香蕉束顶病毒株系生物学特性的研究

 在广东香蕉束顶病株症状基本相同的情况下,在8个产区分别随机采集11~15个标样共111个分离物,接种在香蕉苗上,其后又从8个产区的分离物中各选取1个代表分离物用于进行各项研究。寄主范围试验结果,这8个代表分离物可分为能侵染粉蕉的NSP株系(以广州天河分离物为代表的7个分离物)和不能侵染粉蕉的NS株系(高州代表分离物)。用Eco RI对8个毒源地的111个分离物DNA组分1进行酶切分析,结果表明:所有高州分离物共15个和信宜分离物14个中的9个都可以被酶切,应属NS株系;而其余6个毒源地的所有分离物及信宜分离物中的另外5个都不能被酶切,应属NSP株系。在病害潜育期方面,2个株系在大蕉上的差异达到显著水平;在香蕉4个品种上,2株系也存在较明显的差异,但其中有些差异未达到显著水平。在病毒增殖、运转速度及病毒达到高浓度所需的时间上,2个株系也存在显著的差异。

BIOLOGICAL CHARACTERISTICS OF BANANA BUNCHY TOP VIRUS STRAINS

Since the symptoms of the banana bunchy top virus (BBTV) occurred in Guangdong are so similar, it is impossible to identify any existing different strains of BBTV by symptom. One way to solve the problem is to analyze diseased samples collected randomly from different locations in banana growing regions in the province. Eleven to fifteen samples from each locations of 8 banana growing regions and a total of 111 samples were collected in the province. BBTV in these diseased samples was each artificially transmitted to healthy banana (Musa nana) tissue culture seedlings via banana black aphids (Pentalonia nigronervosa) in greenhouse. One isolate was selected from each region as the representative isolate. The result of the host range tests showed that the 8 representative isolates could be divided into NSP strain that could infect banana, plantain (M. sapientum) and pisang awake (M. pisang awake) , and NS strain that could infect only the first two but not the later. By means of the EcoRI digestion test, the DNA component 1 of the 87 out of the 111 isolates could not be cleaved. These isolates could be grouped into NSP strain, while 24 out of the 111 isolates (15 isolates from Gaozhou region and 9 out of the 14 isolates from Xinyi) could be cleaved. These isolates could be grouped into NS strain. Between the two strains, the differences were significant on the latent periods in the plantain. They differred, among the four banana varieties. They also differred, in the Guangdong 2 banana, in the rate of virus multiplication and virus translocation and in the time needed to reach the highest concentration in the host.