ROOTING RESPONSES OF MIRACLE FRUIT (&lt;i&gt;SYNSEPALUM DULCIFICUM&lt;/i&gt;) SOFTWOOD CUTTINGS AS AFFECTED BY INDOLE BUTYRIC ACID

K K

doi:10.3844/ajabssp.2012.442.446

Abstract

Large scale productions of miracle fruit ( Synsepalum dulcificum ) faces some restrictions as the seeds are recalcitrant and propagation by cuttings is difficu lt to root. When grown from seed, miracle fruit tak es 3 to 4 years to begin fruiting. A propagation technique by cutti ngs needs to be devised to produce early fruiting p lanting materials. However there has been no report on the rooting performance of miracle fruit stem cuttings using Indole-3-Butyric Acid (IBA) and the location of roo t primordia initiation is unknown. Softwood miracle fruit cuttings were treated with five IBA concentrations (0, 200, 400, 600 and 800 mg L -1 ) and placed in a propagation area with intermittent mist. Data for percentage of rooting (%), mean root numbers per rooted cutting, mean root length per rooted cutting (cm) and root dry weight per rooted cutting (g) were collected 3 months afte r planting. Thirty softwood cuttings were propagated for histol ogical study. The basal 5 mm of three cuttings were harvested randomly weekly. The specimens were sectioned and the cross sections were viewed to locate the root pr imordia initiation. Callus formation started three weeks af ter sowing and the adventitious roots emerged from the basal end eight weeks after planting. High concentration of IBA treatment was significantly increase the roo ting percentage when compared with other treatments. Anatomy of stem 800 mg L -1 day 0 showed the phloem was surrounded by 2-3 layers of fibers. Root primordial developed from the secondary phloem and penetrated the fiber layers 5 weeks after planting. IBA concentrat ions gave little effect in roots initiation and dev elopment of miracle fruit. Root primordial was developed from t he secondary phloem and surrounded by fiber layers was could hinder its emergence. However, IBA applications promoted cell expansion and proliferations which able to break the fiber layers and allowed the root primord ial to emerge.

Highlights

Miracle fruit (Synsepalum dulcificum Daniell family: Sapotaceae) is a tropical evergreen shrub or small tree indigenous to tropical West Africa (Ayensu, 1972; Duke and DuCellier, 1993; Keay, 1992; Opeke, 1982)
Anatomy of stem 800 mg L−1 day 0 showed the phloem was surrounded by 2-3 layers of fibers
Indole-3-Butyric Acid (IBA) was proven effective in promoting rooting in woody plant species (Kesari et al, 2009) there has been no report on the rooting performance of Synsepalum dulcificum stem cuttings using IBA

Summary

Introduction

Miracle fruit (Synsepalum dulcificum Daniell family: Sapotaceae) is a tropical evergreen shrub or small tree indigenous to tropical West Africa (Ayensu, 1972; Duke and DuCellier, 1993; Keay, 1992; Opeke, 1982). Miracle fruit tree produces small ellipsoid berries (2- could possibly help diabetic people in eating sweet food 3 cm long) throughout the year (Fig. 1A). When grown from seed, Synsepalum dulcificum took 3 to 4 years to reach maturity and begin to bear fruit whereas plants grown from stem cuttings started to bear fruit earlier (Joyner, 2006). Auxins are well known phytohormone in promoting adventitious root from stem cuttings of tree species (Kesari et al, 2009). IBA was proven effective in promoting rooting in woody plant species (Kesari et al, 2009) there has been no report on the rooting performance of Synsepalum dulcificum stem cuttings using IBA. The objectives of this study are: to investigate the optimum IBA concentrations in promoting rooting of miracle fruit cuttings and to identify the location of root primordia initiation

Objectives

Methods

Results

Discussion

Conclusion