ស្វែងរកតាមប្រភេទឯកសារ
ស្វែងរកតាមប្រភេទដំណាំ
អត្ថបទថ្មីៗ
ចំនួនភ្ញៀវចូលទស្សនា
        
ថ្ងៃនេះ
ថ្ងៃម្សិលមិញ
សប្តាហ៍នេះ
សប្តាហ័មុន
ខែនេះ
ខែមុន
ពាក្យគន្លឺះ  

ស្វែងរក
ស្វែងរកលំអិត
បណ្ណាល័យ
ចំណងជើង:
Transgenic accumulation of a defective cucumber mosaic virus (CMV) replicase derived double stranded RNA modulates plant defence against CMV strains O and Y in potato, by Ntui VO, Kynet K, Azadi P, Khan RS, Chin DP, Nakamura I, Mii M. Transgenic Res DOI 10.1007/s11248-013-9721-8
បរិយាយ:

Abstract

Cucumber mosaic virus is an important plant pathogen with a broad host range encompassing many plant species. This study demonstrates the production of transgenic potato lines exhibiting complete resistance to cucumber mosaic virus strain O and Y by post transcriptional gene silencing. Two constructs were used, one, pEKH2IN2CMVai, contains inverted repeat of 1,138 bp fragment of a defective CMV replicase gene derived from RNA2 of cucumber mosaic virus strain O (CMV-O), while the other, TRV-based VIGS vector (pTRV2CMVai), contains the same fragment of the replicase gene, but without inverted repeat. These constructs were used to produce transgenic potato lines of cultivar 'Danshaku', a susceptible genotype to CMV. Transgenic lines derived from pEKH2IN2CMVai accumulated small interfering RNA (siRNA) before and after virus challenge, whereas those derived from pTRV2CMVai showed siRNA expression after virus challenge. When transgenic lines were challenged with CMV-O or CMV-Y, four lines exhibited complete (100%) resistance to both strains, whereas the other lines had high levels of resistance. Infectivity of CMV-O was lower than that of CMV-Y in the highly resistant plants. There were no significant differences with regard to resistance between plants derived from pEKH2IN2CMVai and those obtained from pTRV2CMVai. The presence of CMV-specific siRNA in the resistant phenotypes indicates that the resistance was acquired through RNA silencing.

Full article

 

keyword:
dsRNA. PTGS. Replicase gene. siRNA. Solanum tuberosum. Virus induced gene silencing

Abstract

Cucumber mosaic virus is an important plant pathogen with a broad host range encompassing many plant species. This study demonstrates the production of transgenic potato lines exhibiting complete resistance to cucumber mosaic virus strain O and Y by post transcriptional gene silencing. Two constructs were used, one, pEKH2IN2CMVai, contains inverted repeat of 1,138 bp fragment of a defective CMV replicase gene derived from RNA2 of cucumber mosaic virus strain O (CMV-O), while the other, TRV-based VIGS vector (pTRV2CMVai), contains the same fragment of the replicase gene, but without inverted repeat. These constructs were used to produce transgenic potato lines of cultivar 'Danshaku', a susceptible genotype to CMV. Transgenic lines derived from pEKH2IN2CMVai accumulated small interfering RNA (siRNA) before and after virus challenge, whereas those derived from pTRV2CMVai showed siRNA expression after virus challenge. When transgenic lines were challenged with CMV-O or CMV-Y, four lines exhibited complete (100%) resistance to both strains, whereas the other lines had high levels of resistance. Infectivity of CMV-O was lower than that of CMV-Y in the highly resistant plants. There were no significant differences with regard to resistance between plants derived from pEKH2IN2CMVai and those obtained from pTRV2CMVai. The presence of CMV-specific siRNA in the resistant phenotypes indicates that the resistance was acquired through RNA silencing.

Full article

 

