紫芽品种茶树芽叶多酚类物质组成特征

通过测定茶树特异性紫芽品种芽叶的茶多酚、儿茶素及其各组分、黄酮类、花青素的含量,探讨紫芽品种芽叶中多酚类物质组成上的差异。结果表明,紫芽品种茶树芽叶中的花青素含量与芽叶紫色深浅关系密切,芽叶紫色程度越深,花青素含量越高。深紫品种的花青素含量约为浅紫品种的5倍,常规品种紫色芽叶中的花青素含量为其正常黄绿色芽叶的2．46倍。紫芽品种茶树芽叶中的茶多酚总量、黄酮类、儿茶素总量及儿茶素各组分的含量与芽叶紫色深浅均无直接关系。     

茶树紫色芽叶的呈味特征及降低苦涩味的研究

茶树群体品种常见的紫色芽叶所制成的绿茶苦涩味明显。分离测定了茶树紫色芽叶主要苦涩味特征成分,用苦涩味阈值和苦涩味指数定量评价了各成分的呈味特征。结果表明,茶树紫色芽叶花青素含量高达1.14%,紫色芽叶中花青素和儿茶素的含量分别是绿色芽叶的57倍和1.13倍,花青素和儿茶素含量较高是其苦涩味较强的主要原因。茶叶苦涩味成分阈值的大小顺序为:咖啡碱(0.30)<花青素(0.40)<儿茶素(0.80);以苦涩味指数评价成分对紫色芽叶苦涩味实际影响大小顺序为:儿茶素(3.32)>咖啡碱(2.13)>花青素(0.57)。研究还表明,在紫色芽叶加工绿茶的过程中,添加约0.2%的酪蛋白具有降低苦涩味的作用,可使品质得到改善,使茶汤中多酚类浓度降低19.5%,苦涩味指数由3.70降至2.98,由此提供了一种降低紫色芽叶苦涩味的技术途径。采用多酚-蛋白复合反应模型,提出了用相对沉淀率(RA)作为酪蛋白对多酚类物质的苦涩味抑制能力的评价指标。     

紫色芽叶茶树研究进展

以紫娟为代表的紫色芽叶品种,由于其高花青素含量所具有的抗氧化、消炎、预防心血管疾病、抗癌等独特的保健功效,使其具有更加独特的开发特色以及健康茶产品的发展前景.文章分别从花青素合成途径与调控因素、特异性紫色芽叶茶树种质资源创新利用、紫色芽叶茶树品种的生理特性、紫色芽叶茶加工工艺等4个方面就当前紫色芽叶茶树品种研究、开发、...     

紫芽茶研究进展

近年来,随着科学研究的深入,造成茶树红紫芽现象的主要组分花青素的医疗保健功能被逐渐证明,选育稳定遗传的红紫芽茶树品种以及红紫芽茶的加工成为当前茶树新品种开发利用的热点。紫娟为可稳定遗传紫色芽叶性状的新品种茶树资源,有关其主要生化成分、保健功能的研究已有不少,它的育成有力推动了紫化茶树品种的选育以及紫芽茶相关领域的研究。本文综述了紫芽茶在生理生化、适制性、特色产品开发,以及保健功能等方面的研究进展,以期为特色茶树种质资源的进一步创新利用提供参考。     

云南稀有茶树品种"紫娟"的植物学特性和品质特征

稀有茶树品种"紫娟"新梢芽叶呈紫芽、紫叶、紫茎,加工制品,茶汤水色亦为紫色,香气郁香独特,叶底呈靛青色.适宜云南主产茶区种植.黄酮类、锌、 花青素和EGC含量比云南大叶种茶高.花青素含量约为一般红芽茶的3倍.经动物试验表明其降压效果优于云南大叶种茶.     

茶树品种紫娟茶鲜叶的染色特性研究

紫鹃茶树是一种特殊的红紫芽茶树品种,单株新梢长有约2～4片红紫色叶片,花青素含量为普通红芽茶的3倍,具有较高的综合利用价值.为了探索该茶树品种鲜叶的染色特性,本试验以紫娟的鲜叶为原料,对不同冷冻时间、染液温度、固液比、煮染时间以及不同材质布料煤染效果进行比较.结果显示,紫娟鲜叶在冷冻15 d、固液比1:3、染液温度90...     

