Biochemical Changes Induced by Varying Irrigation Levels During Annual Growth Cycle in Fantasy Seedless (Vitis vinifera L.)

Presently, a number of commercial varieties of grapes are being introduced with Fantasy Seedless as one of them. Varying irrigation levels lead to biochemical changes affecting the vine productivity. In the present study, five irrigation levels (I) based on variable rates of replenishment of pan evaporation were imposed and the biochemical constituent levels were monitored on the field-grown grapevine cultivar Fantasy Seedless raised on 110R rootstock. During vegetative season, the levels of proline, anthocyanin, reducing sugars and malondialdehyde in leaves were higher in water deficit I-3, whereas it was lower in I-1 at all the stages. This suggests the adaptive response of grapevine leaves to cope and maintain the water stress. On the other hand, the levels of protein were higher in I-1, whereas it was lower in I-3 indicating the protein degradation caused by the oxidative damage under water stress. During fruiting season also, the results showed similar trends for all parameters in leaves. During berry development stages, the changes in composition revealed the protective and adaptive mechanisms by osmolyte accumulation. The irrigation level I-2 based on the yield (17.86 t/ha) and the water use efficiency (71.93 kg/mm) was found significantly superior over I-3, I-4 and I-5 with low applied irrigation. This study provides insights into the adaptive biochemical mechanisms, and comparing these biochemical responses under varying irrigation levels has elucidated the stress tolerance mechanisms in Fantasy Seedless. © 2018, The National Academy of Sciences, India.