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Morphorlogical Characteristics and Growth Performance of Hac Phong Chicken

Nguyen Thi Phuong Giang, Nguyen Thi Chau Giang, Nguyen Van Thong, Nguyen Thi Vinh, Pham Kim Dang

Received: 17-12-2021 / Accepted: 05-04-2022
This study was conducted to evaluate morphological characteristics and growth performance of Hac Phong chicken. A total of 100 birds(50males and 50females)at 1 day of age were raised at the experimental station of the Faculty of Animal Science,Vietnam National University of Agriculture. Animals were fed and taken care following the standards for colored chicken. The results showed that Hac Phong chicken is a small chicken breed.Adult chickens (at 20 weeks of age) have black color of feather, skin, meat, and bone and the foot has five toes. All most animals have bud comb with purple-black color and all hens (100%) have head feather. The survival rate until 20 weeks of age was high at 96%. The body length of the cock at 8, 12 and 16 weeks of age was 13.00cm; 16.30cmand 18.14cm, respectively, and was higher (P <0.05) than the hens with the value of 10.76cm; 15.57cm; 16.20cm, respectively. At 20 weeks of age, the average body weight of the males and females was 1,381.90g and 1,150.49g, respectively. Feed conversion ratio was 4.58kg feed/kg weight gain during 1-20 weeks of age.
Testing the Antiprotozoal Potential of Nanosilver Against Ichthyophthirius multifiliis on Snakehead Fish (Channa argus)

Le Viet Dung

Received: 25-08-2020 / Accepted: 01-10-2022
This study evaluated the efficacy of nano-silver (NS) for treatment of disease caused by I.multifiliisin snakehead fish (Channa argus) both vitroand vivoexperiments. A series of NS concentrations (0, 0.1, 0.5, 1, and 1.5 ppm) was tested on the parasitic stage (Trophont) and reproductive stage (Tomont). In vitrotesting results showed that NS was effective in killing germs in both trophont and tomont stages. The pathogen mortality was highest at 1.5 ppm NS; after 12h the mortality rate was 95.45 and 98.15% for trophont and tomont, respectively. All snakehead fish (3g) in the 7-day in vivoexperiment died at treatments of 1.5, 1 and 0 ppm NS on the 1st, 1st, and 6thday, respectively. The survival of fish in the 0.1 and 0.5 ppm treatments was 63.3% and 33.3%, respectively, on the 7thday. Hence, the NS might have killing effects on trophont and tomont but also toxic effects on 3-g snakehead fish.
Effects of Gamma Co60Irradiation for Some Local and Imported Rice Varieties

Nguyen Thi Mien, Nguyen Trong Khanh, Tran Van Quang

Received: 05-08-2021 / Accepted: 29-10-2021
This study was carried out to effects of gamma ray irradiation of irradiation Co60 source forsome local and imported rice accessions. This experiment was designedwith 3 dose (200Gy, 300Gy and 400Gy) on the mutagenesisof three rice (12% seed humidity). At generation M1, the results showed that the seed germination and survival percentage of all rice accessions decreased with the increase of the irradiation doses. Mutated plants with shorter growth duration, lower plant height, more upright flat leaves appeared, greater tillering capacity with high mutation frequency at irradiation dose of 200Gy, 300Gy for imported rice varieties NN1, NN3 in the M2generation. The mutation appeared with very low frequency when irradiating the local rice variety Khau Mang. Selection on M3generation of 200Gy and 300Gy irradiation treated varieties NN1 and NN3 picked up some promising rice lines with short growth duration, short plant height, more upright flat leaves appeared and high tillering capacity. To sum up, gamma Co60irradiation at 200Gy and 300Gy dose on dried seeds could renovated some agronomic traits such as growth duration, plant height, flag leaf morphology and tillering capacity on two imported rice varieties NN1 and NN3.
In VitroPropagation of Yellow-Flesh Taro (Colocasia Esculenta(L.) Schott) Collected in Thanh Son District, Phu Tho Province

Nguyen Thi Lam Hai, Pham Thi Thu Hang, Dinh Truong Son, Dang Thi Thanh Tam, Nguyen Thanh Hai, Do Thi Kim Ngoc, Nguyen Thi Thanh Thuy

