ẢNH HƯỞNG CỦA THỜI GIAN TRỒNG ĐẾN SINH TRƯỞNG, PHÁT TRIỂN CỦA NẤM TRÂN CHÂU (Agrocybe aegerita)

Nghiên cứu được thực hiện trong vụ Xuân Hè tại trường Đại học Nông Lâm, Đại học Huế nhằm xác định được thời vụ thích hợp cho sinh trưởng, phát triển của nấm Trân Châu tại Thừa Thiên Huế. Thí nghiệm được bố trí theo phương pháp hoàn toàn ngẫu nhiên (CRD), gồm 5 công thức với 5 thời điểm cấy giống khác nhau trong tháng 4 và tháng 5 là 1/4; 10/4; 20/4; 30/4 và 10/5, 3 lần lặp lại, mỗi lần lặp theo dõi 10 bịch. Kết quả cho thấy công thức I, thời điểm cấy giống vào 1/4 cho kết quả tốt nhất. Thời gian phủ kín nguyên liệu 43,26 ngày, thời gian xuất hiện quả thể 57,53 ngày và thời gian quả thể trưởng thành và thu hái 65,87 ngày. Chiều dài quả thể đạt 10,69 cm, đường kính quả thể 3,99 cm và trọng lượng quả thể đạt 90,28 g/cụm quả thể, không xuất hiện mẫu nhiễm. Năng suất đạt 225,70 kg/ tấn nguyên liệu khô dẫn đến lãi ròng thu được 13,92 triệu đồng, cao hơn so với các công thức cùng nghiên cứu. ABSTRACT The experiment was carried out during the Summer-Autumn season at University of Agriculture and Forestry, Hue University to determine the suitability of planting time for the growth performation of Southern Poplar mushroom in Thua Thien Hue province. The experiment was arranged in completely randomized design, including 5 treatments, which were 5 different seedling propagation times of April 1st; April 10th; April 20th; April 30th and May 10th in 3 replications and 10 monitoring bags per each replication. The results showed that the experimental treatment I, which were inoculation time on April 1st, gave the best results compared to other experimental treatment such as the time mycelium covered material at 43.26 days; The time to appear mushroom body reached 57.53 days and the time to mature and harvest of mushroom body was 65.87 days; The length of the mushroom body at 10.69cm, the mushroom body diameter at 3.99cm and the weight of the mushroom body gave 90,28 g/mushroom cluster; infection rate gave 0%. The yield was 22.57% compared to the volume of dry material led to the net profit got 13,92 million VND, higher than all of treatments in the same study.

Effects of Incubation Time and Inoculation Level on the Stabilities of Bacteriostatic and Bactericidal Antibiotics against Salmonella Typhimurium

This study was designed to evaluate the stability of chloramphenicol, erythromycin, tetracycline, cephalothin, ciprofloxacin, and tobramycin against antibiotic-sensitive Salmonella Typhimurium (ASST) and antibiotic-resistant S. Typhimurium (ARST) during the broth microdilution assay. The antimicrobial activity in association with antibiotic stability was measured by using antibiotic susceptibility, time-delayed inoculation, time-extended incubation, and inoculum effect assays. The loss of the antimicrobial activity of cephalothin against ASST exposed to 1 MIC was observed for the 10 h delayed inoculation. The antimicrobial activities of tetracycline and ciprofloxacin against ASST and ARST exposed to ½ MIC were significantly decreased after the 10 h delayed inoculation. All antibiotics used in this study, except for ciprofloxacin, showed the considerable losses of antimicrobial activities against ASST and ARST after 40 h of incubation at 37 °C when compared to the 20 h of incubation during AST. Compared to the standard inoculum level (6 log CFU/mL), the MIC0.1 values of bactericidal antibiotics, ciprofloxacin and tobramycin against ASST were increased by more than 4-fold at the high inoculum level of 9 log CFU/mL. This would provide practical information for better understanding the clinical efficacy of the currently used antibiotics by considering the antibiotic stability during incubation time at different inoculum levels.

