【作者】 胡桂萍；

【导师】 尤民生； 刘波；

【作者基本信息】 福建农林大学 ， 植物检疫， 2010， 硕士

【摘要】 1.水稻品种内生细菌群落结构多样性以分离培养方法对野生稻、常规稻及杂交水稻内生细菌的多样性进行了初步研究。结果表明野生、常规及杂交水稻植株内存在大量的内生细菌,共分离到29株内生细菌,29种分离物进行Sherlock MIS微生物全自动鉴定,相似度系数大于0.5的有27个细菌,隶属于11个种, 5个属,分别为芽孢杆菌属(Bacillus)、假单胞菌属(Pseudomonas)、寡养单胞菌属(Stenotrophomonas)、金杆菌属(Microbacterium)、不动杆菌属(Acinetobacter)。其中优势属为芽孢杆菌属(Bacillus),对以内生细菌为样本,以品种为变量进行主成分分析可以得到内生细菌可以聚为三类,与品种有关。以汕优63不同部位为材料,并采用0-1聚类分析得到:内生细菌分布与部位有关。2.水稻品种内生细菌与根系土壤细菌的相关性以航1号,航2号,Ⅱ优航1号,Ⅱ优航2号,汕优63为材料分析内生细菌和根系土壤细菌群落结构。结果显示:内生细菌有13种,根系土壤细菌10种,总共18种,群落多样性指数分析得到,内生细菌群落多样性高于根系土壤细菌;对内生细菌和根系土壤细菌群落结构典型相关分析得到,相关系数有4个,当R=0.9447时,两者呈最高相关;内生细菌和根系土壤细菌与水稻的生物学特性相关分析得到:两者都与穗粒数,结实率,千粒重,理论亩产存在极显著正相关,而与水稻有效穗呈负相关。3.水稻内生菌群落总体脂肪酸多样性通过磷脂脂肪酸(PLFAs)改良法并分析水稻内生菌PLFA多样性发现:水稻内生菌PLFA丰富,共检测到27种内生菌脂肪酸,其中8种为完全分布,19种为不完全分布。内生菌脂肪酸具有特异性,聚类分析得到内生菌脂肪酸可以聚为两大类,非线性映射分析得到,内生菌脂肪酸在不同品种分布有特征性。4.水稻根系微生物群落总体脂肪酸多样性采用脂肪酸生物标记(PLFAs)法,分析4个Ⅱ优为母本的水稻品种和3个优制5为父本的水稻品种在同等栽培条件下根系土壤微生物群落结构,从而探讨其与水稻品种特性的内在联系,为水稻育种和品种改良提供科学依据。试验结果表明:水稻根系土壤脂肪酸生物标记丰富,共检测到PLFAs 38条,其中完全分布的生物标记有23条,不完全分布的有15条;水稻根系土壤中细菌的PLFAs含量>真菌>放线菌。不同品种,其根系微生物脂肪酸生物标记组成结构存在差异:对根系土壤特征脂肪酸生物标记16:0(细菌)、18:1ω9с(真菌)、10Me l7:0(放线菌)、10Me 16:0(硫酸盐还原细菌)和16:1ω5с(甲烷氧化菌)比较可知,优制5为父本的品种含量高,最高的为金生优制5,Ⅱ优为母本的低,含量最低的为Ⅱ优797。对PLFAs总量和水稻生育特征进行Pearson相关分析结果表明:PLFAs与植株有效穗和产量呈正相关,但与株高呈负相关。对水稻根系土壤脂肪酸生物量总量进行聚类分析发现:Ⅱ优为母本的品种聚为一类,优制5为父本的聚为一类,表现出水稻遗传特性在其根系微生物脂肪酸生物标记(PLFAs)上的差异性。本研究结果表明:水稻根系土壤微生物群落PLFAs结构丰富,根系土壤微生物群落PLFAs结构与品种生育特性有相关性,同时受水稻遗传亲缘关系远近的影响。更多还原

