chakravarthy, a kSUBHASH BEEMASHEPPA, KANDAKOOR2017-07-052017-07-052014-06-10TH-10765http://krishikosh.egranth.ac.in/handle/1/5810024293Climate change may lead to expansion or intensification of damage to cucurbit groups by melon fruit fly. Global warming may also impact management practices which are currently being practiced against melon fruit fly in cultivated ecosystems. Therefore, biological studies under elevated temperature and CO2 levels were carried out in the laboratory. As the temperature increased beyond 240C the mortality of melon fruit fly increased from 19.07 % at 240C to 100 % at 360C. Melon fruit fly exhibited almost normal growth and development at 240C. Levels of elevated carbon dioxide (380 and 570 ppm) did not elicit varied response to melon fruit fly growth and development. In a given cucurbit vegetables and varieties, levels of phenols, tannins, sugars and proteins significantly influenced in rendering the resistance or susceptible. Phenols and tannins assist the cucurbit fruits in defending against the attack of melon fruit fly while sugars and proteins make it vulnerable for the cucurbits to fruit fly damage. Estimates on activity of antioxidant enzymes viz., POD, SOD, PAL and CAT revealed that high activity in chow chow and bottle gourd did not support the growth and development of melon fruit fly. For instance, in chow chow, the peroxidase activity increased two folds from healthy (6.14 μmoles min-1mg protein) to affected fruits (11.33 μmoles min-1mg protein) and exhibited increased peroxidase activity of 252% more activity compared to snake gourd with only 84.13% increase. The SOD showed increased activity of 39.16% from healthy to apparently healthy fruits compared to only 10.52% increase in snake gourd which is highly susceptible. Similarly, increased PAL activity of 389% more in apparently healthy fruits compared with healthy fruits and only 17.61% increase was observed in snake gourd. In contrary to the above enzymes, the maximum decrease in catalase activity was observed in chow chow i.e. 56.62% compared to snake gourd which showed increased activity of 7.75%. Molecular diversity of melon fruit fly populations are genetically heterogenous across different climatic zones of Karnataka. This indicted that, further studies involving ITS markers are essential for detecting differences among genetically different populations. Such studies are essential as they provide crucial information for developing management practices in different agroclimatic zones.ennullThesis