Soil and fertilizer management and management of factors affecting
Crop production in organic farming
Management of soil, fertilizer, and pest control on golf course for environmental friendly system
The efficiency of using guano as fertilizer for crop production
Using of plant immunity stimulator and the control of nitrogen level in leaves for increase the productivity and quality of green leaf mustard
Improving of irrigation system and fertilizer management to produce high quality of grapevine
Soil Microbiology
Fertilizer production
Current Research
Soil and fertilizer management and management of factors affecting
Crop production in organic farming
Management of soil, fertilizer, and pest control on golf course for environmental friendly system
The efficiency of using guano as fertilizer for crop production
Using of plant immunity stimulator and the control of nitrogen level in leaves for increase the productivity and quality of green leaf mustard
Improving of irrigation system and fertilizer management to produce high quality of grapevine
Soil Microbiology
Fertilizer production
Year
Month
Title
Journal
Information
2006
Variation in the nod gene RFLPs, nucleotide sequences of 16S rRNA genes, Nod factors, and nodulation abilities of Bradyrhizobium strains isolated from Thai Vigna plants Yokoyama T., Tomooka N., Okabayashi M., Kaga A., Boonkerd N., Vaughan D.A.
Phylogenetic Diversity of Wild Edible Russula from Northeastern Thailand on the Basis of Internal Transcribed Spacer Sequence Manassila M., Sooksa-Nguan T., Boonkerd N., Rodtong S., Teaumroong N.
Diversity of nitrogen-fixing cyanobacteria under various ecosystems of Thailand: Population dynamics as affected by environmental factors Chunleuchanon S., Sooksawang A., Teaumroong N., Boonkerd N.
World Journal of Microbiology and Biotechnology
Abstract: Investigation of N2-fixing cyanobacteria from Thai soil was carried out at 2-month intervals between July 1997 and November 1999 to determine the population number, population dynamics and favourable habitats. Sites were selected in three parts of Thailand; North, Central and Northeast. In each part, various soil ecosystems were used as sampling sites; at highest elevation as on the top of the mountain, in the middle and at the foot of the mountain, as well as in flat areas of agricultural practice and uncultivated areas. Generally, a high population of N2-fixing cyanobacteria was found in agricultural areas where rice cultivation was practised, rather than in other sites. The population dynamics in the mountain and uncultivated areas were less fluctuating than in agricultural areas. The population densities in agricultural areas increased in the rainy season and decreased during the dry season. Other environmental factors such as temperature, moisture and pH also affected the population densities in different habitats. Cyanobacterial diversity was notably influenced by the type of ecosystem in both dry and rainy seasons. The cultivation area containing rice in rotation with other crops contained the most genetically diverse range of species.
Keyword: Environmental factors; N2-fixing cyanobacteria; Population dynamics
Diversity of nitrogen-fixing cyanobacteria under various ecosystems of Thailand: I. Morphology, physiology and genetic diversity Teaumroong N., Innok S., Chunleuchanon S., Boonkerd N.
World Journal of Microbiology and Biotechnology
Abstract: The diversity among 853 isolates of nitrogen-fixing cyanobacteria obtained from soil samples collected from different ecosystems including mountainous, forest and cultivated areas in the central, northern and northeastern regions of Thailand was examined. Most isolates showed slow growth rate and had filamentous, heterocystous cells. The percentage of heterocysts in the filaments of different isolates varied from 8.3 to 9.6. Only a few strains showed high nitrogen-fixing potential, while most of the strains exhibited low capacity for nitrogen fixation. Anabaena and Nostoc were the dominant genera among these isolates. One hundred and two isolates were randomly selected from this diverse collection to determine the extent of genetic diversity on the basis of DNA fingerprinting using the PCR method. Based on the PCR products obtained by using a combination of three primers, all strains could be distinguished from one another. When a subset of 45 isolates of Nostoc and a subset of 44 isolates of Anabaena were further analysed by PCR, a wide range of diversity was observed within each of these genera.