【Abstract】 1. Diversity of endophytic bacteria community structure of riceThe diversity of endophytic bacteria in the wild rice, hybrid rice and cultivated rice was studied. Twenty-nine endophytic bacteria were isolated from the rice and identified by Microbial Identification System (MIS). Among the bacteria, 11 species were classified with Similarity Index more than 0.6, that belonged to 5 genuses such as Bacillus, Pseudomonas, Stenotrophomonas, Microbacterium and Acinetobacter. The genus Bacillus was the abundance one in the endophytic bacteria community. The principal components analysis was introduced into grouping the characteristics of bacteria community structure by using endophytic bacteria as samples and cultivar as variables. The results showed that the 11 species could be classified into 3 groups correlated with the rice cultivars. Moreover, the distribution of endophytic bacteria were found to have relationship with the part of rice by 0-1 cluster analysis2. Diversity of endophytic bacteria and rhizosphere bacteria on riceThe relationship between the diversity of endophytic bacteria and rhizosphere bacteria of rice cultivar was investigated. In total, 18 species of bacteria were collected from both of the plant and the rhizosphere. Among which, the endophytic bacteria were identified and classified into 13 species and rhizosphere bacteria belonged to 10 species. According to the diversity indexes of Simpson index, Shannon-Wiener index, Brillouin index, Pielou index and McIntosh index, the community diversity of endophytic bacteria was found to be greater than that of rhizosphere bacteria. The results of statistics analysis showed that there was canonical correlation between the community structures of endophytic bacteria and rhizosphere bacteria. They had 4 correlational coefficients and reached the greatest correlations, while the correlational coefficient was 0.9447. The relationships were positively correlated between the amount of bacteria and the grain number per spike, seed setting rate, 1000-grain weight and plant production, respectively. However, the bacteria content performed negative correlation with the effective spikes.3. Microbial community diversity of endophytic bacteria of riceThe microbial community diversity of endophytic bacteria of different rice cultivars was explored by using improved method of phospholipid fatty acid biomarkers detection (PLFA). The PLFAs of endophytic microbial of rice were abundant and different. Twenty-seven PLFAs biomarkers were detected, among which 8 PLFAs distributed completely and 19 PLFAs distributed incompletely in the plant of rice. The PLFAs were collected into 2 groups by cluster analysis. The structure of PLFAs of endophytic bacteria in different rice cultivars were discovered to be characteristic by Non-linear mapped analysis.4. Microbial community diversity of rhizosphere bacteria of riceUsing phospholipid fatty acid biomarkers detection, the genetic relationship between the rhizosphere microbial community structure and the rice variety was studied. The rhizosphere microbial communities of rice varieties were sampled from 7 rice varieties,e.g.Ⅱyou 797,Ⅱyou HK05,Ⅱyou 355,Ⅱyou 455, xinan youzhi 5, jinsheng youzhi 5, tian youzhi 5, with the same cultivating conditions in the experimental plot. The PLFAs was detected by MIDI to get the microbial community diversity. The quantities of PLFAs were clustered to observe the characteristics of rhizosphere microbial community in the rice varieties. The results showed that 38 PLFAs biomarkers were detected out, in which there were 23 PLFAs completely distributed and 15 PLFAs incompletely distributed in the rhizosphere soils of 7 rice varieties respectively. The quantities of PLFAs related to bacteria were higher than either that to fungi or that to actinomycetes. The results also revealed that the roots’microbial community structure represented by PLFAs was closely related to the variety biology, in which the relationship between the PLFA and the effective ear was positive, so did the production, whereas the relationship between the PLFA and the plant height was negatively correlated. Simultaneously, the cluster analysis displayed that the PLFAs were concerned with the rice heredity characteristic. It was concluded that the microbial community based on PLFAs in the rice rhizosphere soil was rich, which sensitively reflected the relation between the PLFAs and the biological and hereditable characteristics of the rice variety.更多还原