Journal of Tropical Crop Science
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Effects of Plant Growth Promoting Rhizobacteria on Seed Germination Characteristics of Tomato and Lettuce
Get PDFPlant growth promoting rhizobacteria (PGPR) represent a wide genera of rhizospheric bacteria which, when introduced in association with the host plant in proper amount, can enhance plant growth and productivity. A series of experiments were conducted to determine the germination responses of tomato and lettuce to PGPR inoculation. Seeds were inoculated with different strains of Azospirillum brasilense Sp7, Sp7-S and Sp245, Herbaspirillum seropedicea and Burkholderia phytofirmans PsJNT. The results reveal that Sp7-S inoculation yielded better germination rate and total germination of tomato. PGPR inoculation, except Sp7, produced longer (28%) and heavier (37%) roots with superior vigor. In lettuce, PGPR strains, except B. phytofirmans PsJNT, and Sp7 and B. phytofirmans PsJNT, enhanced germination vigor and length of roots (26%), respectively. The results provide further evidence concerning their importance as PGPR and indicate the potential of exploiting some of these PGPR to improve seedling emergence and establishment of vegetables
Extraction of Antioxidant Compounds from Rambutan (Nephelium lappaceum L.) Peel as Agricultural Waste in Taiwan
No full textBesides being an agricultural waste, rambutan (Nephelium lappaceum L.) peel has been widely known as good antioxidant source. However, no information about the antioxidant or their way of extraction for rambutan grown in Taiwan can be found. Since its major bioactive compound is geraniin, one of polyphenol compounds, so that total phenolic was used as an index to investigate the optimum condition of extraction from rambutan peel (red and yellow) in Taiwan. Extraction was conducted based on solvent ratio (1:10 to 1:30 g/mL), ethanol concentration (0 to 95 %), ultrasonic extraction temperature (30 to 70°C), and extraction method (conventional from 6 to 36 h at room temperature and ultrasonic from 0.5 to 10 min at 50oC). Results showed that the highest total phenolic content found in red rambutan variety was at 1:15 (g/mL) ratio, but no significant difference for yellow rambutan. Forty percent of ethanolic extraction and 50°C for ultrasonic extraction for both varieties. Conventional method (12 h) and ultrasonic method (2 min) resulted in the highest total phenolic recovery. As to their antioxidant activity in this study, FRAP ranged from 3800.25±86.49 to 4116.5±88.41 (µmol Fe2+/g D.W), flavonoid from 6.41±0.48 to 8.57±0.35 (mg Quercetin/g D.W), and total phenolic recovery from 297.78±4.06 to 358.42±4.63 (mg GAE/g D.W.). This is the first paper regarding the study of rambutan peel in Taiwan.Keywords: Rambutan (Nephelium lappaceum L.), geraniin, antioxidant, agricultural wast
Effect of Film Packaging on the Quality of Tomato Fruits under Ambient Conditions
Get PDFPolyethylene bags of different permeability were tested to extend the life of tomatoes (Lycopersicon esculentum) under ambient conditions. Tomato fruits at Breaker stage of ripening were packed in low density polyethylene bags (thickness 0.0046 mm) with four different types of perforation, i.e. without pinholes, bag with 10, 15 and 20 pinholes. All bags were stored for 21 days at 28ºC and 74% relative humidity. Fruits were evaluated for changes in colour, physical appearance, firmness and weight loss. Soluble solids content was determined at the end of storage. All unwrapped tomato fruits were red ripe 6 days after storage and after 21 days of storage fruits were soft, appeared deep red, shriveled and dusty. Fruits sealed in bags delayed red colour development, appeared glossy after 21 days of storage. Fruits sealed in polyethylene bags were significantly (p<0.05) firmer and had low weight loss than fruits stored unwrapped. Fruits sealed within polyethylene bag with 20 pinholes had the highest soluble solids content after 21 days. This study shows that storage of tomatoes in polyethylene bag under ambient condition is a promising alternative to refrigeration to reduce wastage and consequently increase the marketable life of harvested tomatoes in tropical countries.Keywords: tomatoes, storage, low density polyethylene bags, ambient condition
Correlations between Leaf Nutrient Content and the Production of Metabolites in Orange Jessamine (Murraya paniculata L. Jack) Fertilized with Chicken Manure
