Cyrkon、Kosmo230、KB2704）叶片中分离出的6个测试菌株中发现了nifH基因。我们的结果表明，基于菌落外观在RC固体培养基上选择类固氮螺菌菌株与它们的固氮能力不相关，或者所使用的简并引物（PolF、PolR）不够通用。
