Universiti Putra Malaysia
Download Latest Complete Journal - JTAS Vol. 37 (2) May. 2014
Foreword by the Chief Executive Editor
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Abstract (Viewed: 6) Flower senescence is the terminal phase of developmental processes that leads to the end of its life span. Since a number of developing countries are attracted to this global fresh flower trade for commercial purpose, this phenomenon is major obstacle for all the floricultural industries. Therefore, research related to postharvest changes was carried out to mitigate this problem. The post-harvest events in floricultural crops reflecting petal senescence are being reviewed in this paper, whereby various physiological and biochemical studies having data regarding lipid peroxidation, loss of membrane integrity and protein degradation central to petal senescence are included. Ultrastructural changes involving change in various cell organelles viz. rupturing of vacuole, tonoplast membrane invagination, chloroplast degradation in mesophyll cells, as well as change in mitochondria ultrastructure have also been recited. This review also pays attention to the issues related to carbohydrate metabolism and change in anthocyanin pigmentation during postharvest life. Various enzymatic activities, supporting petal senescence and current status of post-harvest technology applied to cut flowers to enhance their vase life especially by using preservatives in the form of energy source like sucrose and other sugars, biocides, mineral ions, growth regulators or various metabolic inhibitors, providing practice solution to global cut flower market, are cited. Cut flowers, postharvest, ultrastructural changes, senescence, biochemical changes, growth regulators
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Abstract (Viewed: 5) The digestive enzyme activities of the pancreas and small intestinal contents were examined in two strains of chickens which differ in growth rates from 1 day to 4 months of age. The total body weight (BW) of Commercial Broiler Chicken (CBC) showed marked increase (P<.05) during the experiment, in contrast to Malaysian village chicken (MVC) which only increased slowly over the same period. The pancreas weight of MVC (g/100g BW) was greater (P<.05) than CBC throughout the experiment except for 1 day of age. The pancreatic enzyme activity (unit/g and unit/100g BW) was significantly higher (P<.05) in the CBC, particularly at 10 days old. However, there was no difference between the strains at 20 to 56 days of age for amylase and 120 days for chymotrypsin. The enzyme activity (unit/g) for all intestinal segments increased with age in both strains. In particular, CBC attained a maximal value at 10 days of age for jejunal and ileal trypsin, as well as for duodenal, jejunal and ileal chymotrypsin. Meanwhile, the enzyme activities (unit/100g BW) decreased with age for both the strains. In specific, CBC had a relatively greater enzyme activities (P<.05) at day 1, except for the jejunal trypsin and the chymotrypsin. Thereafter, the relative activities were higher for MVC until the end of the experiment. Although significant differences in the digestive enzyme activities were obtained between the two strains, these differences were generally associated with the differences in body weight. The selection affected the development rate of the synthesis of these enzymes according to the body requirements and biological function and this might affect the digestion and finally the growth rate.Enzyme activity, pancreas, intestinal contents, amylase, trypsin, chymotrypsin
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Abstract (Viewed: 4) This report describes the mucosal immune response in the gastro-intestinal and respiratory tracts of buffalo calves following oral exposure to live wild-type Pasteurella multocida B:2. Nine buffalo calves of approximately 8 months old were treated with intramuscular injections of dexamethasone for 3 consecutive days before they were divided into 3 groups. Calves of group 1 were exposed orally to 50 ml inoculums containing 109 colony forming units (CFU)/ml of live wild-type P. multocida B:2. Calves of group 2 were exposed intra-trachea with 5ml of the same inocula while calves of group 3 were given 50ml of PBS orally. At the end of day 7 post-exposure, all surviving calves were killed and organs of gastro-intestinal and respiratory tracts were processed for histology examination. The presence of lymphoid nodules, the size of the nodules and the number of lymphocytes were noted. Both oral and intra-trachea exposures elicited mucosal responses in both gastro-intestinal and respiratory tracts. Oral exposure stimulated significantly (p<0.05) superior mucosal response in the gastrointestinal tract, while intratracheal exposure stimulated significantly (p<0.05) superior mucosal response in the respiratory tract. Overall, oral exposure was able to stimulate the distance mucosal sites such as the respiratory tract and provides potential use for oral administration of live vaccine against haemorrhagic septicaemia. Mucosal immunity, oral administration, gastro-intestinal tract, respiratory tract, Pasteurella multocida B:2, buffalo calves
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Abstract (Viewed: 61) Acidity is released in high amounts when pyrite-bearing sediments in the coastal plains of Malaysia are drained for development, either agriculture or otherwise. The soils formed from these materials are called acid sulphate soils, which are characterized by low pH and high exchangeable Al that adversely affect plant growth. A study was conducted with the objective of increasing rice yields on these soils under rain-fed condition in Merbok, Kedah, Malaysia, using various lime sources. The acid sulphate soil was treated with ground magnesium limestone (GML), hydrated lime and liquid lime at specified rates. Paddy variety MR 219 was tested in a field experiment as this variety is the most common variety grown in Malaysia. Prior to treatments, the pH of water sample in the rice field was 3.7, while Al concentration was 878 µM. Thus, rice plants grown under these conditions would suffer from H+ and Al3+ stress without amelioration, thus retard and/or minimize rice growth and yield. In the first season (1st season) rice plants were affected by drought during the vegetative period, while in the subsequent season (2nd season), they were infested with rice blast fungus (Magnaporthe grisea). In spite of that, however, the rice yield was 3.5 t ha-1 based on the application of 4 t GML ha-1, which was almost equivalent to the average national yield of 3.8 t ha-1. As a result, it was noted that the ameliorative effects of lime application in the 1st season had continued to the 2nd season. Liming at 4 t GML ha-1 incurs high cost to the farmers. However, the yield obtained is worth the effort and cost. Acid sulphate soil, aluminium, ground magnesium limestone, pyrite, rice, rice blast
