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Study on TheTechnological Condition for Submerged Fermenter Culture of Clitocybe Maxima Strain

Ngo Xuan Nghien, Nguyen Thi Bich Thuy

Received: 26-07-2016 / Accepted: 06-12-2016
Clitocybe maxima is an edible mushroom with light brown color. Its fruiting body grows out as a stick, and then differentiates into a cap. Clitocybe maxima is also called bamboo shoot or long stem mushroom. The fruiting body contains plenty of amino acids and beneficial minerals esental for the human health. The present study investigated growth of C. maxima strain under liquid fermentation conditions. The experiment results indicated that the C. maxima mycelium grew best on medium containing 2 g yeast extract + 2 g pepton + 0.5 g MgSO4.7H2O + 15 g glucose + 1.5 mg thiamin + 1,000 ml distilled water. On this medium, C. maxima mycelium grew fast and mycelial dry weight attained 33.9 g/ 1,000 ml with highest number of mycelial pellet. Different oxygen supply significantly affected the morphology and mycelial biomass. The optimal concentration of oxygen is 0.75 liters/1 liter of medium/minute; the rate of original spawn of grade 1 for inoculation is 10% of the medium volume. The most suitable incubation time was 84-96 hours. The use of liquid spawn for mushroom cultivation can reduce cultivating cycle by 12 days.
Gastrointestinal Tract Morphology and Clark Index of the Linecheek Tank Goby Glossogobius sparsipapillus Caught from Coastal Estuaries of Bac Lieu and Ca Mau Provinces

Tran Tri Canh, Nguyen Huu Duc Ton, Nguyen Thi Thuy Hien, Dinh Minh Quang

Received: 08-11-2020 / Accepted: 24-12-2020
This study was aimed to provide data on gastrointestinal tract morphology and the relationship of Clark indexand gender, season and sampling site variables of the Linecheek tank goby Glossogobius sparsipapillus. Fish specimens were sampled monthly using trawling nets from September 2019 to August 2020, at three sites in Bac Lieu and Ca Mau provinces. After catching, the samples were determined sex, total length and weight, gastrointestinal tract morphology, gut length and Clark index.The analysis results of 729 specimens showed that this species had a long and pointed snout, flattened head, the mouth was wide and oblique, the lower jaw protruded, and the incision extended to the front eye. There were many rows of teeth on each jaw. It was a carnivorous fish as its intestine length was shorter than the total length of fish (RLG ranged from 0.18to0.83(0.44 ± 0.00)). This species had a high energy storage capacity due to the high value of the Clark index. The Clark of this species varied with season, sampling site, month and season × sampling site, but not gender, gender × sampling site and gender × season. The results have contributed to understanding in future aquaculture of this species.
Ảnh hưởng của trồng xen ngô-đậu tương và biện pháp làm cỏ thủ công đến kiểm soát cỏ dại

Vu Duy Hoang, Ha Thi Thanh Binh

Received: 10-08-2014 / Accepted: 21-04-2015
Nghiên cứu này nhằm đánh giá ảnh hưởng của trồng xen ngô-đậu tương và biện pháp làm cỏ thủ công đến sinh trưởng của cỏ dại. Thí nghiệm đồng ruộng được bố trí theo kiểu Split-plot với ba lần nhắc lại. Ô lớn được bố trí tương ứng với số lần làm cỏ thủ công: Không làm cỏ (NW), làm cỏ một lần ở giai đoạn ngô 3-4 lá (HW1), làm cỏ hai lần ở giai đoạn ngô 3-4 lá và 8-9 lá (HW2). Ô nhỏ được bố trí tương ứng với kỹ thuật trồng xen: M0 (ngô trồng thuần), M1 (trồng xen 1 hàng đậu giữa hai hàng ngô), M2 (trồng đậu trên cùng hàng với ngô) ở vụ xuânhè, hoặc M3 (trồng hai hàng đậu giữa hai hàng ngô) ở vụ đông. Mật độ và chất khô của cỏ dại cũng như cây mọc lẫn được đo đếm trong ba khung điều tra ngẫu nhiên (0,25 m2) cho mỗi ô thí nghiệm ở ba thời kỳ: ngô 3-4 lá (S1), 8-9 lá (S2) và 13-14 lá (S3).Kết quả chỉ ra rằng trồng xen và làm cỏ thủ công đều làm giảm đáng kể sinh trưởng của cỏ dại. Trong các thí nghiệm này, cỏ mần trầu (Eleusine indica) là loài cỏ chiếm ưu thế nhất trên ruộng ngô với mật độ và khối lượng chất khô cao, tuy nhiên sinh trưởng của loài cỏ này bị giảm đáng kể bởi trồng xen và làm cỏ thủ công. Làm cỏ hai lần làm giảm mật độ và sinh khối cỏ nhiều hơn so với làm cỏ một lần. Nghiên cứu này một lần nữa xác nhận tầm quan trọng của biện pháp cỏ thủ công trong việc kiểm soát cỏ dại hiệu quả. Ngô-đậu tương trồng xen nên được kết hợp với hai lần làm cỏ thủ công khi không sử dụng thuốc trừ cỏ.
EFFECTS OF IRRIGATION METHODS ON THE GROWTH,YIELDAND WATER USE EFFICIENCY OF TOMATOES IN RED RIVER DELTAALLUVIAL SOIL