Received: 10-06-2020 / Accepted: 22-09-2020
The yellow-fleshtaro belongs to the group of taro (Colocasia esculenta(L.)Schott)andis the native taro of Thanh Son district, Phu Tho province with high nutritional and economic value. The yellow-flesh variety is now being degenerated due to clonal propagation for many generations,therefore this study aims to rejuvenate this taro variety usingplanttissue culture. The mature tubers were used as a material to initiate in vitroculture.The in vitroshoots formed after the initial culturewerecut and culturedin MS medium supplemented with the different plant growth hormones for rapid shoot multiplication. The shoots were subcultured to MS medium supplemented with growth regulators belonging to the auxin group for rooting. The results showed that the optimal medium for rapid shootmultiplication was MSmedium supplemented with1.0mg/L BAP which would multiply 9.65 shoots/sample. The rooting medium for in vitroshoots was MS mediumsupplementedwith0.3 mg/L α-NAA with a rooting rate of 100%. The in vitroplants weretransferred to the greenhouse and grown in soil substrate and coconut fiber in 1: 1 ratio, the survival rate was 90%, the plantlets showed vigorous growth and produced new leaves after 2 weeks of acclimatization.
Effects of Dietary Inclusion of Canthaxanthin from Halophiles on Growth and Muscle Pigmentation of Rainbow Trout (Oncorhynchus mykiss)

Tran Thi Mai Huong, Do Van Thinh, Cao Thi Linh Chi, Le Van Khoi, Dang Viet Anh, Tran Quoc Toan, Tran Thi Thuy Ha

Received: 04-05-2020 / Accepted: 04-08-2020
This study aimed to evaluate the effect of dietary supplementation of canthaxanthin extract derived from Paracoccus carotinifaciensVTP 20181 (bio-canthaxanthin) into diet for grow-out rainbow trout (Oncorhynchus mykiss) on the growth performance and pigment of rainbow trout muscle. The experiment was performed with five treatments including four levels of canthaxanthin from rich bacterium P. carotinifaciens VTP 20181 as a feed for rainbow trout at 0, 25, 50, 75 mg/kg (CT0, CT25, CT50, CT75), respectively and a diet contained chemical canthaxanthin 40 mg/kg as the control diet (ĐC). After the time of 90 days of feeding trial, there was no significant difference in survival rate, growth performance and carcass composition of rainbow trout (P >0.05). The score of pigmentation in diet was added 50.75 mg/kg higher than that of in diet were added 0.25 mg/kg canthaxanthin but no significant with control (P >0.05) was found. Fish fed the diet contained 50 or 75 mg/kg of bio-canthaxanthin showed the same efficacy with the commercial diet.
Growth Performance and Meat Quality of 3/4 Dong Taoand1/4 Luong PhuongCrossbred Chickens

Nguyen Van Duy, Nguyen Dinh Tien, Vu Dinh Ton

Received: 01-06-2020 / Accepted: 25-06-2020
This study was carried to determine the growth performance, meat productivity and quality of 3/4 Dong Tao (ĐT) and 1/4 Luong Phuong (LP) crossbred chickens raising. The growth performance was determined on the 180 chicks from one day of age to 24 weeks. We first randomly divided all the chicks into 3 cocks and 3 hens to determine the meat yield and meat quality at 16, 20 and 24 weeks of age. The survival rate of 3/4ĐT and 1/4LP from one day of age to 24 weeks was 98.33%. At 24 weeks, the alive weight was 3068.33 g for cocks and 2046.67 g for hens. The average daily gain of chickens gradually increased from 1 to 12 or 13 weeks for hens and cocks, respectively and then decreased. From 19 to 20 weeks of age, the growth rate was very low with ADG/day at 12.9 g (cocks) and 8.21 g (hens). The FCR of chickens in period 20 weeks was 4.47 and in period 24 weeks was 5.15. The 3/4ĐT and 1/4LP chickens had a high meat yield and good quality of meat. In conclusion, it is possible to use the 3/4 Dong Tao and 1/4 Luong Phuong in the production of broiler chickens.
Morphological Characteristics, Growth Performance, Carcass Yield of Indigenous Tien Yen Chicken

