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31.
中国某些野生和栽培茶的核型研究   总被引:9,自引:0,他引:9  
研究了茶的4个变种和广东野生毛叶茶等共12个材料的核型。所有材料的染色体数目均是2n=30,为二倍体。所有中国大叶变种(越南大叶除外)(Cametlia sinensis var. macrophylla)和阿萨姆大叶变种(C. sinensis var. assamica)均具比较对称或原始的“2A”核型;中国小叶变种(C.sinensis var.bohea)(“铁观音”品种除外),掸部变种(C.sinensis var. shan form)和广东野生毛叶茶(C. ptilophylla)均具较不对称或较进化的“2B”核型。根据核型特征,植物习性和地理分布,作者认为中国四川和云南可能是茶的起源中心,向东或北迁移,演变为中国小叶变种;向南移则演变为阿萨姆变种和掸部变种。  相似文献   
32.
He-Ne和CO2激光对茶树花药培养的药裂率和出愈率的影响,既有促进作用,也有抑制作用。按出愈率和愈伤组织生长状况的序列:He-Ne:20J/cm^2〉CK〉He-Ne:30J/cm^2〉CO2:35.4J/cm^2。对He-Ne激光照射花药及其愈伤组织的过氧化物酶同工酶分析,主要表现在弱酶带的变化上,无规律差异。  相似文献   
33.
红茶菌抗菌蛋白提取与纯化   总被引:7,自引:0,他引:7  
红茶菌液经过滤、离心、减压浓缩 ,丙酮加盐沉淀 ,Sephadex G-50柱层析后 ,得到两个分子量部分 ,其中小分子量部分有抗菌活性 ,采用尿素— SDS—PAGE测定抗菌蛋白分子量未获成功  相似文献   
34.
Structure-antioxidant activity relationships of flavonoids and phenolic acids   总被引:53,自引:0,他引:53  
The recent explosion of interest in the bioactivity of the the flavonoids of higher plants is due, at least in part, to the potential health benefits of these polyphenolic components of major dietary constituents. This review article discusses the biological properties of the flavonoids and focuses on the relationship between their antioxidant activity, as hydrogen donating free radical scavengers, and their chemical structures. This culminates in a proposed hierarchy of antioxidant activity in the aqueous phase. The cumulative findings concerning structure-antioxidant activity relationships in the lipophilic phase derive from studies on fatty acids, liposomes, and low-density lipoproteins; the factors underlying the influence of the different classes of polyphenols in enhancing their resistance to oxidation are discussed and support the contention that the partition coefficients of the flavonoids as well as their rates of reaction with the relevant radicals define the antioxidant activities in the lipophilic phase.  相似文献   
35.
M. Kato 《Plant cell reports》1996,15(12):920-923
Immature leaves of in vitro grown shoots of tea were cultured on various levels of 2,4-D. Somatic embryos were induced directly on leaves or via embryogenic callus produced at the basal regions of the leaves. Induction of embryogenesis appeared to be correlated with the maturity of the leaf explants, with younger leaves responding better. The embryogenic response of leaf explants also was correlated with the period of culture in 2,4-D containing liquid medium. Embryogenic calli or repetitive somatic embryos maintained their regeneration capacity for more than 3 years. Histological observation revealed somatic embryos were formed on various regions of the leaf midrib. Somatic embryos germinated and developed into plantlets on agar medium containing BA and IBA.Abbreviations BA 6-benzylaminopurine - IBA indole-3-butyricacid - 2,4-D 2,4-dichloro phenoxyacetic acid  相似文献   
36.
Application of nitrogenous fertilisers (NPKS 25: 5: 5:5) for yield of tea and to induce tolerance to the red crevice ( Brevipalpus phoenicis Geijskes) mite was found to be rates between 150 and 200 Kg N ha-1 yr-1 rates above 400 Kg N ha-1 encouraged the build up of mites on tea. Damage symptoms resulting from mite infestation declined with increase in application of nitrogenous fertilisers.