Ngo Thi Dung, Nguyen Van Dzung, Hoang Thai Dai

Received: 28-10-2016 / Accepted: 20-11-2016
Thisexperiment was conducted duringthewinterof2014 on the alluvial soils of the Red River delta to evaluate the effect of irrigation method onthegrowth, yield and water use efficiency of tomato. Soils used for experiments are alluvial, neutral, less acidic, not silted annually. Experimental results have shown that drip irrigation positively affected growing period, plant height, fruiting rate, yield and water use efficiency. Drip irrigation prolonged tomato growing periodfrom 6-11 days compared to furrowirrigation; plant height in the treatments with drip irrigation was also higher compared withfurrowirrigation. The fruiting rate in the treatments with drip irrigation was higher than in furrowirrigation, the highest fruiting rate was obtained in drip treatment T4 with (70-100)% βdr (βdr is field capacity) of 71.3%. Drip irrigation has increased individual yieldof tomato plants from 8.9 - 36.3%, while reduced the amount of irrigation water from 22 - 39.1% and water use efficiency increased from 30 - 57% compared to furrowirrigation. The drip irrigation treatmentwith (70-100)% βdr (T4) achieved highest individual yieldand water use efficiency(2788.2 gplant-1; 16 kgm-3).
Germination Characteristics of some Wild Banana Species and Effect of Storage Conditions on the Germination Rate of Musa balbisiana

Vu Dang Tuong, Vu Dang Toan, Vu ThiThu Hien

Received: 07-01-2022 / Accepted: 15-08-2022
Banana is the most important fruit crop in the world. Using wild bananas as parents in the breeding programs can help develop new banana varieties with pest and disease resistance, high yield, and cold and drought tolerance. The goals of our research were to find out the different germination characteristics of wild banana species and storage conditions on the germination to conserve wild banana resources and to use these wild banana species as materials for future breeding programs. The general experiment evaluation of seed germination was arranged according to the “cutting test” method of and). The experiment of evaluation in different stored conditions of Musa balbisiana seeds was seeded in a fully randomized block with three replications. The results showed that the germination rate of Musa balbisiana collected from western mountainous areas was higher than seeds collected from other regions. The seed germination rate of Musa balbisiana species was up to 27.53%, higher than that of M. acuminata (9.43%), M. itinerans (12.67%)and M. paracoccinea (0%). Stored at silica gel with 15.5% RH and room temperature 25C, Musa balbisiana gave the germination rate up 45.33% (VTN858), while those same samples stored in regrigerator at 4C and 19.5% RH gave only from 6.67% (VTN858).
Ảnh hưởng của mức đạm bón đến sinh trưởng của cây lúa trong các điều kiện hạn khác nhau

