A Study on Elimination of Contamination in Field-derived Explants and Flower Morphology of Dabai (Canarium odontophyllum Miq.)

• Main Author: Chai, Kwan Lin
• Format: Final Year Project Report
• Language: English
• Published: Universiti Malaysia Sarawak (UNIMAS) 2007
• Subjects: S Agriculture (General); SB Plant culture
• Online Access: http://ir.unimas.my/id/eprint/28765/1/Chai%20Kwan%20Lin%20ft.pdf; http://ir.unimas.my/id/eprint/28765/

Dabai (Canarium odonlophyllum Miq.) is an indigenous fruit tree of Sarawak. Dabai tree has two sex forms, male and hermaphrodite. Seed-derived planting materials will not be true-to-type as it is difficult to distinguish sex of Dabai seedlings. In addition, conventional propagation of Dabai is extremely difficult. This study has included three areas namely, development of an effective protocol for establishing axenic culture of explants obtained from field-grown plant, forcing of epicormic shoots to aid axenic explant acquisition and Dabai flower morphology study. A protocol for control of in vitro contamination of explants from field-grown hermaphrodite Dabai trees for use in micropropagation of this species has been developed. This has included manipulation of pre-sampling treatment, surface sterilisation methods and culture medium. New buds growth was observed two weeks after pruning of main branches of Dabai tree. Before wrapping with polyethylene bags, new shoots were treated with 70% ethanol, followed by 0.1 % benomyl solution by spraying. An insecticide, Le. CMCTermitoff (50% v/v) was applied at the basal part of main branches. Shoots were harvested after one week. Shoots were agitated respectively in 0.3% benomyl solution for 1 hour, 70% ethanol for 30 seconds and 25% Clorox added with Tween 20 for 15 minutes. After surface sterilisation, explants were cultured in solid MS basal medium supplemented with 2 ml ]"1 Plant Preservative Mixture (PPMlM) and 0.3% activated charcoal. This treatment has resulted about 30% contamination-free explants as compared to 0% from the control. Forcing of epicormic shoots was aimed at improving cleanliness of Dabai shoots prior to surface sterilisation in the laboratory to achieve higher percentage of axenic explant acquisition. However, no positive result was recorded from forcing of epicormic shoots. Flower morphology study has confirmed Dabai has two sex forms, male and hermaphrodite.