Impact of plant pathogens infection on Salmonella enterica subsp. enterica serotype Typhimurium persistence in tomato plants

We investigated whether the co-occurrence of phytopathogens ( Clavibacter michiganensis subsp. michiganensis [ Cmm ] and Xanthomonas gardneri [ Xg ]) frequently encountered in tomato production and Salmonella enterica subsp. enterica serotype Typhimurium (JSG626) affects the persistence of these pathogens in tomato plant tissues during the early stages of plant growth . We observed that Cmm increased the persistence of Salmonella Typhimurium JSG626 (up to 1.8-log CFU/plant at 21 days post-inoculation; DPI) from co-inoculated tomato plants compared to plants inoculated with S. Typhimurium JSG626 alone (P<0.05). Xg had no effect on S. Typhimurium JSG626 persistence in planta . The increased persistence of S. Typhimurium JSG626 was also observed when it was inoculated seven days after Cmm inoculation of the same plant tissues (P<0.05). On the other hand, S. Typhimurium JSG626 reduced the population of both Cmm and Xg (up to 1.5-log CFU/plant at 21DPI; P<0.05) in co-inoculated plants group compared to plants inoculated with Cmm or Xg alone. Further, the Xg population increased (1.16-log CFU/plant at 21DPI; P<0.05) when S. Typhimurium JSG626 was inoculated seven days after Xg inoculation compared to plants inoculated with Xg alone. Our findings demonstrate that the type of phytopathogen present in the phyllosphere and inoculation time influence the persistence of S. Typhimurium JSG626 and its interactions with phytopathogens co-colonized in planta . Further, Salmonella seems to reduce the phytopathogen load in planta , while Cmm enhances the persistence of Salmonella from the co-inoculated plant tissues; however, further investigations are needed to understand mechanisms behind these interactions.

Effectiveness Test of Orchid Mycorrhizal Isolate (Ceratorhiza and Trichoderma) Indonesia and Its Role as a Biofertilizer

Aim: The existence of Orchid Mycorrhizal Fungi (OMF) has a role to stimulate growth and support the supply of orchid nutrition as a biofertilizer agent. This study aimed to determine the association of mycorrhizal with Phalaenopsis amabilis (L.) Blume which was carried out through the effectiveness test of two Indonesian orchid mycorrhizal isolates i.e. Ceratorhiza and Trichoderma. Study Design: This study consisted of 4 treatments. Each treatment was repeated 3 times, each repetition of 5 plantlets, so that the total plantlet used was 60. Place and Duration of Study: Laboratory of Plant Biotechnology, Department of Biology, Universitas Gadjah Mada, Indonesia, between June 2017 and April 2018. Methodology: The method of inoculating orchid mycorrhizal by placing a plantlet in a petri dish containing orchid mycorrhizal for 1, 2, 3, and 4 days. Then plantlets are grown on sterile moss growing media and acclimatized in a greenhouse. Observation of each treatment is carried out every day for the next month. Observation variables include the number of initial and final roots, the number of live and dead roots, and the number of living and dead plants. Results: The results of the orchid mycorrhizal induction test showed that the Ceratorhiza inoculation treatment showed a fluctuation in the mean increase in the number of final roots, live roots, dead roots, and dead plantlets that were higher than the Trichoderma inoculation treatment. The results also showed that the best inoculation time on Ceratorhiza and Trichoderma was day 3 and 4. The adaptation process had the effect of increasing the number of dead roots in weeks 1 and 2. The adaptation process stopped at the beginning of week 4 with the number of new roots appearing a lot. Conclusion: Orchid mycorrhizal Ceratorhiza shows the value of effectiveness test compared with Trichoderma. The results of this study are expected to be basic information in efforts to cultivate natural orchids in Indonesia.

