【作者】 张学英；

【导师】 张上隆；

【作者基本信息】 浙江大学 ， 果树学， 2008， 博士

【摘要】 李(Prunus spp.)是蔷薇科李属植物,中国李为我国原产,我国李的栽培面积和产量居世界第一位,但研究相对落后。目前在世界各地广泛栽培的李有中国李、欧洲李、美洲李、樱桃李和一些杂种后代。李果实外观色泽丰富,有绿色、黄色、粉红、红、紫红、紫黑、蓝紫等。本文以不同色泽的李为试材,建立了果皮内花色素苷的液相检测方法,分析了不同色泽李果皮内花色素苷的种类和含量,研究了李果实发育过程中花色素苷含量及相关酶活性的变化,探讨了套袋、乙烯、温度和有机酸对花色素苷合成的影响,结果如下:优化了李果皮花色素苷的浸提方法,即5mL pH值2的甲醇甲酸提取液在4℃下浸提8小时较好。建立了李果实中花色素苷的HPLC测定方法,用4种花色素苷标样检测发现,李果皮中花色素苷主要是矢车菊素-3-葡萄糖苷(Cyahin-3-glucoside)、矢车菊素-3-芸香糖苷(Cyahin-3-rutinoside),2种花色素苷在0.00104～0.0104mg/mL范围内线性良好,最低检出限为0.02μg/mL,平均回收率为99.5%和99.25%,RSD=1.98%和2.5%。中国李果皮中花色素苷种类相同,不同色泽的李果皮中两种花色素苷含量不同,欧洲李果皮中花色素苷种类不同。大石早生在幼果期PAL活性高,随果实发育下降后持续上升,果实着色期,PAL活性与花色素苷含量呈显著正相关(r=0.985,p＜0.05)。紫琥珀在着色前期,PAL活性不断增加,着色开始后,花色素苷含量增加,PAL活性逐步下降,两者呈显著负相关(r=-0.987,p＜0.05)。大石早生和紫琥珀着色开始时,CHI都出现了上升的趋势,随后逐渐下降,该酶活性变化与花色素苷积累无明显相关性。大石早生在整个果实发育期,UFGT活性不断增加,着色期两者呈显著正相关(r=0.988,p＜0.05)。紫琥珀在着色初期至果面全着色(花后12周),UFGT活性与花色素苷的变化一致,此后随果皮中花色素苷浓度增加,酶活性下降,在此期间果皮内花色素苷浓度增加缓慢。在成熟前,花色素苷含量又迅速增加,UFGT活性也增强。UFGT活性与花色素苷含量在着色期无显著相关性。果袋的透光率与果皮外观色泽有密切关系,透光率越高,a*越大,果皮颜色越红。白色果袋与对照、红袋与黄袋果实外观无显著差异,白袋与红袋,黑袋(完全不透光)与黄袋,红袋与黄袋处理之间的果实外观色泽存在显著差异。果实成熟时果皮中花色素苷含量与纸袋的透光率呈正比,波长580nm以上橙、红光的透光率与果皮中花色素苷含量相关系数r＞0.99;不同颜色果袋影响果实成熟时果皮的糖酸积累,成熟时果皮中酸含量与花色素苷含量呈显著正相关(r=0.9815,p＜0.05),果皮的糖含量与花色素苷含量无显著相关性;不同颜色果袋对果肉中糖酸含量无显著影响。不同颜色果袋影响PAL、UFGT酶活性,果实成熟时不同果袋PAL酶活性与花色素苷含量相关性显著(r=0.9613,p＜0.05),UFGT酶活性与花色素苷含量相关性显著(r=0.9365,p＜0.05)。乙烯可以不依赖于光照诱导花色素苷合成,并且可以在幼果糖含量很低(总糖含量9.6mg╱g)的情况下诱导花色素苷合成,乙烯对不同品种和同一品种的不同发育时期的作用效果是不同的,乙烯能使黑宝石幼果PAL和CHI酶活性提高,果皮中花色素苷合成,在佛莱索幼果上没有影响。果皮内花色素苷含量的增加伴随着果皮内有机酸含量的提高,苹果酸合成相关的MDH和PEPC酶活性测定显示,果皮中的酶活性比果肉高,但果皮中MDH活性变化与苹果酸含量变化无显著相关性,这说明果皮中苹果酸含量的增加不完全是酶活性提高的结果,苹果酸在液泡中积累的能力差异也起着重要的作用。外源有机酸促进了果实着色,使果皮中花色素苷含量增加,这说明果皮内酸含量与花色素苷合成存在一定关系,但成熟是一个复杂的过程,究竟酸是怎样影响花色素苷合成的,还需进一步的试验验证。大石早生与紫琥珀两个品种李采后果面颜色变化与温度密切有关。果实处于0℃下,花色素苷含量增加缓慢,20℃下增加迅速,大石早生果皮中花青苷3-葡萄糖苷含量在采后10天中一直呈增加趋势,花青苷3-芸香糖苷含量在前6天增加迅速,8天达高峰,而后下降;紫琥珀果皮中以花青苷3-葡萄糖苷为主,在20℃条件下,4～8天为迅速增加期,8天后略下降,而花青苷3-芸香糖苷含量低且变幅小。在0℃时,果肉糖、酸及pH值变化不大;而20℃下果肉中酸含量明显下降,pH值上升;总糖尤其是果糖和紫琥珀中的山梨醇含量下降明显。更多还原

