Abstract:

Cisaberoptus kenyae Keifer, the mango leaf coating mite is a widely distributed eriophyid species in the tropics, infesting all varieties of mango trees. The mite produces a white colored leaf coating on the adaxial surface of mango leaves, which extends to the entire leaf lamina in severely infested leaves. The present paper discusses the feeding impact of the mite on the photosynthetic pigments, and other biochemical parameters of mango leaves. Biochemical studies enabled to record a significant decrease in the chlorophyll and carotenoid pigments in mite infested mango leaves when compared to the uninfested leaves. The percentage loss in chlorophyll a, chlorophyll b, total chlorophyll and carotenoids was observed to be 65.80-84.64, 76.57-95.29, 68.69-87.13 and 39.31-56.75 respectively. Analysis of photosynthetic efficiency by measuring chlorophyll fluorescence (Fv/Fm) using the Handy PEA Hansatech Instrument pt. Ltd, UK revealed a decreased value, falling in the range of 25.15-28.43%. Mite infestation induced a significant loss in total carbohydrate also (57.86-80.58%) when estimated through Anthrone’s method. Contrary to the above, a significant increase was observed in the proline and total phenol concentrations in mite infested leaves. An increase from 2.9578±0.36 to 5.2611± 0.61 µg/g was observed in the concentration of proline in mite infested leaf tissue. Total phenol content showed an increase from 55.14± 1.72 to 81.16± 0.85 mg/g in mite infested leaves. Results showed a statistical significance (p<0.05), confirming that infestation by C. kenyae induced severe stress, leading to enhanced production of defense compounds like proline and total phenol, thereby adversely affecting the photosynthetic efficiency and primary metabolite production of the host, M. indica.

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