Monthly Archives: August 2018

Altitudinal distribution and quantitative vegetation analysis of the monocotyledonous flora in Mt. Pangasugan, Leyte, Philippines


Author(s): Pamela M. Po-Abit and Norma O. Aguilar

Abstract

The attitudinal distribution of monocotyledonous species in Mt. Pangasugan, Leyte, Philippines was described. Quantitative vegetation analysis to evaluate attitudinal effect was also done from the four sites established in the western side of the mountain.
Hierarchical cluster analysis showed that the families Araceae, Gramineae, Orchidaceae, Palmae, and Zingiberaceae can adapt to wide environmental conditions since these groups were observed in all sites. Cyperaceae preferred the open, welt-lighted and cooler summit. Widely distributed species were Alocasia heterophylia, Alocasia zebrine, and Homalomena philippinensis (Araceae), Schizostachyum diffusum (Gramineae), Languas haenkei, Languas illustris and Globba marantina (Zingiberaceae), Scleria scrobiculata (Cyperaceae), and Heterospathe philippinensis (Palmae). Discriminant analysis revealed that the families Pandanaceae and Apostasineae, Palmae and Araceae, Liliaceae to Orchidaceae and Zingiberaceae were related based on their distribution and frequency in the different sites.

Keywords : Quantitative analysis, discriminant analysis, altitude

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Biology of yam mealybug, Planococcus pacificus Cox (Hemiptera: Pseudococcidae)


Author(s): Erlinda A. Vasquez and MeIecio A. Buyser

Abstract

The mealybug, Planococcus pacificus Cox, is one of the most important insect pests attacking stored yam in the Philippines. This paper reports the results of our study on the life history of the insect on greater yam (Dioscorea alata var Kinampay). The insect underwent four development stages for the male and three for the female. The total developmental period (egg to adult) lasted 28-30 (28.79) days for the male and 28-30 (33.70) days for the female. The female laid 7-132 eggs/mass for its entire life span. A male to female ratio of 1:4.43 was recorded. Adult male lived shorter (1-4 days) than the female (4-11) days.

Keywords : Yam mealybug, Planococcus pacificus Cox, life history study

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Effect of some edaphic factors on microbial decomposition of leaf fibre biomass of Toona ciliata Roxb. and Trema orientalis Bl.


Author(s): Sunanda Chanda, Kakali Ghosh, Priyanka Majumbar and Swapan K. Bhaduri1

Abstract

Leaf fiber residue generated as a by-product during the bulk production of leaf protein from forest tree leaves poses disposal problems in the absence of any proper utilisation. The fiber residue can be returned to the forest floor for mineralization as a soil amendment. A short term in vitro study was conducted to determine the microbial population and activity as well as the rate of decomposition of the mixture of leaf fiber residues from two perennial plants viz. Toona ciliata Roxb. and Trema orientalis Bl. in the forest soil in relation to moisture, temperature and pH. The most favourable condition for microbial association and fiber decomposition was found to be 25% moisture content at 35°C and 6.5 pH for microbial association and fiber decomposition. Effects of temperature, moisture and pH on the species composition of fungal flora associated with decomposition were also investigated. Aspergillus, Mucor, Rhizopus, Trichoderma, Penicillium, Cladosporium, etc. were the most common genera isolated from decaying fibrous residues, which ultimately governed the decomposition of leaf fiber in the soil. Some species of Aspergillus such as A. flavus, A. fumigatus, A. nidulans, A. terreus, and some species of Penicillium, Sporotrichum and Thichoderma were found 10 survive at 50°C.

Keywords : Toona caliata, Trema orientalis, leaf fiber biomass, litter. chemical composition, microbial decomposition, edaphic factors, fungal flora

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Biochemistry of postharvest spoilage of sweetpotato (Ipomoea batatas L.)1. Changes in starch, total sugar, praline and ascorbic acid content


Author(s): R.C. Ray and Swayam Prava Pati

Abstract

Java black rot and soft rot are two important postharvest diseases of sweetpotato caused by Botryodiplodia theobromae Pat. and Rhizopus oryzae Went & Prins. Geerl., respectively. There was a gradual decline in starch and ascorbic acid contents in sweetpotato roots following harvest and this decline was further aggravated by infection by these putative fungi B. theobromae and R. oryzae. However, the total sugar and proline contents did not exhibit much variation between fungi-infected and uninfected tubers.

Keywords : Botryodiplodia theobromae, Ipomoea batatas L. java black rot, Rhizopus oryzae, soft rot, spoilage, sweetpotato

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Cell-free synthesis of tachyplesin, an antimicrobial peptide from tachypleus tridentatus


Author(s): Edgardo E. Tulin, Anabella B. Tulin, and Shin-ichiro Ejiri

Abstract

Tachyplesin is an antimicrobial peptide isolated from the he es of horseshoe crab (Tachypleus tridentatus). Due to the importance of producing highly active peptides that have great commercial application, we attempted to produce this protein using a continuously coupled transcription-translation in a wheat germ extract system. The system works by using a continuous flow of feeding solution containing nucleoside triphosphates and amino acids into a 1-ml reactor containing wheat germ extract, plasmid DNA, and transcription enzyme, and continuous removal of translation product through an ultrafiltration membrane fitted in the reactor. The amount of protein synthesized reached to about 80 mg after 27 h of continuous reaction. Autoradiogram of the translated product showed a distinct band at about 8.44 kDa corresponding to the calculated molecular weight of tachyplesin. Continuously coupled transcription-translation in a cell-free system offers many possible applications to create new products in biotechnology

Keywords : mil-free protein synthesis, coupled transcription-translation, Tachyplesin, Tachypleus tridentatus, antimicrobial peptide

