Lingnan Gardeners Newsletter (No. 38) = 嶺南彩園通訊 (第38期)

Banana flower 香蕉花https://commons.ln.edu.hk/ln_gardeners_newsletter/1038/thumbnail.jp

香蕉农杆菌介导高效转化体系

以香蕉 (Musaspp .)的横切薄层切片 (tTCL)外植体作为转化受体 ,研究影响根癌农杆菌转化香蕉的因素。研究表明 ,菌液的预处理和重悬液的pH值是影响香蕉转化的主要因子 ,而乙酰丁香酮 (AS)是香蕉遗传转化中必需的酚类物质 ,80 μmol/L是较理想的浓度 ;感染时间以 8～ 15min ,共培养的时间和温度分别以 4～ 5d及 2 6℃为最佳的条

影响根癌农杆菌介导的香蕉遗传转化因素研究

以香蕉 (Musa spp.)的横切薄层切片 (transverse thin cell layer,t TCL)外植体作为转化受体 ,通过对外植体 GUS基因瞬时表达率的研究以及受体材料对抗生素的敏感性实验 ,找出了较适合的外植体转化条件和培养条件。研究表明 :用低代香蕉无菌苗为材料 ,横切薄层切片芽再生率高 ,有较高的 GUS基因瞬时表达率 ;香蕉对头孢霉素 (Cefotaxime)和羧苄霉素 (Carbenicillin)不敏感 ,而对潮霉素(Hygromycin)很敏感 ;菌液的预处理是影响香蕉转化的主要因子 ,重悬液中的蔗糖浓度也是影响转化的因素之一 ,对遗传转化有明显的促进作

Lingnan Gardeners Bimonthly Newsletter (No. 47) = 嶺南彩園通訊 (第47期)

Balsamines 鳳仙花https://commons.ln.edu.hk/ln_gardeners_newsletter/1047/thumbnail.jp

香蕉横切薄层切片芽分化的培养技术

以香蕉横切薄层切片为材料,研究了不同因素对薄层切片芽分化的影响。结果表明:利用横切薄层培养技术能更有效、快速地进行香蕉的无性繁殖;TDZ(英文名为Thidiazuron,N-pheny-N'-1,2,3.-thia-diazol-5-ylurea,中文译为苯基噻二唑基脲)对香蕉薄层切片芽的分化有抑制作用,没有得到生长正常的不定芽;横切薄层切片在暗培养且培养温度为30℃时比25℃有较高的不定芽分化率,不定芽分化能力强,丛芽多;蔗糖和AgNO_3对薄层切片芽分化有一定的影响

A general review of China’s fruit import status

This study provides a general review of China’s fruit import status based on literature review, governmental reports, and trade data from China customs department, and international organizations. The study first reviewed the general trend of China’s fruit import, discussing the imported product compositions and origins, factors affecting the imports, and related administrative procedures. Secondly, the study focuses on China’s fruit imports from ASEAN countries, one of the largest trade partners of China, analyzing the characteristics of fruit trade between the two economies. This section also covers a discussion of the trade impact of Belt Road Initiative. The last part of the study offers policy implications and suggestions

Strolling the Lingnan Garden = 涓流彩園錄, 2016-2019 : 下集

This current collection (Part 2) is a documentation of the Lingnan Gardeners project, from January 2018 up till December 2019. The 12 issues of Lingnan Gardeners Newsletter are collected here, which give some sense of what was happening month by month, in words and pictures. Included are also some related articles on the project – academic interviews, reflections on exchange visits, thoughts after gardening, as well as information about our partners and Lingnan garden healthy recipes (part one and two). 本結集 (下集) 是嶺南彩園項目從2018年1月至2019年12月的活動總結。這裡收集了12期《嶺南彩園通訊》，每月發生的活動和留影記錄在這裡。還收錄了一些與項目相關的文章，有學術訪談、交流回顧、參與者感言、夥伴機構介紹及彩園食譜 (上、下)。https://commons.ln.edu.hk/ln_gardeners_book/1020/thumbnail.jp

Antioxidant Activity and Stability of Polysaccharide from Banana Flower

Objective: Banana flower polysaccharide was used as raw materials to analyze the antioxidant activity and stability. Methods: Bioactive polysaccharide from banana flower was extracted using hot-water extraction method combining with alcohol-precipitation method. Initially, the chemical composition of banana flower polysaccharide was detected and analyzed. Then, the total antioxidant capacity (T-AOC), as well as DPPH, hydroxyl and superoxide anion radicals scavenging activities were utilized to analyze the antioxidant activity of banana flower polysaccharide in vitro. On this basis, the antioxidant stability of banana flower polysaccharide was evaluated further by simulating different food processing conditions, including light, pH value, temperature, metal ions, common food ingredients, as well as sterilization methods, using the hydroxyl radical scavenging activity as the evaluation index. Results: The extraction yield of banana flower polysaccharide was about 14.56%, and the total sugar content, uronic acid content, protein content, phenolic content and flavonoid content of banana flower polysaccharide were 515.61, 287.88, 53.46, 2.23 and 7.94 mg/g, respectively. The result in this paper showed that polysaccharide obtained from banana flower possessed good reducing power, as well as DPPH and hydroxyl radicals scavenging capacities. The antioxidant property of banana flower polysaccharide was degraded by lighting, but remained stable under strong acidic as well as alkaline conditions. Banana flower polysaccharide had good heat resistance, specially under heating 60~80 ℃ from 2 to 3.5 h, its antioxidant stability was strong. Then, the good antioxidant stability of banana flower polysaccharide was observed in the presence of Na+ metal ion, whereas the antioxidant activity of banana flower polysaccharide was decreased with the increasing in the concentration of K+, Fe3+ and Cu2+ metal ions. Additionally, the antioxidant activity of banana flower polysaccharide was improved within the common food ingredients such as citric acid and sodium benzoate, but was decreased under sucrose and glucose as common food ingredients. The sterilization methods had different degrees of adverse effect on the antioxidant activity of banana flower polysaccharide, hence, high pressure sterilization could be used for sterilizing banana flower processing products. Conclusion: Banana flower polysaccharide had good antioxidant activity. The environmental factors including continuous light, Fe3+ and Cu2+ metal ions, as well as sucrose and glucose as common food ingredients might have the great influence on the antioxidant activity of banana flower polysaccharide. Hence, the direct contact with these environmental factors should be avoided during the processing and storage of banana flower

Identification of Polyphenolic Components in Unripe Banana Pulp and Their Inhibitory Effects on α-Amylase and α-Glucosidase

The composition of phenolics extracted from unripe banana flesh was identified using ultra-high performance liquid chromatography coupled with Q-Exactive Orbitrap mass spectrometry (UPLC-Q-Exactive Orbitrap-MS), and the inhibitory effects of banana polyphenols on α-amylase and α-glucosidase were estimated in vitro. In total, 28 compounds were identified, including 21 polyphenols such as esculetin, hyperoside, and kaempferol-3-O-glucoside, 2 organic acids, 3 ellagitannin metabolites, vanillin and coumarin. In addition, dimethyl ellagic acid and urolithin A were the major chromatographic peaks. Banana polyphenols exhibited excellent inhibitory effects on both α-amylase and α-glucosidase with half maximal inhibitory concentration (IC50) of 0.53 mg/mL and 35.76 µg/mL, respectively. At concentrations of 1.0 mg/mL and 160 µg/mL, the inhibition rates of α-amylase activity and α-glucosidase were (76.25 ± 3.79)% and (92.54 ± 0.69)%, respectively. Therefore, polyphenols may be one of the active ingredients contributing to the anti-hypoglycemic effect of unripe bananas