BIOTROPIA - The Southeast Asian Journal of Tropical Biology
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AGRONOMIC TRAITS OF LOCAL WETLAND RICE VARIETIES IN JAMBI PROVINCE
Get PDFIndonesia’s swamplands are among the areas earmarked for future agricultural development. As a type of wetland, swamplands are periodically inundated and have soil properties that are uniquely different from other agroecosystems. In Indonesia, some of these areas are currently used for rice cultivation, representing the country’s very diverse genetic resources of local rice varieties. Most farmers continue to plant and cultivate local swampland rice varieties because of their ability to adapt to extreme environments. This study on the agronomic traits of local swampland rice varieties was conducted to evaluate their agronomic characteristics and to identify varieties with superior quality traits. The research was carried out from April to October 2016 using a single-plot method at Rantau Kapas Mudo Village, Batanghari Regency, Jambi Province. Eleven rice varieties were planted in 10 × 5 m single plots, with a spacing of 25 × 25 cm and a distance of 1 m between plots. The eleven genetic resources of local swampland rice varieties included Serendah Halus, Rimbun Daun, Karya, Serendah Bawang, Sereh Aek, Botol, Pontianak, Semut, Dawi, Ketan Itam, and DI. The observed characters consisted of plant height at harvest, number of productive tillers, age at harvest, number of grains per panicle, number of filled grains per panicle, number of empty grains per panicle, weight of 1,000 grains, seed shape, and production volume. Differences were observed among the local swampland rice varieties. The highest production volume (3.32 tonnes ha⁻¹) was obtained from the Rimbun Daun variety, followed by 2.86 tonnes ha⁻¹ from the Dawi variety. These two varieties showed strong potential to become leading regional swampland rice varieties
REPRODUCTIVE BIOLOGY OF THE FRESHWATER CLAM POKEA (Batissa violacea var. celebensis, von Marten 1897) (Bivalvia: Corbiculidae) IN THE POHARA RIVER, SOUTHEAST SULAWESI, INDONESIA
No full textThe freshwater clam, locally known as Pokea (Batissa riolacea var. celebensis, von Martens 1897; Bivalvia: Corbulidae), is a popular and widely consumed food in Kendari, Southeast Sulawesi. Despite its popularity, basic information required for conservation management, such as reproductive biology, is lacking. Hence, this study aims to examine the reproductive biology of the clam obtained from the Pohara River, Kendari, Southeast Sulawesi Province, Indonesia. Pokea samples were collected monthly from February 2012 to January 2013. Its reproductive biology, including sex ratio, stage of gonadal maturity, gonadosomatic index (GSI), fecundity, and size at first mature gonad for each sample, was recorded. Data were analyzed using the chi-square test and linear regression in the software package SigmaPlot v.6.0. The Pokea population in the Pohara River was male-biased. The population spawns throughout the year, with the peak spawning season occurring in August–September. Mature gonads were found at small shell sizes, indicating early sexual maturity. This gonadal development in Pokea, which might have been influenced by food availability, provides very relevant baseline information for the conservation of the Pokea population in the Pohara River
ASSESSMENT OF THE QUALITY OF ARABICA COFFEE BEANS FROM THREE PROCESSING METHODS AND TWO TYPES OF PACKAGING MATERIALS
Get PDFIn Southeast Asia, Indonesia is the second highest-producing country of coffee beans after Vietnam. Consequently, Indonesia competes with other countries in producing good quality coffee beans. However, not many people have sufficient skills in tackling problems related to the postharvest handling of these coffee beans. The objective of this study was to assess the quality of Arabica coffee (Coffea arabica) beans in terms of moisture content, fungal infection (especially ochratoxin A or OTA producing fungi), OTA contamination, and the taste of the coffee during storage. The three processing methods used were dry, wet, and semi-wet methods. The beans were packed using two types of packaging materials, i.e. Kantong Semar high gas barrier and polypropylene