Wyniki wyszukiwania - Biblioteka Nauki

1

Factors promote germination and initial growth of Monochoria vaginalis

100%

Xuan T. D. , Anh L. H. , Minh T. N. , Khanh T. D.

International Letters of Natural Sciences

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2016

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tom 59

2

Evaluation of genetic diversity and identification of Huperzia species collected in some different areas in Vietnam by molecular markers

100%

Ha T. T. T. , Khanh T. D. , Trung K. H.

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tom 80

3

Identification of Vietnamese Ochna integerrima (Lour.) merr species based on ribosomal DNA internal transcribed spacer sequence

88%

Trang D. H. , Van Dong D. , Chung B. H. , Gioi D. H. , Khanh T. D.

International Letters of Natural Sciences

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2018

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tom 68

EN

Ochna integerrima is a medicinal and ornamental plant, is widely distributed in Southeast Asia areas. In Vietnam, it has been ranked as the rare and endangered species due to its high demand trade of the beautiful species. In this study, total 21 Ochna samples, collected from the northern and southern areas, were used to characterize the morphological traits using morphological analyses and molecular tool. The results have revealed that the morphological characterization of flower and its quality of Yen Tu Ochna samples showed differences in comparison with the common Ochna and southern Ochna samples. To accurately distinguish genetic traits of the samples, we have sequenced the internal transcribed spacer (ITS) region (including ITS1, 5.8S) of 21 species. The results have disclosed the genetic correlations of the samples ranging from 96.25% to 100% among the studied Ochna samples, of which 5 samples include B1, B2, B3, B6 and N3.1 were divided into the separate groups. The current work is the first report in constructing a molecular database of Ochna for further assessment of inter-and intra-specific molecular diversity of Ochna species in Vietnam.

4

Responses of flavonoids, phenolics, and antioxidant activity in rice seedlings between Japonica and Indica subtypes to chilling stress

75%

Rayee R. , Xuan T. D. , Tran H.-D. , Fakoori N. A. , Khanh T. D. , Dat T. D.

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tom 77

EN

Chilling is one of the major abiotic stress which limites yield and quality of many crops. The seedlings of rice varieties namely Koshihikari (Japonica subtype) chilling tolerant, and the susceptible NMR2 (Indica subtype) were treated at 25/15 °C and 5/4 °C day/night to determine the growth parameters, phenolic contents, and antioxidant activity. It was found that in all treatments, the growth of MNR2 including root and shoot lengths, and leaf and root weights were inhibited at greater levels than Koshihikari. There were seven phenolic acids identified in leaves of Koshihikari including caffeic acid, vanillin, ferulic acid, sinapic acid, benzoic acid, ellagic acid, and cinamic acid, but only benzoic acid and ellagic acid were found in leaves of MNR2. In contrast, only vanillic acid and ellagic acid were observed in roots of Koshihikari, whilst ellagic acid and cinnamic acid were found in roots of MNR2. It was found that rice reduced amount of phenolic acids but promoted quantity of total phenolic content (TPC) and total flavonoid content (TFC) and level of antioxidant activity in chilling stress, although the level of responses varied between Japonica and Indica subtypes. Tolerant rice possessed greater bound flavonoids, phenolics and phenolic acids, but susceptible rice accumulated greater free TPC and TFC in reduced temperature. Findings of this study highlighted that phenolic constituents in bound forms of phenols, polyphenols, and flavonoids may play an active role in rice plants than phenolic acids under chilling stress but need further elaboration.

5

Evaluation of genetic diversity of local-colored rice landraces using SSR markers

75%

Thi Hue H. , Nghia L. T. , Minh H. T. , Anh L. H. , Thi Thu Trang L. , Khanh T. D.

International Letters of Natural Sciences

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2018

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tom 67

EN

Analysis of genetic diversity of 90 Vietnamese local-colored rice accessions was carried out using 40 SSR markers. The numbers of polymorphic alleles ranged from 3 to 12 alleles per locus and average of 7.1 alleles per locus. The similarity coefficients of the rice landraces fluctuated from 0.76 to 0.93; at a genetic correlation level of 0.78. Ninety accessions of rice landraces were divided into five groups based on analysis of genetic relationships. The results have indicated that 11 markers included M250, RM302, RM10926, RM208, RM227, RM17231, RM23251, RM5647, RM1376, RM339 and RM228 which gave the unique allele. These markers can be used effectively for genetic diversity of colored rice and provided a specific database and useful materials for landraces identification, local germplasm conservation for further colored rice improvement on rice quality via rice breeding programs in Vietnam.

6

Allelopathic activity of dehulled rice and its allelochemicals on weed germination

51%

Khang D. T. , Anh L. H. , Thu Ha P. T. , Tuyen P. T. , Quan N. V. , Minh L. T. , Quan N. T. , Minh T. N. , Xuan T. D. , Khanh T. D. , Trung K. H.

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tom 58

EN

In this study, the allelopathic potential of dehulled rice, rice, and hulls of rice on germination of weeds was evaluated in laboratory. Phenolic acids in growth media of these plants were also identified and quantified using HPLC. Identified allelochemicals were reversely tested for phytotoxic effects on germination and seedling growth of barnyardgrass, lettuce, radish and rice. The results showed that the inhibitory effects of dehulled rice were stronger than those of hulls and rice. Dehulled rice caused 66.7% and 50.6% reduction in radish root length and lettuce shoot height, respectively. Dehulled rice showed strong inhibitory effects on root length of lettuce and shoot height of radish while hulls and rice exhibited stimulation. Regarding phenolic identification, vanillin and vanillic acid were detected as allelochemicals in root exudates of rice and tested plants. The results revealed that most of the vanillin and vanillic acid treatments showed high inhibitory effects on germination rates and seedling growth of lettuce and radish, high stimulatory activity on root elongation of rice. Vanillic acid (100 ppm and 200 ppm), vanillin (100 ppm) and their mixture (200 ppm) completely inhibited survival of lettuce. The findings indicate the allelopathic potential of dehulled rice which can be used for identification of more phytotoxins to produce bioherbicides in agricultural practices.

7

Identification of candidate gene SalT and designing markers involving in salt tolerance of Vietnamese rice landraces

51%

Trung K. H. , Khoa N. T. , Diep N. T. , Thuy T. T. , Ha D. T. T. , Cuong T. D. , Xuan T. D. , Trung D. M. , Toan N. N. , Quyen P. T. , Linh L. H. , Khanh T. D.

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tom 63

EN

Rice (Oryza sativa L.) is a principle crop as the main economic importance in Vietnam, providing daily food for over 90 million people in this country. However, a large rice growing areas and rice production are being seriously affected by salinity intrusion, the threats of devastation from climate change. The need to develop salinity tolerance rice varieties to cope with adverse climate change is very imperative. In this study, based on the genome sequence databases of 36 Vietnamese rice landraces, we have identified nine Vietnamese rice landraces carrying nine SalT candidate genes with the sequence similarity to O. sativa SalT (the published GenBank: Z25811.1) which have shown salinity tolerance are included: Te Nuong, Khau mac buoc, Chan thom, Khau giang, Tan ngan, Nang thom cho dao, OM5629, Hom rau and Thom Lai landraces). Amongst them, four rice landraces, Nang thom cho dao, OM5629, Hom rau and Thom lai have revealed two fragments of deletion with six and seven nucleotides which were the most identical to the SalT reference gene. Two primer pairs have been successfully designed to identify the SalT candidate genes in Vietnamese rice landraces. This study provides useful information of salinity tolerance of some Vietnamese rice landraces for breeding programs.