Variability in Rhizoctonia solani f sp sasakii causing Banded Leaf and Sheath Blight in Maize and its Integrated Management

Abstract

newlineThe crop of maize (Zea mays L.) has multipurpose uses and it is considered to very important crop after wheat and rice. Maize belong to the family poaceae and has adaptability to varied agro- climates. It is widely distributed throughout out the world in tropical and subtropical climate. Banded Leaf and Sheath Blight in Maize caused by Rhizoctonia solani f .sp. sasakii is maize pathogen in most of the regions where followed rice maize cropping systems frequently occurs as foliar disease that reduce crop yield significantly. Present investigation entitled Variability in Rhizoctonia solani f. sp. sasakii causing Banded Leaf and Sheath Blight in Maize and its Integrated Management was an attempt to explore disease severity, to assess variability (morphological, pathological, compatibility and molecular), to exploit source of resistance and to manage disease efficiently. Pathogenic variability was also studied that Isolate UDP Rs-1 denoted as most virulent isolate among all and Isolate SIR Rs-06 denoted as most avirulent isolate. Out of the total 102 genotypes in screening experiment, 1 maize genotypes showed (HR) highly resistant reaction, 34 genotypes were (R) resistant, 36 genotypes were (MR) moderately resistant, 22 genotypes were found (MS) moderately susceptible, 8 genotypes were (S) susceptible and 1 genotypes were (HS) highly susceptible against the disease. BLSB causes up to 40-45% yield loss in grain yield under artificial inoculations in both kharif 2020 and 2021 seasons. newlineThe high levels of DNA polymorphism observed with OPD-07 primer showed newline91.6 per cent polymorphism. A total of 140 RAPD scored bands from different primers in which total 116 RAPD Polymorphic scored bands resulted from 12 primers and were available for analysis. Maximum similarity value of 0.666 (66.6%) was observed between isolate R-6 and R-10. Isolate R-6 and R-8 was found to be genetically diverse with minimum similarity value of 0.012 (1.2%). newline newlineSeven fungicides namely Azoxystrobin + tabuconazole, Mancozeb