Asymmetric synergism and heteroencapsidation between two bipartite begomoviruses, tomato leaf curl New Delhi virus and tomato leaf curl Palampur virus

•One isolate of tomato leaf curl Palampur virus was cloned, sequenced and proved Koch's postulates.•Pseudorecombinants produced exchanging DNA A and DNA B components of ToLCNDV and ToLCPalV indicated asymmetric synergism between them.•One of the pseudorecombinants (ToLCNDV DNA A and ToLCPalV DNA B) was supervirulent than the native virus.•Whitefly transmission of pseudorecombinant was demonstrated clearly indicating the possibility of heteroencapsidation.