鸡爪槭叶片色素组成及叶色变化

以鸡爪槭叶片发育期间叶色明显差异的芽叶期、展叶期、初叶期、小绿期、大绿期、绿叶期和红叶期的叶片为材料,利用紫外分光光度法、薄层层析色谱法、颜色特征反应、高效液相色谱法对色素种类和质量分数进行检测,并分析了叶色变化的原因。结果表明:鸡爪槭叶片中的色素主要有叶绿素、类胡萝卜素、矢车菊素、矢车菊素半乳糖苷、矮牵牛素、儿茶素、绿原酸、表儿茶素、二氢杨梅酮、芦丁、香豆酸、对香豆酸、根皮苷、杨梅素和槲皮素;芽叶期到初叶期叶片红色变浅主要是因为矢车菊素半乳糖苷的质量分数降低;初叶期到绿叶期叶色由浅红转为深绿主要是因为叶绿素大量积累的同时矢车菊素半乳糖苷质量分数降低;叶色由绿叶期的深绿到红叶期的紫红,是矢车菊素半乳糖苷质量分数增加和叶绿素质量分数降低共同作用的结果。     

大花葵花色苷抑菌功能研究

本项研究通过采用固体培养和液体培养的试验方法,进行大花葵花(Malvasylvestris)色苷对金黄色葡萄球菌、大肠杆菌和黑曲霉的抑菌试验。结果表明:大花葵花色苷对金黄色葡萄球菌有很强的抑制作用,而对大肠杆菌和黑曲霉没有抑制现象发生。在固体培养试验中大花葵花色苷随着浓度的增加,对金黄色葡萄球菌的抑制程度越大,当大花葵花色苷浓度为10g/L时抑菌圈平均直径为6mm,当浓度增加至30g/L时,抑菌圈平均直径为16mm。而且,高浓度的大花葵花色苷溶液对金黄色葡萄球菌有长时间的抑制作用。     

不同品种桑椹的抗氧化作用与其花色苷含量的相关性研究

分析了25个不同品种桑椹的抗氧化能力与其花色苷含量的相关性。结果表明,25个供试品种桑椹的总抗氧化能力、清除DPPH自由基能力和花色苷含量的变幅分别为57.17~17.80 U/mL、84.5%~18.5%和2.33%~0.09%,表现出明显的基因型差异。25个桑椹品种按系统聚类法可聚类为5大类群,分别包括2、11、2、6和4个品种。桑椹的总抗氧化能力和清除DPPH自由基能力与其花色苷含量之间的相关系数分别为0.815 2和0.876 1,呈极显著正相关(P<0.01?,表明桑椹的抗氧化能力与花色苷含量密切相关。     

Postharvest pigmentation in red Chinese sand pears (Pyrus pyrifolia Nakai) in response to optimum light and temperature

The development of red color in the peel of red Chinese sand pears (Pyrus pyrifolia Nakai) is influenced by temperature and light; however, the response patterns vary among different cultivars. In this study, we systematically investigated the influence of postharvest treatment with various temperatures (low, high, variant and constant) on detached mature fruit of red Chinese sand pear ‘Mantianhong’ and ‘Meirensu’. Fruit of red apple (Malus domestica Borkh.) ‘Royal Gala’ and red European pear (P. communis L.) ‘Cascade’ received the same treatments for comparison. Furthermore, the effects of light quality and irradiance level on ‘Mantianhong’ pears were evaluated at the optimum temperature for anthocyanin accumulation. Fruit firmness and concentrations of total soluble sugars and organic acids were measured to determine fruit quality. The effect of temperature on red Chinese sand pear fruit color was similar to that of apples, but not European pear. Moreover, low temperature more effectively induced red coloration in ‘Mantianhong’ and ‘Meirensu’ pears than high temperature; anthocyanin levels increased with increasing irradiance level from 0 to 532 μmol m⁻² s⁻¹, and UV-B and visible light synergistically improved the red color of the fruit. Therefore, a combination of low temperature and high intensity of UV-B/visible light could improve the postharvest coloration of red sand pear fruit. The results will contribute to an improved understanding of the mechanism responsible for the coloration of red Chinese sand pears and will aid development of new techniques to improve color in postharvest fruit.     

响应面法优化超声提取墨石榴皮中花青素

为研究超声提取墨石榴皮中花青素的最优工艺条件,以墨石榴皮为试材、酸性乙醇为提取剂、提取率为考查指标,通过单因素和Design-Expert 8.0.5b软件设计的回归正交试验,用响应面法分析优化各因素及其相互作用的最佳组合,得出墨石榴皮超声提取花青素的最优工艺参数:超声温度恒定40℃时,乙醇体积分数70%,料液比1g∶25mL,超声时间40min,超声功率90W。在此条件下,花青素提取率为182mg/kg,与理论值(183mg/kg)基本一致。     

根癌农杆菌介导的花青素调节基因 LC NtAn2 转化烟草的研究

旨在研究花青素调节基因LC-NtAn2对烟草花青素合成的影响,以普通烟草品种"97204"叶片为受体,采用根癌农杆菌(Agrobacterium tumefaciens,C58C1)介导法,进行LC-NtAn2基因转化普通烟草的研究。经共感染和潮霉素抗性筛选,获得29株抗性再生植株。经PCR特异性检测和RT-PCR检测,初步证明LC-NtAn2基因已被整合到烟草基因组,并可以正常转录。观察发现,导入LC-NtAn2基因的烟草植株的叶片颜色并无明显改变;检测发现,转基因植株与非转基因植株叶片中花青素无显著差异。