Studies were conducted for the in vitro culture of pili nut. Different explant sources, such as petiole, leaf, mature cotyledon, immature cotyledon and embryo axis were used. Horizontally placed petioles produced vigorous callus growth in half and full strength WPM with combinations of 2, 4-D and Kinetin. The highest callus fresh weight was obtained in the medium with 1 mg/1 2, 4-D, or 1 mg/1 2, 4-D plus 1 mg/1 Kinetin. Embryogenesis or shoot inductions were not successful from the petiole callus. Leaf and cotyledon explants produced limited callus using the same medium and growth regulator treatments, and immature embryo axes produced no callus. Shoot tips harvested from in vitro seedlings showed shoot and new leaf growth in WPM with a combination of BA and Kinetin, at 1 or 2 mg/1, but no root induction occurred when NAA and lAA were used. Shoot tips and nodal cuttings harvested from greenhouse grown seedlings were difficult to disinfect and did not perform well in in vitro culture.
In this study, isozyme phenotypes (fingerprinting) of seven Canarium species were also developed using six enzyme systems (LAP, MDH, PGI, PGM, TPI and UGPP) utilizing a histidine - citric acid (pH 6.5) buffer system. Fifty-two plant samples of different Canarium species (twenty-two C. ovatum, five C. album, four C. megalanthum, six C. harveyi, eight C. mehenbethene, two C. odontophyllum, three C. indicum and two unknown) and one Dacroydes rostrata plant were surveyed. Ninety-seven different phenotypes of the six enzyme systems were obtained. All six enzymes showed high polymorphism. Phenotypic polymorphism (Pj) ranged from 0.93 (MDH) to 0.75 (TPI). The average Pj was 0.86 and the weighted polymorphism (Pw) was 0.84 among the accessions tested. All seven species were polymorphic, the Pj ranged from 0.53 for C. ovatum to 0.18 for C. mehenbethene. The pattern from cluster analysis agreed with most of the accession identities. Accessions of the same species formed a distinct cluster from other species. Some unique banding in different species have been tentatively identified and could be useful for the classification of the Canarium species
