SURVEY ON WHEAT BLAST AND MORPHOLOGICAL CHARACTERIZATION AND IN-VITRO MANAGEMENT OF MAGNAPORTHE ORYZAE TRITICUM THROUGH BOTANICALS

Abstract

Wheat blast disease caused by Magnaporthe oryzae triticum (MoT) has become a serious constrain in increasing the wheat area of infection and decreasing the cultivable area of the crops. A survey was conducted in 30 villages of blast infected South-Western wheat growing region of Bangladesh during January to April, 2019. During the survey at Meherpur Sadar, Mujibnagar and Chuadanga Sadar Upazilla, the highest incidence and severity was recorded in cultivar BARI Gom-24 (Pradip) at Kutubpur, Monkhali and Parkrisnapur village and the lowest incidence and severity was found in BARI Gom-26 and BARI Gom-28 at Pirojpur, Charulia and Bollolpur village. Thirty-five MoT isolates were isolated, identified and tested their pathogenicity. Growth response and cultural characteristics of the MoT isolates were done on PDA. In the present study, the highest radial mycelial growth observed on the isolate CHMoT 09 (25.67 mm) on the 7 days, CHMoT 06 (56.33 mm), CHMoT 07 (55.83 mm), CHMoT 08 (56.33 mm) and CHMoT 09 (57.00 mm) on the 14 th days incubation and CHMoT 08 (75.50 mm) on the 30 days incubation. Based on mycelial growth per day, isolates of M. oryzae triticum were classified into three cluster groups, cluster I, cluster II, cluster III that indicates the presence of a morphologically diversified group of pathogens. Aloe vera (Allovera leaf) extracts and Nigella sativa (Black cumin seeds) extracts @ (1:1 w/v) concentration were found the most effective botanicals to reduce mycelial growth of M. oryzae triticum under in-vitro condition. However, this experiment with more plant extracts needs to be coined out to assess the field efficacy of these botanical extracts with different concentrations and frequencies in controlling blast disease of wheat. th th