Lasiodiplodia theobromae, a potential post-harvest threat to agri-horticultural crops and its morpho-molecular diversity

Abstract

The fungus Lasiodiplodia theobromae is one of the potentially important plant pathogens and known to cause serious post-harvest losses in wide range of crops covering more than 500 hosts including vegetables, ornamental, woody plants and agri-horticultural crop species. Keeping its importance in view, the present study was undertaken for morpho-molecular characterization of nine monoconidial isolates of the fungus isolated from seeds of Gossypium hirsutum, Glycine max, Decalepis hamiltonii, Amaranthus sp. Luffa acutangula and Trichosanthes sp. representing different geographical regions of India. During
seed health testing, the level of seed infection ranged from 20% to 100%, which affected seed germination with varying level ranging from 0.0% to 100.0% in different hosts. Morphological study revealed some variation such as colony pigmentation from cottony white to dark grey and black and linear colony growth
ranging from 44 to 57 mm among isolates, which could not distinguish isolates efficiently. However, molecular characterization using URP markers could distinguish diversity to some extent among the isolates. To the best of our knowledge, this is a first report of the use of URP marker for diversity analysis
of L. theobromae isolates.