Physiological status of shoot in mango (Mangifera indica L.) bearing healthy and malformed floral buds.
Pandey D., Pandey S. N.
Author Affiliation: Division of Fruits and Horticultural Technology, Indian Agricultural Research Institute, New Delhi 110 012, India.
Indian Journal of Horticulture 64 : 131-135
Abstract : Physiological parameters were studied in shoots of mango cv. Amrapali (grown in New Delhi, India, during 1995 and 1996) in October (at the time of flower bud differentiation) and in February (at the time of flower bud burst). Two types of shoots, i.e. shoot having simple bud (solitary apical) and shoot having multiple buds (apical and axillary buds with several protuberances at their base), were selected. Different physiological parameters, i.e. macro- and micro-nutrients, plant hormones, enzymes, total phenols, protein content, total organic C and C/N ratio were estimated in bud, stem and leaf of different types of shoots. At the time of flower bud differentiation, the maximum quantities of IAA, gibberellic acid (GA3), P, Ca and Cu were found in bud, total organic C, C/N ratio, total phenols, K, Na, abscisic acid (ABA) and activities of polyphenol oxidase [catechol oxidase] and IAA oxidase in stem and total proteins, N, Mg, Fe, Mn and Zn in leaves. The shoot bearing multiple buds contained higher levels of IAA, total phenols, C/N ratio and higher IAA oxidase activity. Lower levels of GA3, ABA, polyphenol oxidase, total protein, N, P, Ca, Mg, Fe, Mn, Cu and Zn were found than in stem of shoot bearing simple bud. The levels of total organic C and K were found equal in the stems of both types of shoots. The leaf of shoot bearing multiple buds had higher levels of ABA, IAA oxidase, total phenols, C/N ratio and total organic C and lower levels of IAA, GA3, polyphenol oxidase activity, total proteins, N, P, K, Ca, Mg, Fe, Mn, Cu and Zn than the leaf of shoot bearing simple bud but the level of Na was the same in the leaf of both types of shoots. Multiple buds, which later terminated into malformed panicles, contained higher levels of ABA, IAA oxidase activity, total phenols, total proteins, N, K and Mg and lesser contents of IAA, GA3, C/N ratio, P, Ca, Fe, Mn, Cu, Zn, Na and polyphenol oxidase activity compared to simple bud.