Nguyen Dinh Tien, Nguyen Cong Oanh, Nguyen Van Duy, Vu Dinh Ton

Received: 28-05-2020 / Accepted: 06-06-2020
This study was conducted to determine morphological characteristics, growth performance, carcass yield and meat quality of purebred Tien Yen chicken raised at the experimental farm of Vietnam National University of Agriculture, and at household farms in Tien Yen district Quang Ninh province. A total of 114 individuals was were morphologically characterized. Growth performances were assessed on 55 chickens, and carcass yield was evaluated on 6 individuals for each period. The results showed that, at 1-old-day, chicks had 2 main feather colors including yellow with black stripes (90%) and yellow (10%); At 38 weeks old, cocks’ body feather color was characterized by black bronze (71.8%) and bronze brown (28.2%), while the hens were characterized by bright yellow 80% and dark brown 20%. Chickens had a chin’s feather (beard) 90% or a typical head’s feather 10%. The survival rate was high 94.6% and the males had significantly heavier body weight compared with the females during from 3 weeks old (P <0.05). At 16 weeks old, the average body weight of males and females was 1685g and 1372 g respectively. The feed conversion efficiency was 3.8 kg feed/kg weight gain during 0-16 weeks old. The relative percentage of carcasses was 61-64%, percentage of breast meat and thigh meat were 13.2-17.2% and 19.6-23.1% respectively. Drip loss percentage of preservation and cooking for 24 hours post-mortem were 2.6-3.2% and 22.6-24.9%, respectively, and its meat quality was within the normal range of value.
Effect of Dietary Protein Level on Growth Performance and Feed Utilization of Asian Swamp Eel (Monopterus albus)

Mai Van Tung, Nguyen Thi Oanh, Le Xuan Chinh, Tran Thi Nang Thu

Received: 10-05-2019 / Accepted: 31-10-2019
The experiment was conducted to study the effect of feed protein level onthe growth performance and feed utilisation of ells (Monopterus albus). Four types of industrial feed with protein level were 42, 40, 35 and 30%, respectively, were used in the study, each experiment was repeated thrice. Breeding eels with the average mean body weight of approximately 4 g/eel were distributed in composite tanks of 2 m3, density of 40 eels/m3. The experimental time was 5 months. The protein level of the feed did not affect the eel survival rate, but had a significant effect on the growth rate, feed efficiency and feed cost. Eels using feed with 30% protein content showed low growth rate, low feed efficiency, high feed cost. Eels use feed with 42% protein content, 35% for high growth rate but high cost. Eels using feed with 40% protein content showed a high growth rate, high feed efficiency and lowest feed cost and therefore is recommended for farmers to use.
Study on In vitroPropagation ofGlinus oppositifolius(L.) DC.

Vu Thi Hoai, Ninh Thi Phip

Received: 25-09-2018 / Accepted: 02-04-2019
Glinus oppositifolius (L.), an indigenous medicinal plant, has long beenused as a liver detoxification in Vietnam. Generally, seeds could be used for propagation. However, the drawbacks of this method include small seeds, low germination rateand slow seedling growth. In vitropropagation is apotential approach to increase the quantityand quality of planting meterials. In this study, a protocol for in vitromultiplication of Glinus oppositifolius was established by optimizing initial culture, shoot propagation and rootinductionin vitroand plantlet acclimatization.For explant isolation from stems,sterilization by Johnson (1%) for10 minutes yieldedthe highest survival rate(76.67%).BA concentration of 0.5 mg/L was most suitablefor shoot formation and growth. The medium added with0.5 mg/LBA and 0.5 mg/L-NAA/IAA showed the highestmultiplication rate, leaf number and plant height after four weeks of culture. Supplementing with0.5 mg/L-NAA for rooting stage resulted in100% rootinduction.The substrate containing100% coconut coiryieldedbest quality of plantletsat 40 days after planting.
Effectof Salinity onOutbreak of Swollen Siphon Disease in Otter Clam(Lutraria philippinarumReeve, 1854)

