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Effect of lactic acid on alpha-amylase activity and phytic acid content in germination of rice (Oryza sativa L.)

100%

Thi Thu Ha P., Xuan T. D.

International Letters of Natural Sciences

|

2018

|

tom 67

Lactic acid has been known as one of compounds to cause cellular harm in waterlogged tissues through the process of cytoplasmic acidosis. The effects of lactic acid on α-amylase activity and phytic acid (myo-inositol 1,2,3,4,5,6-hexaphosphate) content using an assay for high phosphate in the germination stage of rice were evaluated. It is showed that lactic acid inhibited rice germination at every treated dose. The reduction of α-amylase content attributed to lactic acid at 24 h after germination of rice seeds was observed. The findings highlighted the effects of lactic acid on α-amylase activity and phytic acid content and suggested that this compound may play a potent role as a germination regulator in rice.

2

Antioxidant activity, quality parameters and grain characteristics of rice varieties of Afghanistan

81%

Rayee R., Xuan T. D., Kakar K., Haqani M. I.

International Letters of Natural Sciences

|

2019

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tom 73

Rice is one of the main source of food calories in the world, especially in Asia where the people eat it more than any other food. The goal of this study was to evaluate the antioxidant activity, grain traits and quality contents in Afghanistan’s selected rice varieties. The antioxidant capacity was measured using DPPH (1,1-diphenyl-2-picrylhydrazyl) and Reducing Power methods. Grain length, grain width and grain thickness were in the range of 5.4-7.6, 1.7-3.2, and 1.5-2.2 mm respectively. Selah Zoodras, Taram Irani and Attai-1 had the longest grain length whereas Loke was associated with high width and thickness among the varieties. Protein, amylose and lipid content varied from 6.5-9.9, 20.3-23.5, and 10-18% respectively. Barah Kunduz showed the highest protein and lipid content while Selah zoodras was associated the highest amylose content. The selected rice varieties possessed moderate antioxidant activity and their physiochemical properties were not correlated with antioxidant capacity. Results of this study provided useful information on the selection and production of rice varieties with high nutritional and pharmaceutical values in Afghanistan.

3

Effects of rice blast fungus (Pyricularia grisea) on phenolics, flavonoids, antioxidant capacity in rice (Oryza sativa L.)

81%

Toan N. P., Ha P. T. T., Xuan T. D.

International Letters of Natural Sciences

|

2017

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tom 61

Rice blast fungus (Pyricularia grisea) is one of the most problematic pathogen to significantly reduce rice production worldwide. In this study, after being inoculated with P. grisea, changes in phenolic components and antioxidant capacity and correlation with the resistant level against rice blast fungus were investigated. Among screened rice cultivars, AV-3 was the strongest resistant, whereas BII-3 was the most susceptible. It was found that although total contents of phenolics and flavonoids, and antioxidant capacities varied among studied varieties, no significant coefficient with the resistance against P. grisea was observed. After rice was affected by rice blast fungus, total phenolics and flavonoids were markedly reduced, but in contrast, the DPPH scavenging activities of only the susceptible rice cultivars was reduced. Among the 11 phenolic acids detected, catechol was found only in the tolerant cultivar AV-3, whereas the amount of cinnamic acid was increased after infection. Quantity of vanillin was also promoted, except in the susceptible cultivar BII-3 that was significantly reduced. Findings of this study showed that the resistant level against P. grisea was proportionally correlated to the antioxidant capacity. Catechol, cinnamic acid, and vanillin may play a role but it needs further elaboration. Observations of this study suggested that the infection of blast disease by reducing amount of phenolics and flavonoids that may weaken the resistance of rice against this detrimental fungus.

4

Involvement of phenolics, flavonoids and phenolic acids in high yield characteristics of rice (Oryza sativa L.)

81%

Xuan T. D., Bach D. T., Dat T. D.

