Star fruit trees propagation by cuttings and anatomical and histological characterization of the formation of adventitious roots

Author(s)

Débora Costa Bastos

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2006-02-03

Examining board members

João Alexio Scarpare Filho; Antonio Baldo Geraldo Martins; Moacir Pasqual; Rafael Pio; José Darlan Ramos

• Advisor: João Alexio Scarpare Filho

Abstract

The star fruit seedling production is one of the limiting factors to the commercial expansion of this culture, due to the time that they take to be formed and begin the production. The aim of this paper is to study the most adapted processes to increase the efficiency of stem propagation for star fruit using different types of cuttings, etiolating techniques and wound in the base combined to the use of growth regulators (IBA), and also to study the anatomical and histological structure of the different types of cuttings with related to the formation of adventitious roots. The work was accomplished with the installation and conduction of 3 (three) experiments. In the first two experiments (I and II) techniques were tested in order to improve the propagation by cuttings of the star fruit. Cuttings of the variety Malaysia were used and standardized with a pair of whole leaves, with 12 (twelve) cm of length and 3 (three) gems. The statistical design used was entirely randomized in arrangement to factorial 3 x 4, where the studied factors were the techniques applied in the cuttings (etiolating, wound in the base and control) and different concentrations of IBA (0, 3000, 6000 and 9000 mg L-1) for hardwood cuttings (experiment I) and (0, 2000, 4000 and 6000 mg L-1) for herbaceous cuttings (experiment II). The cuttings were maintained in chamber of intermittent mist and after 75 days, the percentages of root formation, survival, formation of calluses and number of roots per cuttings were evaluated. It is concluded for both experiments, that the etiolating techniques and wound in the base of the cuttings were harmful to the formation of adventitious roots and the application of IBA did not show significant difference for root formation of both types of cuttings studied. The third experiment carried out anatomical and histological studies that involve the process of formation of roots in the cuttings. Herbaceous, softwood and hardwood cuttings treated in fast immersion at 0 and 3000 mg L-1 of indolbutyric acid (IBA) were maintained in mist chamber under controlled conditions for up to 70 days. Periodically the cuttings were cut, fastened, dehydrated and prepared for the serial histological cuts and analysis through optical microscopy. As conclusion, it was verified that the herbaceous, softwood and hardwood cuttings of star fruit present different anatomical and histological structures and the endogenous formation of roots primordium in herbaceous cuttings occurred from the cambium. (AU)