关键词: 交脉蚜, 香蕉束顶病毒, 介体, 消化系统, 传播方式

Abstract: 【Aim】In order to more systematically reveal the transmission mode of banana bunchy top virus (BBTV) in the transmission vector Pentalonia nigronervos. 【Methods】Non-viruliferous P. nigronervos adults were allowed to acquire BBTV by feeding on infected plants of Musa acuminata AAA Groups, Cavendish cv. Baxi for 6, 12, 24, 36, 48 and 72 h. Then the expression levels of coat protein (CP) genes in these P. nigronervos adults were detected using PCR and qPCR to determine the virus acquisition time of non-viruliferous P. nigronervos. The distribution of BBTV in various tissues within the digestive system of P. nigronervos adults was observed through immunofluorescence detection and in situ hybridization, and the presence of BBTV in the honeydew of P. nigronervos and in Solenopsis invicta adults fed on this honeydew was detected by PCR.【Results】The expression of BBTV CP gene could be detected in P. nigronervos adults at 6 h after virus acquisition. Fluorescent labeling result indicated that BBTV was predominantly located in the anterior midgut (specifically in epithelial cells and circular muscles), accessory salivary glands, and excretory ostium of P. nigronervos adults. In situ hybridization result confirmed the presence of BBTV in the foregut, anterior midgut (epithelial cells), and principal salivary glands of P. nigronervos adults. PCR result revealed that the fragments of all six genetic components of BBTV could be detected in the honeydew secreted by viruliferous P. nigronervos as well as in S. invicta adults fed on this honeydew. 【Conclusion】A portion of BBTV acquired by P. nigronervos from banana bunchy top disease (BBTD) infected banana plants is transmitted in a persistent-nonpropagative circulative manner within the salivary glands, foregut, anterior midgut (epithelial cells and circular muscles), and excretory ostium of P. nigronervos adults. Conversely, another portion of BBTV is eliminated from the body of P. nigronervos in the form of honeydew. This study enhances our understanding of BBTV distribution in its transmission vector P. nigronervos and further confirms that BBTV spreads in its vector in a persistent-circulative manner. These findings are crucial for advancing research on the virus transmission mechanisms in P. nigronervos and for developing effective disease prevention and control strategies.

Key words: Pentalonia nigronervos, Banana bunchy top virus, vector, digestive system；transmission mode