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.