Qualitative Resistance of Sarawak Rice Landraces Against Pyricularia oryzae

Malaysia rice production is threatened by rice blast disease, caused by Pyricularia oryzae. Yield can be greatly reduced by this disease as it can attack all the aerial parts of rice including leaves, node, neck, and collar. The use of resistant cultivar, which can be produced from resistance breeding, can control the disease effectively. Sarawak, in Malaysian Borneo, has diverse rice landraces, which can be genetic resources for resistance breeding. Study on the resistance of Sarawak rice landraces against P. oryzae, is still limited. In this study, diseased leaf samples were collected from rice fields in Serian division, Sarawak. One isolate was successfully obtained and designated as B2PG. The morphological characteristics were documented. Six Sarawak rice landraces were challenged with isolate B2PG. Four of the rice landraces were resistant and might carry resistance gene(s), which can be utilised in future breeding program

Optimal Aeration Management Strategy for A Small-Scale Food Waste Composting

Food waste is a significant contributor to greenhouse gas emissions when it ends up in landfills. Composting is a sustainable solution to this problem, but it requires controlled and continuous airflow for optimal performance. The objective of this study is to investigate the effect of aeration rates and airflow directions on food waste composting using a closed system with forced aeration. Air was entered into the composting vessel in three directions, which were upward, downward, and a combination of both directions. Each direction was run at aeration rates of 0.1, 0.4, and 0.7 L/min. The findings show that the compost pile aerated at 0.4 L/min by using two-directional airflow can reach the thermophilic temperature within half of the day. The compost pile achieved temperature of 40.94°C after 10.5 hours. Although the compost experienced slightly high in moisture loss (4.3%), the compost still attained the standard values for maturity. The compost produced from food waste could be applied in soil to improve its fertility

Value added productivity performance of the peninsular Malaysian wood sawmilling industry

Value added manufacturing activity in the wood sawmilling industry of Peninsular Malaysia is important for employment opportunities, particularly for low income citizens living in this rural area, to provide returns to the local economy while being environmentally sustainable. This paper is a review on the value added wood sawmill industry in Peninsular Malaysia, using the value of major import and exports of major timbers products and forested area in Peninsular Malaysia over the period 2003 to 2012. The productivity performance measures that are based on the concept of value added are emphasized in this paper. The value added in wood sawmill industry was found to increase from year 2003 to 2012. Consequently, Malaysia is moving on the right path to achieve the goal of National Timber Policy 2020, transforming the timber industry into high value addition industry. However, further analysis using the value added productivity measure found that the value addition rely on international timber price rather than skilled workers

Isolation and characterization of Pyricularia oryzae isolated from lowland rice in Sarawak, Malaysian Borneo

Aims: Rice blast disease caused by Pyricularia oryzae is one of the major biotic diseases of rice in Sarawak, Malaysian Borneo. This study aims to isolate and characterize rice blast fungus obtained from infected leaf collected from four different divisions in Sarawak, viz, Miri, Serian, Sri Aman, and Kuching. Methodology and results: Twelve succeeded isolates were pre-identified as P. oryzae by morphological characteristics of spores, followed by verification through (internal transcribed spacer) ITS sequencing. The isolates were evaluated for morphological characteristics, growth rate and sporulation rate, which were grown on two types of media, (filtered oatmeal agar) FOMA and (potato dextrose agar) PDA. Morphological characterization showed that the colony surface of the different isolates varied from smooth and fluffy to rough and flattened mycelia; some were with the present of concentric rings, and some with aerial mycelia. The growth rate and sporulation rate of each isolate varied based on types of media used. Most of the isolates grew faster on PDA than on FOMA but produced higher number of spores on FOMA as compared to PDA. Conclusion, significance and impact of study: This preliminary study showed that there were variations observed based on morphological and physiological characterization for the different isolates collected in Sarawak, Malaysian Borneo. This study is the first step towards understanding variation in the population of P. oryzae from Sarawak

Morphological and Physiological Development of Pyricularia oryzae Isolates from North-western Region of Sarawak on Different Media under Laboratory Conditions Laboratory Conditions

Rice blast (causal agent: Pyricularia oryzae) is an important disease of rice in Sarawak. Understanding the pathogen’s morphological characteristics, genetic diversity and pathogenicity is important. Having a suitable medium for culturing and maintaining P. oryzae is important to ensure the availability of inoculum or materials under laboratory conditions. Oatmeal agar (OMA) and potato dextrose agar (PDA) are common media used for growing P. oryzae. OMA allows better mycelial growth and better sporulation as compared to PDA. There are also other alternatives such as fresh rice leaf agar and rice straw agar. Although OMA seems to be the best medium, unfortunately the opaqueness of the medium causes difficulty in observing the morphology and growth of mycelia. In addition, it is known that different isolates of P. oryzae will respond differently to different media. This study aims to identify the best media for culturing and maintaining P. oryzae isolates from Sarawak. A total of 14 P. oryzae isolates were characterised for their morphological characteristics, growth rate and sporulation rate using seven growing media. These 14 isolates included seven newly identified isolates in this study and seven isolates from a previous study, which were verified using internal transcribed spacer DNA sequence. The colony surface of the 14 P. oryzae isolates varied on different growing media. The pigmentation of colony surface varied from different shades of grey, translucent light brown, white and colourless. Pyricularia oryzae isolates grew better on OMA and PDA, while OMA was the best for sporulation. These two media can be recommended for culturing and maintaining different P. oryzae isolates under laboratory conditions

