Anizan Isahak

Formulation of Trichoderma sp. SL2 inoculants using different carriers for soil treatment in rice seedling growth

BackgroundTrichoderma sp. SL2 has been previously reported to enhance rice germination, vigour, growth and physiological characteristics. The use of Potato Dextrose Agar as carrier of Trichoderma sp. SL2 inoculant is not practical for field application due to its short shelf life and high cost. This study focuses on the use of corn and sugarcane bagasse as potential carriers for Trichoderma sp. SL2 inoculants.FindingsA completely randomized design was applied for this study. Trichoderma sp. SL2 suspension mixed with corn and sugarcane bagasse were used as treatment mixture in soil. Growth parameters including rice seedling height, root length, wet weight, leaf number and biomass were measured and compared to control. The results showed that Trichoderma sp. SL2 mixed with corn significantly enhanced rice seedlings root length, wet weight and biomass compared to Trichoderma sp. SL2 mixed with sugarcane bagasse and control.ConclusionCorn can be a potential carrier for Trichoderma spp. inoculants for field application.

Enhancement of antioxidant enzymes activities in rice callus by ascorbic acid under salinity stress

Ascorbic acid (AsA) is naturally occurring compound with antioxidant activity and plays a pivotal role in plant cell adaptation to salinity stress. The objective of this work was to assess the influence of exogenous AsA on the embryogenic callus of indica rice (Oryza sativa L.) cv. MRQ74 cultivated under saline conditions. NaCl (200 mM) decreased callus fresh and dry masses, relative growth rate, and K+ and Ca+2 content, and increased Na+ content and Na+/K+ ratio. Application of AsA (0.5 or 1 mM) alleviated these effects of salinity. Activities of peroxidase, catalase, superoxide dismutase, as well as content of proline increased due to the NaCl treatment, and these parameters were mostly further increased by 0.5 mM AsA. Thus, AsA can increase callus tolerance to NaCl stress.

Relationships observed between Trichoderma inoculation and characteristics of rice grown under System of Rice Intensification (SRI) vs. conventional methods of cultivation

The System of Rice Intensification (SRI), a management-based approach for improving rice production, has demonstrated various positive effects on rice plants’ growth, resilience and yield. These effects have been attributed in part to symbiotic interactions between rice plants and the microbes that live around, on and inside them; but research on this is still very limited. To examine such relationships, a multifunctional symbiotic fungus Trichoderma asperellum SL2 was evaluated to assess its effects, if any, on the germination and growth of young seedlings and then the subsequent performance of rice plants during their crop cycle. Greenhouse studies were conducted under gnotobiotic conditions to assess any effects associated with inoculating rice seeds with Trichoderma asperellum SL2 compared with uninoculated controls in terms of seedling establishment, an essential part of SRI methodology; and then assessing the capacity of this fungus to enhance the growth, physiological characteristics, nutrient uptake, and yield of rice plants growing under simulated SRI conditions. Results showed that the presence of Trichoderma asperellum SL2 in association with SRI cultural practices led to significant increases in rice seedling growth, germination rate, vigour index, and chlorophyll content, and elicited more favourable phenotypical responses from given genotype potential. The research observations further illustrated that for some parameters, there were no significant differences between inoculated and uninoculated SRI plants, both giving results superior to those for conventionally-grown plants even when inoculated. This indicated that SRI growing conditions are more favorable for Trichoderma to contribute towards the growth, physiological traits, nutrient uptake, and yield of plants, whereas conventional management methods diminish or inhibit these effects. Focused research remains to be done to establish how aerobic microbes such as Trichoderma can affect and accelerate the performance of rice plants being grown in SRI environments above and below ground.

Impact of gamma rays exposure and growth regulators on Oryza sativa L. c.v MR269 callus induction

The study is aimed to evaluate in vitro somatic embryogenesis to gamma ray exposure and the use of growth regulators to mature embryos explants for rice callus induction. Seeds of local rice genotype (MR269) were exposed to gamma rays at 350 Gy (Source: Caesium-137). Matured embryos were cultured to induce callus on Murashige and Skoog (MS) supplemented at different concentrations of 1.0, 2.0, 3.0 mg/L 2.4-D and 0.1 and 0.2 mg/L Kinetin for 4 weeks. Callus induction and callus fresh weight were decreased after exposure to gamma ray. The most efficient response to callus induction and callus fresh weight was found at 3 mg/L 2,4-D and 0.1 mg/L kinetin.

