Location: Plant Genetic Resources Conservation UnitTitle: Evaluation of loofah lines for resistance to Tomato leaf curl New Delhi virus, downy mildew, and key horticultural traits
|DHILLON, NARINDER P.S. - The World Vegetable Center (AVRDC) - Taiwan|
|ABU TAHER MASUD, MOHAMMED - Bangladesh Agricultural Research Institute|
|PRUANGWITAYAKUN, SOMCHIT - The World Vegetable Center (AVRDC) - Taiwan|
|NATHEUNG, MONPAPA - The World Vegetable Center (AVRDC) - Taiwan|
|LERTLAM, SUYUPORN - The World Vegetable Center (AVRDC) - Taiwan|
|Jarret, Robert - Bob|
Submitted to: Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/13/2020
Publication Date: 7/15/2020
Citation: Dhillon, N., Abu Taher Masud, M., Pruangwitayakun, S., Natheung, M., Lertlam, S., Jarret, R.L. 2020. Evaluation of loofah lines for resistance to Tomato leaf curl New Delhi virus, downy mildew, and key horticultural traits. Agriculture. 10(7):298. https://doi.org/10.3390/agriculture10070298.
Interpretive Summary: Luffa gourds are an important food crop for small-holder farmers in many parts of the world. However, viruses and bacterial diseases often limit production. The development of disease-resistant varieties remains one of the most effective means of maintaining crop yields in the presence of disease organisms. This report describes efforts to identify luffa gourd lines in a germplasm collection that are resistant to a common virus (Tomato leaf curl New Delhi virus) and the fungal-like organism that causes downy mildew. The study identified 13 and 59 lines of ridge gourd and sponge gourd, respectively, that were resistant to both the virus and downy mildew. These resistant lines also exhibited variability for several horticultural traits such as fruit size, fruit shape, and days to 50% flowering.
Technical Abstract: Two loofah (Luffa) species, including the ridge gourd [Luffa acutangula (L.) Roxb.] and the sponge gourd [L. cylindrica (L.) M. Roem. - syn. aegyptiaca], are economically and nutritionally important cucurbitaceous vegetables in Asia grown chiefly by smallholder farmers. However, the occurrence of Tomato leaf curl New Delhi virus (ToLCNDV) and downy mildew (DM) caused by Pseudoperonospora cubensis are currently important biotic constraints to loofah production throughout Asia. Loofah landrace-derived breeding lines, developed at the World Vegetable Center (WorldVeg) were evaluated at the WorldVeg East and Southeast Asia Research and Training Station, Kasetsart University, Kamphaeng Saen, Thailand – where natural epidemics of ToLCNDV and DM regularly occur. Lines were also evaluated for other commercially important horticultural traits such as days to 50% staminate and pistillate flowering, fruit color, fruit bitterness, and market segment classification. Thirteen and 59 lines of ridge gourd and sponge gourd, respectively, were determined to be resistant to both ToLCNDV and DM. These lines covered all the market segments of loofah and exhibited variability for all evaluated horticultural traits. The results of these evaluations and their breeding implications are discussed.