Optimizing in vitro surface sterilization of Cyathea latebrosa spore

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%

Efficient callus induction and plant regeneration of Malaysian indica rice MR219 using anther culture

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

Establishment of effective plantlets regeneration protocol via isolated microspore culture in Malaysian indica rice MR219

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