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SEX IDENTIFICATION

Sex Identification in Canarium odontophyllum Miq. (dabai) using DNA Markers

Dabai (Canarium odontophyllum Miq.) is locally known in Sarawak as Sibu olives. It is an important indigenous fruit species that has immediate potential for commercial exploitation. It has been domesticated in Sarawak and cultivated extensively in Sibu, Kapit, Sarikei and Limbang. Dabai is dieocious with male and female flowers borne on different trees. The male trees are usually chopped down for economic purposes in order to save space and labour cost. It is desirable that only female individuals are cultivated in the field to increase the fruit production and profitability. Unfortunately for dabai growers, there is no way to determine a dabai’s sex from the external morphology of embryogenic form. Seed is still the most practical and economical propagation method of raising the crop due to the difficulties in propagating the tree using vegetative methods such as cuttings and grafting. The sex of the seedlings is known only after the trees attain reproductive maturity, i.e. after 4 years. Thus, the objective of the project is to determine the sex of dabai trees using molecular DNA marker technologies by developing the sex-specific DNA makers specific to male and female dabai trees. With the development of these markers, it is anticipated that the early sex identification of dabai seedlings using molecular marker approach prior to the flowering stage would avoid the need for removing undesired sex type, i.e. the male trees from the field, thus saving labour, time and other resources.