Activity of IAA oxidase, catalase and amylase in morphactin-induced malformations of mango inflorescences.
Pal R. N., Kalra S. K., Tandon D. K., Chadha K. L.
Author Affiliation: Central Mango Research Station, Lucknow 226 006, India.
Scientia Horticulturae 19 : 271-277
Abstract : Healthy (H), naturally malformed (N) and morphactin-induced malformed (M) Dashehari, Mallika, Benazir and Taimuria mango inflorescences were studied. Morphactin [chlorflurecol] (500 mg l-1) treatment markedly reduced the growth and fresh weight of the panicles. IAA oxidase activity was significantly different in the 3 types of panicle, and ranged from 6.5 mu moles IAA/g tissue per h in Taimuria to 39.4 in Benazir for H, while it was from 25.5 in Taimuria to 51.0 in Mallika for N. However, for M it was more than double that for H. Catalase activity was the lowest for M, followed by N and then H. Amylase activity did not exhibit any definite trend. IAA oxidase had a significant negative correlation with catalase and growth parameters. Because of the increase in the activity of IAA oxidase by morphactin treatment and the observed high activity of the enzyme in naturally malformed panicles it is suggested that malformation may be due to decreased levels of auxins or to hormonal imbalance.