bags (4 kg/bag). They were then stored under warehouse conditions during 4 months of storage. The moisture content of coffee beans processed using the three methods and packed using polypropylene bags was higher than that of coffee beans packed using Kantong Semar high gas barrier; however, it was still lower than the safe moisture content for coffee determined by the Indonesian National Standard (12.5%). Aspergillus niger was found in coffee processed using the three methods and packed using a Kantong Semar high gas barrier. Its population was relatively low (< 0.1 x 10 cfu/g wet basis). Aspergillus ochraceus was found in coffee processed using dry and wet methods at the beginning of storage. Its population was also relatively low (< 0.3 x 10 cfu/g w.b. OTA content was not detected in all coffee samples, because it was lower than the detection limit of the instrument used (< 1.85 ppb). At the beginning of the storage, all coffee samples were dominated by yeast with the population of 1.9 x 102 – 1.2 x 103 cfu/g w.b. The taste of coffee in various treatments during 4 months of storage was still above the total standard score for specialty grade ≥ 80. The highest total score (84) was found in coffee beans processed using a dry method and packed in Kantong Semar high gas barrier. The three processing methods and the two types of packaging materials can be used to maintain the quality of coffee beans during 4 months of storage
DETERMINING AN APPROPRIATE AGE FOR ESTIMATING SITE INDEX OF Acacia HYBRID PLANTATIONS IN SOUTHEASTERN VIETNAM
Get PDFThis article introduces the research results of a site index classification for Acacia hybrid plantations in Dong Nai Province. The objectives of this study were to (i) determine a baseline age of Acacia hybrid plantations to establish their site indices and (ii) develop site index curves for Acacia hybrid plantations. Three standard plots were established for each age group of 1-10 years with 111 trees per plot; 108 trees were measured for the estimation of growth criteria. Three trees were used for tree truncation, and truncated trees did not count for the estimation of tree growth criteria. In this study, the site index (SI) for Acacia hybrid plantations was divided into three levels according to the total height of the dominant trees. The heights collected from 108 trees were used to build the functions of the SI, and three truncated trees were used to examine the possibilities of the functions of SI. Research results showed that the appropriate baseline age of Acacia hybrid plantations at Dong Nai Province is 8 years. The site indices of hybrid plantations were divided into three site levels of I, II, and III, corresponding to heights of 24, 20 and 16 m, respectively. To improve the effectiveness of Acacia hybrid plantation businesses, owners should focus on growing plantations at site index levels of I or II
OVEREXPRESSION OF Gα GENE INCREASES GROWTH AND HYPOSALINE TOLERANCE IN Kappaphycus alvarezii TRANSGENIC PLANTLETS
Get PDFG proteins are membrane proteins that play roles in signal transduction in living organisms. They consist of α, β and γ subunits. The G protein α subunit (Gα) plays a role in plant resistance toward biotic and abiotic environmental stresses. Transgenic plantlets of Kappaphycus alvarezii carrying the Gα gene (derived from soybean) have been successfully obtained through Agrobacterium tumefaciens-mediated transformation. The present study aimed to: 1. compare the growth of non-transgenic and transgenic plantlets of K. alvarezii in vitro using Provasoli enriched seawater (PES) medium with normal salinity and hyposalinity and 2. analyze the expression level of the Gα gene in transgenic plantlets using quantitative Polymerase Chain Reaction (qPCR). The results showed that all transgenic plantlets (six clones) had significantly higher daily growth rate (DGR, % / d) than that of non-transgenic under the condition of normal salinity (30 ppt) and hyposalinity (15 and 20 ppt) for 5 weeks of observation. At 15 ppt, transgenic plantlets were more tolerant than non-transgenic ones, as most thalli of transgenic plantlets remained brown in color, whereas most thalli of non-transgenic plantlets were bleached. The results of the qPCR analysis showed that the expression of the Gα gene in transgenic plantlets increased by 6.43 - 8.03 times compared with that of non-transgenic plantlets. The result of Pearson correlation analysis showed that relative expression of Gα gene had a strong correlation, both with DGRs in normal salinity and hyposalinity of transgenic plantlets (correlation coefficient > 0.7). The correlation was linearly positive, where increased expression of the Gα gene was strongly associated with an increase in DGRs
