Enhanced rooting in in vitro derived shootlets of Jasminanthes tuyetanhiae T.B. Tran & Rodda (Apocynaceae, Asclepiadoideae) through microponic system

A microponic system (MP system), a propagation system combines micropropagation and hydroponic that, has beenstudied on some flower and fruit plants; however, the MP system has not yet been tested on herbal plants, especially Jasminanthes tuyetanhiae (Apocynaceae, Asclepiadoideae). This study used the MP system with nylon film (A4 cover nylon) to evaluate rooting, abnormal developmental phenomena, antioxidant enzyme activities, secondary metabolites ofplantlets, and subsequent growth. Results showed that 2-cm shoots cultured on a micropropagation system obtained a rooting rate of about 50–60%, and plantlets recorded abnormal phenomena reaching 85% consisting of 22.33% vitrifica-tion, 19.33% leaf abscission, 43.33% callus at the root and only 15% plantlets without abnormalities. In contrast, the MP system pre-treated with 0.5 mg/L indole butyric acid (IBA) and supplemented with 4 mg/L silver nanoparticles (AgNPs) obtained 100% rooting and improved plantlet quality. Furthermore, the plantlets developed using the MP system recordeda 2-fold reduction in vitrification and leaf abscission compared to those using the micropropagation system. A reduction in callus formation and increased antioxidant activities were also noted. The acclimatization of plantlets derived from the MP system pre-treated with 0.5 g/L IBA and 4.0 g/L AgNPs was higher than the conventional treatments.21571-13Viện Nghiên cứu và Ứng dụng Nông nghiệp Công nghệ cao10Nguyễn Bá Na

A model for distribution systems performance evaluation

In today's business environment, as the competitiveness becomes increasingly fierce, improving the business performance becomes more important. A major factor affecting business operations is distribution systems performance control. In a distribution network, if an independent point well manages its performance, the efficiency of the entire enterprise will improve. In order to do this, it is essential to evaluate the effectiveness of each distribution point. However, at present, this evaluation is usually based on experience or only a few indicators such as revenue or profit. The effectiveness of a distribution point should be simultaneously considered for sales with resources used such as costs, manpower or business market characteristics such as the number of similar stores within 4 kilometers radius... Therefore, DEA (Data Envelopment Analysis) method is proposed and used to evaluate the performance of independent distribution points and analyze the factors that affect efficiency by the Tobit regression model. This model was tested for a food distribution system in Ho Chi Minh City to prove its feasibility and usefulness.</jats:p

Silver nanoparticles as the sterilant in large-scale micropropagation of chrysanthemum

Micropropagation has proven to be an effective method for large-scale plant production in a short time and a useful tool for plant breeding. Microbial contamination is one of the most difficult micropropagation challenges, resulting in reduced plant quality and loss of valuable stocks. Therefore, sterilization of culture media is a critical step in plant micropropagation. However, sterilized media might reduce the activity of plant growth regulators and nutritional components of culture media. The sterilization effects of silver nanoparticles (AgNP) on the growth of explants and culture media were examined. The treatment with 250 ppm AgNP for 15 to 20 min of 4-wk-old ex vitro leaves proved optimal for controlling the contamination. Furthermore, the Murashige and Skoog medium containing 4 ppm AgNP resulted in 100% medium disinfection (no contamination) after 4 wk of culture. The plantlets obtained from non-sterilized MS medium (NoM) containing 4 ppm AgNP and 4 g L−1 agar gave similar results as the control medium with 8 g L−1 agar and the absence of AgNP. Large scale culture systems using NoM in large plastic containers of two different sizes (NoM1 and NoM2) could produce quality plantlets. Chrysanthemum plantlets in the NoM1 system showed higher antioxidant enzyme activities of ascorbate peroxidase and superoxide dismutase than plantlets in the autoclaved medium. Furthermore, the plantlets from NoM were better acclimatized under greenhouse conditions than those from the autoclaved medium (AuM) system. The developmental stages (flower buds and blooming time) of NoM1 and NoM2 plantlets, were 1 wk earlier than those from the AuM system. The successful use of AgNP as a sterilizer and as a component of culture media would reduce the cost of micropropagation and improve plants' quality.Published online 15 March 202

THE EFFECTS OF SOME FACTORS ON IN VITRO BIOMASS PRODUCTION OF VIETNAMESE GINSENG {PANAX VIETNAMENSIS HA ET GRUSHV.) AND PRELIMINARY ANALYSIS OF SAPONIN CONTENT

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