广东香蕉肾状线虫病的分布为害及病原鉴定

通过对广东省香蕉(Musa nana Lour)主要产区东莞、高州等地调查,发现香蕉肾状线虫不但分布普遍,而且有些地方虫口密度很大。在70个根和土样中有肾状线虫的占61.4％虫口密度可高达1754/100克干土。肾状线虫仅以年青雌虫侵染香蕉根,以虫体前部插入皮层取食,营半内寄生生活发育至成熟。成熟雌虫固着在靠近内皮层处取食,侵染香蕉根引起侵染点附近内皮层细胞壁加厚,容易断裂;内皮层、中柱鞘和维管束薄壁细胞融合成合胞体,每年4月中旬至5月下旬为侵染发病高峰期。根据形态特征、生活史和寄主范围,初步鉴定主要种群是肾形肾状线虫(Rotylenchulus reniformis Linford and Oliveira,1940)。

A STUDY TO THE RENIFORM NEMATODE DISEASE OF DWARF BANANA IN GUANGDONG PROVINCE OF CHINA

According to the survey in the main area producing Dwarf Banana (Musa nona Lour. ) in Cuangdong of China eg. Dongguang, Gaozhou and other counties. We have found that the Dwarf Banana reniform nematode (DRN) is not only widespreadly distributed in the areas, but also has quite great population densities in some places, The DRN has been isolated from 61.4% of 70 samples of the roots and rhizosphere soil. The population densities can be up to 1754 /100 gram, dried soil.The roots of Dwarf Banana were infected only by the young females of reni-form nematode, whose anterior part of the boby eneased in the cortes of the root for feeding. The permenent feeding site of adult female is usually initiated in the near emdodermal cell. The peak of infestation and disease period appeared a from mid April to later May.Reniform nematodes could cause the endodermal cell walls around the infecting site thicking, being broken easily; and also could cause the endodermal,pericycle and vascular parenchymal cells fusing into a syncytium.A species of the major pathogenic neraatodes infected the Dwarf Banana roots was identified to be Rotylenchulus reniformis Linford and Qliveira, 1940,according to its morphological characters, life cycle and host range.