Dang Thi Lua, Pham Thi Yen

Received: 15-03-2018 / Accepted: 29-01-2019
Swollen siphon disease has been considered to be a serious threat to otter clam farmingin Vietnam; however, the cause of the disease has not been clearly understood. In this study, salinity factor (salinity concentrations of 20‰, 25‰, 30‰, 35‰ and 40‰) was selected for evaluating its impact on the survival and outbreak of the swollen siphon disease in in vivoexperiments. The results showed that the otter clams died at salinity level less than or equal to 25‰and higher or equal to 35‰. However, the dead otter clamsdid not show any clinical signs of the swollen siphon disease. The results of the experiment of otter clam injected with diseased siphon’s filtrates and maintained at different salinity conditions ranking from 20‰to 40‰showedthat the salinity was significantly associated withmortality and outbreak of the swollen siphon diseaseshowing clinical signs. This study indicated that the salinity is not the cause of the swollen siphon disease in otter clam but it may be a risk factor that was significantly associated with the outbreak of the disease, particularly high salinitylevel(higher or equal to 35‰).
In vitropropagation of Taiwanese Sweet Mulberry

Nguyen Thi Ly Anh, Nguyen Thi Thiet, Tran Thi Luyen, Dang Thi Nhan, Nguyen Thi Han

Received: 26-07-2018 / Accepted: 03-12-2018
In vitropropagation of Taiwanese sweet mulberry was carried out to determine technical parametersinthe production of high quality planting materialsfor expanding cultivated area of the newly introducedfruit tree. One-month-old shoots of two-year-old Taiwanese sweet mulberry plantswere used as initial materialsfor in vitroculture. Results showed that BA at the concentration of 3mg/l in MS medium was suitable for stimulating in vitroshoots from stem nodes with highrate(83.33%). BA at 3 mg/l in combination with0.5 mg/l IBA and 10% coconut water gave the best shoot multiplication rate (2.93 shoots/explant) and the highest shoot quality after 4 weeks of culture. The highest rooting percentage at 96.67% of shoots was observed after 4 weeks onMS medium containing 0.5 mg/l IBA. The plantlets were successfully acclimated in sandy substrate with a survival rate of 80%. The liquid fertilizer “Buffalo Head 502” foliar spary 1 time/weekyielded good quality plantlets suitable for transplanting into pots.This in vitropropagation process is highly effective and easy to apply at production scale.
Growth Characteristics of Co Lung Broiler Ducks Raised in Thanh Hoa Province

Do Ngoc Ha, Nguyen Ba Mui

Received: 11-07-2018 / Accepted: 21-08-2018
A study was conducted on 100 Co Lung broiler ducks (50 males and 50 females) raised in Thanh Hoa province from 1 day to 12 weeks of ageto evaluatetheir growth characteristics, FCR and the economic efficiency, and thus determine the suitable slaughter age. Results showed that the survival rate of Co Lung ducks up to 12 weeks of age was 95.33%. At 10 weeks of age, the body weight was 1960.03 g and 1876.84 g for males and females, respectively. At 12 weeks of age, the males and females weighed 2103.08 g and 2005.97 g, respectively. The absolute growth rate increased gradually from 11.99 g/duck/day at 1 week of age, reached highest value of 35.05 g/duck/day at 7 weeks of age and gradually decreased to 8.54 g/duck/day at 12 weeks of age. FCR during 0-10 weeks of age was 4.02, 1-11 weeks of age was 4.69, and from 1 to 12 weeks of age was 5.41 kg of feed/kg live body weight gain. The economic efficiency was highest when the broiler ducks sold at 10weeks of age and gradually decreased thereafter. It was therefore recommened that Co Lung broiler ducks should be sold for slaughter at 10 weeks of age for high economic profits.
Population Dynamics of Javaen Barb(Systomus rubripinnisValenciennes, 1842) along Hau River, Mekong Delta of Vietnam

