Use of Systemic Acquired Resistance and Whitefly Optical Barriers to Reduce Tomato Yellow Leaf Curl Disease Damage to Tomato Crops.

Epidemics of tomato yellow leaf curl disease (TYLCD) caused by tomato yellow leaf curl-like begomoviruses (genus , family ) severely damage open field and protected tomato crops worldwide. Intensive application of insecticides against the whitefly vector is generally used as control strategy to reduce TYLCD impact. This practice, however, is frequently ineffective and has a negative impact on the environment and human health.

Resistance to Monopartite Begomoviruses Associated with the Bean Leaf Crumple Disease in Phaseolus vulgaris Controlled by a Single Dominant Gene.

ABSTRACT Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Málaga virus are monopartite begomoviruses (genus Begomovirus, family Geminiviridae) that infect common bean (Phaseolus vulgaris), causing bean leaf crumple disease (BLCD). This disease was found to be widespread in southern Spain and causes stunted growth, flower abortion, and leaf and pod deformation in common bean plants. Commercial yield losses of up to 100% occur.

Begomovirus genetic diversity in the native plant reservoir Solanum nigrum: Evidence for the presence of a new virus species of recombinant nature.

We examined the native plant host Solanum nigrum as reservoir of genetic diversity of begomoviruses that cause the tomato yellow leaf curl disease (TYLCD) emerging in southern Spain. Presence of isolates of all the species and strains found associated with TYLCD in this area was demonstrated. Mixed infections were common, which is a prerequisite for recombination to occur.

A natural recombinant between the geminiviruses Tomato yellow leaf curl Sardinia virus and Tomato yellow leaf curl virus exhibits a novel pathogenic phenotype and is becoming prevalent in Spanish populations.

This work provides evidence of the significant contribution of recombination to the genetic diversification of emerging begomovirus populations. In southern Spain, Tomato yellow leaf curl Sardinia virus (TYLCSV) and Tomato yellow leaf curl virus (TYLCV) are distinct geminivirus species that coexist in the field and contribute to the tomato yellow leaf curl disease epidemic. A natural recombinant between TYLCSV and TYLCV has been detected and an infectious clone of a recombinant isolate (ES421/99) was obtained and characterized.