Role of biochemical constituents and minerals against cotton leaf curl disease in cotton

Cotton LeafCurl Disease (CLCuD) is among the most devastating disease infecting the cotton plants. The plants have developed both inherent, consecutive and induced defence mechanism against the disease like pre-existing physical and chemical barriers, such as inducible defence responses that interfere with pathogen establishment. Therefore, the present study was conducted to examine the status of biochemical constituents and minerals with their imparting defensive role against CLCuD. The four cotton genotypes H 1478, H 1098i, H 1156 and H 1463 were screened for cotton leaf curl disease on the consecutive and induced defensive role basis of polyphenoloxidase, peroxidase, biochemical constituents and minerals. The genotypes were grown under field condition at Cotton Research Farm, Chaudhary Charan Singh Haryana Agricultural University, Hisar. Leaf samples of healthy and diseased cotton plants were collected and analyzed for biochemical constituents, minerals and enzymesactivities. The amount of phenol, gossypol and soluble protein were significantly higher in healthy plant as compared to diseased plant in all genotypes, whereas sugar content differed non-significantly and inconsistently among the genotypes. The polyphenoloxidase and peroxidase activities were also found significantly higher in healthy plant in all genotypes and correlate with high amount of phenolic compounds. Potassium, manganese, zinc and sulphur were significantly less in diseased plant of all genotypes. Inconsistent pattern was observed among genotypes in response to CLCuD for copper content. It differed significantly between healthy and diseased plants only inH1156 and H 1463 genotypes. The high content of potassium, manganese, sulphur and phenolic compounds in healthy plant of H 1463 genotypes leads to path for plant protection by means of their direct and indirect role against plant pathogen.