Tran Thi Thiem, Yamauchi Akira

Received: 10-08-2015 / Accepted: 29-11-2015
Nghiên cứu này nhằm mục đích đánh giá ảnh hưởng của lượng đạm bón đến sự phát triển bộ rễ, quang hợp và tích luỹ chất khô của cây lúa trong các điều kiện hạn khác nhau. Thí nghiệm được tiến hành trong nhà lưới dưới hệ thống tưới phun nước theo hàng tạo ra độ ẩm đất khác nhau. Ba mức phân đạm: 60, 120 và 180 kg N ha-1được trộn đều với 50 kg P2O và 50 kg K2O ha-1 và bón sau cấy 8 ngày. Kết quả thí nghiệm cho thấy, tổng chiều dài rễ và khối lượng chất khô tăng khi tăng lượng đạm ở mức bón 60 lên 120 kg N ha-1, nhưng khi tăng ở mức bón 120 lên 180 kg N ha-1không làm tăng các chỉ tiêu trên trong điều kiện hạn nặng (<17% w/w độ ẩm đất). Tuy nhiên, trong điều kiện hạn nhẹ (17-25% w/w độ ẩm đất) cũng như tưới nước đủ ẩm (>25% w/w độ ẩm đất), tổng chiều dài rễ tăng, cây hút nước nhiều hơn, quang hợp tốt hơn, dẫn đến cây tích luỹ chất khô cao hơn khi tăng lượng đạm bón từ 60 đến 180 N ha-1. Ngoài ra, chỉ trong điều kiện tưới nước đủ ẩm, tổng chiều dài rễ có mối quan hệ thuận và chặt ở mức ý nghĩa với khối lượng chất khô khi bón đạm ở mức bón 120 và 180 kg N ha-1, nhưng khi bón ở mức 60 kg N ha-1khối lượng chất khô không có mối quan hệ chặt ở mức ý nghĩa với tổng chiều dài rễ. Như vậy, trong điều kiện tưới nước đủ ẩm, việc bón đạm ở mức 120 và 180 kg N ha-1đều làm tăng khả năng tích luỹ chất khô do tổng chiều dài rễ tăng.
Influence of Intercropping and Fertilizer for Mondo Grass on Weeds, Disease and Insect Pests at Young Tea Garden

Nguyen The Hinh, Nguyen Dinh Vinh, Nguyen Van Tuat

Received: 05-09-2012 / Accepted: 28-11-2012
Intercropping of Mondo grass (Ophiopogon japonicus Wall) into tea garden of cv. Kim Tuyen (1-3 years old) is aimed to increase the land coverage, create the favorable conditions for the tea growth and improve the farmers’ income. The impacts of mondo grass intercropping and seven fertilizing formulae on pest occurrence (diseases, insects and weeds) and plant damages were investigated. The major findings are: (i) 15 weed species were found in tea garden, (ii) Mondo grass intercropping can reduce the biomass of weeds in the tea garden, and (iii) The mondo grass is not the host plant of pests on tea. The intercropping of mondo grass led to changes in solar radiation, soil moisture and land coverage which favor pest occurrence and damage such as increasing the density and damage of Empoasca flaescens Fabr. & E. onukii Mats., Helopelthis theivora Waterh, and Colletotrichum camelliae Marasmius equinis Muler Derk. but reduce the density of Physothrips setiventris Bagn and Oligonychus coffeae Niet. on the tea plants.
BREEDING SHORT GROWTH DURATION OF RICE DERIVEDFROM A CROSS BETWEEN INDICA CULTIVAR IR24 (ORYZA SATIVAL.) AND ORYZA RUFIPOGONSPECIES

Pham Van Cuong, Mai VanTan, DoThiHuong, NguyenVanHoan

Received: 16-03-2013 / Accepted: 22-11-2013
The cross between indica cultivar IR24 (Oryza sativa L.) and an accession of Oryza rufipogon Griff., was backcrossed to the recurrent parent (IR24) for four generations followed by repeated selfing and selection for short growth duration lines. A total of 19 backcross lines at BC4F5 generation were evaluated at spring crop seasons of 2011 in Ha Noi and 23 BC4F6 were further evaluated for agronomical traits in 2011 autumn cropping seasons in Hanoi, Thai Nguyen, and Lao Cai provinces. Among the introgression lines (IL), four lines (IL3-4-2-1-1, IL3-4-2-7-1, IL3-4-7-2 and IL19-4-3-8-2) showed shoter growth duration (10-12 days) than that of the recurrent parent IR24 and the control variety Khang dan 18 (10 -12 days), but grain yield was significantly higher than IR24 and Khang dan 18.
The Results of Breeding New Aromatic Thermosensitive Genic MaleSterile (TGMS) Line in Rice

