红树林植物桐花树内生真菌类群分布的研究

Studies on distribution of fungal endophyte in mangrove plant Aegiceras corniculatum

从红树林植物桐花树Aegiceras corniculatum的叶、叶脉、树皮、茎等4个部位,湿季共分离到297株内生真菌,干季共分离到232株内生真菌。叶片内生真菌优势类群为青霉属和盘长孢霉,叶脉为青霉属和枝孢霉属,树皮内生真菌中不产孢类所占比例最高,而茎部的优势类群为枝孢霉属和短梗孢霉,说明内生真菌的分布具有一定的器官和组织特异性。比较各部位内生真菌湿季类群和干季类群发现其优势类群也有一定的变化:叶片内生真菌湿季优势类群是青霉属和盘长孢属,而干季优势类群为不产孢类群B和C;叶脉、树皮、茎的内生真菌的优势菌群在湿季和干季也有差异。这说明不同季节的环境因素(降水量、气温、湿度、光照强度等)的变化对内生真菌的类群及其分布具有较强的影响。

Five hundred and twenty-nine isolates of fungal endophytes were isolated from the lamina, mid-rib, bark and the xylem of stem of Aegiceras corniculatum, among them 297 isolates in wet and 232 in dry season. The taxa of preponderant fungal endophyte communities differed in the four organs of Aegiceras corniculatum： in lamina are Penicillium and Aureo- basidium, in mid-rib are Penicillium and Cladosporium, in bark are the sterile groups, and in xylem of stem are Aureobasidium and Cladosporium. These results indicated that there was some degree of organ specific in distribution of fungal endophytes. The preponderant taxa of endophyte assemblages in organs were different between wet and dry seasons. For example, in lam- ina, wet season were Penicillium and Aureobasidium, but dry season were sterile groups B and C. It showed that the density and the taxa of the endophyte communities in Aegiceras corniculatum were influenced by the environmental factors such as precipitation, temperature, humidity, and intensity of sunlight.