Au Van Hoa, Tran Van Viet

Received: 10-05-2018 / Accepted: 05-10-2018
A study on population dynamics of Javaen barb (Systomus rubripinnis)was carried out from January toDecember, 2016 along Hau River in An Giang and Can Tho provinces. Trap fence nets and gill nets were used for monthly fish catch sampling. Fishes were counted and measured for body weight (g) and length (cm) to monitor the temporal and spatial fluctuation on quantity and size. Results showed that the growth rate was high (K = 0.5/year); the survival rate after hatching to fishing size in the wild was low (6.2%); the total mortality was 2.8/year, and the fish was mostly caught at 8-11 cm in body length. The fish of smaller sizes was not affected by fishing gears and larger sizes were rarely found in the wild. The total length of fish could reach 20.5 cm. The breeding of this species occurred the whole year round with the peak in rainy and flooding seasons. Phytoplankton and detritus were the main food of this species. Larger fish was found more abundant upstream.
Effects of Dietary Canthaxanthin on Growth and Skin Color of Permit (Trachinotus falcatus)

Nguyen Quang Huy, Do Van Thin

Received: 21-08-2018 / Accepted: 08-11-2018
This study was conducted to evaluate the effects of dietary canthaxanthin on growth and skin color of permit (Trachinotus falcatus) cultured in sea cages. Four formulated diets with the same nutritional composition (45% protein and 15% lipid) were supplemented with canthaxanthin at 0 mg/kg, 40 mg/kg, 80 mg/kg and 120 mg/kg. Yellow color on the body and fins of the fish was evaluated by colorimetry using Yolk Color Fan. The growth, feed conversion ratio and survival of the fish were not significantly different (P >0,05) after 30 days of culture. However, the yellow color on the body and fins was markedly different among treatments. Fish fed diet supplemented with with 120 mg canthaxanthin/kg had higher yellow scores than those fed control diet (0 mg/kg) and 40 mg/kg diet (P <0,05). There was no difference in color score between treatments supplemented with 0, 40 and 80 mg canthaxanthin/kg. The results showed that supplementation of 120 mg canthaxanthin/kg diet effectively enhanced skin color of permit.
Effects of Chemicals and Induced Methods on Reproduction Efficiency of Mud Clam (Geloina sp.)from U Minh Thuong, Kien Giang

Ngo Thi Thu Thao, Danh Nhiet, Tran Ngoc Hai, Nguyen Xuan Niem

Received: 27-02-2018 / Accepted: 16-05-2018
Clam broodstocksGeloinasp were collected at U Minh Thuong areas, Kien Giang province to investigatethe effects of different spawning methods on efficiencyin the hatchery. The study consisted of3 experiments: 1) Using chemicals, 2) Changing temperature and 3) combining chemicals and temperature changes. Several indicators such as number of reproductive individuals, reproductive rate, survival, effective time and the numbers of eggs were significantly differentamong treatments (P < 0.05). Results showed that lowering temperature combined withflow through water system was most suitable for clam spawning withr 50%efficiency, high eggs/individual (1.203.000 ± 199.983)andshorter spawning time..
Study on Micropropagation of Strawberry “Smia”

Nong Thi Hue, Pham Thi Thu Hang, Tuong Thi Thanh Huyen, Nguyen Thi Thuy Linh, Nguyen Thi Lam Hai, Nguyen Thanh Hai

Received: 20-09-2017 / Accepted: 31-01-2018
Strawberry “SmiA” is a potential variety with outstanding features such as heart- shaped fruit, dainty little red berries with an ambrosial flavor of strawberry, rose, pineapple and honey. This study was carried out to establish in vitro micropropagationprotocol from in vitro germinated plants. The best shoot proliferation (7.8 shoots/explant) was obtained from explants grown on MS medium supplemented with 0.4 mg/l BA after 5 weeks. In vitro shoots were rooted on semi-solid MS medium with 0.25 mg/l α-NAA, maximum rooting rate (93.33%) with 12.36 roots/shoot and average length (1.49 cm) of roots was achieved after 4 weeks. The plantlets were successfully acclimated and well developed in soil substrate with a high survival rate. NPK fertilizer combined with Atonik solution was most appropriate for growth and development of in vitro SmiA plantlets with the average height of 19.13 cm after 1 month. Flowering was observed after 20 - 25 days of flower-bud formation, and masses of dainty, sweet tasting berries were produced after 30 - 35 days.
Establishment of In vitroPropagation Protocol for Golden Camellia(Camellia sp.)

