Vol. 19 No. 3 (2021)

Baikal skullcap (Scutellaria baicalensisGeorgi.),a member of the Lamiaceae familyhas been commonly used in traditionalmedicine. Baikal skullcap (called“Hoang cam” in Vietnamese) was introduced into Vietnam and has been planted in some areasin this country. Due to its naturally slow growth and development, large growing areas have not been developed yet. Presently, the most common method of propagation of Baikal skullcap isusingits seeds. Thisstudywas conducted toestablish a rapid micropropagation protocol that can beappliedfor multiplicationof elite strainsand actively provide the disease-free seedlings. The seeds were sterilized using0.5% Presept solution for 15 min, then placed on a medium containing water, sucrose, and agar for germination. Microshoots were highly induced and multiplied (7.47 ± 0.57 shoots/explant) on MS medium supplemented with 1mg/l BA. The suitable sucrose concentrations for the growth and development of microshoots were 20 g/l or 30 g/l. Allshoots were rootedby 100% by addingMS medium supplemented with 0.8-1.6 mg/l IBA. Therefore, theestablished protocol can be applied forin vitro micropropagationofBaikal skullcap.

As one of the most precious medicinal and edible mushrooms, monkey head mushroom (Hericium erinaceus)is widely cultivated in the world and use for treatment as well asprevention of several diseases. The aim of this study was to improve media and substratesfor the cultivation of monkey head mushroom. Optimized nutritional conditions were set up by one-individual factor-at-a-time.It was found that the most optimal carbon source for mycelial growth of monkey head mushroom was glucose. The favorable nitrogen sources were yeast extract, ammonium nitrate, and ammonium sulfate. A modified medium containing (ingredient, g/l) potato 200, glucose 20, yeast extract 5, and agar 15 was proposed to enhance mycelial growth. Monkey head mushroom exhibited the highest biological efficiency (65-69%) when cultivated on a basal substrate (89% sawdust and 1% CaCO3powder) enriched by corn powder or rice bran at 10%. The findings in this study will provide useful information in regard tospawn production and monkey head mushroom cultivation at the industrialscale.

This experiment was conducted to find the fungal strains with high saccharification activity isolated from the alcohol fermentation starters collected in Nga Son, Hau Locdistrict, Thanh Hoa province and growing well under normal conditions to increase the alcohol yield and decrease fermentation time in alcohol production. The contents of the study include the isolation of mold strains from traditional alcoholic fermentation starters, evaluation of amylase production, and saccharification of the isolated fungal strains using methods described by Xu-Cong & cs., (2012); Scheherazed & cs., (2016); Samson & Hoekstra(2002). Besides, the effects of cultural conditions on the saccharification of selected fungal strains were surveyed. Seventeen strains of fungi isolated from alcoholic fermentation starter samples produced amylase with activitiesfrom 2.0 to 4.5 U/ml. Among them, two mold strains NS1.1 and HL2 exhibited the highest saccharification when they grew on the block of sticky rice. The sugar content in the solution obtained from the fermented rice block of the NS 1.1 strain reached 7.02µM, 6.18µM with the HL2 strain. The appropriate temperature for the selected strains exhibited amylase activity ranging from 25C-35C, optimum at 30C. The comparative result of the 18S rRNA nucleotide sequence showed that the strain NS 1.1 has 99% similarity to the one of Rhizopus oryzea strain 150138 and was named Rhizopus oryzaestrain NS1.1.

This study aimed to investigate the effects of adding several organic additives on the growth of the Dendrobium lituiflorum shoots. In vitro shoots of 1cm length were separated from protocorm-like body and cultured on the MS medium supplement with different organic additives such as homogenate of potato, germinated green bean, yam bean or banana pulp or coconut water with the concentrations of 50 mg/l or 50 ml/l, respectively. The results indicated that adding potato or yam bean homogenate promoted shoot elongation. Combination of 50 g/l potato homogenate with 10 g/l green bean homogenate or 50 g/l yam bean homogenate with 0.5 g/l active charcoal resulted in longer shoots. This is the first report on the effects of yam bean homogenate on orchid shoot development. The findings could be applied on a large scale of producing in vitro plantlets of Dendrobium lituiflorum. 

The cooking and eating quality of rice, which are defined by amylose content (AC) and gel consistency (GC), are important criteria determiningthe export price of Vietnamese rice. These properties mainly depend on the amylose content in rice grain endosperm and are regulated by the Waxygene. This study aimedto determine the effect of point mutation G/T in the first intron of Waxygene with AC and GT traits in Vietnamese rice accessions. The AC evaluation in 64 accessions resultedfrom26 accessions with high AC and 5 accessions with average AC; 20 accessions with low AC; 2 accessions had very low AC and 11 accessions of glutinous rice, respectively. The GC evaluation results classified the materials into 5 groupsincluding: very hard (25 accessions); hard (1 accession); medium (13 accessions); soft (11 accessions) and very soft (14 accessions). Using CAPS markers, there were 31 samples possessed SNP G and Wxaalleles and 33 samples possessed SNP T and Wxballeles. Comparison of genotypic and phenotypic results showed that the PCR-AccI has high accuracy for detection of Waxygenotype and needed to apply in breeding programs for quality rice.