DIVERSITY OF ENDOPHYTIC FUNGI ASSOCIATED WITH FRUITS AND LEAVES OF TAMARIND (Tamarindusindica L.) BASED O N ITS RIBOSOMAL DNA SEQUENCES
Get PDFPlant-associated microbes are among the important natural resources that abundantly exist in natural environment such as endophytic fungi. The studies on endophytic fungi in medicinal plants have allowed the discovery of numerous fungi species and their hidden potentials. Therefore, this study focused on the isolation and identification of endophytic fungi from several plant parts of tamarind such as leaves and fruits. A total of 69 fungal cultures were successfully isolated and identified into 33 distinct species from 14 genera based on morphological characteristics and internal transcribed spacer (ITS) sequence analysis using a Maximum Likelihood method. There were six different species obtained from the genus Colletotrichum (C. aenigma, C. brevisporum, C. cobbittiense, C. fructicola, C. gloeosporioides and C. siamense), and Diaporthe (D. arecae, D. ceratozamiae, D. phaseolorum, D. pseudomangiferae, D. pseudooculi and D. pseudophoenicicola), four species of Aspergillus (A. aculeatus, A. carbonarius, A. flavus and A. tubingensis), three species of Curvularia (C. aeria , C. geniculata and C. lunata) and Nigrospora (N. lacticolonia, N. oryzae and N. sphaerica), two species of Lasiodiplodia (L. pseudotheobromae and L. theobromae) and Penicillium (P. rolfsii and P. verruculosum). Other fungal species that were also identified are Botryosphaeria mamane, Fusarium solani, Perenniporia tephropora, Phyllosticta fallopiae, Sarcostroma bisetulatum, Trichoderma asperellum and Xylaria feejeensis. The isolates were grouped into different clades according to their class. In conclusion, endophytic fungi isolated from tamarind plant are diverse and provides an insight into species diversity of endophytic fungi in tamarind
GROWTH INHIBITION OF FUNGAL PLANT PATHOGENS BY ANTAGONIST BACTERIA USING DUAL CULTURE ASSAYS
Get PDFThere has been excessive use of chemical-based pesticides globally, resulting in significant environmental consequences with adverse effects on human health. Therefore, more sustainable and environmentally friendly alternative solutions are needed to counter such environmental and health challenges. Development of biocontrol methods is a sustainable solution to these challenges. The main objective of this research was to investigate the efficacy of potential antagonist bacteria to inhibit important fungal plant pathogens in vitro by applying dual culture assays on potato dextrose agar (PDA) or trypticase soya agar (TSA) media, with a view to isolate and screen potential antagonists for the development of future biocontrol agents. The target pathogens were Fusarium oxysporum, Ceratocystis sp., Aspergillus flavus, and Aspergillus niger, commonly found infecting horticultural plants in Bedugul Village in North Bali Island. The antagonist bacteria were isolated from various sources such as soil from the rhizosphere zone, roots of lettuce plants, and mature compost. The potential of antagonist candidates was screened on the basis of inhibitory activity against targeted fungal pathogens. Bacterial antagonists with the highest zones of inhibition were identified up to the genus level using biochemical tests, and the results were matched with those specified in Bergey’s Manual of Determinative Bacteriology. Fifteen bacterial isolates were successfully isolated from various sources, and 60% of these isolates showed antagonistic activity in vitro against fungal pathogens with varying degrees of inhibition. This indicated the initial potential for development as biocontrol agents. Based on preliminary identification, the genera Bacillus and Pseudomonas were found to be the predominant isolates, and in addition, the genus Acinetobacter was also identified in this study