Dang Quang Bich, Nguyen Thi Phuong Thao, Nguyen Van Phu, Dinh Truong Son, Ninh Thi Thao, Nguyen Van Huan, Tran Van Lin, Nguyen Thi Thuy Linh

Received: 29-08-2017 / Accepted: 31-01-2018
Golden camellia (Camellia sp.)is a medicinal plant containing a wide range of pharmacologically active compounds that can be used in anti-inflammatory, prevention and treatment of cancer. Golden camillia is also used as an ornamental plant because of its bright yellow flowers. This study successfully established in vitro multipropagation protocol of Camellia sp. collected at Ba Che district, Quang Ninh province, Vietnam. Unopened fruits were identified as the best initial material. Unopened fruits were surface sterilized with 7% NaOCl solution for 30 minutes. Seeds were then placed on MS medium supplemented with 1 mg/l BA and 3 mg/l GA3 for germination. Shoots were multiplied on MS media containing 5 mg/l BA + 1 mg/l GA3 + 300 ml/l coconut water + 30 g/l sucrose + 7 g/l agar. The rate of shoot multiplication was 4.7 shoots per explant. The shoots were then transferred onto medium of 1/4 MS + 0.5 mg/l α-NAA + 2 mg/l IBA + 30 g/l sucrose + 7 g/l agar for rooting. At the nursery stage, in vitro plants were grown in sand and reached the survival rate of 93.75%. The established protocol can be applied for multipropagation and conservation of the golden camellia.
Utilization of Natural Haploid Inducer, UH400, for Hybrid Maize Breeding

Pham Quang Tuan, Dòng Huy Giói, Nguyen Viet Long, Vu Van Liet, Nguyen Thi Nguyet Anh, Nguyen Van Ha, Doan Thi Yen, Nguyen Trung Duc

Received: 25-07-2016 / Accepted: 20-11-2016
Adaptability and haploid inducing ability of UH400 were evaluated in 4 cropping seasons during 2014 and 2015 at Gialam, Hanoi, Vietnam. Twenty yellow dent maize hybrids were crossed with UH400 and the F1 seeds were evaluated for haploid induction rate using anthocyanin color marker. Ploidy doubling was done by colchicine treatment at 0.06% for 8 hours to develop double haploid (DH) lines. DH lines were evaluated for growth and yield in 2015 spring cropping season and ploidy level determined in spring 2016. The studies showed that UH400 can be grown in fall-winter and spring cropping seasons in the North of Vietnam, while seed multiplication and line maintenance be done in spring. UH400 can be used for haploid induction on yellow dent maize hybrids with induction rate of 7.05%. DH lines developed in this study had poor survival rate (14.4%). The use of SSR marker phi065 to identify haploid seeds from six crosses with UH400 showed that five crosses (M8, M12, M19, M21 and M22 crossed to UH400) are haploid.
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.
Salinity Tolerance of Black Carp (Mylopharyngodon piceus)at The Fingerling Stage

Kim Van Van, Doan Thi Nhinh, Trinh Thi Trang

Received: 18-08-2015 / Accepted: 22-01-2016
To test the culturability in brackish water the experiment was carried out to evaluate the salinity tolerance of Black carp (Mylopharyngodonpiceus) at the fingerling stage. Fish at size of 45 ± 0,3 gram/individual were stocked in several 120L-buckets with stocking density of 15 fish/bucket. The experiment included in 2 trials: trial 1 was conducted to assess salinity tolerance without acclimation when putting Black carp fingerlings directly from fresh water into treatments with different salinity concentration of 0, 5, 10, 13, 15, 17, 20‰; trial 2 was designed similar to trial 1 but fish was acclimated in brackish water before putting into different salinity concentration treatments. The results showed that non-acclimation black carp have 100% survival rate at the salinity of 13‰, but 100% mortality after 102 hours at 15‰, 12 hours at 17‰ and 4 hours at 20‰. Similarly, in the trial 2 with acclimation condition, Black carp were alive 100% at the salinity 13‰ and died quickly at higher salinity levels. Comparison of trial 1 and trial 2 in both condition revealed that Black carp could adapt and grow well in the arrange of salinity from 0-13‰, but quickly died without acclimation at 15‰ and showed no significant differences at 17 or 20‰. The growth rate of Black carp fingerlings in salinity 0‰ was highest with7,9a ± 0,61(gram/fish/week) and in lowest in 13‰ salinity (5,6c ± 1,12 (gram/fish/week). Histological observation indicated that there was no change in shape and structure of gills and kidney at the salinity of 0, 5, 10, 13‰, but at the 15‰ fish gills were dehydrated and shrinked and the kidney was clustered.
Nghiêncứuảnhhưởngcủanhiệtđộnướcthấpđếnsựgâybệnhcủavirútđốmtrắng(WSSV) trêntômhe NhậtBản(Marsupenaeusjaponicus)

