Mechanical sap transmission of Tomato leaf curl New Delhi virus infecting ridge gourd [Luffa acutangula (L.) Roxb.] in south India

Abstract

Ridge gourd (Luffa acutangula L.) is an important cucurbitaceous crop cultivated throughout India. The crop is severely affected by yellow mosaic disease caused by Tomato Leaf Curl New Delhi Virus (ToLCNDV). The symptoms of ToLCNDV consists of yellow mosaic spots on young leaves, reduction in leaf area, leaf thickening flower abortion and severe stunting of the plants. High disease dissemination under epiphytotic conditions also affects the chemical control measures and leads to heavy crop losses. Identification of resistant sources is most important tool to reduce the economic loss and maximize quality and quantity of output. Efficient and simple screening procedures are very crucial in disease resistant breeding program. In this experiment, mechanical sap inoculation of ToLCNDV has been studied in twelve ridge gourd genotypes. All the inoculated plants developed characteristics ToLCNDV symptoms and severe infection after three-week post inoculation. In all the assays ToLCNDV transmission was confirmed by PCR amplification using virus specific primer followed by sequencing of random samples. Mechanical sap transmission is easy and simple screening method which will facilitate the development of ToLCNDV resistant breeding cultivars.