The levels of nitrogen in the leaf tissues increased with soil applied nitrogen and also was related to the mite numbers found on the leaves suggesting a link. The symptoms of the discoloured necrotic leaf base that accompanied mite infestation was significantly ( P ≤ 0.05) and linearly correlated (r = 0.60) to mite numbers in the control plot. The levels of applied nitrogen were negatively correlated to % leaf necrosis suggesting a tolerance leading to reduction in necrotic symptoms with fertiliser applications.  相似文献   
37.
良种茶树芽叶中氨基酸研究   总被引:2,自引:0,他引:2  
本文报导利用日立-EG型氨基酸自动分析仪测定的六个茶树良种芽叶中十九种氨基酸组成情况,并以此为依据对良好的品质风格进行了探讨。  相似文献   
38.
Previous studies have shown that tea consumption can impair trace element metabolism, particularly iron status, and increase the risk of anemia in humans and animals. More recently, however, evidence has been accumulating to show that, in animals, consumption of green tea or its polyphenols is associated with a reduction of the incidence and severity of a variety of experimentally induced cancers. In this study we have monitored the growth, trace element status, including hematological parameters of weanling rats given either (1) water, (2) 1% black tea, (3) 1% green, tea, or (4) 0.2% crude green tea extract as their sole drinking fluid while consuming diets containing either adequate or low amounts of iron. With the exception of manaanese, none of the trace elements studied (iron, copper, zinc, and manganese) or the hematological indices measured were affected by the type of beverage supplied, even though the polyphenol extract was shown to chelate metals in vitro and all the animals fed the low iron diet were shown to be anemic. There appeared to be an effect of black and green teas on manganese balance in, both the first and last weeks of the study. A lower level of brain managanese was associated with green tea consumption, and a higher level of this element in the kidneys of animals fed black tea. The results demonstrate that both black and green teas and a green tea polyphenol extract do not represent a risk to animals consuming the beverages as their sole fluid intake with respect to iron availability, although the interactions with manganese deserve further study.  相似文献   
39.
Tea production in North-East India hit a record loss due to the widespread severe outbreak of a mixed brood of three species of looper caterpillar pests of geometrid moths (Lepidoptera) in 2008-2010. In addition to Buzura suppressaria, two newly recorded geometrids, viz., Hyposidra infixaria and Hyposidra talaca have caused widespread severe damage in recent years. In the present study we report the nucleopolyhedroviruses (NPV) isolated from the tea looper caterpillar from North-East India. We identified and characterized the NPV by cloning and sequencing a partial segment of polyhedrin gene of virus infected larvae of B. suppressaria, H. talaca and H. infixaria. A comparison of deduced amino acids of polyhedrin gene among H. talaca, H. infixaria and B. suppressaria showed that same strain was found to infect all the three loopers in India, which show high sequence identity with B. suppressaria Chinese isolates. Based on the polyhedrin sequence homology, it is predicted that a variant of B. suppressaria Chinese isolate of NPV found to infect H. talaca, H. infixaria and B. suppressaria in India.  相似文献   
40.
Young anthers excised from closed tea flower buds ( Camellia sinensis L.) were stained as fresh tissues with p-dimethylaminocinnamaldehyde reagent to localize flavanols associated with nuclei and chromosomes, apart from those flavanols stored in vacuoles. This staining reagent yields a blue colour for flavanols. In the nonsporogenic somatic cells of developing anthers, flavanols were found to be attached to chromosomes at all mitotic stages. Male meiosis started at a bud size of about 3.5 mm in diameter in pollen mother cells which displayed generally more or less pronounced blue nuclei and cytoplasm. The meiotic divisions from prophase I to telophase II were characterized by blue stained nuclei and chromosomes, but within the cytoplasm there was, if any, a random and very poor reaction for flavanols. Metaphase and telophase of meiotic divisions showed maximally condensed chromosomes staining dark blue. Early in telophase II, the cytoplasm was again stained blue; this faded at late tetrad stage. Flavanols of young mitotic and older non-mitotic anthers were determined using high pressure liquid chromatography--chemical reaction detection (HPLC-CRD). Catechin, epicatechin, B2, and epigallocatechin were minor compounds, whereas epicatechin gallate and epigallocatechin gallate were found in higher amounts. The major flavanol compound of the anthers, epicatechin gallate, exhibited a significant affinity to histone sulphate, as shown by UV-VIS spectroscopic titration.  相似文献   
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