International Letters of Natural Sciences

|

2018

|

tom 68

The present study examined the correlation between phenolic acids and flavonoids with high and low yield traits of rice. It was observed that the difference of phenolic contents among the tested rice lines occurred only at the vegetative stage. The concentrations of phenolic acids were higher in the high yield cultivars than low yield varieties at the vegetative stage, but they either decreased dramatically or disappeared during the development stage. Caffeic acid was found only in high yield, whereas chlorogenic acid was detected only in low yield rice. Sinapic acid was the dominant phenolic acid in high yield cultivars at vegetative stage (3.7 mg/g), followed by ferulic acid (1.2 mg/g). These findings suggested that caffeic acid, ferulic acid, sinapic acid and chlorogenic acid may play a particular role in forming yield components in rice. The cultivar B3 contained high amount of sinapic acid may be used as a natural source for pharmaceutical use.

5

Factors promote germination and initial growth of Monochoria vaginalis

81%

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

International Letters of Natural Sciences

|

2016

|

tom 59

6

Changes in chemical composition, total phenolics and antioxidant activity of Alpinia (Alpinia zerumbet) leaves exposed to UV

71%

Xuan T. D., Khanh T. D., Khang D. T., Quan N. T., Elzaawely A. A.

International Letters of Natural Sciences

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2016

|

tom 55

Alpinia zerumbet (Pers.) B.L. Burtt. & R.M. Sm is an important perennial ginger plant in the tropics with various uses as foods, dietary supplement, cosmetics, essential oil production and traditional medicines. In this study, essential oils, phenolic acids, fatty acids, kavains, total phenols and antioxidant activity in A. zerumbet plants exposed to UV-C were investigated. Number and weights of essential oils increased rapidly from 1 to 3 days of exposure. Major extend of essential oils was recorded in methyl cinnamate and followed by benzyl acetone. The correspondence to the accumulation of palmitic acid was 15 folds, in contrast to the strong reduction of stearic quantity was 10 folds at 3 days of treatment. Changes in chemical components and antioxidant capacity in A. zerumbet are differed reversely between the exposure of UV-C and heavy toxic chemicals. The exposure of UV-C is beneficial for the increasing of essential oil production in A. zerumbet.

7

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

61%

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

International Letters of Natural Sciences

|

2020

|

tom 77

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.

8

Phenolic compounds and antioxidant activity of Castanopsis phuthoensis and Castanopsis grandicicatricata

61%

Tuyen P. T., Khang D. T., Minh L. T., Minh T. N., Ha P. T. T., Elzaawely A. A., Xuan T. D.

International Letters of Natural Sciences

|

2016

|

tom 55

In this study, total phenolic and flavonoid contents, antioxidant capacity, and phenolic compositions of Castanopsis phuthoensis and Castanopsis grandicicatricata (Fagaceae family) were investigated. It was found that bark extracts were rich of phenolic contents, whereas leaf extracts were abundant of flavonoids. The total phenolics varied from 11.20 to 35.47 mg gallic acid equivalent g-1 dry weight (DW), and the total flavonoids were from 2.24 to 12.55 mg rutin equivalent g-1 DW. The results of antioxidant activity evaluation showed that the DPPH (1,1- diphenyl-2-picryl-hydrazyl) radical scavenging activity of the free phenolic extracts were higher than the bound phenolic extracts. Regarding the reducing power and β-carotene bleaching assays, the free phenolic extracts showed remarkably strong antioxidant capacity that were similar to the levels of the standard BHT (dibutyl hydroxytoluene) did. It could be concluded that free phenolic extracts were more effective in antioxidant activities than bound phenolic extracts. Highly significant correlations were observed between phenolic contents and antioxidant activities (0.813 for DPPH and 0.841 for reducing power). By HPLC analysis, seven phenolic acids were detected including gallic, p-hydroxybenzoic, vanillic, sinapic, p-coumaric, ellagic acids, and vanillin. Of which, gallic, ellagic, and sinapic acids were the most abundant compounds in the two species. The results suggest C. phuthoensis and C. grandicicatricata contain rich sources of natural antioxidants and phenolic compounds which are probably considered in pharmaceutical use.

