No abstract

Cocos Nucifera Linn. Var. MATAG is a Dwarf coconut variety that had high demand in Malaysia but low supply. Vegetative propagation of high-yielding MATAG coconut by using in vitro cloning must be considered in contributing to increase coconut productivity. Thus, attempts were made to develop a protocol that would enhance callogenesis as a first preliminary step towards a protocol for mass propagation of C. nucifera L. var. MATAG. The anther isolated from immature inflorescence was used as explants and cultured on modified Eeuwens Y3 media in different concentrations of 2,4-dicholorophenoxy acetic acid (2,4-D) and activated charcoal. The highest callus induction percentage (31.25 ± 12.18) was observed in 20 mg/L 2,4-D. However, 2,4-D at any level tested were not statistically significant. Callus induction media supplemented with 0.5 mg/L activated charcoal gave the highest callusing percentage (25.89 ± 13.59 %) indicating a positive effect of activated charcoal on callusing even though the result obtained not significant compared to control (15.95 ± 6.76 %). But, activated charcoal supplemented in media produced a significant effect compared to control in reducing the percentage of browning. In conclusion, media supplemented with activated charcoal produced a higher rate on callus induction and preventing tissue browning in explant. Besides that, the anther and ovule explant may serve as an efficient explant to study the callus induction of C. nucifera L. var. MATAG and as a basis to screen the potential useful plant growth regulators for somatic embryogenesis.

No abstract

Banana (Musa spp.) is an economically vital fruit crop in Malaysia and therefore, micropropagation was applied to meet the market demand for disease-free seedlings. However, microbial contamination is a significant obstacle in micropropagation techniques. In this research, the microorganisms that were present in the banana culture were characterized and the efficacy of antimicrobial and antifungal agents to inhibit contaminants was evaluated. Three bacterial and two fungal isolates were isolated from the contaminated culture. Klebsiella pneumoniae, Klebsiella quasipneumoniae, and Klebsiella variicola were identified by molecular identification based on the 16S rDNA sequence. The gram-staining method confirmed all three bacteria were gram-negative. Oxidase and catalase tests showed the presence of cytochrome oxidase system and catalase enzyme in all bacteria. The bacteria can also hydrolyze starch, ferment sugars, and reduce sulfur from the amylase test. Phenotypic identification of fungi revealed the presence of conidia and hyphae, indicating the presence of Colletotrichum spp. and Aspergillus spp. In fungi characterization, Colletotrichum gloeosporioides and Aspergillus flavus were detected. Chloramphenicol was identified as an effective antibacterial agent from the disc diffusion method. Fluconazole was a potent antifungal agent by screening the sterilizing agents. The findings may potentially lead the way for the implementation of reducing the contamination rate in banana micropropagation.