P-67. Chilli leaf curl disease in India is caused by the co-infection of a Begomovirus and a beta satellite
Abstract
Chilli is a spice cum vegetable crop cultivated throughout India. Leaf curl disease of chilli is one of the major constraints for successful cultivation of the crop wherever the crop is grown. The infected plants exhibiting varied symptoms of mild yellowing, severe leaf curling with puckering and reduced size of leaves were found in Varanasi region. This disease is caused by complex association of a monopartite begomovirus, Chilli leaf curl virus (ChiLCV) and a small satellite DNA¡V£] component. Viral DNA was isolated andfull-length genome of DNA-A and DNA-fÒ was cloned in pUC18 and pTZ57R/T vector, respectively. Sequence analysis showed that DNA-A (EF190217) is of 2750 bp and DNA-£] (EF190215) is of 1361 bp in length. Genomeorganization of both DNA A and DNA fÒ resembles other Begomoviruses and DNA-£] satellites. Maximum sequence identity (95%) of DNA-A was observed with Chilli leaf curl virus ¡V Pakistan [Multan isolate] ChiLCV-PK[PK-Mul:98]and DNAfÒ shared maximum sequence identity (88%) with DNA £] associated with tomato leaf curl disease from Rajasthan (ToLCB-[IN:Raj:03]).Hence, the causal virus is a strain of ChiLCV-PK and is called as ChiLCV-PK [IN:Var:06]. Partial tandem repeat of ChiLCV-PK[IN:Var:06] DNA-A was agroinoculated either alone or in combination withToLCB-[IN:Var:06] DNA fÒ onto chilli cv. Kashi Anmol, Nicotiana benthamiana and tomato. Typical symptom of chilli leaf curl disease was observed when DNA A was coinoculated with DNA £] whereas DNA A alone could produce delayed and mild symptoms viz. leaf yellowing and mild leaf curling on test plants. These results confirmed that ChiLCV-PK[IN:Var:06] belongs to monopartite begomoviruses and requires a satellite beta to increase symptom severity.
