ABSTRACT

Papaya leaf curl disease (PaLCuD) is a serious problem to the production of papaya (Carica papaya L.) in India and infection due to this virus is not limited to papaya, but to chilli and tomato. In this study, leaf samples from diseased papaya plant showing extreme leaf curling and venation were collected from New Delhi region, India during the period of 2016–2017. Rolling Circle Amplification(RCA) – PCR-sequencing showed the presence of typical Old World begomovirus. The nucleotide sequence of two cloned begomovirus genome of this study shared maximum percentage nucleotide identity with chilli leaf curl virus (ChiLCV) and tomato leaf curl virus reported from different parts of India. Interestingly, a defective betasatellite DNA of 0.6 kb was found to be associated with one of the isolates of begomovirus under study. Agroinfectious clone of one isolate was developed and tested with the help of needleless syringe in chilli leaves which later developed into leaf curl disease symptoms. This is a first study in which biological and molecular characterisation of a recombinant ChiLCV isolated from papaya plant is demonstrated.

摘要

木瓜叶卷曲病（PaLCuD）是木瓜生产的严重问题（Carica papayaL.）在印度，这种病毒引起的感染不仅限于木瓜，还包括辣椒和番茄。在这项研究中，从2016-2017年期间，从印度新德里地区采集了患病木瓜植株的叶片样品，显示出极度的卷曲和叶脉。滚环扩增（RCA）– PCR测序表明存在典型的旧世界begomovirus。这项研究的两个克隆的begomovirus基因组的核苷酸序列与印度不同地区报道的辣椒卷叶病毒（ChiLCV）和番茄卷叶病毒共享最大的核苷酸同一性百分比。有趣的是，发现有一个0.6 kb的有缺陷的β卫星DNA与正在研究的begomovirus分离株之一有关。开发了一种分离株的农业感染性克隆，并借助无针注射器在辣椒叶片中进行了测试，该辣椒叶片随后发展成叶片卷曲病症状。这是第一项研究，其中证明了从木瓜植物分离的重组ChiLCV的生物学和分子表征。