No full textPlant secondary metabolites are unique sources for pharmaceuticals and food additives. Orange jessamine (Murraya paniculata) contains secondary metabolite that is beneficial to human health including lowering blood cholesterol levels, anti-obesity, and has the antioxidant capacity. Leaves of orange jessamine have several chemical constituents including L-cadinene, methyl-anthranilate, bisabolene, β-caryophyllene, geraniol, Carene, 5-guaiazulene, osthole, paniculatin, tannins, eugenol, citronelled, coumurrayin and coumarin derivatives. This study aimed to determine the correlation between leaf concentrations of N, P and K with leaf bioactive compounds following chicken manure application to the plants. The experiment was conducted at IPB Experimental Station at Cikarawang, Bogor (6o30' - 6o45' S, 106o30'-106o45' E) from March to November 2014 (250 m above sea level). The study used a randomized block design (RBD) with rates of chicken manure as a treatment, i.e. 0, 2.5, 5 and 7.5 kg per plant. Chicken manure was applied at 30 months after planting (MAP). Leaves were harvested by pruning the plants to a height of 75 cm above the soil surface. The results showed that the optimum rates of chicken manure to produce maximum fresh and dry leaf weight were 3.1 kg and 6.5 kg per plant, respectively. This rate was sufficient for leaf production at the first harvest (34 MAP) but was insufficient for the second harvest (38 MAP). K concentration of the leaves from different positions within the plant and leaf age positively correlated with leaf dry weight (P <0.01), but negatively correlated with total flavonoid content (P <0.01). Leaf P concentration was negatively correlated with dry weight of the 5th young leaves, or mature leaves from all positions. Leaf K concentration was categorized very high (3.59-4.10%), whereas leaf P concentration was high (0.28-0.29%) to very high (0.33-0.35%). The 5th mature leaves determined plant K requirements.Keywords: antioxidant, bioactive compounds, leaf position, organic, NPK leaf concentration
Improving Performance of Coleus through Mutation Induction by Gamma Ray Irradiation
No full textThe objective of this study is to study the effect of gamma ray irradiation (15, 30, 45, and 60 gray (Gy) to determine Lethal Dose 50 (LD50) values, and to obtain new Coleus variances in a relatively short time. The study was conducted in a greenhouse at Cikabayan experimental field, Bogor Agricultural University, Darmaga, Bogor in May to July 2013. Gamma irradiation treatment significantly affected height, number of leaves, and number of nodes. Increasing the dose level of gamma irradiation tend to inhibit plant growth. LD50 for yellow/green, green/brown, variegated green/brown of Coleus blumei, and Coleus amboinicus Lour were 48.66, 65.2, 52.81, and 37.62 Gy respectively. C. amboinicus irradiated at a dose level of 45 Gy had different leaf shapes compared to control. Keywords: Coleus, gamma ray irradiation, LD50 values, ornamental plant, torbangu
Cloning and Characterization of Partial Chlorophyll a Oxygenase (CAO) Gene Involved in Soybean Shade Tolerance Mechanism
No full textPlant tolerance mechanism under shade stress is indicated by high chlorophyll-b content, which is synthesized from chlorophyll a by chlorophyll a-oxygenase (CAO) gene. The study was aimed to clone and characterize the partial of CAO gene involved in shade tolerance mechanism in soybean. Total RNA was isolated from the second trifoliate leaves of soybean plants and the first strand cDNA was prepared using Reverse Transcriptase Moloney Murine Leukemia Virus (RT-M-MLV) (RNase H-). Northern blot hybridization was used to analyze expression of partial CAO gene. The result showed that one partial gene, CAO 3-4 (1,052 bp), comprised of 292 adenine (a), 241 cytosine (c), 276 guanine (g) and 242 thymine (t), therefore the number of amino acid deduction was 338. The expression of CAO 3-4 partial gene was higher in shade tolerant genotypes than in shade sensitive genotypes, both under 50% shade and dark. These results demonstrated that the CAO gene is involved in shade tolerance mechanism of soybean
Study of Oil Palm (Elaeis guineensis Jacq) In Vitro Embryogenesis using Young Leaves Explants
No full textThis study reported in vitro embryogenesis of oil palm using young leaves as explants. Explants were grown in solid modified MS or Eeuwens medium containing different concentrations of NAA and 2,4-D, i.e. media C1, C2, C3, C4 and C5, M1, M2, M3 and M4, to induce embryogenic calli. Compact and pearly-white, globular calli were obtained from the youngest leaf explants 28 weeks after culture.C1 media (MS medium + 107.41 µM of NAA + 100 mg.L-1 of asparagine + 100 mg.L of glutamine-1) produced the highest percentage of calli formation (30.56%), whereas C4 media (C1 supplemented with 67.86 µM of 2,-D ) was the optimal media for embryogenic callus induction. Direct embryoids were obtained from slightly older leaf explants on the C3 media containing NAA after 36 weeks of culture. However, four subcultures using the same medium with gradual reduction of auxin concentration were not successful to develop embryogenic callus and embryoid cells during the course of this study.