Dang Thi Lua, Ikuo Hirono

Received: 08-07-2015 / Accepted: 09-12-2015
Vi rút đốm trắng (WSSV) là vi rút gây bệnh có độc lực mạnh trên tôm nhưng dễ bị ảnh hưởng bởi các yếu tố gây sốc. Các biện pháp khống chế WSSV đã và đang được nghiên cứu nhưng vẫn chưa được áp dụng vào thực tiễn, do vậy việc quản lý môi trường nhằm hạn chế các yếu tố gây sốc đóng vai trò quan trọng trong việc ngăn ngừa bệnh WSSV. Nghiên cứu này đánh giá ảnh hưởng của nhiệt độ nước, đặc biệt là nhiệt độ nước thấp, đến khả năng gây bệnh của WSSV trên tôm he Nhật Bản. Kết quả nghiên cứu cho thấy tỷ lệ tôm chết sớm và cao nhất, lên tới 100% sau 7 ngày gây nhiễm WSSV, đã quan sát thấy ở nghiệm thức tôm nuôi ở 25oC, tiếp đến là ở nghiệm thức tôm nuôi ở 20oC và tỷ lệ chết thấp nhất ở nghiệm thức tôm được giữ ở 15oC. Nghiên cứu cũng cho thấy, tỷ lệ tôm chết xuất hiện muộn và thấp hơn ở tôm thí nghiệm nuôi ở 25oC nhưng được hạ nhiệt độ xuống 15oC sau khi gây nhiễm khi so với tôm trước và sau khi gây nhiễm đều giữ ở 25oC. Ngược lại, tỷ lệ tôm chết tăng lên ở nghiệm thức tôm giữ ở 15oC sau đó được nâng lên 25oC sau khi gây nhiễm khi so với nghiệm thức tôm giữ ở 15oC trước và sau khi gây nhiễm. Kết quả này được kiểm chứng bằng kỹ thuật PCR và RT-PCR. Kết quả nghiên cứu cho thấy sự gây bệnh của WSSV trên tôm he Nhật Bản phụ thuộc vào nhiệt độ và tôm mẫn cảm nhất với WSSV ở nhiệt độ khoảng 25oC. Nhiệt độ thấp (khoảng 15oC) đã làm chậm sự nhân lên của WSSV trên tôm nhiễm bệnh và ở nhiệt độ này tôm được xem như là nguồn mang mầm bệnh WSSV tiềm ẩn, khi nhiệt độ nước tăng lên bệnh sẽ bùng phát.
The Production Capability of Grandparent Flock of CVSuperM Duck Raised without Pond at HaNoi University of Agriculture

Bui Huu Doan, Pham Kim Dang, Hoang Anh Tuan, Sonepaseuth Oudomxay, Dang Vu Binh

Received: 07-02-2015 / Accepted: 18-05-2015
An exotic grandparent flock of CV super M ducks conisisting of 4 lines A, B, C and D was completely raised without pond at Ha Noi University of Agriculture to assess the productive performance of gilt and laying stage. The results showed that, in gilt period (up to 24 weeks), the survival rate was very high, reaching 95 - 97%. At maturation age, the physical appearance of ducks was characteristic of high-yield of super meat duck. The body weight of two male lines A and C was 4.3 kg and 3.8 kg, respectively; while the other two female lines B and C was 3.6 and 2.8 kg, respectively, equivalent to the supplier firm’s specification. The average feeding cost for a grandparent gilt duck was VND 248,802.5. About 5% of CV super M ducks lays egg at 175 - 177 days of age, and reached the peak at 223 - 224 days old. Within 24 laying weeks, an average birth rate and egg production of B line was 69.12% and 116.1 egg/duck, respectively. The similar figure for D line was 75.70% and 127.2 egg/duck. The feed used for producing 10 eggs of B line was 4.4 kg, and for 10 hatching eggs was 5.0 kg. The figure for D line was 4.1 kg and 4.8 kg. The cost to produce 10 hatching eggs of both these lines was VND40,400 and VND 38.267, respectively. Both lines had good quality hatching eggs, the percentage of type I / total hatching eggs was 71% and 73% with line B and line D, respectively.
In vitro Propagation ofSalvia miltiorrhiza Bunge