ចំណងជើង:
Transgenic tobacco and tomato plants expressing Wasabi defensin genes driven by root-specifc LjNRT2 and AtNRT2.1 promoters confer resistance against Fusarium oxysporum, by Kynet Kong, Valentine Otang Ntui, So Makabe, Raham Sher Khan, Masahiro Mii, Ikuo Nakamura. Plant Biotechnology Vol. 31 (2014) No. 2 p. 89-96
បរិយាយ:
Abstract
Antifungal peptides are a potential group of defense molecules that have been utilized to develop resistance to various plant pathogens. Wasabi defensin (WD) gene (0.5 kb) consists of cysteine-rich peptides that show potent growth inhibition of pathogenic filamentous fungi, such as Botrytis cinerea. Under regulation by the root-specific LjNRT2 or AtNRT2.1 promoter, WD gene was expressed in the roots of transgenic tobacco and tomato plants by Agrobacterium-mediated transformation. The regenerated plants showed stable integration of the transgene, with different insertion sites, and the transgene was expressed in the root tissues but not in the leaf tissues. This result confirmed that WD protein accumulated only in the roots of transgenic plants. In a bioassay for resistance to Fusarium oxysporum, all transgenic plants showed increased resistance to the fungus as compared to non-transformed plants. Protein extracts from root and leaf tissues were assayed for antifungal activity and the activity was express as the number of colonies formed per cm2 (CFU cm−2). The CFU values of the root and leaf extracts of control plants did not show significant differences. In contrast, the CFU values of the root extracts of the transgenic plants were significantly lower than those of the leaf extracts and much lower than those of control. These results suggest that LjNRT2 and AtNRT2.1 promoters triggered the antifungal gene expression in the roots and conferred increased resistance to the root pathogen F. oxysporum. In the view of bio-safety, the root-specific expression of the transgene is desirable because the roots of tomato are not edible.

 Full article
keyword:
Bio-safety, Fusarium wilt, root colonization assay, root-specific promoter, soil-borne disease
Abstract
Antifungal peptides are a potential group of defense molecules that have been utilized to develop resistance to various plant pathogens. Wasabi defensin (WD) gene (0.5 kb) consists of cysteine-rich peptides that show potent growth inhibition of pathogenic filamentous fungi, such as Botrytis cinerea. Under regulation by the root-specific LjNRT2 or AtNRT2.1 promoter, WD gene was expressed in the roots of transgenic tobacco and tomato plants by Agrobacterium-mediated transformation. The regenerated plants showed stable integration of the transgene, with different insertion sites, and the transgene was expressed in the root tissues but not in the leaf tissues. This result confirmed that WD protein accumulated only in the roots of transgenic plants. In a bioassay for resistance to Fusarium oxysporum, all transgenic plants showed increased resistance to the fungus as compared to non-transformed plants. Protein extracts from root and leaf tissues were assayed for antifungal activity and the activity was express as the number of colonies formed per cm2 (CFU cm−2). The CFU values of the root and leaf extracts of control plants did not show significant differences. In contrast, the CFU values of the root extracts of the transgenic plants were significantly lower than those of the leaf extracts and much lower than those of control. These results suggest that LjNRT2 and AtNRT2.1 promoters triggered the antifungal gene expression in the roots and conferred increased resistance to the root pathogen F. oxysporum. In the view of bio-safety, the root-specific expression of the transgene is desirable because the roots of tomato are not edible.

 Full article
ចំណងជើង:
Transgenic Tobacco Lines Expressing Defective CMV Replicase-Derived dsRNA Are Resistant to CMV-O and CMV-Y, by Valentine Otang Ntui, Kong Kynet, Raham Sher Khan, Mari Ohara, Yasuko Goto, Manabu Watanabe, Masanobu Fukami, Ikuo Nakamura, Masahiro Mii. Mol Biotechnol DOI 10.1007/s12033-013-9681-5
បរិយាយ:

Abstract

Cucumber mosaic virus (CMV) is a tripartite, positive sense RNA virus causing infections and yield losses to many plant species. Here, we generated a construct containing inverted repeat of 1,793 bp fragment of defective CMV replicase gene derived from RNA2 of cucumber mosaic virus strain O (CMV-O). The replicase gene was modified by deleting a 9 bp region between nucleotides 1909–1918. This caused a deletion in the active centre motif of polymerases, producing defective translated product 9 nucleotides shorter than the full length protein. The RNAi construct containing inverted repeat of the defective gene was used to produce transgenic tobacco lines expressing CMV-derived double-stranded RNA via Agrobacterium-mediated transformation. Of the four transgenic lines inoculated with CMV-O or CMV-Y in vitro and ex vivo, three lines (T1, T4 and T5) showed immunity to both strains of CMV as no symptoms were detected, whereas one line (T7) exhibited high resistance with mild symptoms limited to inoculation portions. No virus could be detected in uninoculated new leaves of the transgenic lines after RT-PCR and Dot-immunobinding assay analyses. Small interfering RNAs present in transgenic lines before and after virus challenge indicates that the resistance was acquired through RNA silencing.