Research on Advance of Rice False Smut Ustilaginoidea virens (Cooke) Takah Worldwide: IV. Identification of Rice Resistance to RFS, Management and Prospection of RFS

Technological issues in identification of rice resistance were discussed in this part, including inoculum and its preparation, inoculation concentration of inoculum, inoculation time and method. It is very difficult to control RFS, RFS can only prevent but not cure, i.e., to control the RFS only spray fungicides before symptomatic appearance (rice smut balls appeared) can achieve better control efficiency, while once the smut ball appeared it could not be controlled even the concentration of fungicides increase several times, or spraying multiple times. Therefore, in order to achieve better control efficiency to RFS, integratd control measures need to be adopted. The integratd control measures including agricultural control, rice resistant varieties application, cultivation techniques, fertilization and water management, and fungicides application is the last approach and emergency measure for controlling RFS.

REACTION OF BANANA CULTIVARS TO THE Meloidogyne javanica X Fusarium oxysporum f. sp. cubense COMPLEX

ABSTRACT The interaction Fusarium oxysporum f. sp. cubense (Foc) x nematode and the genetic variability of Foc are the main problems with potential to affect the use of resistant varieties in the management of the Panama disease. The objective of this work was to evaluate the interaction between Foc and Meloidogyne javanica on the banana of the Prata Anã, Grande Naine and BRS Princesa cultivars. The experiment was conducted in a randomized block design, with six treatments and ten replications, which differed in the inoculation time of each pathogen. Simultaneous inoculation with Foc and M. javanica, inoculation with Foc one week before inoculation with M. javanica, and inoculation with M. javanica one week before inoculation with Foc. In addition to the controls, Foc isolated, M. javanica isolated, and cultivars without the pathogens. The seedlings were transplanted in 3-liter pots with sterile soil infested with 40 grams of Foc inoculum at the concentration of 1x106CFU/gram and 1000 eggs and J2 of M. javanica. At the end of 56 days, the treatments with 'Grande Naine' presented the highest reproduction factors of M. javanica. In the 'Prata Anã' no interaction was observed between Foc x M. javanica. The treatments with simultaneous inoculation of the two pathogens, and with Foc a week before, in the 'BRS Princesa', presented the highest external disease indices (DI), which promoted the highest AUDPC. The highest internal DI were observed in the treatments Foc+Mj+Grande Naine, Foc+Mj+BRS Princesa, Mj+Grande Naine+Foc and Foc+BRS Princesa+Mj. The simultaneous presence of M. javanica and Foc increases the severity of the Panama disease in Grande Naine and BRS Princesa cultivars.

PRICK AND SOAK Agroacterium tumefaciens-MEDIATED IN PLANTA TRANSFORMATION IN TOMATO (Lycopersicon esculentum Mill.)

One of the modern plant breedings through genetic engineering is Agrobacterium tumefaciens-mediated transformation. Agrobacterium tumefaciens-mediated transformation can be performed in vitro or in planta. In planta transformation arises from the weaknesses of the in vitro method such as need high hygiene standard, professional tissue culture experts, and more time to prepare explants and somaclonal variation. In planta transformation is a method to transfer the gene to the plant genome without any tissue culture stages. The aims of this research were to know the possibility of the prick and soak in planta method with the target of tomato seeds and to know the most suitable inoculation time for tomato seeds transformation by prick and soak method the transformation is done by pricking the seeds and soaking them in the A. tumefaciens suspension. The treatments in this study were 1 and 2 days inoculation time to test the efficacy of prick and soak in planta transformation method. Tomato seeds were pricked with a needle on the center once, and then soaked in A. tumefaciens strain LB4404 suspension carrying pKYS-SoSPS1 plasmid with Neomycin Phosphotransferase (NPTII) and Saccharum officinarum Sucrose Phosphate synthase (SoSPS1) genes. Visualization of tomato’s DNA samples after PCR showed that 1-day inoculation sample was positively integrated with NPTII gene and negative in the 2 days inoculation treatment.