9

Study on physical-chemical characters and heritability for yield components in rice (Oryza sativa L.)

61%

Ha P. T. T., Khang D. T., Tuyen P. T., Minh T. N., Xuan T. D., Lang N. T., Buu B. C.

International Letters of Natural Sciences

|

2016

|

tom 57

Present study was performed to analysis both physical and chemical properties of rice germplasm and heritability for yield components in combinations. A total of 44 lines/varieties obtained from Cuu Long Rice Research Institute genebank, and 30 F1 generation combinations were evaluated. The results showed that the rice line IR79008-B-11-B-B-1 showed overall good physical characters (head rice, grain length, grain width, chalkiness). In terms of chemical characteristics, three varieties IR75499-73-1-B, OM6162, and OM4900 were found to have good amylose content, gel consistency, protein content, gelatinization temperature, and aroma. A very notable finding was that the cross between OM6162/SwarnaSub1 that low amylose content (20.2%), high gel consistency (78.2 mm), high protein content (8.1%), appropriate gelatinization temperature (scale 5), low chalkiness (level 0), high heritability (0.9) for grain yield trait/cluster, and (0.84) for the number of panicles/cluster. Moreover these characters consist of plant height, panicle length, number of panicles/cluster, number of filled grains/panicle, number of unfilled/panicle, and grain yield/ cluster showed moderate to high heritability of mean for combination OM6162/SwarnaSub1. The results suggest that the grain yield trait/cluster and the number of panicles/cluster are important yield contributing traits to rice breeders for selecting ideal combinations for higher yield and quality of next generations.

10

Abundance Frequency of Plant Species as Animal Feeds to Determine Ideal Cattle Grazing

61%

Yulianto R., Xuan T. D., Kawamura K., Lim J., Yoshitoshi R., Xinyan F., Zhe G.

International Letters of Natural Sciences

|

2016

|

tom 58

The objectives of this study were to determine the dominant frequency of plant species, and provide useful information toward the conservation management of animal feed in grazing areas, Hiroshima, Japan. The numbers of plant species were 32 and 21 in spring and summer, respectively. The appearance frequency of plant species more than 50% in the spring, consist of Veronica arvensis (75.57%), Trifolium repens (73.86%), Paspalum dilatatum (69.32%), Lamium purpureum (68.75%), Trifolium dubium (65.34%), Cerastium glomeratum (63.64%), whereas in summer, it consists of Paspalum notatum (98.30%), Trifolium repens (81.25%), Paspalum dilatatum (78.98%), and Kyllinga brevifolia (74.43%). It was observed that the plant high of the plant species were 16.64 and 21.55 cm; vegetation cover rates were 77.18 and 81.36%; chlorophyll content were 41.72 and 36.28 mg/g Fw, and species numbers were 17.91 and 10.18, in spring and summer, respectively. Findings of this research propose that Trifolium repens (clover), Rumex japonicus (weed), and Paspalum dilatatum (grass) are dominant species in the studied areas that can be utilized as animal feeds.

11

Effects of salinity stress on growth and phenolics of rice (Oryza sativa L.)

61%

Minh L. T., Khang D. T., Ha P. T. T., Tuyen P. T., Minh T. N., Quan N. V., Xuan T. D.

