Abstract

                                The blast disease caused by the fungus Piricularia Oryzae is the most serious disease of the rice crop, but is prevalent only on certain strains of paddy while others are immune to it. Hence the effective control of the disease at present is only through the use of resistant strains. Among the Madras strains, Co, (Coimbatore 4) is highly resistant even under worst conditions while the variety Adt, (Aduthurai 10) is highly susceptiable to the disease. The latter strain is however a high yielder and hence very popular in the Tanjore Delta. In modern times with the advancement of science many of the characters such as resistance and other factors which are indissoluble Mendelian factors of inheritance, located in the genes of chromosomes have been explained through enzymology in terms of certain set chemical reactions resulting in definite chemical compounds. Hence this inheritance of resistance to blast, located in specific strains were aimed to be studied in terms of possible chemical constituents in the strains which bestowed on the strains the disease resistance.

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