Tran Van Quang, Tran Manh Cuong, Nguyen Thi Hao, VuQuoc Dai, Pham My Linh, Dam Van Hung

Received: 12-03-2013 / Accepted: 18-06-2013
The new E15Sline is thermosensitive genic male sterile line thatwas selected from 135S/Hoasuacrossingby pedigree method. The E15S has short growth duration, leaves numbers 14.1 and good phenotype such as: good tillering, stem and violet awn, long grain. The leaves and endosperm of E15S have aromatic smell mark 4. The critical sterility inducing point (CSIP) of E15S is 240C and high outcrossing ratio. The F1 was crossed between E15S and pollinators which have short growth duration, high yield, good quality and moderated resistance for disease and insects. The results of evaluation on F1 was selected E15S/Huongcom combination that has short growth duration (128 days), high yield (7.4 tons-1ha), milling rice 71.2%, head rice recovery 58.0%, long grain 7.1 mm and aromatic smell mark 3.8.
Biological and Molecular Biological Characterizations ofa Pseudorabies Virus Strain Isolated from Pigs in Vietnam

Nguyen Van Giap, Nguyen Ba Hien, HuynhThi My Le, Dang Huu Anh, Le Van Truong, Vu Thi Ngoc, Cao Thi Bich Phuong, Le Huynh Thanh Phuong

Received: 22-12-2023 / Accepted: 12-04-2024
Pseudorabies has been known in Vietnam for a long time and is still one of the most devastating diseases of particular concern of animal breeders. Despite the emerging and prevailing of variants the virus in many countries around the world since 2010, to date, there is scarce information about the disease as well as the virus circulating in Vietnam. This study aimed to clarify some basic biological and molecular characteristics of an isolate, PRV.PT.001 strain. The isolated strain quickly adapted, induced typical syncytium on Vero cells and reached a relatively high titer after 7 passages (106.58TCID50/ml). The isolate had common characteristics of the virus that causes pseudorabies: it is pathogenic to rabbits and piglets, induces consistent lesions in the respiratory tract, and is widely distributed in many internal organs. Regarding genetic characteristics, strain PRV.PT.001 belongs to genotype 2, carrying typical insertion-deletion mutations in 3/4 of the investigated surface glycoproteins (gB, gC, gD ); but has the characteristic insertion-deletion mutation of genotype 1 in gE glycoprotein.
ExternalCharacteristicsand Reproductive Performance of Bang Troi Chicken

Nguyen Hoang Thinh, Nguyen Thi Vinh, Phan Thanh Lam, Mai Thi Thanh Nga, Bui Huu Doan

Received: 02-07-2020 / Accepted: 12-09-2020
The Bang Troi chicken is one of the Vietnamese native chicken breeds, which is raised mainly in Hoang Bo district, Quang Ninh province. The study was conducted to determine external characteristics and reproductive performance of Bang Troi chicken. In experiment 1, 400 chicks from newborn to 20 weeks of age were raised to record the appearance characteristics and some dimensions of Bang Troi chicken. In experiment 2, 171 chickens from 21 to 74 weeks of age were raised to assess their reproductive performances. Results showed that 1 day-old chicks had 71% with pale yellow feathers, 29% darker yellow brown; at 20 weeks of age, 20% of males had yellow mixed with black, 65% of yellow wings account and 15% of yellow apricot flowers; 65% hens had gray feathers, 15% yellow and 20% apricot, 87% single crested, 13% bud crested; Bang Troi chicken legs were small and short, 92% yellow legs, 8% lead legs. At 20 weeks of age, Bang Troi chicken had an average back length of 19.44cm; the breast length was 12.96cm; the wing length was 19.44cm; thigh length was 10.24cm and shin was 4.76cm. The body weight at laying rate of 5% was 1.69kg; peak production was 2.25kg. Egg yield at 74 weeks of age reached 97.87 eggs; the average farrowing rate was 26.38%; The average egg weight was 48.43g. The rate of egg embryos was 94.83%.
Morphological Characteristics and Productive performance of Co Lung Ducks

