Bains, GurdeepVinai Kumar2019-04-232019-04-232018-08http://krishikosh.egranth.ac.in/handle/1/5810100889Mango malformation is one of the most threatening malady of mango (Mangifera indica L.). Present investigation was carried out at Experimental Mango Garden Department of Plant Physiology and Horticulture Research Center (HRC), GBPUA&T, Pantnagar, to study the effect of salicylic {0 mM (SA0), 0.5 mM (SA0.5), 1.5 mM (SA1.5), 2.5 mM (SA2.5), 5.0 mM (SA5.0), 10 mM (SA10)} acid and glycerol {0 mM (G0), 25 mM (G25), 50 mM (G50), 100 mM (G100), 200 mM (G200) and 500 mM (G500)}on physiology of malformation in four cultivars of mango cv. Amrapali, Dashehari, Langra and Chausa. The experiment was conducted in pot and field conditions in three year old and twenty five year old grafted mango plants during years 2014-15, 2015-16 and 2016-17 respectively. The design of the experiment was factorial completely randomized design (CRD) and factorial randomized block design (RBD) respectively. The effect of salicylic acid and glycerol treatment was evaluated with respect to morphological characters and physio-biochemical characters. The ten isolates of Fusarium mangiferae were isolated from malformed floral tissues and characterized on the basis of purple orange colour on patato dextrose agar (PDA) media and conidia production on carnation leaf agar (CLA). The mycelial growth and conidial germination of Fusarium mangiferae were tested on Spezieller-Nährstoffarmer Agar (SNA) media. It was observed that salicylic acid and glycerol treatment significantly reduced occurrence of floral malformation as compared to control. However, fruit yield increased up-to certain levels after that it decreased with respect to control. Salicylic acid treatment significantly increased proline content, phenolic content, SOD activity in dose dependent manner whereas relative water content was decreased. SA1.5 concentration was found best for most morphological and physio-biochemical characters. Lower doses of glycerol caused increase in chlorophyll florescence, chlorophyll content whereas higher doses of glycerol increased proline content, malondialdehyde content, phenolic content and relative water content decreased gradually with increasing concentrations. Glycerol, 100 mM concentration was found best for morphological and physio-biochemical characters. Salicylic acid decreased mycelial growth and conidial germination whereas glycerol decreased mycelial growth and promoted conidial germination of Fusarium mangiferae at acidic pH. Overall findings of the present investigation suggested that Fusarium mangiferae is not solely responsible for mango malformation. Exogenously applied salicylic acid and glycerol might reduce floral malformation either by inhibiting the infection and colonization of Fusarium mangiferae in host tissue or by strengthening plant defense mechanism.ennullThesis