Rosimah Nulit

Effects of anthropogenic activities on the heavy metal levels in the clams and sediments in a tropical river

The present study aimed to assess the effects of anthropogenic activities on the heavy metal levels in the Langat River by transplantation of Corbicula javanica. In addition, potential ecological risk indexes (PERI) of heavy metals in the surface sediments of the river were also investigated. The correlation analysis revealed that eight metals (As, Co, Cr, Fe, Mn, Ni, Pb and Zn) in total soft tissue (TST) while five metals (As, Cd, Cr, Fe and Mn) in shell have positively and significantly correlation with respective metal concentration in sediment, indicating the clams is a good biomonitor of the metal levels. Based on clustering patterns, the discharge of dam impoundment, agricultural activities and urban domestic waste were identified as three major contributors of the metals in Pangsun, Semenyih and Dusun Tua, and Kajang, respectively. Various geochemical indexes for a single metal pollutant (geoaccumulation index (Igeo), enrichment factors (EF), contamination factor (Cf) and ecological risk (Er)) all agreed that Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn are not likely to cause adverse effect to the river ecosystem, but As and Pb could pose a potential ecological risk to the river ecosystem. All indexes (degree of contamination (Cd), combined pollution index (CPI) and PERI) showed that overall metal concentrations in the tropical river are still within safe limit. River metal pollution was investigated. Anthropogenic activities were contributors of the metal pollution. Geochemical indexes showed that metals are within the safe limit.

Effect of formulated bioorganic containing Burkholderia GanoEB2 in suppressing Ganoderma disease in oil palm seedlings.

Ili Nadhrah N., Nulit R., Nurrashyeda R., Idris A.S. (2015): Effect of formulated bioorganic containing Burkholderia GanoEB2 in suppressing Ganoderma disease in oil palm seedlings. Plant Protect. Sci., 51: 80–87. The ability of Burkholderia GanoEB2 formulated in two different bioorganic powders as carriers – bioorganic empty fruit bunch (BEFB) and real strong bioorganic fertilizer (RSBF), and the efficacies of Burkholderia GanoEB2 in sup pressing Ganoderma boninense infection in oil palm seedlings were determined. Results showed that the highest reduction in disease incidence (DI, 18.2%), severity of foliar symptoms (SFS, 26.6%), and disease severity foliar index (DSFI, 27.7%) was achieved by the seedlings treated with RSBF containing Burkholderia GanoEB2 compared to the seedlings treated with BEFB containing Burkholderia GanoEB2 (36.4% DI, 33.4% SFS, and 31.8% DSFI). Untreated seedlings (as control) had 100.0% DI, 90.4% SFS, and 87.5% DSFI. The disease was reduced by as much as 85.3% for seedlings treated with RSBF and by 70.5% for seedlings treated with BEFB. The formulated bioorganics containing Burkholderia GanoEB2 were proven to suppress Ganoderma disease in oil palm.

Selection, Characterizations and Somatic Embryogenesis of Malaysian Salt-tolerant Rice (Oryza sativa cv. MR219) through Callogenesis

Salt-tolerant lines of MR219 were produced through somatic embryogenesis from salt-tolerant callus of Oryza sativa L. cv.MR219 using in vitro selection procedure. Callus was developed aseptically from seeds on MS media supplemented with 2 mg/L 2, 4-D. Then, callus directly was sub-cultured on MS media with different concentrations of NaCl (0, 50, 100, 200, and 300 mM) to produce salt-tolerant callus. Based on the callus characteristics which are morphological, physiological and biochemical cascades such as proline content, total protein, total soluble sugar, lipid peroxidation, activity of ascorbate peroxidase and catalase, salt-tolerant callus was screened and selected. After 4 months, callus cultured in 50 and 100 mM NaCl showed yellow color, soft, friable and nodular proliferating. However, callus cultured in 200 and 300 mM NaCl turn blackish-brown and stiff and acutely-necrotic. The selected salt-tolerant callus was sub-cultured on MS media for somatic embryogenesis. The salt-tolerant plantlets were transferred into pots individually for acclimatization purpose. Salt stress caused significant reduction in water content, fresh and dry weight of callus. The level of total soluble sugar, proline, lipid peroxidation and ascorbate peroxidase significantly increased under salt stress. Salt-tolerant callus indicated high activity of catalase that determined more protection against production of reactive oxygen species. According to growth performance and antioxidant capacity, the plantlets from 50 and 100 mM NaCl, selected as salt-tolerant line. This study suggests the methodology to produce salt-tolerant cultivar of rice which could be a step forward to commercialization.

Formulation of Cost-effective Medium Using Urea as a Nitrogen Source for Arthrospira platensis Cultivation under Real Environment

Even though Arthrospira is a well-known superfood, it is not extensively commercialized in developing countries like Malaysia due to the high production cost with low biomass yield. Based on literature, the algal production cost can be discounted by reducing the cost of medium utilizing cheaper and readily available chemicals. Therefore, the present study was conducted to Original Research Article Sukumaran et al.; ARRB, 22(2): 1-12, 2018; Article no.ARRB.38182 2 experiment the prospect of Arthrospira platensis cultivation in newly designed medium with commercial or industrial grade fertilizers under real environment. Consequently, growth and yield of A. platensis was investigated under outdoor condition using modified Kosaric medium (MKM) which was designed by substituting the major laboratory chemicals in standard Kosaric medium (SKM) with commercial grade baking soda, sea salt, urea, phosphoric acid, potassium hydroxide and Epsom salt. Urea as an alternative nitrogen resource to sodium nitrate was pulse-fed throughout the cultivation period. The algal growth was measured through optical density, biomass dry weight and chlorophyll a content. The algal yield was determined by calculating its productivity and specific growth rate. The growth and yield of A. platensis was significantly higher (p < 0.05) in MKM in terms of optical density with 2.541 ABS, biomass dry weight with 1.30 g L, chlorophyll a content with 12.96 mg L, productivity with 0.141 g L d and specific growth rate with 0.253 μ d compared to SKM in eight days of cultivation period. The present finding showed the potential of MKM in lowering the medium cost up to 97% compared to SKM without compromising the algal yield under natural condition with proper cultivation techniques such as preadaptation and fedbatch addition of urea in the late evening.

Factors affecting shoot and root apical meristem tissue culture of Thai supersweet corn (Zea mays var. rugosa)

ABSTRACT During last recent years, in vitro propagation technic is widely used to produce plants with desirable traits. This experiment was conducted to produce an ideal protocol for in vitro propagation of Thai supersweet corn by using shoot apical meristem (SAM) and root apical meristem (RAM) as explants. Four-day-old germinating seedlings were used as the experimental materials on culture media supplemented with a range of auxin, kinetin, and carbohydrates. The primary establishment for SAM showed the highest percentage of survival (80%) while RAM showed the highest survival (67%) and in Murashige and Skoog (MS) media supplemented. Upon acclimatization, regenerated plantlets from shoot showed the highest survival rate (12%) with the production of 21 plantlets; however, the survival rate of plantlets from root was only 20% with the production of 9 plantlets. The efficient and economic protocol that is produced in this study can be applied as an alternative to conventional propagation method for the large-scale production of Thai supersweet corn throughout the year.