Do Ngoc Ha, Dang Thi Hoe, Nguyen Ba Mui, Nguyen Van Duy

Received: 28-02-2020 / Accepted: 21-04-2020
The study was conducted on Co Lung ducks in Ba Thuoc district, Thanh Hoa province and Co Lung ducks on the third generation at Dai Xuyen Duck Research Center to survey the numbers, distributions of Co Lung ducks in Ba Thuoc district and evaluate morphological characteristics of Co Lung ducks. The results showed that the number and distribution of Co Lung ducks in Ba Thuoc district are mainly congregated at 6 communes of Quoc Thanh area, including Ban Cong, Co Lung, Lung Niem, Lung Cao, Thanh Lam and Thanh Son commune. Co Lung ducks have been raised by both grazing and semi-grazing methods. Feed sources used were self-mixed feed and local agricultural production. It was observed that at one day of age, the plumage color is mostly dark gray and pale yellow. In mature, the plumage color is mostly dark brown. The main morphological characteristics of Co Lung duck is: short leg, big head, short neck and medium body. The length of the body of Co Lung duck is 24.72cm in male and 24.82cm in the female; the breast size of the male is 30.06cm, the female is 29.80cm with breast size/ body length ratio of 1.22 and 1.20; The feet height of a male is 7.58cm and female is 7.35cm; The length of wing feathers of male and female duck are 16.36 and 16.23cm respectively.
Utilization of Elongated Uppermost Internode (eui) Gene for Improving Panicle Exsertion of Rice Cytoplasmic Male Sterile

Nong Thi Hue, Nguyen Trong Tu, Bui Thi Thu Huong, Hoang Thi Ngan, Dinh Truong Son, Nguyen Thi Tram

Received: 13-10-2016 / Accepted: 14-02-2017
The major problem encountered in F1 hybrid seed production using cytoplasmic male sterile (CMS) lines is the incomplete panicle exsertion at a rate of 30-60% depending on genotype. Application of exogenous GA3 is often required to overcome this problem. A recessive mutant gene (eui) that causes elongation of the uppermost internode at heading stage can be used as a genetic approach to GA3. In this study, DNA markers were used to identify and screen rice plants with eui gene in CMS lines and in F2 segregating and BC1F1 population. The results showed that 6 CMS lines, 12A, L1A, L2A, L3A, L4A and L5A contained eui gene. Phenotypic and genotypic analysis of F2 and BC1F1 population confirmed that elongated uppermost internode trait was regulated by a single recessive gene and followed of Mendelian segregation ratio..
Genetic Variation of Rice (Oryza sativaL.) Accessions based on Morphological Characteristics

Vu Thi Thu Hien

Received: 25-06-2012 / Accepted: 12-10-2012
The present experiment was conducted to assess bio-agronomical characteristics and genetic diversity of forty-one rice asseccions. Results showed that these rice assessions possess short growing period and several of them are of short stature suitable for intensive farming. The number of panicles/hill, length of panicles, length and width of flag leaves, and 1000 grain weight are genetically diverse. Most of the accessions have long grain and serve as genetic resources for breeding of quality rice. Based on 14 phenotypic traits, forty-one rice accessions were classified into 10 groups of genetic diversity with coefficient of 0.08. The diversity of the morphological characters of rice accessions can be used in breeding pure-line rice for higher yield and quality.
EFFECTS OF SALINITY STRESS ON GROWTH AND YIELD OF QUINOA (Chenopodiumquinoa Willd.) AT FLOWER INITIATION STAGES

Nguyen Viet Long

Received: 08-01-2016 / Accepted: 12-04-2016
The objective of this study was to evaluate the growth and yield characteristics of quinoa genotypes grown under salinity stresses at different stages of development. The experiment was conducted in Vietnam National University of Agriculture. Two quinoa genotypes and four NaCl salt concentrations (0, 50, 150 and 300 mM) were laid out in factorial experiment in RCBD with three replications. Salinity stress was induced by irrigation with nutrient solution containing NaCl with corresponding concentrations to quinoa plants grown in sands for two weeks during flowering initiation (35 days after sowing). The results showed that salinity reduced plant height, number of leaves on main stem, number of branches on plant, root length, root dry weight, shoot dry weight, SPAD Chlorophyll Meter Reading (SCMR), panicle length, seed amount, the number of branches per panicle and 1000-seed weight. Quinoa genotypes with high potential for the number of leaves on main stem, the number of branches on plant, root length, root dry weight, SCMR and shoot dry weight under non-stress conditions performed well under salinity conditions.
Evaluation of Agronomic Traits and Genetic Variation of Gladiolus Varieties (Gladiolussp.)