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Abstract (Viewed: 5) Mimosa pudica is the most abundant and problematic invasive species in tropical pastures. This study investigates the effects of two cattle grazing systems, long-term moderate grazing (LTG, 2.7 animal unit/ha/yr for 33 years) and short-term heavy grazing (STG, 5 animal unit/ha/yr for 2 years) compared with ungrazed exclosure pasture on the invasion of M. pudica and its relationship with herbage production in tropical pasture. M. pudica and pasture production were concurrently sampled four times at the end of grass growing period at both grazed and ungrazed pastures. Mean density of M. pudica was 56% greater (P<0.05) in the LTG pasture than that in the ungrazed exclosure although it did not vary (P>0.05) between the STG pasture and ungrazed exclosure. Mean importance value (IV) of M. pudica in the LTG pasture was 46% lower (P<0.05) than that in the ungrazed exclosure, and this was 220% greater (P<0.05) in the STG pasture than that in the ungrazed exclosure. Pasture herbage production was unrelated (P>0.05) to the density, IV and dry matter (DM) of M. pudica in either pasture system. An insignificant negative relationship was found between the density and DM of M. pudica with pasture production. In contrast, a positive but insignificant relationship was observed between %IV of M. pudica and pasture production in both pasture sites. The LTG system had adverse effect on M. pudica population, whereas STG system supplied relatively desirable conditions for M. pudica establishment and infestation. heavy grazing, invasive species, Malaysia, Mimosa pudica, moderate grazing, pasture production
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Abstract (Viewed: 3) The stored carbon in the thallus of three seaweed species (Enteromorpha intestinalis, Ulva lactuca and Catenella repens) was estimated in three different seasons (pre-monsoon, monsoon and post-monsoon) from four sampling localities in the deltaic ecosystem of Indian Sundarbans (21040/ N to 22040/N and 88003/E to 89007/E). The average stored carbon content varied from 1022.18 g m-2 (during monsoon) to 1067.02 g m-2 (during pre-monsoon) in Enteromorpha intestinalis. In Ulva lactuca, the stored carbon ranged from 46.41 g m-2 (during post-monsoon) to 152.43 g m-2 (during pre-monsoon). In case of Catenella repens, the range of stored carbon is 13.70 g m-2 (during monsoon) to 51.44 g m-2 (during pre-monsoon). Amongst the seaweed species undertaken in the study, E. intestinalis showed uniformity in biomass between sectors (pcal = 1.62 < pcrit = 18.51) and seasons (pcal = 2.43 < pcrit = 4.14), which implies tolerance of the species to variable salinity. Highest values of stored carbon were recorded in E. intestinalis, which might indicate its role as potential candidate species in the blue carbon series of Indian Sundarbans deltaic complex. Seaweeds, Standing stock, Carbon content, Indian Sundarbans
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Abstract (Viewed: 11) The objective of this research was to study the effects of mixed viral infection and growth stage on chilli (Capsicum annuum L.) production. This study was carried out in a split plot design with plant stage as the main plot and viral infection as the sub-plot. Plant stage as the main plot consisted of four levels, i.e 15 days, after transplanting (DAT), 40 DAT, 65 DAT, and 90 DAT, whereas viral infection as sub-plot consisted of 5 innoculation of viruses, i.e., no viral infection (control), cucumber mosaic virus (CMV) + tobacco mosaic virus (TMV), cucumber mosaic virus (CMV) + potato virus Y (PYV), CMV+PYV and CMV+PYV+TMV. Each treatment was replicated five times. The inoculations were conducted mechanically by rubbing single young leaves which had been dusted with carborandum 400 mesh, with inoculum of respective viruses. Parameters observed in this research were plant height, biomass, and chillies production (number of fruits and the weight of total fruits yield) for each plant. Results of the study showed that that growth stage and viruses significantly affect the plant height and yield components of chilli. Mixed viral infection among CMV, PYV and TMV caused a significant reduction in the chilli biomass and production. Although viral infection increased the plant height, the infected chilli seemed unhealthy. There existed interaction effects of mixed viral infection and growth stages on the chilli biomass. All viral infection and growth stages reduced significantly the biomass of the chilli, with the lowest found at the mixed viral infection of TMV+PYV (18.5%) and the highest was at CMV+TMV (44%). Double mixed infection of CMV+TMV and CMV+PYV caused 52 and 49% reduction of both the total number of fruits and total weight of fruits/plant respectively being the highest reduction compared to other treatments. Chilli production, tobacco mosaic virus, potato virus Y, cucumber mosaic virus, growth stage
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Abstract (Viewed: 4) Spodoptera exigua (Lepidoptera: Noctuidea) is a polyphagous pest that attacks many important agricultural crops. Identifying an insect specimen is a crucial step in entomology. This study demonstrated a molecular method to identify the species of pest and its parasitoid in the case of a lack of a morphological identification key. To facilitate the identification of these pest-parasitoid species, a DNA barcoding approach was used for accurate and time-consuming identification based on nucleotide sequencing analysis of the mitochondrial Cytochrome Oxidase subunit I (COI) gene. DNA barcoding sequences successfully identified both pest and parasitoid species by comparing barcode sequences to the GenBank database. This study provided evidence of Pediobius sp. as a parasitoid of S. exigua in Malaysia. DNA barcoding, COI gene, Spodoptera exigua, Pediobius sp., fern

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