土壤干旱与柿叶片膜脂及脂质过氧化的关系

在不同灌水条件下,对盆栽柿幼树叶片组织相对含水量,细胞透性,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,膜脂脂肪酸组分和脂质过氧化作用产物——丙二醛(MDA)含量进行测定,结果表明:当水势Ψ_S下降时,细胞透性(PERM)增大,SOD和CAT活性下降,脂质过氧化作用增强,膜脂中不饱和脂肪酸含量下降,饱和脂肪酸含量升高。试验证明:土壤水势(?)_S=-3.80±0.47bar,各指标变化最明显。本试验条件下,幼柿叶片SOD活性,CAT活性,MDA含量,PERM,不饱和脂肪酸指数(IUFA)与组织相对含水量(RWC)和土壤水势(Ψ_s)间具显著相关关系。     

柿叶提取黄酮类化合物方法及鉴定

以柿叶为原料,研究了提取黄酮类化合物的不同方法,并对提取物进行分离研究.通过比较不同方法的提取结果,说明用乙醇作为提取荆所提取出的芦丁含量最高;用微乳液展开剂对提取物进行薄层色谱法分离鉴定,得出柿叶中含有黄酮化合物中的黄酮醇类,为进一步研究柿叶中黄酮类化合物提供借鉴.     

抗旱造林新技术在甜柿建园中的应用

在甜柿建园中，通过ABT生根粉,SAP高效抗旱保水剂和地膜覆盖技术的应用．可显著提高造林成活率和苗木生长量。通过试验研究．总结出组装配套技术．造林成活率达到98％以上．值得大力推广。     

Chemical structures of the condensed tannins in the fruits of Diospyros species

The structural variety of the condensed tannins (proanthocyanidins) in the fruits of 16Diospyros species are reported. Eleven species contained condensed tannins mostly consisting of a mixture of catechin (CA) and gallocatechin (GCA) repeating units; the other five species did not. The GCA content in the CA-GCA total varied from 0.3% to 84.6%. The number of esterified gallic acid per one flavan repeating unit (degree of galloylation, DG) ranged from 0.01 to 0.89. The GCA content was found to be proportional to the DG values. Thus, 16Diospyros species tested may be classified into five groups by the analytical data of their condensed tannins. It may be interesting to compare their structural characteristics with those of the condensed tannins in other fruits, leaves, woods, and barks from the viewpoint of their biosynthesis and function in the plants.Part of this paper was presented at the 46th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1995     

渭北旱原柿树苗嫁接试验

苗木培育是渭北旱原柿树生产面临的困难之一。嫁接是培育高质量柿树苗的主要措施。本文对柿树砧木苗培育,砧木苗龄、粗度选择以及嫁接时间、嫁接方法,嫁接技术等进行了试验,探索出一条本地区比较实用的柿树嫁接苗培育技术,期望在生产上有一定参考价值。     

柿树光合速率日变化及其影响因子的研究

采用Li-6400型光合作用仪对柿树光合特性进行测定分析,结果表明,柿树净光合速率日变化里双峰曲线,最大值出现在中午10时,次峰值出现在下午14时,午休现象明显。柿树光合作用受气孔因素和非气孔因素共同作用。     

柿果单宁组成及其生物学特性的研究状况

柿果单宁是一种多酚类物质，除了通常能发生的‘酚类反应外还具有其特殊的性质，在柿产品加工中既是重要的呈味物质也是影响产品质量的关键因素。主要介绍了柿果单宁的结构和性状，柿果单宁细胞的研究现状和柿果单宁生理活性的研究现状，以期将柿果单宁的研究深入的进行下去，推动柿果产业的发展。     

Effect of antioxidants in controlling enzymatic browning of minimally processed persimmon ‘Rojo Brillante’

‘Rojo Brillante’ is an important variety of persimmon that after removal of the astringency with high levels of CO₂, maintains firmness and sweetness, making possible its commercialization as a fresh-cut commodity. However, the commercial success of the product is limited mainly by enzymatic browning. This work presents the effect of a wide range of antioxidants on enzymatic browning of ‘Rojo Brillante’ persimmon combining in vitro (extracts and precipitates) and in vivo (cut tissue) studies. Preliminary screening of the antioxidants, determined by absorbance and color measurements of persimmon extracts and pellets, showed that 4-hexylresorcinol (Hexyl), citric acid (CA) and calcium chloride (CaCl₂) were effective at controlling browning at 10 mM; whereas, ascorbic acid (AA) required a higher concentration (25 mM). Peracetic acid, cyclodextrin, cysteine, and hexametaphosphate were not effective at controlling browning, even at a concentration of 50 mM. In in vivo studies, AA (1.12%) and CA (0.21%) were the most effective treatments to control enzymatic browning of fresh-cut material, reaching the limit of marketability in 5–7 days, whereas, Hexyl and CaCl₂ did not reach 1 day of storage. The results showed that optimum concentrations in cut tissue did not always correlate with the in vitro studies, indicating that antioxidants have an effect not only in browning reactions, but also in metabolic activity and cell wall changes during wound-induced reactions. The results provide relevant information for further development of minimally processed ‘Rojo Brillante’ persimmon during storage at 5 °C.     

柿树受日本龟蜡蚧危害后丙二醛及保护酶变化的研究

柿树受日本龟蜡蚧危害后,分别以轻微受害(对照)、中等受害、严重受害三个等级研究了柿树体内丙二醛及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的动态变化过程,旨在揭示树体保护酶与树体抗虫作用的关系。结论如下:树体内丙二醛(MDA)含量受害区有两个增高峰,分别在4月底和6月底,丙二醛含量与受害程度成正相关。超氧化物歧化酶在中等受害区形成两个高峰期,第一个高峰期为4月底至5月中旬,第二个高峰期为7月。严重受害区在前期与对照相当,7月达到高峰,为三区之最,一直到树体生长后期,严重受害区都与对照和中等受害区保持着显著的差异,受害程度越重,SOD活性越强,有利于柿树对害虫的防御。过氧化物酶在受害区5月为第一个高峰期,第二个高峰期是7月。过氧化氢酶活性在受害区柿树生长中后期出现高峰,7月初中等受害区CAT活性最大,而严重受害区出现高峰时间较迟在7月下旬,但持续增长时间更长。     

CO2浓度和温度对柿子脱涩效果的影响

以新鲜涩柿果为试材,采用CO2脱涩法对柿子进行脱涩,研究了温度和CO2浓度对柿果的涩度、硬度和可溶性固形物含量的影响.结果表明:鲜涩柿在25℃、CO2浓度60%条件下进行脱涩,24h就可以脱去涩味,并保持较高硬度和原有品质.