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Azhar A.,Kasetsart University | Sathornkich J.,Kasetsart University | Rattanawong R.,Kasetsart University | Kasemsap P.,Rubber Research Institute of Thailand
Advanced Materials Research

This experiment aimed to evaluate the leaf chlorophyll fluorescence and gas exchange response to drought conditions of young rubber plants with different scions. Buds from four genotypes of a progeny derived from crossed clones of RRIM600 × RRII105 from Nongkhai Rubber Research Center, T187, T186, T149 and T172, were grafted to RRIM 600 rootstocks. Eight-month old plants with two flushes were used in this study. Two levels of water treatment were used, drought condition (W1) and well-watered as control (W0). Leaf chlorophyll fluorescence, stomatal conductance (gs) and net photosynthesis rate (Pn) were investigated in three phases: before drought, during drought and after re-watering. Leaf gas exchange parameters were measured using Li-6400 (LiCor Inc.). Leaf chlorophyll fluorescence was measured using FluorPen FP 100 (Photon Systems Instruments). Before drought, genotype T186 had the greatest net photosynthesis rates followed by T172, T187 and T149; there was no difference in maximum quantum yield of photosystem II (Fv/Fm) and performance index on absorption basis (PIABS). Drought conditions caused reduction in stomatal conductance, net photosynthesis rates, and leaf chlorophyll fluorescence in all genotypes. In re-watering conditions, genotype T186 and T172 experienced quick recovery while the others showed partial recovery but the values of all parameters did not reach previous levels before treatment. © (2014) Trans Tech Publications, Switzerland. Source

Phumichai C.,Kasetsart University | Phumichai T.,Rubber Research Institute of Thailand | Kongsiri N.,Kasetsart University | Wongkaew A.,Kasetsart University | And 2 more authors.
Biologia Plantarum

Jatropha curcas L. (physic nut) is native to Central America and now naturalized widely in many tropical and subtropical areas. Microsatellite markers were isolated and characterized. Eleven out of 55 markers showed polymorphisms, and the allelic variation was investigated using 26 accessions of J. curcas collected from several provinces in Thailand. Each marker showed 2 to 5 alleles and the average polymorphic information content (PIC) was 0.49. Thirty four markers (62 %) were also successfully amplified in J. integerrima, J. gossypifolia and J. podagrica. © 2011 Springer Science+Business Media B.V. Source

Phumichai C.,Kasetsart University | Phumichai T.,Rubber Research Institute of Thailand | Wongkaew A.,Kasetsart University | Wongkaew A.,Tokyo University of Agriculture and Technology
Plant Molecular Biology Reporter

Understanding the genetic diversity and population structure of Hevea is of great importance for managing its conservation and for utilization of rubber genetic resources. In this study, we investigated the genetic diversity and population structure of eight populations of Hevea rubber genotypes from Malaysia (MY), India (IN), Sri Lanka (LK), Indonesia (ID), France (FR), Thailand (TH), Brazil (BR), and China (CN), in addition to individual primary clones, using 10 nuclear and 11 polymorphic novel chloroplast microsatellite markers (nSSRs and cpSSRs, respectively). The BR population exhibited the greatest genetic diversity (He) for both nSSR (0.841) and haploid genetic diversity (cpSSR; 0.207) markers. Bayesian analysis was applied to infer genetic structure based on nSSR data using STRUCTURE software, and a neighbor-joining tree was used to construct an unrooted phylogram based on Nei’s genetic distance that clustered these Hevea genotypes into three groups. Six polymorphic cpSSR markers produced 13 alleles and eight chlorotypes. Seven chlorotypes, A, B, C, D, E, F, and H were detected among Brazilian populations from Acre (AC), Rondônia (RO), and Mato Grosso (MT) locations. The G and H chlorotypes were found in Asiatic genotypes or Wickham clones and only one genotype, 15 AC-F-7 38-62 from AC location. These results provide valuable data for in situ or ex situ conservation and utilization of germplasm collections for breeding programs. © 2015, Springer Science+Business Media New York. Source

Ghosh R.K.,Kasetsart University | Phumichai T.,Rubber Research Institute of Thailand | Sreewongchai T.,Kasetsart University | Nakasathien S.,Kasetsart University | Phumichai C.,Kasetsart University
Asian Journal of Plant Sciences

Evaluation of jute genotypes for salt tolerance is highly important because of salt affected areas are constantly increasing worldwide especially in Bangladesh where salt tolerant jute variety is unavailable. A hydroponics experiment was conducted in the glasshouse to evaluate the salt tolerance of various jute (Corchorus spp.) genotypes. Sixty jute genotypes were evaluated in a factorial experiment under Hoagland's nutrient solution with three levels of salinity (0, 100 and 200 mM NaCl) in a randomized complete block design with three replications. Root length, shoot length, root dry matter, shoot dry matter, total dry matter and leaf Relative Water Content (RWC) decreased significantly with increasing salinity. However, the chlorophyll content of jute leaves was higher at 100 mMNaCl (42.89) than in control plants (37.76). The C. capsularis genotypes demonstrated higher levels of salt tolerance than did C. olitorius genotypes. The physiological traits shoot length (R2 = 0.95), RWC (R2 = 0.80) and chlorophyll content (R2 = 0.91) was strongly correlated with total dry matter production and was exhibited good potential for evaluation of salt tolerance in jute. The C. capsularis accessions 4965 and 4955 were the most salt tolerant in terms of their high index of salt tolerance (85.20 and 84.10% at 100 mM NaCl) and lowest reduction in shoot length, RWC and chlorophyll content under salt stress. These accessions could be useful for agriculture in saline areas, particularly at 100 mM NaCl (EC = 10 dSirT1) salinity. © 2013 Asian Network for Scientific Information. Source

Pootakham W.,National Center for Genetic Engineering and Biotechnology | Chanprasert J.,National Center for Genetic Engineering and Biotechnology | Jomchai N.,National Center for Genetic Engineering and Biotechnology | Sangsrakru D.,National Center for Genetic Engineering and Biotechnology | And 3 more authors.
American Journal of Botany

Premise of the study: We demonstrated the application of high-throughput 454 sequencing technology in the identification of single nucleotide polymorphism (SNP) markers in Hevea brasiliensis. Methods and Results: A total of 5883 putative SNP positions were discovered in silico, and 10 biallelic SNP markers were validated from 454-derived EST sequences. The polymorphism information content (PIC) and the observed heterozygosity (Ho) ranged from 0.0963 - 0.5135 and 0.1071 - 0.4643, respectively. Conclusions: These markers can be useful for the construction of genetic maps, the identification of quantitative trait loci linked to commercially desirable traits, and the study of genetic structure in H. brasiliensis. © 2011 Botanical Society of America. Source

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