过去的60年,中国柑橘遗传改良与品种选育研究取得长足进展。据统计,在中国重庆、武汉等地建立的柑橘种质资源迁地保存圃、愈伤组织库分别保存了1 700多份芸香科材料和100多个柑橘品种的胚性愈伤组织。经调查,发掘到道县野橘、莽山野柑、红河大翼橙等多个野生种及迷你野生柑橘——单胚山金柑;发掘的'资阳香橙'已作为砧木应用于产业。累计选育柑橘新品种122个,包含121个接穗品种和1个砧木品种,涉及宽皮橘、橙、柚等主要柑橘类型。上述接穗品种88.5%来自芽变和实生选种,余下的11.5%来自人工创制的变异,包括杂交、诱变和细胞融合等途径产生的变异;改良的性状主要是无籽、熟期和色泽等。在育种技术方面,组学技术全面应用于柑橘遗传改良,完成了甜橙等柑橘主要类型的基因组测序,发掘到柑橘重要农艺性状的相关基因,如控制多胚的基因CitRWP等;建立起柑橘遗传转化和基因编辑技术体系,为柑橘基因组设计育种奠定了坚实基础。

以‘塔罗科’血橙为试材，采用48、52、56 ℃的热水分别短时处理1 min和2 min，研究其在贮藏期（3 ℃、相对湿度（relative humidity，RH）90%～95%条件下21 d）、模拟运输期（10 ℃、RH 60%～70%条件下7 d）和货架期（20 ℃、RH 60%～70%条件下7 d）3 个物流变温阶段的保鲜效果。结果表明，适宜的热水处理能明显减缓物流过程温度变化引起的不利影响，提高血橙果皮中多酚氧化酶、过氧化物酶、超氧化物歧化酶、过氧化氢酶的活性，使其维持在较高水平；同时，也能够保持很好的色泽（柑橘色泽指数、色相）、硬度和营养品质（花色苷含量、总酸含量、可溶性固形物含量）。然而处理温度超过56 ℃造成血橙产生不可逆的热损伤，物流过程中的温度变化促进了其腐烂。综合分析，52 ℃、2 min条件下血橙的保鲜效果最佳。

The effects of gaseous ozone exposure on in vitro growth of Penicillium digitatum and Penicillium italicum and development of postharvest green and blue molds on artificially inoculated citrus fruit were evaluated. Valencia oranges were continuously exposed to 0.3 ± 0.05 ppm(vol/vol) ozone at 5°C for 4 weeks. Eureka lemons were exposed to an intermittent day-night ozone cycle (0.3 ± 0.01 ppm ozone only at night) in a commercial cold storage room at 4.5°C for 9 weeks. Both oranges and lemons were continuously exposed to 1.0 ± 0.05 ppm ozone at 10°C in an export container for 2 weeks. Exposure to ozone did not reduce final incidence of green or blue mold, although incidence of both diseases was delayed about 1 week and infections developed more slowly under ozone. Sporulation was prevented or reduced by gaseous ozone without noticeable ozone phytotoxicity to the fruit. A synergistic effect between ozone exposure and low temperature was observed for prevention of sporulation. The proliferation of spores of fungicide-resistant strains of these pathogens, which often develop during storage, may be delayed, presumably prolonging the useful life of postharvest fungicides. In vitro radial growth of P. italicum, but not of P. digitatum, during a 5-day incubation period at 20°C was significantly reduced by a previous 0.3 ± 0.05 ppm ozone exposure at 5°C for 4 days. Inoculum density did not influence the effect of gaseous ozone on decay incidence or severity on oranges exposed to 0.3 ± 0.05 ppm ozone at 20°C for 1 week. Susceptibility of oranges to decay was not affected by a previous continuous exposure to 0.3 ± 0.05 ppm ozone at 20°C for 1 week. A corona discharge ozone generator was effective in abating ethylene in an empty export container.