Lien Minh chicken is an indigenous breed with several favorable propertiesand associated with the economic development of the people in the Lien Minh village, Cat HaiDistrict, Hai PhongCity. Chicken Insulin (INS) and Insulin-like growth factor binding protein 2 (IGFBP2) are physiological candidate genes involved in the growth traits. This study aimed to investigate the association of single nucleotide polymorphism (SNP) of INS and IGFBP2genes concerned with bodyweight inLien Minhchicken.The indexes for 100 Lien Minh chickens were observed individually about their body weights from 01 day to 20 weeks age.Blood samples were used for DNA extraction and then genotyping by PCR-RFLP method. Two SNPs of INSandIGFBP2genes were analyzed. Allele frequencies ofINSand IGFBP2were: A (0.65), G (0.35) and A (0.46), T (0.54), respectively. Genotype GG INSshowed the highest values of mean body weight at 14, 16weeks of age for hen, 18 weeks of age for cock (P <0.05), and genotype AAof IGFBP2 (IGFBP2)wasalsoshown thehighest values of mean body weight at 20 weeks of age. These results suggested that the beneficial alleles/genotypes could be used to support the improvement of the egg production capacity in the breeding of Lien Minh chicken.

Trichodermais a genus of fungus potential for probiotic preparation because it is safe and has strong resistance against many fungal species.The objective of this study was to evaluate the P. digitatumantifungal ability of Trichodermaculture in order to find the potential fungal strains for the production of P. digitatumantifungal probiotics that cause orange rot.In this study, twenty Trichodermasamples (Tr.HG1 - Tr.HG20)were isolated from orange-growing soil in Ha Giang province, of which Tr.HG6 and Tr.HG11 samples were assessed as being highly resistant to P. digitatumcausing orange rot(The diameters of the resistant zones were 64,0 ± 1,0 and 45,3 ± 1,5 mm, respectively). Based on the morphological characteristics and sequence of ITS region of rDNA, Tr.HG6 and Tr.HG11 samples were identified as Trichoderma asperellum. On PDB media, after 72 h of incubation at 30°C, cultures of two strains of T. asperellum Tr.HG6 and Tr.HG11 showed the strongest P. digitatum resistance(The diameters of the resistant zones were 64.0 and 45.3 mm, respectively). The culture solution of T. asperellum Tr.HG6 showed high thermal stability and had ability to keep its high activity at 50°C. Simultaneously, the culture solution of Tr.HG6 showed the inhibitory activity of P. digitatumon orange. This study was able to select twoT. asperellumfungal strains, viz. Tr.HG6 and Tr.HG11, that had strong ability to resist fungi with great potential for applying into probiotic preparation.

Globe amaranth(Gomphrena globosaL.) is one of the beautiful flowers and is popularly grown in Vietnam and many worldwide countries. The objective of this study was to assess the effect of nano silver on the in vitropropagation of Globe Amaranthfrom leaves. The different concentrations of silver nanoparticles (2, 4, 6, 8 and 10ppm) were added to the culture medium at all stages of the tissue culture. The results showed that the callus induction mediumsupplemented with 4-6ppm of nano silver gave the callus formation rate to reach 100%, callus were ivory white, soft and spread across of sample surface after 4 weeks of culturing; the callus of Globe Amaranthwas cultured in shoot regeneration medium supplemented with 4ppm of nano silver for the best shoot generation effect, the shooting rate reached 100%, the average number of shoots was 5.32 shoots/callus, the average height of shoots reached 2.36cm; the highest number of shoots per explant (8.36) was found onshoot multiplication medium supplemented with 6 ppm of nano silver; the root induction mediumadded with 8 ppm of nano silver gave rooting rate of 100%,the average number of roots was 4.08 roots/shoots, the root length reached 4.16cm after 4 weeks of culturing.

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.

