Water stress and rootstocks influences on hormonal status of budded grapevine

Summary Four grape cultivars namely 'Flame Seedless', 'Thompson Seedless', 'Sharad Seedless' and 'Tas-A-Ganesh' (mutant of 'Thompson Seedless') were given different levels of moisture stress to study their physiological responses. The marginal reduction in photosynthesis and greater reduction in transpiration rate in 'Flame Seedless' have resulted in higher water use efficiency (WUE) in this variety under moisture stress. Testing of five rootstocks Dogridge, Salt Creek, 1613 C, St. George and Vitis chamipnii (VC) clone for drought tolerance revealed better performance of Dogridge under moisture stress conditions in terms of increased root to shoot length ratio, root to shoot dry weight ratio, increased accumulation of abscissic acid (ABA) and reduced cytokinin concentration. Budding three cultivars 'Flame Seedless', 'Thompson Seedless' and 'Sharad Seedless' on different rootstocks viz., Dogridge, Salt Creek and VC clone and subjecting to moisture stress resulted in better performance of 'Flame Seedless' and 'Sharad Seedless' budded on Dogridge in terms of increased WUE and ABA content under 50% moisture stress. Own rooted 'Sharad Seedless' recorded least WUE under 50% moisture stress, but when it was budded on Dogridge and subjected to moisture stress it recorded higher WUE suggesting the role of some rootstocks in manipulating the physiological changes in few scion cultivars grafted on them.