Paclobutrazol affects the extension growth and the levels of endogenous IAA of almond seedlings

Abstract

The effect of paclobutrazol on plant height and the concentration of free indole-3-acetic acid (IAA) in almond seedlings grown in 0.5 L pots with moist perlite and subjected to 15 "C and photoperiod of 16 hours was studied.In the first two experiments the paclobutrazol was applied as a drench at 0, 0.5, 1.5 and 5 mg/pot. Seven and sixteen days respectively after application a gradual decrease in the growth rate and concentration of free IAA in the tops of the growing shoots of almond seedlings on which paclobutrazol was applied, was observed. Furthermore, a gradual increase in the concentration of free IAA in the four younger leaves at the time of application was also detected.In the third experiment the effect of paclobutrazol(5 mg/pot) on plant height and the concentration of free IAA measured over 10 day period was studied. From the 4th day following application differences in the height of seedlings and in the concentration of free IAA in the growing tops between the control and treated seedlings were observed.Abbreviations: IAA = Indoleacetic acid; GA3 = Gibberellic acid; CCC = 2 Chloroethanephosphonic acid; B-995 = N-dimethyl aminosuccinamic acid

Regulating Growth of Betula alnoides Buch. Ham. ex D. Don Seedlings with Combined Application of Paclobutrazol and Gibberellin

“…PBZ application resulted in a significant decrease in seedling height of Betula alnoides in the present study, which was in agreement with Williams As shown in a study on 30-day-old almond seedlings, the inhibitory effect of PBZ application on height growth appeared since the fourth day after PBZ treatment [21]. While in the present study, height of B. alnoides seedlings were inhibited quite obviously since a month after treatment (Figure 1).…”

Response of Growth Inhibitor Paclobutrazol in Fruit Crops

“…Paclobutrazol treatments have also shown to increase Delicious fruit firmness at harvest, [3]. Paclobutrazol, a gibberellins inhibitor, has been effectively used in reducing canopy volume and increasing flower intensity in peach [4], plum [5], almond [6], grapes [7] and mango [8]. Paclobutrazol is effective not only in flower induction but also in early and off season flower induction in mango [9,10].…”

Comparative analysis of transcrptome profiling to identify genes involved in bulged surface of pear fruits (Pyrus bretschneideri Rehd. cv. Yuluxiangli)

“…It was previously reported that the developed vascular bundles were densely distributed at the calyx end of the bulged surface of pear fruits. However, these vascular bundles were developed slowly and distributed loosely at the calyx end of fruits in PBZ treated group [4,5]. And phloem cells appeared to become much smaller and tighter treated by PBZ than that of CK group [6].…”

“…Plant growth retardants, negatively regulate plant growth and development by inhibiting hormones and help in partitioning of assimilates effectively [4][5][6]. Spraying growth retardants, such as paclobutrazol (PBZ), a member of the triazole family, at full bloom stage could significantly relieve bulged surface of pear fruits and improve its appearance [3].…”