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Journal : HAYATI Journal of Biosciences

Physiological Responses and Fruit Retention of Carambola Fruit (Averrhoa carambola L.) Induced by 2,4-D and GA3 BEKTI KURNIAWATI; HAMIM HAMIM
HAYATI Journal of Biosciences Vol. 16 No. 1 (2009): March 2009
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (229.753 KB) | DOI: 10.4308/hjb.16.1.9

Abstract

One of the problems in cultivation of carambola fruit is the high of flower and fruit drop during fruit development. To understand these problems and to improve fruit retention, the content of indole-3-acetic acid (IAA) and total sugar in carambola fruit and leaves were analysed in response to application of gibberellic acid (GA3) and 2,4-dichlorophenoxyacetic acid (2,4-D). The experiments used 1,5 year old of carambola plants (Averrhoa carambola L. var Dewi) grown in polybag of 40 x 50 cm. GA3 with the concentration of 0, 20, 40, and 60 ppm and 2,4-D of 0, 5, 10, and 15 ppm were applied to the flower and the supporting leaves of carambola plant. The parameters analysed were number of flower drop, fruit formation, fruit retention, number of harvestable fruit per cluster, fruit weight per cluster, the content of sugar in the leaves and IAA in the fruit. The result showed that IAA content of the fruit increased in response to single as well as combination of GA3 and 2,4-D application. Sugar content of the leaves also increased in response to GA3 and 2,4-D application; however, the pattern was different with that of IAA. The best treatment to improve fruit retention was a single application of 10 ppm 2,4-D or 60 ppm GA3, and combined application of 5 ppm 2,4-D and 60 ppm GA3. Key words: fruit drop, fruit retention, carambola fruit, auxin, gibberellin
Photosynthesis of C3 and C4 Species in Response to Increased CO2 Concentration and Drought Stress HAMIM HAMIM
HAYATI Journal of Biosciences Vol. 12 No. 4 (2005): December 2005
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (250.934 KB) | DOI: 10.4308/hjb.12.4.131

Abstract

Photosynthetic gas exchange in response to increased carbon dioxide concentration ([CO2]) and drought stress of two C3 (wheat and kale) and two C4 species (Echinochloa crusgallii and Amaranthus caudatus) were analysed. Plants were grown in controlled growth chambers with ambient (350 mol mol-1) and doubled ambient [CO2]. Drought was given by withholding water until the plants severely wilted, whereas the control plants were watered daily. Even though stomatal conductance (Gs) of C4 species either under ambient or double [CO2] was lower than those in C3, doubled [CO2] decreased Gs of all species under well watered conditions. As a result, the plants grown under doubled [CO2] transpired less water than those grown under ambient [CO2]. Photosynthesis (Pn) of the C4 species was sustained during moderate drought when those of the C3 species decreased significantly. Doubled [CO2] increased photosynthesis of C3 but not of C4 species. Increased [CO2] was only able to delay Pn reduction of all species due to the drought, but not remove it completely. The positive effects of increased [CO2] during moderate drought and the disappearance of it under severe drought suggesting that metabolic effect may limit photosynthesis under severe drought.
Overexpression of B11 Gene in Transgenic Rice Increased Tolerance to Aluminum Stress Devi Media Siska; . Hamim; . Miftahudin
HAYATI Journal of Biosciences Vol. 24 No. 2 (2017): April 2017
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1789.324 KB) | DOI: 10.4308/hjb.24.2.96