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Effective production of recombinant esterase in Bacillus brevis using a pH-controlled fed-batch culture


Author: Edgardo E. Tulin

Abstract

An automated two-component substrate (polypepton plus glucose) feeding strategy with a pH-stat modal fed-batch culture using a high pH limit was developed to effectively produce esterase from a protein-hyperproducing Bacillus brevis HPD31 harboring the plasmid pHSC131 which carries the Bacillus stearothermophilus esterase gene. Highest activity of the secreted esterase (34 U/ml) was obtained when the concentrations of polypepton and glucose in the nutrient feed solution were 250 g/l and 41.60 g/l, respectively. The absence and excessive amount of glucose in the nutrient feed solution were ineffective for extracellular esterase production because without glucose cell growth was minimal while excessive amount of glucose flavored cell growth at the expense of esterase production. The feed rate, automatically controlled by a direct signal of pH change, at 0.30 ml/pulse was found optimum for extracellular esterase secretion. The activity of the secreted esterase was increased more than eight times from 4 U/ml in the conventional batch culture to 34 U/ml obtained in this studs. The esterase productivity was likewise increased more than three-fold.

Keywords : automated substrate feeding, Bacillus brevis, pH-slat modal fed-hatch culture, esterase

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Promotive factors for callus initiation and plant regeneration in upland rice


Author: Marilyn M. Belarmino

Abstract

Factors promotive to the initiation of embryogenic callus and regeneration of plants in upland rice were investigated using mature dehulled seeds. The objectives are to enhance the production of embryrogenic callus and increase regeneration of plants. In upland rice, light incubation as well as 30 sorbitol and 50 mg/L tryptophan were promotive for the formation of embryogenic callus and green shoot buds when added in the rice callus initiation (RCI) medium during the initial culture stage. Likewise, the Combinations of 0.5 mg/L NAA and 0.5 mg/L BAP or, 0.5 mg/L IAA and 0.5 mg/L BAP supplement in the rice plant regeneration (RPR) medium enhanced the production of green shoot buds and plants from callus that were precultured in RCI medium containing 1.0 mg/L abscisic acid. The upland rice regenerants exhibited phenotypic variation from their parental counterparts in the field.

Keywords : callus initiation, culture medium, plant regeneration, promotive factors, upland rice

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Effectiveness of cassava plastic storage technology and marketability of plastic-packed cassava roots


Author(s): Emma S. Data1, Editha G. Cagasan2 and Joselito B. Layola3

Abstract

This study was conducted to verify the effectiveness of plastic packaging and fungicide treatment in prolonging the shelf life of fresh cassava roots for marketing, determine the acceptability of the plastic-picked cassava among urban consumers, and determine the profitability of marketing plastic-packed cassava.
Results further showed that there is potential market for the plastic-packed cassava. Of the 1.911 packs delivered to the different market outlets, .769 packs (93%) were sold.
In the follow-up survey, it was found that the plastic-packed cassava was generally acceptable among the urban consumer-respondents. All of the 380 respondents revealed that they would like to continue buying the plastic-picked cassava. Among the reasons cited were: the roots remained fresh even if they were stocked for several days (36.8%): the roots tasted sweet and juicy when cooked (32.6%): and the price (P15.00/pack at 2 kg/pack) was just enough (18.7%).
Marketing plastic-packed cassava directly to consumers gave the highest return on investment (ROI) of 189%.

Keywords : plastic-packed cassava, shelf life, marketing

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Effect of temperature and water activity on quality deterioration and shelf life of dried mangoes


Author(s): Lemuel M. Diamante1, Ken-ichi Ishibashi2 and Kazunori Hironaka2

Abstract

A study was conducted on the effect of storage temperature and sample water activity on ascorbic acid degradation, browning development and shelf life of dried mangoes. The moisture content of dried mangoes increased with water activity at all temperatures which is consistent with the theory of physical adsorption. However, at a water activity of about 0.65. the amount of sorbed water at a given water activity increased with increasing temperature. The ascorbic acid (AA) degradation in stored dried mangoes can be described by a first order reaction. The effect of water activity and temperature on the rate constant for AA degradation can be modeled by a modified exponential equation. The activation energy for AA degradation in dried mangoes was almost constant at 65000 J/mole for water activity range of 0.65 to 0.85. The browning development in stored dried mangoes can be described by a zero order reaction. The effect of water activity and temperature on the rate constant for browning development can be modeled by a modified exponential equation. The activation energy for browning development in dried mangoes was almost constant at 57000 J/mole for water activity range of 0.65 to 0.85. The basis for shelf life prediction in dried mangoes was ascorbic acid degradation since acid degradation since this gave shorter shelf lives as compared with browning development. The shelf lives of dried mangoes decreased with increasing storage temperatures and sample water activity.

Keywords : intermediate moisture foods (IMF), dried mangoes, temperature, water activity, ascorbic acid, browning, rate constant, activation energy, shelf life

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Cultural management manipulation for baby corn (Zea mays Linn.) production. I. Effects of variety and organic manure growth and yield of baby corn


Author: Reynaldo R. Javier

Abstract

The percentage organic matter and total N and Olsen P in the soil were significantly increased with 120-180 kg N ha-1 organic matter manure application.
The application of organic manure at increasing rates (611P180 kg N ha-1) shortened the days to tassel, silk, and harvest of baby corn; increased the leaf area index (LAI), crop growth rate (CGR), net assimilation rate (NAR) and herbage yield: and improved the yield components which markedly increased the baby corn yield. The highest marketable and total yield of baby corn were attained by Pioneer 3014 at 180 kg N ha-1 and by VM2 and Davaonon at 120 kg N ha-1 of organic manure application.

Keywords : baby corn, organic manure, hybrid corn, open pollinated corn

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