This study was conducted to isolate lactic acid bacteria and apply them to preserve oyster mushrooms, as well as improve its nutritional value. Lactic acid bacterial strains were isolated, selected in MRS broth medium and tested for fermentation ability of oyster mushroom. The results showed that six bacterial strains potentially belonging to Lactobacillusgenus were isolated. By using a method of determining acidity in Therner degree, two strains D2.1 and D2.2 were determined with the highest ability to produce lactic acid (19,17 mg/ml and 19,38 mg/ml, respectively) after 72h culture. These two strains have been able to grow well on the mushroom extracts and reached the highest cell density after 16-24h of culture. The D2.1 and D2.2 strains were used for oyster fermentation. The fermented product has attractive colors and delicious taste, as well as meets the product safety requirements for microbiological criteria (Salmonella sp. andE. coli). After fermentation, total carbohydrate and protein contents were determined by the phenol-sulfuric acid and Kjeldahl methods. The results indicated that D2.1 strain has only reduced the amount of mushroom protein by 2.4%, while D2.2 strain has reduced by 5.3%; For carbohydrate amount of mushrooms, D2.1 strain has decreased by 7.73%, and D2.2 strain has reduced 9.32%, respectively.

Biofilm is a complex structure that is formed by the adherence of living-organisms on their surfaces. The biofilm has been well studied and effectively applied in various-different fields, particularly in solving polluted environmental issues. This research aimed to find and identify the biofilm-forming bacteria which can be used in wastewater treatment in trade villages. Total 23 strains of formed biofilm bacterium were isolated from 15 wastewater samples collected from Khac Niem village (Bac Ninh province) where produced rice noodles by spreading on the agar LB medium. There were strains, viz.B22.5, B22.8, B22.9, B22.10, B22.11, B22.18, and B22.20, were not only composed of the highest ability to form biofilm but also resisted to four or five pathogenic bacterial strains. Additionally, 04strains (B22.5, B22.9, B22.10, and B22.18) had a high emulsifying activity of biosurfactants with an emulsification index above 60%. The complementary study of identifying the biological characteristics of representative strain B22.9 showed that this strain belongs to the Bacillus spp.,which is gram-positive and having the ability to form a biofilm at high temperatures. The optimum conditions for this strain to form biofilm are on LB medium adding glucose or fructose as a carbon source at 37C, pH 7, respectively.

Tomato yellow leaf curl disease (TYLC) is one of the most dangerous tomato diseases in Vietnam. So far, using resistant genes for breeding tomato is one of the most effective solutions to control this disease. Currently, 5 resistance genes to yellow leaf curl have been identified as Ty1, Ty2, Ty3, Ty4and ty5genes. DNA markers linked to those genes were also discovered that have assisted to select the resistance genes more easily and accurately. In this study, we used TG97 marker to select Ty1resistance gene in F2population (H12 ×AVRDC188) and P6-25 marker to select Ty3 resistance gene in F2population (H12 ×AVRDC195). As a result shown, 7 individuals possess Ty1homozygous resistance gene and 4 individuals possess Ty3homozygous resistance gene were selected. The individuals that carrying resistant genes were mixed together, planted for self-fertilization until the F7generation. The two promising lines were selected including: TP130 line containing Ty1gene and TP135 lines containing Ty3gene. TP130 and TP135 lines were basically tested in three cropping seasons and evaluated their resistance to yellow leaf curl by artificial infection. The results showed that TP130 and TP135 lines had high yield and high resistance to TYLC diseases.

Lactoferrin (LF) is a glycoprotein of the transferrin family whose general function is to transport iron. LF is capable of enhancing the immune system, antibacterial, antioxidant, anti-tumor, and antiviral activities. The gene encoding LF derived from bovine has been successfully expressed in recombinant P. pastoris KM71H-3 strain on 2xMMP medium. This study aims at investigating the effects of culture conditions including initial biomass cell density (equivalent to OD600 value from 0.5-2.0), temperature (20°C, 24°C,28°C), and initial pH of the medium (5.5-7.5). The LF expression level was evaluated by SDS – PAGE and Dot bloting methods. The SDS- PAGE andDot - blot results showed that LF was expressed in 2xMMP mediumwell with the optimal conditions were at 28°C, pH 6.0 and the initial biomass cell density (OD600) 0.5.

Inattempts to generate high-yield and good-quality rice varieties to ensure food security in the context of reducing rice-growingareasdue to the urbanization process and the current agricultural restructuring in Vietnam, the genetic informationof rice landracesat the molecular level is essential. In this study, QTLs were identified with some agronomic traits inrice varieties being grown in Vietnam by analysing data of plant height, number of tillers and total dry weightand QTL Cartographer version 2,5soft ware. The result showed 12 QTLs for plant height, number of tillers and total dry weight onthechromosomes 1, 2, 4, 7, 9 and 10. The QTL for plant height on chromosome 2 was the QTL with a high LOD value and ahigh percentage of phenotypic variation explained by 5.23 and 39.81%, respectively. This QTL has been identified in several other independent researches. These results might provide useful information for rice breeders and will be an important basis for further research to identify genes that regulate plant height traits in rice varieties grown in Vietnam.