Nguyen Thi Hong Nhung, Bui Thi Hong, Dang Van Dong, Vu Dinh Hoa

Received: 13-07-2017 / Accepted: 19-12-2017
Genetic variability of the initial materials is considered as the prequistie to generate the genetic variation for the selection process. Twenty-five gladiolus accessions were grown at Gia Lam-Ha Noi in 2015-2016 Winter-Spring season to study genetic variation of traits and direct and indirect attributes affecting flower quality for selection of parents for breeding. The experiment was designed in a randomized complete block design (RCBD) with three replications. Analysis of genetic divergence using morphological characters devided the gladiolus accessions into 4 groups, of which 13 genotypes of groups II and III showed high flower quality without leaf scorch symptoms. All traits had high heritability (79.6-99.7%) and the expected genetic advance varied from 0.38 to 66.53%. Leaf length, diameter of spike can be improved by cultivation practices. Length of leaf and leaf numbers were positively correlated with the length and diameter of the spike.
Evaluating the Impacts of Rice Value Chain Upgradingin Three Sub-Regions of the Mekong Delta

Tran Minh Hung, Le Canh Dung

Received: 20-04-2021 / Accepted: 15-07-2021
This study evaluated the general impacts of the value chain upgrading process and the positive aspects of the upgraded value chain in comparison with the value chain of external cooperatives/cooperative groups. The chain upgrading process was conducted in three cooperatives/cooperative groups categorized into three types of value chains, including open chain, linked chain, and closed chain. The product lines selected for the chain upgrading based on the classification of the Vietnam Food Association (VFA) consisted of two groups. The first one involved specialty rice that is fragrant, soft, and of high quality such as ST24, Dai Thom 8, and Jasmine 85. The second group consisted of long-grain white rice with light fragrance and high quality. The expansion models (MHMR) followed VietGAP, SRP, and organic standards in rice cultivation to meet the market needs. In the course of organizing global value chains, the connection between the market represented by export enterprises and raw material areas is essential. It becomes a primary condition to upgrade the value chain, in which risk and benefits sharing must be discussed and maintained over the long term. This contributes to create standardized products according to the current market needs and to affirm the Vietnamese rice brand.
Nguyen Van Lam, Thuy Huong Nguyen, Hong Anh Thi Nguyen

Received: 16-11-2018 / Accepted: 06-04-2019
Ổi (Psidium guajavaL.) là một loại cây nhiệt đới, được sử dụng làm thực phẩm và thuốc để chữa một số bệnh. Nghiên cứu này nhằm đánh giá sự biến đổi về chỉ số sinh lý, hàm lượng phenolic và khả năng kháng oxy hóa trong quá trình chín của hai giống ổi, Đồng Du và Đại Loan. Quả ổi được thu hoạch ở bốn giai đoạn khác nhau, giá sinh lý, chuyển màu, chín và chín quá. Hàm lượng phenolic và hoạt tính kháng oxy hóa được xác định bằng phương pháp Folin-Ciocalteu và DPPH. Kết quả cho thấy trong quá trình chín, đường kính và trọng lượng của giống ổi Đông Du tăng đáng kể, trong khi các biến số này của giống Đại Loan không thay đổi đáng kể. Về chỉ số màu sắc, các giá trị L, a và b tăng lên, trong khi giá trị hue giảm ở cả hai giống trong quá trình chín của quả. Hàm lượng acid ascorbic tăng trong quá trình chín và không có sự khác biệt giữa hai giống. Hàm lượng phenolic và hoạt tính kháng oxy hóa giảm trong quá trình chín và hai chỉ số này cao hơn ở giống Đông Du so với giống Đại Loan. Hàm lượng phenolic và khả năng chống oxy hóa có mối tương quan chặt (P <0,001), cho thấy các hợp chất phenolic là chất kháng oxy hóa chính trong ổi. Giai đoạn chín là thời điểm thích hợp để thu hoạch trái cây để tiêu thụ để. Thời gian thu hoạch phù hợp là rất quan trọng để sản xuất các sản phẩm ổi chất lượng cao như nước ép ổi và mứt.
Growth, Carcass Yield and Meat Quality of Dong Tao Chickens

