Endogenous hormones and phenols in rootstock seedlings of mango cultivars and their relationship with seedling vigour

摘要

Studies on morpho-physiological characters, contents of total phenols and endogenous hormones in the seedlings of seven polyembryonic mango cultivars, 'Muvandan', 'Vellaikolamban', 'Chandrakiran', 'Kurukan', 'Bappakai', 'Mylepelian' and 'Olour' andmonoembryonic cultivar, 'Alphonso' raised under pot culture conditions monitored at 30, 60 and 120 days of growth from transplanting revealed that the seedling vigour of polyembryonic cvs 'Muvandan' and 'Bappakai' and of the monoembryonic cv. 'Alphonso'was high. The cv. 'Vellaikolamban' was least vigorous. The leaf area at 60 days of seedling growth was low in less vigorous cvs 'Kurukan' and 'Vellaikolamban' and high in 'Muvandan'. The leaf water potential was less negative in less vigorous cvs 'Vellaikolamban', 'Kurukan' and 'Chandrakiran'. The total phenol and ABA in the leaves were high in less vigour cvs 'Vellaikolamban' and 'Kurukan' at all seedling growth stages. The leaves of vigorous cvs 'Bappakai1 and 'Muvandan' had high cytokinins, tzeatin riboside and dihydrozeatin zeatin riboside levels at 30, 60 and 120 days and IAA level at 30 and 60 days. Plant height and stem girth were negatively correlated with leaf total phenol and ABA contents. Plant height was positively correlated with leaf water potential and cytokinins (t-zeatin riboside and dihydrozeatin zeatin riboside) content. Thus a higher level of growth inhibitor, ABA and phenols concurrently with lower levels of growth promoters imparted growth restriction of seedlings. It is suggested that the selection of size controlling rootstocks at nursery stage can be made by assessing the leaf water potential, total phenols and/or ABA.