Le Tien Vinh, Ninh Thi Thao, La Hoang Anh, Nguyen Thi Thuy, Nguyen Thi Phuong Thao

Received: 06-06-2014 / Accepted: 10-08-2014
Salvia miltiorrhiza Bunge, one of the high-valued medicinal plants, is mainly used for the treatment of cardiovascular and cerebrovascular diseases. This study was conducted to establish the procedure for in vitro propagation of Salvia miltiorrhiza Bunge with the aim of preservation and development this precious medicinal species. The highest seed germination of 40.43% was observed on MS medium supplemented with 1.0 mg/l GA3 within 2 weeks. The seedling nodal explants (approximately 2-3 cm in height and one axillary bud) were used as source of in vitro propagation. The multiplication rate was highest (5.05 shoots/explant) after 4 weeks of culture when MS with 0.5 mg/l BA was used. α-NAA, IAA or IBA had positive effect on in vitro rooting of shoot. The optimal medium for in vitro rooting was MS medium containing 0.75 mg/l IAA, on which 100% of shoots induced roots with a mean of 6.19 roots/plant within 4 weeks of culture. In vitro plantlets after 30-days period of rooting were the most appropriate for successful acclimatization in greenhouse. Survival percentage of planlets was 100% in the substrate containing 50% of coconut fiber and 50% of sand and acclimatized plantlets showed good growth and development.
Propagation of Red Calliandra (Calliandra calothyrsus)by Tissue Culture

Mai Vu Duy, Le Vinh Thuc, Le Minh Ly, Nguyen Thiet, Nguyen Van Hon, Dang Phuong Duyen, Vo Thi Huyen Tran, Nguyen Khanh Ly

Received: 22-04-2014 / Accepted: 15-07-2014
The study was conducted for the following objectives: to ascertain the optimal concentration of plant growth regulators (BA, NAA), the MS macromineral concentrations for shoot establishment and root induction of Calliandra calothyrsusin vitro and to identify the suitable substrates for acclimatization. The research comprised 3 experiments arranged in completely randomlydesignd . The results showed that MS medium supplemented with 0.5 -1 mg/l BA was the best condition for shoot establishment (2.5-2.9 shoots); ½ MS medium supplenmented with 2 mg/l NAA induced more normal roots.Acclimatization of micropropagated plants in plastic pots containing a mixture of sand showed highest survival rate (80%).
Study onin Vitro Micropropagation of Six hybridsHippeastrum esquestre (Aition) Herb.

Pham Duc Trong, Nguyen Hanh Hoa, Phi Thi Cam Mien

Received: 19-03-2014 / Accepted: 29-05-2014
This study was conducted to establish a preliminary protocol for in vitrorapid propagation of six Hybrids of H.esquestre. Results showed that the optimal medium for shoot initiation from bulb scales of six hybrids (H1, H3, H5, H37, H85, H12) wasMS + 2-3mg/lBA +1.0 mg/l kinetin + 0,25mg/l αNAA.Shoot propagation was 2.79-3.75 shoots/explant. Small shoot and bulds were divided in to four parts and cultured in to MS + 3-5mg/l BA +1.0 mg/l kinetin + 0,25mg/l αNAA.Shoot propagation was 4.23-5.65 shoots/explant.Rootingmedium consisting of MS+ 1.5-2.0mg/l NAAinduced shoots with 100%root formation. Well-rooted plantlets were successfully transplanted to sand and rice husk substrate (3:1). The rate of plants survival was 100% and plants grew and developed well.

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