Le Thi Tham, Ngo Xuan Thai, Vu Van Thang, Dao Thi Hiep, Doan Van Soan, Vu Dinh Ton, Dang Vu Binh

Received: 27-09-2016 / Accepted: 20-11-2016
The study was conducted to evaluate the growth performance, carcass yield and meat quality of Dong Tao chickens raised under semi-pasture at households. Five households in Dong Tao commune were selected for raising 250 Dong Tao chickens from 1 day old to 24 weeks old. The results showed that after 24 weeks, the survival rate was 86.4%. The males and females reached body weight of 2584.76 and 2.188,95g, respectively. The feed intake and FCR were 105 g/head/day and 4.6 kg, respectively. Dressing, breast, thigh and abdominal fat rate were 66.76, 15.39, 23.40 and 1.62%, respectively (the males had no abdominal fat). The meat colors of Dong Tao chicken were as follows L*: 53.71 - 59.72; a*: 8.20 - 13.76 and tenderness ranged between 28.66 - 37.14 kg/cm2. The thigh muscles were darker, dark red and tougher than breast muscles. Dong Tao chickens were relatively high in carcass yield, normal in meat quality and the meat was red and tough.
In vitromaintenance of indigenous taro (Colocasia esculentavar. esculenta (L) Schott)

Vu Ngoc Lan, Nguyen Thi Phuong Dung, Nguyen Van Phu

Received: 06-11-2013 / Accepted: 04-06-2015
Colocasia esculenta(L)Schott belonging to Araceae family has a long history of cultivation and plays an important role in food production of the poor agricultural and slow developing countries, in including Viet Nam. Tissue culture method is considered as an important method for producingdisease-freeandlong-term conservationof genetic resources and the means forexchange of taro germplasm, especially for conservation of genetic resource distributed inmountainous areas or wild relatives that are difficult to maintain in field conditions. Results of in vitromaintenance of Bac Can taro showed that the suitable materials used for micropropagation were tubers.Themost suitabledisinfection was achieved by dipping taro tubers in 0.1% HgCl2 for7 minutes + 0.1% HgCl2 in 1 minute. Optimum medium for in vitrotaro plantlet maintenancewas MS + 6 g/l agar + 2g/l mannitol, or cultured under conditions of low temperature(5°C). These culture conditionsnot only reduced the growth of in vitroplantsand prolonged thetime for conservationbut alsosustainedgood growth of in vitroplants. The medium used formaintenance ofin vitrotubers was MS + 90g/l saccarose + 6g/l agar + Alar 2g/l and photoperiod16h/day.
Evaluation on Drought Tolerance of Rice Lines with Indica Genetic Background Carrying Chromosome Segment Substitution from Wild Rice (Oryza rufipogon)or Japonica

Pham Van Cuong, Doan Cong Dien, Tran Anh Tuan, Tang Thi Hanh

Received: 21-10-2014 / Accepted: 10-03-2015
Twenty chromosome segment substitution lines (CSSLs) developed from IR24 background (5 lines of Ruf ILs (IR24 × O. rufipogon), 15 lines of IAS (IR24 × Assominori - a Japonica cultivated rice) and IR24 were evaluated for drought tolerance at tillering stage. The 3-leaf seedlings were grown in Kimura B + 20% PEG6000 solution (drought treatment) or in Kimura B solution (non-drought treatment). The results showed that, the drought resistance index (DRI) correlated with the dry matter under drought and non-drought conditions with r = 0,614 and r = 0,604, respectively. The number of leaves, leaf area, root surface area, number of roots and root hairs in both CSSLs and IR24 were reduced in drought condition. But, there was no reduction in root numbers and root hairs numbers in CSSLs, which had higher DRI. The results also showed that, drought tolerance mechanism of IAS lines might involve the increase of root growth, water uptake and root-to-shoot water transport. However, the mechanism in Ruf ILs lines might involve the reduction of leaf number, leaf area and in company with increase of root growth and water uptake. These finding suggested that wild rice O. rufipogon and Asominori would be ideal materials for rice breeding for drought tolerance.
Delaying Flowering of Tobacco Variety K326 by Supplemental Lighting,Night Interruption Lighting and Detopping