【Abstract】 Chinese plum （Prunus genus） originated in China. The yield and area of plum in China is ranked the first in the world, however, its research works is poor. The main speices cultivated is Prunus salicina Lindl., Prunus domestica Linn., Prunus cerasifera, Prunus Americana March and some hybrids in the world. The skin（?） of plums can be red, purple, blue-black, red, green, yellow or amber, while their flesh comes in hues such as yellow, green and pink and orange-a virtual rainbow. This study was conducted to probe the mechanism of pigmentation and anthocyanin synthesis use different color plums （Prunus salicina Lindl.）. A rapid determination method has been developed to elucidate the anthocyanin profiles in plums by high performance liquid chromatography（HPLC）.Three enzymes of flavonoid biosynthesis （phenylalanine ammonia-Iyase （PAL ） , chalcone isomerase （CHI ）and UDP-glucose:anthocyanidin 3-O-glucosyltransferase （UFGT））were assayed during the development of fruit. Anthocyanin concentration was measured during the same period. The effects of bags, ethylene, temperature and organic acid on anthocyanin synthesis were discussed also. The main results were as followings:Anthocyanin extraction with 5mL methanol（mixed with formic acid to pH 2） soaked for 8 hours at 4℃is the best conditions. Four kinds of stantard anthocyanins were used to detect and 2 of them were found in plum peels. The method was developed for determining anthocyanin content in plum fruits by HPLC. The calibration curves was linear over the range of 0.00104～0.0104mg /mL for cyanin-3-glucoside and cyanin-3-rutiniside, with mean recoveries of 99.5% and 99.25%, RSD 1.98% and 2.5% respectively. All the analyzed showed the same anthocyanin pattern but the different amounts among Chinese plums （Prunus salicina Lindl.）, except Richard Early.PAL enzyme activity in Oishi wase was high at 30 days after blossom, followed decreasing with fruit developing then kept rising till ripening and correlated to anthocyanin content during ripening. In immature fruits, PAL enzyme activity in Black Ambar kept increasing and decreasing when fruit reddened. CHI activity in both Oishi wase and Black Ambar showed similar patterns during fruit development, rising at the beginning of pigmentation followed decreasing till mature. In Oishi wase, UFGT increased continuously throughout development and correlated with anthocyanin content during ripening. UFGT in Black Ambar showed indented patterns and there was no relationship between enzyme activity and anthocyanin content. Significant correlation was found between light transmission percentage of bags and fruit pigmentation. A bag of higher light-transmitted has deeper red and the higher a* value in fruit peel. Except for white bag, Bagging with other color brought significant effects on fruit pigmentation as compared to control （non-bagged） except for white bag, though no different effects between with red bag and yellow bag. The most significant effect of bagging on fruit pigmentation was found when using black bag （no light transmitted）. Anthocyanin content in peels of mature frult was positively relevant to light intensity, especially when wavelength longer than 580nm（r>0.99*） by bagging. Sugar and organic acid content in sarcocarp were not affected, while the organic acid content in peel, not the sugar content in peel of mature fruit was positively relevant to anthocyanin content（r=0.9815*）. Moreover, the activities of PAL and UFGT were also positively relevant to anthocyanin content, with a 0.9613* and 0.9365* correlation coefficient respectively.Anthocyanin can be induced by ethylene at conditions of low sugar level and without light. Different effects of ethylene were observed on different cultivars or different period during fruit development of the same cultivar. PAL and CHI activities increased by ethylene in Fraiar little fruits accompanied anthocyanin synthesis compared to Fulaisuo.The increase of anthocyanin content accompanied by increase of organic acid in peels .Pigmentation of Black Ambar accelerated by external organic acid. Though relationship was observed between anthocyanin and acid contents but it can not be guaranted sufficiently.Anthocyanin synthesis of postharvest plum fruit was closely correlated with temperature. At 0℃, anthocyanin synthesis slowly increased as compared to rapid increase at 20℃. Cyanin-3-glucoside content increased within 10 days while cyanin-3-rutinside decreased at 8^th day in Oishi wase peels. Both anthocyanins increased within 8 days, especially cyanin-3-glucoside, but decreased after eight days in Black Ambar peels at 20℃. No significance was observed in sugar and malic acid contents and pH changes at 0℃. However, malic acid and sugars contents especially fructose and sorbitol were significantly decreased as compared to increasing of pH at 20℃. Those changes were related to anthocyanin synthesis.更多还原