A Preliminary Analysis of Combined Liver Resection With New Chemotherapy for Synchronous and Metachronous Colorectal Liver Metastasis

ObjectiveTo compare the survival between patients with synchronous and metachronous colorectal liver metastases after hepatectomy with new generation of perioperative chemotherapy.MethodsFrom October 2002 to January 2008, patients receiving hepatectomy for synchronous or metachronous colorectal liver metastasis were studied retrospectively.ResultsFifty-five patients (synchronous group = 35, metachronous group = 20) underwent hepatectomy for colorectal liver metastases. Besides younger age with male predominance, patients in the synchronous group had more tumour multinodularity and bilobe liver involvement. They had received less hepatic curative hepatectomy (81.1% vs. 100%) with a higher rate of peri-operative chemotherapy (91.4% vs. 50%) and postoperative morbidity (25.7% vs. 0%). However both groups had no statistical significant difference in median overall survival (OS) and disease free survival (DFS). Inferior OS and DFS were observed in the synchronous group for patients who had no peri-operative chemotherapy or those showing poor response to chemotherapy. The most favourable OS is observed in both groups after performing globally curative hepatectomy.ConclusionSynchronous colorectal liver metastasis is not a poor prognostic factor for survival when compared with the metachronous metastasis. Globally curative hepatectomy in combination of new generation of chemotherapy is recommended for the management of resectable colorectal liver metastasis

New variants of AvrPiz-t identified in Pyricularia oryzae from Malaysia

Rice blast disease (causal agent: Pyricularia oryzae) is an important rice disease worldwide as it can cause significant yield loss. Resistance genes in rice can recognise the corresponding avirulence genes (Avr-gene) of P. oryzae and suppress the attack of the pathogen as proposed in ‘gene-for-gene’ interaction. This interaction is highly specific. The resistance will be rapidly breakdown owing to the plasticity of Avr-gene. The breaking down of disease resistance can cause problem in managing the disease as well as sustaining a resistant rice variety. This paper aimed to study and analyse the sequence variation of AvrPiz-t gene from P. oryzae isolates in Malaysia (Sarawak) together with AvrPiz-t sequences available from National Centre for Biotechnology Information (NCBI). This study compared the AvrPiz-t haplotype found with previously reported haplotypes. A total of 20 Malaysian P. oryzae isolates were obtained from six divisions of Sarawak and were verified using internal transcribed spacer. Together with seven Malaysian P. oryzae isolates from a previous study, a total of 27 AvrPiz-t gene sequences from Malaysian isolates were successfully amplified and verified. The AvrPiz-t open reading frame (ORF) of 27 Malaysian isolates were aligned with 123 AvrPiz-t ORF from other countries that were available in NCBI database and 100 AvrPiz-t ORF from a previous study (Total = 250 sequences). Unique sequences were identified and translated into amino sequence. The amino acid sequences were aligned with haplotype sequences from previous studies. In total, there were 19 AvrPiz-t haplotypes, with eight newly identified haplotypes. The AvrPiz-t haplotypes were distributed across 14 countries with haplotype H9 as the dominant haplotype. Neutrality tests were performed for the 250 AvrPiz-t ORF sequences. The 250 isolates of P. oryzae were undergoing directional natural selection.. Detached leaf inoculation using filter paper method of selected Malaysia (Sarawak) P. oryzae isolates carrying one of the new AvrPiz-t haplotypes showed different level of pathogenicity towards Sarawak rice landraces. The data obtained serves as baseline information for disease management in Malaysia, especially for Sarawak state. Additionally, the information is also a reference for future rice breeding program in Sarawak

Albumin-bilirubin grade predicts the outcomes of liver resection versus radiofrequency ablation for very early/early stage of hepatocellular carcinoma

Background and purposeWhether liver resection or ablation should be the first-line treatment for very early/early hepatocellular carcinoma (HCC) in patients who are candidates for both remains controversial. The aim of this study was to determine if the newly-developed Albumin-Bilirubin (ALBI) grade might help in treatment selections and to evaluate the survival of patients treated with liver resection and radiofrequency ablation (RFA).MethodsPatients with BCLC stage 0/A HCC who were treated with curative liver resection and RFA from 2003 to 2013 were included. Baseline clinical and laboratory parameters were retrieved and reviewed from the hospital database. Liver function and its impact on survival was assessed by the ALBI score. Overall and disease-free survivals were compared between the two groups.Results488 patients underwent liver resection (n = 318) and RFA (n = 170) for BCLC stage 0/A HCC during the study period. Liver resection offered superior survival to RFA in patients with BCLC stage 0/A HCC in the whole cohort. After propensity score matching, liver resection offered superior overall survival and disease-free survival to RFA in patients with ALBI grade 1 (P = 0.0002 and P ConclusionsLiver resection offered superior survival to RFA in patients with BCLC stage 0/A HCC. The ALBI grade could identify those patients with worse liver function who did not gain any survival advantage from curative liver resection