Nguyen Van Van, Hoang Minh Tan

Received: 24-06-2013 / Accepted: 22-09-2013
Early flowering is undesirable in tobacco (Nicotiana tabacumL.) production because it reduces yield and quality of raw materials. This study was carried out to determine the possibility of delaying floral induction and flowering without causing undesirable side-effects to the plants. Flue-cured tobacco plants of cultivar K326 were treated with various combinations day length and night break lighting under nethouse conditions. Four hours supplemental lighting (prolong day length duration, equivalent to 16hours/8hours day/night) and one-hour middle-of-night interruption were able to delay flower induction/flowering of the short - day tobacco plants cv. K326. Detopping of plants under field conditions to induce new branch also prolonged days to flowering. If night interruption or supplemental lighting was implemented continuously for 10 or more cycles, flowering could be delayed by 28 to 30days. Detopping to promote branching at 5th and 10thleaf position delayed flowering by 8 days and yielded in increased leaf number and size in comparison with the control.
Techniques ForImproving Vegetative Propagation Rate of (Polyscias fruticosa (L.) Harms

Ninh Thi Phip

Received: 01-02-2013 / Accepted: 18-04-2013
Effect of substrate, stem cutting length, cutting position and concentration of plant growth regulator on vegetative propagation and and growth of Polyscias fruticosa (L.) Harms was investigated.. The results showed that using the rooting medium mixture of 50% soil + 50% rice husk obtained the highest of shoot height, stem diameter, number of leaves/plant) and number of roots/plant). In addition, uing the main stem with 15 - 20cm length quickly dipped in for 2000 - 3000ppm α -NAA solution for 3 - 5 seconds appeared optimal for growth of Polyscias fruticosa L. stem cutting.
Identification of Drought-tolerant Lines and Local Cultivars for Development Genetic Material and Rice Breeding for Rainfed Environment

Nguyen Thi Hao, Dam Van Hung, Pham My Linh, Vu Quoc Dai, Le Thi Hau, Dong Huy Gioi, Vu Van Liet

Received: 02-02-2013 / Accepted: 18-04-2013
Drought is a major constraint affecting rice production, especially in rainfed areas of mountainous regions of Vietnam. Development of drought tolerant varieties will improve rainfed rice production. Identification of drought-tolerance of the lines and local cultivars is useful for the development of genetic material and rice breeding for adaptation to rainfed environments. Forty two rice accessions were evaluated for germination and seedling characteristics by treatment of rice seed with KClO3. The plants were planted in PVC pipe to evaluate root length and root growth under well-watered and water-stressed environments. In addition, QTLs associated with root lengthen and root growth were analyzed using SSR markers. We have identified 11 accessiopns (lines and local cultivars) with drought tolerance. Three best drought tolerant accessions, 455 (Khau li on/Q5), 464 (Mua chua, Dien Bien) and 487 (Khẩu lếch, Bak Kan) are recommended for rice breeding program for rainfed environment.
Effect of MyoGand Lif Gene on Economic Traits in Pigs

Do Vo Anh Khoa

Received: 14-07-2012 / Accepted: 20-08-2012
The study was conducted in 33 castrated male pigs of Yorkshirex Landrace crossbredto analyze the association of polymorphisms of myogenin (MyoG) and Leukemia-Inhibitory-Factor (LIF)genes with some economic traits for growth and carcass performance. The genotypes of MyoG were significantly associated with carcass percent, in which pigs with heterozygous genotype AB (76.32±1.30) was superior to the homozygous genotypesBB (72.77±1.30) and AA (69.46±2.91) (P=0.05). In addition, in LIF locus, the association between genotypes and carcass length also showed significant difference (P<0.05), with the highest carcass length occurring in pigs withhomologous genotype BB (78.00±2.84). Therefore, it is suggested that allele “B” in both candidate genes could be used as a SNP-marker to improve carcass performance in pigs.

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