【背景】 聚乙烯薄膜单果套袋是目前我国最为常用的柑橘贮藏期保鲜方式,近50年来在全国大范围应用。近年来聚乙烯薄膜果袋因使用后回收难带来的环境污染问题引起全社会广泛关注,且由于柑橘单果套袋主要依赖手工完成,导致劳动力日益紧缺、生产成本逐年上升等问题日益凸显。因此,研发一种能替代聚乙烯薄膜的新型涂膜材料,实现柑橘保鲜生产向全程机械化转型是产业的重大需求。【目的】 研发以小烛树蜡及蜂蜡为基础的“BC”（Beeswax-Candelilla Wax Coating）涂膜剂配方,并用于处理温州蜜柑果实,评价其保鲜效果以及替代聚乙烯薄膜单果套袋的可行性。【方法】 选择最优比小烛树蜡、蜂蜡和甘油组合涂膜剂,以成熟‘尾张’温州蜜柑果实为试验材料,进行套袋或涂膜处理。对处理后的果实在不同时间节点检测以下指标：果实失重率、硬度、色差、果汁总可溶性固形物（TSS）/可滴定酸（TA）含量、果皮总酚总黄酮含量、呼吸强度、果实内部气体成分和异味物质含量,并用气相质谱仪检测不同处理果皮初生代谢物含量。扫描电镜观察处理后果面蜡质形态;同时对光泽度、异味、风味、出汁量、甜度、酸度和总体满意度等指标进行感官评价。【结果】 BC涂膜剂处理温州蜜柑果实常温贮藏28 d后,果实失重率从22.62%显著降低到3.83%;同时延缓硬度与色差值的变化,延缓果实内部TSS和TA含量变化,提高果皮总酚、总黄酮及初生代谢物含量。果实内部CO₂浓度适度升高,呼吸强度从43.36 mL·kg^-1·h^-1显著降低到16.75 mL·kg^-1·h^-1;较对照处理而言,BC处理还增强了果实感官品质,总体满意度从3.09提升至3.69。除异味物质、呼吸强度外,其他各项指标检测结果均表明BC与套袋处理无显著性差异,但BC处理的果实中乙醇含量（777.9 mg·L^-1）显著低于人类感知阈值水平（1 500 mg·L^-1）及商业涂膜剂处理后的浓度（2 021.2 mg·L^-1）。【结论】 BC涂膜剂保水性能良好,涂膜处理后与套袋果实相比,果实的内部品质、外观品质以及测定的各项生化指标均无显著性差异。而且涂膜处理与果实采后加工分选线兼容性好,可实现在线打蜡处理,生产效率高,生产用工少。综上表明BC涂膜具备替代套袋保鲜作用。

柑橘是人类膳食中类黄酮的主要来源之一。类黄酮对人体健康有多方面的生理功能，且其抗癌、抗病毒、抗炎及抑菌效果可能基于其强抗氧化活性。柑橘中的类黄酮类物质分为黄烷酮、黄酮、黄酮醇、二氢黄酮醇和花色苷等几类，且以黄烷酮糖苷类含量最为丰富。柑橘中类黄酮组成和含量因种质和组织部位而异，柚果实中含有大量苦味的新橘皮糖苷类，而甜橙和橘果实中以无苦味的柚皮芸香糖苷类为主。目前，对类黄酮代谢途径的认识主要局限于其主通路上，但对类黄酮糖基化、酰基化以及甲基化等相关的基因和酶类研究较少。随着柑橘类黄酮代谢研究的深入，其积累和分布的遗传机理将逐渐得以揭示，这将会为培育功能性柑橘新种质提供理论依据。

Anthocyanins, the red-orange to blue-violet colorants present in fruits, vegetables, and tubers, have antidiabetic properties expressed via modulating energy metabolism, inflammation, and gut microbiota. Acylation of the glycosyl moieties of anthocyanins alters the physicochemical properties of anthocyanins and improves their stability. Thus, acylated anthocyanins with probiotic-like property and lower bioavailability are likely to have different biological effects from nonacylated anthocyanins on diabetes. This work highlights recent findings on the antidiabetic effects of acylated anthocyanins from the perspectives of energy metabolism, inflammation, and gut microbiota compared to the nonacylated anthocyanins and particularly emphasizes the cellular and molecular mechanisms associated with the beneficial effects of these bioactive molecules, providing a new perspective to explore the different biological effects induced by structurally different anthocyanins. Acylated anthocyanins may have greater modulating effects on energy metabolism, inflammation, and gut microbiota in type 2 diabetes compared to nonacylated anthocyanins.