A simple, efficient, and farmer-friendly Trichoderma-based biofertilizer evaluated with the SRI Rice Management System

Trichoderma spp. are highly interactive fungi that live in soil, root, and foliar environments. In addition to assisting plants to resist various diseases and drought stress, Trichoderma has been reported to have positive effects on the growth of many crops. While Trichoderma inoculants have been developed for use with numerous crops, explorations of the use of Trichoderma inoculants in rice farming systems are still in a nascent stage. In this study, a field experiment using a randomized complete block design was conducted to determine the ability of Trichoderma-based biofertilizer (TBF) to enhance the growth, physiological traits, and yield of rice under System of Rice Intensification (SRI) management. The results showed significant potential for TBF to increase a rice crop’s growth, physiological traits, and productivity. Trichoderma-inoculated rice plants exhibited significantly greater plant height, photosynthetic rate, chlorophyll a and b content, stomatal conductance, and tiller and panicle numbers. The grain yield of Trichoderma-inoculated rice plants was 30% more than that from the uninoculated SRI control plots, which simply due to changes in management practices produced paddy yields that were twice the current average in Malaysia. A simple, efficient, and farmer-friendly method for producing TBF, developed for SRI farmers’ use to get these results, is reported here.

Delineating risk zones and evaluation of shelter centres for flood disaster management along the Pahang River Basin, Malaysia

Shelter centres are important locations to safeguard people from helpless situations and are an integral part of disaster risk reduction (DRR), particularly for flood DRR. The establishment of shelter centres, and their design based on scientific assessment, is crucial. Yet, they are very much related to the geographic location, socio-economic conditions and the livelihoods of the affected communities. However, many parts of the developing world are still lagging behind in ensuring such scientific design. Considering the flood disaster in 2014 that affected the residents living along the Pahang River Basin, in this study we delineate the communities at risk and evaluate the existing shelter centres to determine how they reduce people’s vulnerability to the risks associated with rural and urban landscapes. We used spatial analysis tools to delineate risk zones and to evaluate existing evacuation systems. A flood disaster risk map was produced to determine which communities are living with risks. Subsequently, the distribution of shelter centres examined whether they are able to support people living at the flood risk zones. These centres were also evaluated using a set of international guidelines for effective disaster shelters. This reveals that the number of shelter centres is not adequate. The designation and designing of shelter centres are not being done scientifically. The maps produced here have a lot of potential to support disaster management decisions, in particular site selection and the prioritisation of centres. The study concludes with a set of guidelines and recommendations for structural and non-structural measures, such as alternative livelihoods and the potential of ecotourism, which may improve the resilience among flood-affected communities; and the decision-making process for the overall flood DRR initiatives.

Increasing rice plant growth by Trichoderma sp.

Trichoderma sp. is a plant growth promoting fungi in many crops. Initial observation on the ability to enhance rice germination and vigor have been reported. In this study, the effectiveness of a local isolate Trichoderma asprellum SL2 to enhance rice seedling growth was assessed experimentally under greenhouse condition using a completely randomized design. Results showed that inoculation of rice plants with Trichoderma asprellum SL2 significantly increase rice plants height, root length, wet weight, leaf number and biomass compared to untreated rice plants (control). The result of this study can serve as a reference for further work on the application of beneficial microorganisms to enhance rice production.

Impact of exogenous ascorbic acid on biochemical activities of rice callus treated with salt stress

The application of in vitro systems can lead to new methods of crop amelioration. This method has been widely utilized for breeding tenacities, particularly for stress tolerance selection. Salinity causes oxidative stress in callus by enhancing the production of Reactive Oxygen Species (ROS), resulting in an efficient antioxidant system. The exogenous application of ascorbic acid (AsA) is an important requirement for tolerance. The present study aimed to examine in vitro selection strategy for callus induction in rice mature embryo culture on MS culture medium and to produce salt-tolerant callus under sodium chloride (NaCl) and AsA conditions in callus rice variety, MR269. This study also highlights changes in the activities of proline and antioxidants peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) of callus under NaCl stress to understand their possible role in salt tolerance. However, various levels of exogenously applied AsA under saline conditions improved callus, and the antioxidant ...