The Growth of Mangroves in Created Wetland in the Porong River, East Java, Indonesia
No full textMangrove plantation projects have been established in the created mangrove wetland in the mouth of the Porong River, East Java, in parallel with the construction of reclamation area for LUSI mud dumping area. This study was aimed to assess the growth of planted mangrove in a created mangrove wetland in relation to the environmental parameters, which are sediment salinity, sediment fraction, pore water salinity, pH/eH, and total organic matter (TOM) in the sediment. Periodical measurement of mangrove growth Avicennia sp. and the environmental parameters were undertaken in the created wetland and in the mud flats of intact mangrove forest nearby the created wetland as the natural reference in July to November 2012. We found that sediments in the created wetland had different characteristics of sediment fractions, sediment salinity and TOM compared to sediments in the mud flats of intact forests. Sand dominated sediments with low TOM and higher water salinity in the created wetland as compared to those in the mud flats affected growth rate of mangroves in study sites. We suggest that TOM and salinity are important factors that contribute to the growth of mangroves in the Porong River. Keywords: Mangrove, salinity, Porong River, total organic matter
Are Tacca leontopetaloides (Linn.) O. Kuntze Mini-tuber Growth Affected by Media Composition and Tuber Size?
No full textTacca (Tacca leontopetaloides (Linn.) O. Kuntze) is a tropical plant that is widely used for its starch in some countries as well as a medicinal plant. Tacca has advantages as it can grow on sand in tropical seashore areas and rain forests. Farmers in Madura Island Indonesia cultivated tacca by using mother tubers as propagules and harvest the daughter tubers, but no studies have been conducted on the growth of mini tubers and their cultivation. The purpose of this study was to find the best combination of planting media and the size of mini tuber for growing tacca. The experiment was set in a completely randomized block design with two factors and three replications. The planting media are sand : rice-hull charcoal : cow manure (1:1:1 v/v), soil : sand : cow manure (1:1:1 v/v), soil : rice-hull charcoal : cow manure (1:1:1 v/v), and soil : cow manure (1:1 v/v);mini-tuber weight are1-5 and 5.1-20 g. The result showed that Polynesian arrowroot grow best on sand : rice-hull charcoal : cow manure (1:1:1 v/v) and rice-hull charcoal : cow manure (1:1 v/v) media. Both propagules sizes can be used, but plants from large mini-tuber had better growth and produced larger mother and daughter tubers. Key words: mini tuber, parent tuber, Polynesian arrowroot, organic media planting, secondary tube
The Diversity of Epiphytic Wild Orchids in Mallawa Resort Area of Bantimurung Bulusaraung National Park, South Sulawesi, Indonesia
No full textThis research aims to report the diversity of epiphytic wild orchids in Mallawa Resort area of Bantimurung Bulusaraung National Park (BBNP), South Sulawesi, Indonesia. Exploration methods were used in this study to search and record epiphyticwild orchids in this area. The technique of data collection comprised taking pictures with a digital camera for documentation and collecting specimens of wild orchids that were unidentified at the site. The identification of orchid species was conducted by matching the morphology and characterization of epiphytic wild orchids with appropriate photographs showing details to enable identification. The results of the study showed that there were 36 species of epiphytic wild orchids to be found in the study area. The identification to species level included 10 species, there were 17 specimens that were identified to genus level, and seven specimens remained unidentified. Sympodial type orchids dominated the suite of native orchids, with 23 species.Keyword: epiphytes, Mallawa Resort, Bantimurung Bulusaraung National Park, wild orchid