轮作和连作田大豆胞囊线虫胞囊上真菌定殖动态

Dynamics of Fungal Colonization on Cyst in Rotation and Continuous Cropping of Soybean

研究沈阳市汪家乡连作6年和轮作大豆田中胞囊数量以及大豆不同生长期胞囊上定殖真菌的种群及数量变化。结果表明:在整个大豆生长期中,不饱满胞囊量高于饱满胞囊量,连作田中胞囊总量、不饱满胞囊量高于轮作田。从胞囊上分离到的真菌以镰孢菌居多,在大豆不同生长时期镰孢菌属的分离频率不同,其中尖孢镰孢菌Fu-sarium.oxysporum为优势种群,且连作田中数量多于轮作田;除镰孢菌属真菌外,轮作田中胞囊上分离到的青霉属和粘帚霉属真菌数量最多,还分离到毛霉属、毛壳菌属和拟青霉属;而连作田中胞囊上分离到的真菌中粘帚霉属数量最多,其他各属真菌的数量都很少,其中轮枝菌属和腐质霉属在轮作田胞囊上未分离到。镰孢菌的定殖数量与胞囊的饱满程度有关,而青霉、粘帚霉和拟青霉等其他真菌种群也影响到胞囊的饱满程度。

The number of cyst and the fungal colonizing on cyst in the fields of rotation and continuous cropping of soybean for six years were studied at Village Wangjia in Shenyang city. The results showed that unplump cysts were more than plump ones in both rotation and continuous fields. While the total numbers of cysts and numbers of unplump cysts isolated from continuous cropping were more than those in rotation field. Among the fungi isolated from cysts Fusarium presented the highest isolations. The frequency of isolated Fusarium was different in 5 soybean growing stages. F. oxysporum was a dominant population and its isolations were more in continuous cropping than those in rotation field. In rotation field,Penicillium and Gliocladium were another two dominant populations. The other isolated fungi were Mucor, Chaetomium and Peacilomyce. In continuous cropping field, the numbers of Gliocladium were higher but others were lower. Verticillium and Humicola were only isolated from continuous cropping field but not found in rotation field. Our results showed a trend that the numbers of Fu- sarium colonized on cysts were correlated with the numbers of plump cysts among tested samples. The other fungi such as Penicillium, Gliocladium and Peacilomyces affected the plump degree of cysts.