International Letters of Natural Sciences

|

2016

|

tom 57

This study was conducted to determine the correlation between of salinity stress on growth and phenolic compounds in rice. It was observed that salinity stress caused a significant decrease in shoot lengths, fresh and dry weights of all rice varieties. Under salinity stress, changes of chemical contents also differed among phenolic compounds and rice cultivars. Total phenolics and flavonoids, and contents of vanillin and protocatechuic acid in tolerant varieties were strongly increased, whereas in contrast, they were markedly reduced in the susceptible cultivar. Ferulic acid and p-coumaric acid were detected only in tolerance rice. Vanillin and protocatechuic acid may play a role, but ferulic acid and p-coumaric acid may be much involved in the tolerant mechanism against salinity stress. Ferulic acid and p-coumaric acid and their derivatives are potent to be exploited as promising agents to reduce detrimental effects of salinity stress on rice production.

12

Development of new drought tolerant breeding lines for Vietnam using marker-assisted backcrossing

52%

Thu Ha P. T., Khang D. T., Tuyen P. T., Toan T. B., Huong N. N., Lang N. T., Buu B. C., Xuan T. D.

International Letters of Natural Sciences

|

2016

|

tom 59

13

Effect of salt on growth of rice landraces in Vietnam

52%

Anh L. H., Hue H. T., Quoc N. K., Nghia L. T., Trung K. H., Trung T. N., Trang D. H., Xuan T. D., Khanh T. D.

International Letters of Natural Sciences

|

2016

|

tom 59

14

Characterization of (2E, 6E)-3,7,11-Trimethyldodeca-2,6,10-trien-1-ol with antioxidant and antimicrobial potentials from Euclea crispa (Thunb.) leaves

52%

Palanisamy C. P., Cui B., Zhang H., Trung N. T., Tran H.-D., Khanh T. D., Quan N. V., Xuan T. D.

International Letters of Natural Sciences

|

2020

|

tom 80

15

Evaluation of ursolic acid as the main component isolated from Catharanthus roseus against hyperglycemia

52%

Thanh Tam N., Thien D. D., Sung T. V., Thi Hoang Anh N., Thuy T. T., Trung K. H., Xuan T. D., Khanh T. D.

International Letters of Natural Sciences

|

2016

|

tom 50

Ursolic acid with large amount (0.67% of dried plant weight) along with 7 compounds, namely as spatozoate (1), kaurenoic acid (2), ursonic acid (3), 3-hydroxy-11-ursen-28,13-olide (4), ursolic acid (5), vindoline (6) and mixture of β-sitosterol and stigmasterol were isolated from dichloromethane and ethyl acetate extracts which have shown anti-glucosidase activity of the whole plant of C.roseus. Some isolated compounds and their derivatives were also tested for anti-glucosidase and cytotoxicity.Ursolic acid was examined for hypoglycemic activity in alloxan-induced diabetic mice with dose of 200 and 300 mg/kg/day, respectively. The results have shown that the blood glucose level were reduced by 45.75% and 51.31% to compare with the control group. This study has confirmed that the main component of Vietnamese C. roseus has had significant anti-hyperglycemia activity.

16

Involvement of phenolic compounds in anaerobic flooding germination of rice (Oryza sativa L.)

52%

Khang D. T., Ha P. T. T., Lang N. T., Tuyen P. T., Minh L. T., Minh T. N., Bach D. T., Xuan T. D.

International Letters of Natural Sciences

|

2016

|

tom 56

By this study, thirty rice varieties were evaluated for anaerobic flooding tolerance using the direct sowing method. Phenolic profiles of strong and weak tolerant varieties were identified and compared based on HPLC chromatograms. The germination rates and shoot heights of rice were recorded for calculating the seedling vigor, which indicate the tolerant ability of rice in flooding condition. The results revealed a high variation of germination rate (10.01 to 100%), shoot height (0.35 to 78.17 mm) and seedling vigor (0.05 to 72.83). There was a high correlation between (r = 0.71) germination rate in 5 cm and 10 cm flood. Phenolic and flavonoid contents of the strong tolerant cultivar significantly and proportionally increased in the flooding levels (5 cm and 10 cm). There was a total difference in terms of number of phenolic acids found in the strong and weak tolerant varieties. In particular, six phenolic acids (gallic acid, catechol, caffeic acid, syringic acid, vanillin, and ellagic acid) were only identified with high concentration in the strong tolerant cultivar. The findings suggest that the phenolics presented in the strong tolerant varieties probably have a certain function in response and adaptation to anaerobic flooding condition. Further researches on exogenous application of these phenolic acids to increase the flooding tolerant level of rice should be continued at both green house and field treatments.

