Mycofloral Diversity and Molecular Characterization of Species Isolated from Farmer-Saved Rice Seeds in the Irrigated Rice Production Districts of the Coastal Savannah Zones of Ghana

Abstract

Irrigated rice production is the major type of rice production in the Coastal Savannah Zone of Ghana, where farmers rely on their saved seeds for production. A study was carried out to determine the types of storage fungi resident on farmer saved seeds and their distribution in five major rice production areas of the Coastal Savannah Zone. The blotter method was used to isolate fungal species after which they were identified using cultural and morphological features complemented by sequence analysis of the entire Internal Transcribed Spacer (18S-ITS1-5.8S-ITS2) region of isolates. Eleven fungal species namely, Alternaria alternata, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Colletotrichum gloeosporioides, Curvularia lunata, Curvularia geniculata, Fusarium equiseti, Lasiodiplodia theobromae, Rhizopus oryzae and Trichoderma sp. belonging to 8 different genera were isolated and identified on the rice seeds. Curvularia lunata, with a percentage occurrence of 63.9% was the most prevalent fungal species, while Trichoderma sp. (1.3%) was the least prevalent fungal species from the study area. The high infection rate of seeds by Curvularia species may lead to high incidence and severity of Curvularia leaf spot disease in the study area.