TREE COMMUNITY STRUCTURE AND ABOVEGROUND CARBON STOCK OF SACRED FOREST IN PASAMAN, WEST SUMATERA
Get PDFThis is an analysis of the tree community’s composition and structure of Bukit Badindiang sacred forest in Nagari Simpang, Pasaman West Sumatera. The study aims to (1) to obtain a representative account of the structure and composition of tree community of the sacred forest, (2) to estimate the Aboveground Carbon Stock (C-Stock) accumulated on it. A one-hectare plot was divided into 25 subplots of 20 m × 20 m each for tree and debris data collection. In each subplots, there would be a 5m x 5m sapling subplots and 1m x 1m seedling, understorey plant and litter subplots were nested inside. A total of 446 trees were recorded, representing 139 species from 49 families with a total basal area of 38.59 m2. The most dominant tree species was Campnosperma auriculata [Importance Value (IV) of 19.19]. The other prevalent species were Ficus benjamina (IV =16.50) and Mallotus caudatus (IV =14.78). A total of 62 species (44.6%) was considered locally rare with density of 1 tree/ha. Mallotus caudatus had the highest density (37 trees/ha) and Ficus benjamina had the highest Basal Area (BA) (5.61 m2 = 14.51% of the total). Euphorbiaceae (IV= 37.40) was the dominant family. The richest families were Euphorbiaceae (10) and Lauraceae (10). The total estimated Aboveground C-Stock was 190.62 MgC/ha, with the highest C was contributed by trees (178.85 MgC/ha or 93.8% of total). Trees with diameter class of 10 – 69.99 cm stored 62% of total tree carbon. The species richness, tree density and C-Stock of Bakit Badindiang sacred forest were relatively higher than those in several disturbed lowland forests in Sumatera
TRUE SHALLOT (Allium cepa var ascalonicum) SEED PRODUCTION DURING OFF SEASON
Get PDFThe application of seed for true shallot cultivation is an alternative of the more common cultivation practice, in which 30% of harvested tubers used for cultivation purposes. The seed production of this temperate tuber, in the tropical region, is quite challenging due to low flowers and seed formation. Several studies showed that vernalization (cold induction) and application of Benzil Amino Purin (BAP) could be applied to improve flowering and seed production. However, such studies were conducted during the best cultivation period for about 3 months and thus, limit the production period of seeds. This study was conducted to observe the effect of both methods outside cultivation periods to flower and capsule numbers, fruit set, and weight of 100 seeds compared with common cultivation. In this study, bulbs of onion vernalized at 10oC for 30 days then became subjected to synthetic hormone (BAP) prior planted while control group The results showed that BAP treated shallot group has the lowest values for all observed parameters (1552.67, 312.11, 22.5%, 0.2244 gram) compared to those vernalization treated group (1592.44, 623, 30.5%; 0.2261 gram) and control group (6774.67; 3898.44; 57.06%; 0.3304 gram). Based on this study, it could be concluded that common cultivation is a better method to produce true shallot seeds during the offseason
GROWTH AND DEVELOPMENT OF OIL PALM SHOOTS UNDER DIFFERENT LIGHT QUALITIES
Get PDFLight is one of the most important factor in plant tissue culture. The growth and development of plant in vitro are affected by light quality. This study examines the influence of different light qualities on the in vitro growth and development of oil palm shoots. Oil palm shoots were cultured in Murashige & Skoog medium under either white fluorescent lamp, white light-emitting diode (LED), red LED, blue LED, combination of red and blue LED, or in darkness. The results show that the growth and development of oil palm shoots are influenced by the light quality. Root initiation and shoot elongation were good under red light, while chlorophyll and sugar content was better produced under white and blue light than red light. In addition to white fluorescent lamp, the combination of red and blue LED resulted in higher growth parameter compared to other light treatments, but the results were not significantly different