Full article
 

keyword:
CMV dsRNA PTGS Replicase gene RNAi

Abstract

Cucumber mosaic virus (CMV) is a tripartite, positive sense RNA virus causing infections and yield losses to many plant species. Here, we generated a construct containing inverted repeat of 1,793 bp fragment of defective CMV replicase gene derived from RNA2 of cucumber mosaic virus strain O (CMV-O). The replicase gene was modified by deleting a 9 bp region between nucleotides 1909–1918. This caused a deletion in the active centre motif of polymerases, producing defective translated product 9 nucleotides shorter than the full length protein. The RNAi construct containing inverted repeat of the defective gene was used to produce transgenic tobacco lines expressing CMV-derived double-stranded RNA via Agrobacterium-mediated transformation. Of the four transgenic lines inoculated with CMV-O or CMV-Y in vitro and ex vivo, three lines (T1, T4 and T5) showed immunity to both strains of CMV as no symptoms were detected, whereas one line (T7) exhibited high resistance with mild symptoms limited to inoculation portions. No virus could be detected in uninoculated new leaves of the transgenic lines after RT-PCR and Dot-immunobinding assay analyses. Small interfering RNAs present in transgenic lines before and after virus challenge indicates that the resistance was acquired through RNA silencing.

Full article
 

ចំណងជើង:
Nutrient balances for cassava cultivation in Kampong Cham province in Northeast Cambodia, by Sopheap, U Patanothai, A Aye, Tin Maung , U. Sopheap et al. / International Journal of Plant Production (2012) 6(1): 37-58
បរិយាយ:
Abstract
In Cambodia, cassava is mostly grown with little or no fertilizer inputs, but the magnitudes of nutrient balances are not known. This study was conducted to assess nutrient balances for cassava cultivation in Kampong Cham province in Northeast Cambodia. Forty-five households in four cassava production zones were interviewed in relation to their cultural practices and crop residue management, upon which sources of nutrient inputs and outputs were based. Chemical fertilizer, manure, planting materials and rainfall were the defined inputs, while cassava roots and stumps were the outputs. Crop cutting was undertaken in the cassava fields of the 45 households to obtain weights of roots and other plant parts. Nutrient balances were calculated for the individual fields based on nutrient contents of the component sources obtained from the literatures. The results showed negative balances for all the nutrients evaluated. The imbalances were most serious for N, K and Ca with the averages of -64.45 kg N, -52.83 kg K and -10.83 kg Ca ha-1, but were less serious for P and Mg with the averages of -2.85 kg P and -7.20 kg Mg ha-1. These negative balances were the consequence of low nutrient inputs in current practices where only a few farmers applied low rates of chemical fertilizer or manure. Continued use of current practices will threaten the sustainability of cassava production in Cambodia. For long term productivity of the crop, the application of organic manures together with lime and chemical fertilizers high in N and K is recommended.

Full Article
keyword:
Soil nutrients; Agricultural sustainability; Soil fertility management; Cassava fertilization; Long-term productivity.
Abstract
In Cambodia, cassava is mostly grown with little or no fertilizer inputs, but the magnitudes of nutrient balances are not known. This study was conducted to assess nutrient balances for cassava cultivation in Kampong Cham province in Northeast Cambodia. Forty-five households in four cassava production zones were interviewed in relation to their cultural practices and crop residue management, upon which sources of nutrient inputs and outputs were based. Chemical fertilizer, manure, planting materials and rainfall were the defined inputs, while cassava roots and stumps were the outputs. Crop cutting was undertaken in the cassava fields of the 45 households to obtain weights of roots and other plant parts. Nutrient balances were calculated for the individual fields based on nutrient contents of the component sources obtained from the literatures. The results showed negative balances for all the nutrients evaluated. The imbalances were most serious for N, K and Ca with the averages of -64.45 kg N, -52.83 kg K and -10.83 kg Ca ha-1, but were less serious for P and Mg with the averages of -2.85 kg P and -7.20 kg Mg ha-1. These negative balances were the consequence of low nutrient inputs in current practices where only a few farmers applied low rates of chemical fertilizer or manure. Continued use of current practices will threaten the sustainability of cassava production in Cambodia. For long term productivity of the crop, the application of organic manures together with lime and chemical fertilizers high in N and K is recommended.