Keyword: Biodiversity; Cyanobacteria; DNA fingerprint; N2-fixation
Genetic structure of indigenous non-nodulating and nodulating populations of Bradyrhizobium in soils from Thailand Pongsilp N., Teaumroong N., Nuntagij A., Boonkerd N., Sadowsky M.J.
Symbiosis
Abstract: One hundred and thirty symbiotic and non-symbiotic strains of Bradyrhizobium were directly isolated from inoculated soybean and uninoculated legume-free virgin field soils in Thailand using a direct selection medium. About 47% and 58% of the isolates obtained from inoculated and uninoculated fields, respectively, were characterized as being non-symbiotic bradyrhizobia. Partial and nearly full-length sequence analyses of regions encoding 16S rRNA indicated that the non-symbionts were closely related to Bradyrhizobium elkanii (79-99% identity) and Bradyrhizobium japonicum (96-100% identity). Southern hybridization analyses showed that DNA from the non-symbiotic bradyrhizobia failed to hybridize to nif and nod gene probes. rep-PCR DNA fingerprint analyses, done using the BOXA1R primer, indicated the symbionts and non-symbionts could be separated into two distinct clusters. There was no relationship between the geographical origin of isolates and groups made based on serological reaction or their ability to nodulate soybean, cowpea, mungbean, or siratro. These results indicate that a relatively large percentage of non-nodulating bradyrhizobia are present in Thai soils.
Plant nutrient and distibution under different fertilizer management in Nam Dok Mai mango Sukthumrong A., Boonkerd N., Khumlert R., Feungchan S., Luksanawimol P., Prasittikhet J., Suriyapan O.
Acta Horticulturae
Abstract: In order to find suitable packages for plant nutrient management in Nam Dok Mai mango orchard, mature leaves of several mango trees under low input of fertilizer, as well as soil underneath them were analyzed. Experiments on N P K and different plant nutrient managements were established and the leaves of mango in each treatment were analyzed for nutrient and TNC content. Results indicated that the plant nutrients in soils were distributed in very wide ranges and the values of each element were not related to soil textures or regions and most plant nutrients except calcium were medium to low. The plant nutrients in mango leaves were distributed in narrow ranges and could be arranged to establish diagnostic criteria in 3 regions of Thailand. The values of plant nutrients and TNC in mango leaves were not affected much by short term fertilizer treatments. Nitrogen was the only element which was most affected. Under long term high input of fertilizer in some high yielding orchards, the values could go to a very high level. Result from this experiment showed that most of the plant nutrient although available in soil in small amount could be extracted and taken up by mango trees in almost sufficient quantities, allowing the possibility of applying slow release nutrient materials through the soil as basal doses and supplementing by readily soluble forms either through soil or foliar applications. The amount and frequency of supplementary nutrients would be verified in further experiments.
Keyword: Fertilizer management; Nam Dok Mai mango; Nutrient distribution
Detection of Bradyrhizobium spp. and B. japonicum in Thailand by primer-based technology and direct DNA extraction Teaumroong N., Boonkerd N.
Plant and Soil
Abstract: Total chromosomal DNAs from 20 Bradyrhizobium spp. strains (10 strains isolated from Vigna radiata and 10 from Arachis hypogaea) and 18 B. japonicum strains isolated from Glycine max were extracted. These DNAs served as templates for REP, ERIC and RAPD primers in PCR analyses. The patterns of the resulting PCR products were analyzed and highly specific for each strain, especially when grouped together with their antibiotic-resistance profiles. A method for extracting DNA directly from soil was developed. Recovery was approximately 30 μg DNA g-1 soil and the procedure yielded DNA suitable for PCR amplification.
Characterization of Bradyrhizobium strains isolated from soybean cultivation in Thailand Nuntagij A., Abe M., Uchiumi T., Seki Y., Boonkerd N., Higashi S.
Journal of General and Applied Microbiology
Abstract: [No abstract available]
Keyword: Acid tolerance; Bradyrhizobium; IAA production; RAPD; Temperature tolerance; Thailand
Polyclonal antisera production by immunization with mixed cell antigens of different rhizobial species Hoben H.J., Somasegaran P., Boonkerd N., Gaur Y.D.