Abstract

Rice cultivation on acid soils is mainly constrained by aluminum (Al) toxicity. However, rice has tolerance mechanism to Al stress, which is controlled by many genes. B11 gene is one of the Al- tolerance gene candidate isolated from rice var. Hawara Bunar. It has not been known whether overexpression of the gene in Al-sensitive rice is able to increase Al tolerance. The research objective was to analyze root morphological and physiological responses of transgenic rice overexpressing B11 gene to Al stress. The experiment was carried out using five rice genotypes including two varieties (Hawara Bunar and IR64) and three T4 generation of transgenic lines, that are T8-2-4, T8-12-5, and T8-15-41. All rice genotypes were grown in nutrient solution for 24 h (adaptation period), and then were exposed to 15 ppm Al for 72 h (treatment period) and recovered in normal nutrient solution for 48 h (recovery period). The result showed that the overexpression of the B11 gene in T8-2-4, T8-12-5, and T8-15-41 transgenic lines improved tolerance to Al stress based on root growth characters, accumulation of Al, root cell membrane lipid peroxidation, and root tip cell structure.
Impact of Methanotrophic and N2O-reducing Bacterial Inoculation on CH4 and N2O Emissions, Paddy Growth and Bacterial Community Structure in Paddy Field Yuli Siti Fatma; Iman Rusmana; Aris Tri Wahyudi; Hamim Hamim
HAYATI Journal of Biosciences Vol. 27 No. 3 (2020): July 2020
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.4308/hjb.27.3.197

Abstract

Paddy field is one of the anthropogenic sources that produce greenhouse gases emission. This study aimed to investigate the impact of methanotrophic and N2O-reducing bacterial inoculation on CH4 and N2O emissions, paddy growth and bacterial community structure in paddy field. Two treatments of 100% synthetic fertilizer (250 kg urea/ha) without biofertilizer and 50% synthetic fertilizer (125 kg urea/ha) with biofertilizer consisted of methanotrophic and N2O-reducing bacteria were applied in the paddy field. Inoculation of methanotrophic and N2O-reducing bacteria was able to reduce CH4 and N2O emission up to 4.19 mg CH4/m2/day and 351.29 µg N2O/m2/day, respectively. Those bacterial applications were also able to increase paddy growth and yield productivity. According to DGGE profile, inoculation of the biofertilizer seemed to have a transient impact on bacterial communities in paddy soil at 36 days after transplanting (DAT) which showed the lowest similarity with all samples (a similarity index of 0.68). DGGE bands successfully excised have closest relative to uncultured bacteria which comprised 5 phyla, i.e. Proteobacteria (Alphaproteobacteria and Deltaproteobacteria), Nitrospirae, Actinobacteria, Firmicutes, and Acidobacteria. In this study, Alphaproteobacteria was the most dominant phylum. We provide basic information for developing the biofertilizer which supports sustainable agriculture.
Gold Mine Wastewater Induced Morpho-physiological Alteration of Four Biodiesel Producing Species Hamim Hamim; Lutfiani Lutfiani; Deden Saprudin; Putri Nur Azizah Hutagalung; Hadisunarso Hadisunarso; Luluk Setyaningsih; Hirmas Fuady Putra
HAYATI Journal of Biosciences Vol. 28 No. 1 (2021): January 2021
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.4308/hjb.28.1.63

Abstract

This experiment aimed to determine the adaptability of four biodiesel-producing plants to gold mine wastewater based on morpho-physiological properties. Four species namely jatropha (Jatropha curcas), castor bean (Ricinus communis), wild candlenut (Reutealis trisperma) and bead tree (Melia azedarach) were grown in water culture using Hoagland solution for 2 weeks and then treated with gold mining wastewater at 0% (control), 25%, 50%, and 75% (v/v) for 3 weeks. Growth, anatomical and physiological characteristics were observed during the treatment. The results showed that gold mine wastewater significantly decreased growth of the four species despite varied among the species. Wastewater had significant effect on leaves anatomy of Jatropha but not on others. It also significantly induced the increase of malondialdehyde (MDA) content in Jatropha and castor bean, but not in wild candlenut and bead-tree. Meanwhile, the treatment significantly decreased chlorophyll content of all species with the most in bead-tree plant, and leaves relative water content (RWC) particularly in castor bean and bead-tree plants. There was strong negative correlation between the increase of MDA content and the decrease of chlorophyll content and leaf RWC. Among the four species, wild candlenut (R. trisperma) was the most resistant to gold mine wastewater based on morphological and physiological properties.