Full Article


ចំណងជើង:
របាយការណ៍សិក្ខាសាលាថ្នាក់ជាតិស្តីពី ផលិតកម្មនិងការប្រើប្រាស់ដំណាំដំឡូងមី ប្រកបដោយនិរន្តរភាពដើម្បីកាត់បន្ថយភាពក្រីក្រនៅជនបទក្នុងប្រទេសកម្ពុជា
បរិយាយ:

keyword:
cassava



ចំណងជើង:
របាយការណ៍ប្រចាំឆ្នាំ ២០១២
បរិយាយ:
 
keyword:
N/A
 


ចំណងជើង:
ខា១៥
បរិយាយ:

ពូជស្រូវ “ខា១៥” ជាពូជស្រូវស្រាលដែលបានធ្វើការបញ្ចេញ និងផ្សព្វផ្សាយជូនកសិករ
ប្រើប្រាស់ដោយ វិទ្យាស្ថានស្រាវជ្រាវ និងអភិវឌ្ឍន៏កសិកម្មកម្ពុជា នៃក្រសួងកសិកម្ម
រុក្ខាប្រមាញ់ និងនេសាទនាដើមឆ្នាំ២០១៥។  បច្ចុប្បន្ន ពូជស្រូវ
ខា១៥ បាននឹងកំពុង
ផ្សព្វផ្សាយនៅក្នុងព្រះរាជាណាចក្រកម្ពុជា ដោយពូជស្រូវនេះ
មានអាយុកាលខ្លី ផ្តល់
ទិន្នផលខ្ពស់ គុណភាពអង្ករល្អ ថ្លា វែងស្រលូន និងបាយទន់ឆ្ងាញ់ពិសារទៀតផង។

keyword:
N/A

ពូជស្រូវ “ខា១៥” ជាពូជស្រូវស្រាលដែលបានធ្វើការបញ្ចេញ និងផ្សព្វផ្សាយជូនកសិករ
ប្រើប្រាស់ដោយ វិទ្យាស្ថានស្រាវជ្រាវ និងអភិវឌ្ឍន៏កសិកម្មកម្ពុជា នៃក្រសួងកសិកម្ម
រុក្ខាប្រមាញ់ និងនេសាទនាដើមឆ្នាំ២០១៥។  បច្ចុប្បន្ន ពូជស្រូវ
ខា១៥ បាននឹងកំពុង
ផ្សព្វផ្សាយនៅក្នុងព្រះរាជាណាចក្រកម្ពុជា ដោយពូជស្រូវនេះ
មានអាយុកាលខ្លី ផ្តល់
ទិន្នផលខ្ពស់ គុណភាពអង្ករល្អ ថ្លា វែងស្រលូន និងបាយទន់ឆ្ងាញ់ពិសារទៀតផង។



ចំណងជើង:
របាយការណ៍ប្រចាំឆ្នាំ ២០១៣
បរិយាយ:
 
keyword:
N/A
 


ចំណងជើង:
ខា១៤
បរិយាយ:

ពូជស្រូវ “ខា១៤” ជាពូជស្រូវស្រាលដែលបានធ្វើការបញ្ចេញ និងផ្សព្វផ្សាយជូនកសិករ
ប្រើប្រាស់ដោយ វិទ្យាស្ថានស្រាវជ្រាវ និងអភិវឌ្ឍន៏កសិកម្មកម្ពុជា នៃក្រសួងកសិកម្ម
រុក្ខាប្រមាញ់ និងនេសាទនាដើមឆ្នាំ២០១៥។  បច្ចុប្បន្ន ពូជស្រូវ
ខា១៤ បាននឹងកំពុង
ផ្សព្វផ្សាយនៅក្នុងព្រះរាជាណាចក្រកម្ពុជា ដោយពូជស្រូវនេះ
មានអាយុកាលខ្លី
ផ្តល់ទិន្នផលខ្ពស់ គុណភាពអង្ករល្អ  ថ្លា  វែងស្រលូន និងបាយទន់ឆ្ងាញ់ពិសារទៀតផង។

keyword:
N/A

ពូជស្រូវ “ខា១៤” ជាពូជស្រូវស្រាលដែលបានធ្វើការបញ្ចេញ និងផ្សព្វផ្សាយជូនកសិករ
ប្រើប្រាស់ដោយ វិទ្យាស្ថានស្រាវជ្រាវ និងអភិវឌ្ឍន៏កសិកម្មកម្ពុជា នៃក្រសួងកសិកម្ម
រុក្ខាប្រមាញ់ និងនេសាទនាដើមឆ្នាំ២០១៥។  បច្ចុប្បន្ន ពូជស្រូវ
ខា១៤ បាននឹងកំពុង
ផ្សព្វផ្សាយនៅក្នុងព្រះរាជាណាចក្រកម្ពុជា ដោយពូជស្រូវនេះ
មានអាយុកាលខ្លី
ផ្តល់ទិន្នផលខ្ពស់ គុណភាពអង្ករល្អ  ថ្លា  វែងស្រលូន និងបាយទន់ឆ្ងាញ់ពិសារទៀតផង។



ចំណងជើង:
របាយការណ៍សង្ខេបប្រចាំឆ្នាំ២០១៤-២០១៥
បរិយាយ:

keyword:
N/A

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