17

Correlation among agro-morphological variation and genetic diversity of rice (Oryza sativa L.) under drought stress

52%

Thu Ha P. T., Khang D. T., Tuyen P. T., Minh L. T., Minh T. N., Thi Lang N., Buu B. C., Xuan T. D.

International Letters of Natural Sciences

|

2016

|

tom 58

In this study, the correlation coefficients among agro-morphological variation, genetic diversity, and drought tolerance in 44 rice cultivars were analyzed. The drought tolerance at seeding stage (DTS) was significantly proportional to drought tolerance at vegetative stage (DTV) (r = 0.60). In addition, DTS and DTV had strong significant positive correlation to leaf roll (r = 0.87 and 0.54, respectively). Means of unfilled grains and tilling per panicle were proportionally correlated to DTS (r = 0.22 and 0.25, respectively), and DTV (r = 0.20 and 0.36, respectively). However, weight of 1000 grains and filled grains were recorded no correlation to DTS and DTV. At a homologous coefficient of 16.85 integrated from cluster analysis of agro-morphological, quantitative characteristics and drought tolerant scores, the rice cultivars were divided into five groups. Maximum polymorphic information content (PIC) values were detected in three markers including RM11125, RM21, and RM5629, which were from 0.78 to 0.79. Cluster analysis of microsatellite markers revealed that by a genetic distance of 0.63, the rice varieties were separated into three clusters. The results provide valuable information for rice breeders to select donors in breeding rice integrated with drought tolerance and good agronomic characteristics.

18

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

42%

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.

International Letters of Natural Sciences

|

2017

|

tom 63

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.

19

Allelopathic activity of dehulled rice and its allelochemicals on weed germination

42%

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.

International Letters of Natural Sciences

|

2016

|

tom 58

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.

Ograniczanie wyników

Effect of lactic acid on alpha-amylase activity and phytic acid content in germination of rice (Oryza sativa L.)

Antioxidant activity, quality parameters and grain characteristics of rice varieties of Afghanistan

Effects of rice blast fungus (Pyricularia grisea) on phenolics, flavonoids, antioxidant capacity in rice (Oryza sativa L.)

Involvement of phenolics, flavonoids and phenolic acids in high yield characteristics of rice (Oryza sativa L.)

Factors promote germination and initial growth of Monochoria vaginalis

Changes in chemical composition, total phenolics and antioxidant activity of Alpinia (Alpinia zerumbet) leaves exposed to UV

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

Phenolic compounds and antioxidant activity of Castanopsis phuthoensis and Castanopsis grandicicatricata

Study on physical-chemical characters and heritability for yield components in rice (Oryza sativa L.)

Abundance Frequency of Plant Species as Animal Feeds to Determine Ideal Cattle Grazing

Effects of salinity stress on growth and phenolics of rice (Oryza sativa L.)

Development of new drought tolerant breeding lines for Vietnam using marker-assisted backcrossing

Effect of salt on growth of rice landraces in Vietnam

Characterization of (2E, 6E)-3,7,11-Trimethyldodeca-2,6,10-trien-1-ol with antioxidant and antimicrobial potentials from Euclea crispa (Thunb.) leaves

Evaluation of ursolic acid as the main component isolated from Catharanthus roseus against hyperglycemia

Involvement of phenolic compounds in anaerobic flooding germination of rice (Oryza sativa L.)

Correlation among agro-morphological variation and genetic diversity of rice (Oryza sativa L.) under drought stress

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

Allelopathic activity of dehulled rice and its allelochemicals on weed germination