Ayu Nazreena Othman's research while affiliated with Malaysian Agricultural Research and Development Institute (MARDI) and other places

Cyathea latebrosa is one of the lowland tree fern species found in Peninsular Malaysia. This fern species is highly demanded in ornamental landscaping. The in vitro cultures are an important tool for propagation which may contribute toward the reduction of over-exploitation. To overcome these problems, an effective spore surface disinfection protocol is crucial to allow the germination stage to be carried out. This studied had carried out three types of methods which are the packet method (PM), centrifuged method (CM), and soak method (SM) with difference percent of concentration (0, 0.1, 0.5, 1.0, 10 & 30) Mercury Chloride (HgCl2) and Sodium hypochlorite (NaOCl). In contrast, the method and concentration of disinfection affect germination. Our results showed that the soak method in both types of disinfection is a significant difference due to statistical analysis (MANOVA) which gives a positive effect on the germination of the spore. This method is efficient for sterilizing which spore loss is kept to a minimum and has a higher rate of germination (HgCl2-90% & NaOCl-80%). The optimum concentration of HgCl2 was 0.1%, then followed by 0.5% and 1.0%, while for NaOCl was 30%, 20%, and 10%.

Carbenicillin and cefotaxime, two antibiotics routinely employed to exclude Agrobacterium tumefaciens during plant transformation, were studied for their effects on callus growth and the formation of somatic embryos. Antibiotics were tested to see how they responded to the regeneration of Malaysian indica rice cv. MR219. In a preliminary study, callus fresh weight gain appeared to be improved in media containing 200 mg/L carbenicillin and 300-400 mg/L cefotaxime but was severely hindered in media containing higher concentrations. Somatic embryos were discovered in greater numbers in the medium containing 200 mgl-1 carbenicillin or 300 mgl-1 cefotaxime, at 76 and 71, respectively. It was possible that these antibiotics showed a positive response on somatic embryos development when compared to those without antibiotics. Carbenicillin and cefotaxime concentrations greater than 300 mg/L should not be utilized for the process

The current study recognised the issues encountered in regenerating Malaysia MR219 rice plantlet via microspore culture and attempted to develop an efficient protocol in overcoming the restraints. In the present study, a high proportion of uninucleate microspores (49.17%) was isolated from Stage 2-Segment II panicle (59–61 days), which also exhibited the highest callus initiation rate of 8.50%. Maintenance of the panicles under a cool temperature of 4 °C for 7 days before isolating the microspores, resulted in the highest microspore viability of 58.33% and callus initiation rate of 9.33%. The microspore isolation protocol was also optimised in the present study. The filtration sieve engagement with a pore size of 80 µm and further suspension centrifugation at 800 rpm for 5 min produced the highest microspore viability percentage and callus initiation rate. The incorporation of 3.0 mg/L kinetin in conjunction with 0.5 mg/L 2,4-D greatly enhanced the callus initiation rate, with 11.33%. The callus proliferation capacity, with the formation of 481.67 mg callus, was significantly promoted by the addition of 1.0 mg/L kinetin and 0.5 mg/L 2,4-D into the growth medium. Moreover, a higher green plantlet regeneration frequency of 2.83% was induced by the supplementation of 8% sucrose, which produced an average of 3.50 green plantlets.

Micropropagation of orchids are often through the production of Protocorm Like Bodies (PLBs) and this research conducted a study to discover the optimal condition for the growth of Protocorm Like Bodies (PLBs) and also plantlets regeneration of Grammatophyllum speciosum Several aspects such as different carbon sources (sucrose, maltose) and the presence of charcoal alongside with the variety of concentration of agar were taken into account for the optimization. This study discovered that the 30 g/L of sucrose in 1 mg/L of BAP was superior in producing heavy PLBs. However, the trend differs in the number of plantlets where maltose (5 g/L) is seen to produce a higher number of plantlets compared to sucrose. Charcoal plays an important role in the growth of PLBs where the heaviest PLBs were recorded in the medium supplemented with 0.20 % of charcoal along with 4.5 g of agar. Vice versa relationship was recorded for the number of plantlets where without charcoal in 4.5 g of agar produce the highest number of plantlets.

Black ginger or is one useful medicinal plant that urges the need to be cultivated widely. This plant has some previous studies about their rhizomes and callus growth optimization, but their total content and antioxidant activities are not very . This study aims to study the total content and antioxidant activities of callus of K.. This study is to determine the type and concentration of hormone that give the best effect on the growth of callus in culture from different parts (, and basal part) of K.. Different concentrations were tested with medium 2,4-dichlorophenoxyacetic acid (2,4-D) and acid (NAA) in callus cultivation. The highest total content tested in callus is one with 10.00 mg/L 2,4-D from the part of the plant. The highest antioxidant activity is from the part of the plant with 5.00 mg/L 2,4-D.

Rice plant regeneration via anther culture possess several difficulties, these included early anther necrosis and high albinism frequency. In the present study, several biotic and abiotic factors were studied to develop an efficient protocol for the regeneration of Malaysian indica rice MR 219 variety. Callus initiation of anther cultures was evaluated using different N6 media supplemented with 2,4-D in combination with 1-naphthaleneacetic acid (NAA), kinetin (Kin) or 6-benzylaminopurine (BAP). The present study revealed that incorporation of 1.0 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with 3.0 mg/L of NAA significantly elevated callus induction rate with 8.45%. Callus development was further enhanced with the application of 1.0 mg/L of 2,4-D in combination with 1.0 mg/L of BAP, which resulted in 80.83% of globular callus formation rate. Formation of rooty callus (70.83%) was initiated by 0.5 mg/L of 2,4-D in conjunction with 0.5 mg/L of BAP treatment. The highest somatic embryogenesis rate (25.83%) and regeneration frequency (10.92%) was achieved under 4 °C during 7th day, together with the formation of 2.17 green rice plantlets. Nevertheless, culture browning frequency increased over time and reached the highest (100.00%) at 29th day for both 4 and 8 °C treatments. The highest number of albino plantlets was recorded at 18.17 for in vitro cultures maintained under 8 °C at 14th day. The study herein developed an efficient protocol which enhanced callus development as well as the regeneration of green indica rice plantlets while minimizing albinism.