Abstract
Potato dextrose and malt extract agar were found to be suitable for culturing different isolates of Pyricularia oryzae. Colonies of P. oryzae appeared as white on oat meal, rice polish and malt extract agar, grey on potato dextrose agar and whitish grey on rice agar. Spore induction was hastened on maize stem pieces than on rice and Panicum repens. Spore density on maize was 3420/ml of water as against 500/ml on P. repens. When spores of 11 isolates of P. oryzae were compared, conidia of the isolate from Pennisetum purpureum were significantly bigger than the other isolates. The spores of rice isolates from Erode and Gopichettipalayam were significantly smaller in length and width.Fingerprinting of 11 isolates of P. oryzae by retrotransposon - microsatellite amplified polymorphism (REMAP) showed a high level of variability and polymorphism among them. Phylogenetic analysis using REMAP markers grouped out one rice isolate from others. Two isolates of Tirunelveli region were grouped together like Erode and Gopichettipalayam isolates. Isolates causing leaf and neck blast showed 52.9% similarity. Isolates from Coimbatore and Gudalore were 32.7% similar; likewise two non-rice host isolates were grouped together with 27.6% similarity. Key words: Variability, culture media, rice blast, Pyricularia oryzae, retrotransposon, microsatellite.
Highlights
Rice (Oryza sativa L.) is the staple food crop supplying nearly 23% of the per capita energy for six billion people worldwide and fast becoming the model plant for monocot species in molecular biology and genomics studies (Jo et al, 2007)
Colonies of P. oryzae appeared as white on oat meal, rice polish and malt extract agar, grey on potato dextrose agar and whitish grey on rice agar
The growth of P. oryzae was rapid on potato dextrose agar (PDA) followed by malt extract agar (Table 2 and Figure 1)
Summary
Rice (Oryza sativa L.) is the staple food crop supplying nearly 23% of the per capita energy for six billion people worldwide and fast becoming the model plant for monocot species in molecular biology and genomics studies (Jo et al, 2007). Each year P. oryzae was reported to destroy rice enough to feed an estimated 60 million people and 50% of production could be lost in rice field moderately affected by blast (Barman and Chattoo, 2005). Different species of Magnaporthe grisea cause blast disease on a wide range of gramineous plant hosts. Magnaporthe oryzea (T.T. Herbert) Yaegashi & Udagawa (anamorph = Pyricularia oryzae (Cooke) Sacc.) causes disease on more than 50 graminaceous species including important food crops such as rice
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
