Transmission of plant viruses through seed can be one of the major factors contributing to longdistance
dispersal through global trade of seeds and can have important ecological
consequences for virus dissemination. Begomoviruses (genus Begomovirus, family
Geminiviridae), and among them isolates of the species Tomato leaf curl New Delhi virus
(ToLCNDV), cause significant yield losses in economically important crops worldwide. These
viruses are horizontally transmitted in nature in a circulative and persistent manner by the
whitefly Bemisia tabaci but in recent years several reports have raised the possibility of vertical
transmission through seeds for some members of this genus. We have investigated the possible
transmission by melon (Cucumis melo L.) seeds of a ToLCNDV isolate of the “Spain” strain,
in three different melon cultivars (all susceptible to ToLCNDV). The presence of ToLCNDV
in floral tissues and the detection of viral DNA in seeds reveals the seed-borne nature of this
virus. However, grow-out studies conducted with the progeny of melon plants germinated from
seeds collected from ToLCNDV-infected plants and evaluated at early (1 leaf) or at late (20
leaves) growth stages did not support the vertical transmission of ToLCNDV from seeds to the
offspring.