紫芽品种茶树春梢芽叶生化成分分析

研究了紫色深浅不一的5个特定紫芽品种茶树春梢芽叶中的花青素、茶多酚、黄酮类、氨基酸、咖啡碱、水浸出物、儿茶素总量、酯型儿茶素总量、简单儿茶素总量等生化成分含量的差异。结果表明,紫芽品种茶树芽叶深浅与花青素含量关系密切,与茶多酚、咖啡碱、氨基酸、     

红芽直立茶紫色叶形成机制的转录组分析

云南具有丰富的茶树资源,紫芽茶树是其中重要的一种。红芽直立茶具有典型的紫色芽叶,富含花青素,是重要的特异茶树种质资源。本研究通过转录组技术对红芽直立茶的不同叶色进行研究,筛选到8779个差异表达基因,GO和KEGG富集结果显示,差异基因涉及到多个色素形成及积累的功能。构建茶叶中类黄酮和类胡萝卜素生物合成两个途径,紫色叶中大量合成黄酮类化合物的关键基因上调,与茶叶紫色的形成密切相关。同时,紫色叶中类胡萝卜素的生物合成受到抑制,紫色叶具有更好的抗衰老能力。本研究将有助于对茶树紫色叶形成机制的认识,为特色茶育种研究奠定基础。     

云南稀有茶树品种“紫娟＇’的植物学特性和品质特征

稀有茶树品种“紫娟”新梢芽叶呈紫芽、紫叶、紫茎,加工制品,茶汤水色亦为紫色,香气郁香独特,叶底呈靛青色。适宜云南主产茶区种植。黄酮类、锌、花青素和EGC含量比云南大叶种茶高。花青素含量约为一般红芽茶的3倍。经动物试验表明其降压效果优于云南大叶种茶。     

茶树紫色芽叶花青苷组分分析及结构推测

通过筛选流动相、优化洗脱梯度,建立了茶树紫色芽叶花青素HPLC的分析方法,并从提取的花青素粗制品中分离出9个主要色谱峰;运用HPLC-DAD-MS/MS联用技术,获得了其中7个组分的紫外-可见光谱信息、质谱数据,结合文献资料,初步推测了茶树紫色芽叶花青素中5个主要组分,分别为：飞燕草-3-半乳糖苷、矢车菊-3-半乳糖苷、飞燕草-3-芸香糖苷、矢车菊-3-芸香糖苷和天竺葵-3-芸香糖苷,此外,采用外标法对各组分进行了定量分析,并获得了粗提物,纯度为32%。该方法简便快捷,重现性好,可用于茶树紫色芽叶中花青素组分的分析与鉴定。     

竹阔混交模式对毛竹出笋量的影响

通过研究不同混交树种、不同混交密度、不同混交方法对毛竹混交林出笋量的影响,结果表明：在以不同混交树种混交中,组合特性为落叶、喜光的出笋量最高,常绿、喜光的最低;以不同密度混交中,密度为150株·hm^-2的出笋量最高,毛竹纯林的最低;以不同混交方法混交中,块状混交的出笋量最高,毛竹纯林的最低。     

枇杷枝剪口密度对新梢生长及开花结果的影响

研究枇杷枝剪口密度(分别剪1、2、3、4、5、6、7个枝/m2,7个处理)对新梢生长及开花结果的影响。结果显示:不同剪口密度(剪1个枝/㎡除外)对枇杷新梢生长均有促进作用;每个剪口抽生的枝梢数均比对照多;新梢的长度和叶片数各处理(剪1个枝/㎡除外)均有增长和数量增多,与对照的差异均达极显著水平;剪4～5个枝/㎡抽穗率相对较高,开花较早,谢花所占的比例较低,而花穗质量也较理想,单果重、株产均有较大提高。表明剪4～5个枝/㎡效果最好。     

荔枝树冠长势的几种测量方法对比

选择长势稍有差异的两组糯米糍(Nuomici)荔枝树，探索测量荔枝(Litchi chinensis Sonn)树冠长势的简单和精确的方法，分别测量他们的末次秋梢枝条长度、枝条粗度、复叶数、小叶数、小叶长度、小叶宽度、叶片厚度、叶脉粗度、叶片鲜重、自然干燥叶片的重量、烘干至恒重的叶片重量等。结果表明：在两组长势稍有差异的同一个荔枝品种中，他们的枝条长度、枝条粗度、复叶数、小叶数、小叶长度、小叶宽度、叶片厚度、叶脉粗度等数据没有统计学上的显著差异，但叶片鲜重、自然干燥叶片的重量、烘干至恒重的叶片重量则差异显著。作者认为：通过测量叶片鲜重来定量判定荔枝果树树冠长势的方法是既简单又精确的办法之一。     

余甘子各器官超氧化物歧化酶活性的测定

分析比较了余甘子(Phyllanthus emblica L.)不同品种、不同器官的超氧化物歧化酶SOD活性。结果表明,粉甘各器官都表现出一定的SOD活性,其中,鲜果肉的SOD(200.00U/g,FW以上)活性最高,种子最低(20.00U/g,FW以下),同一粉甘品种部分植株间茎与芽SOD活性存在着差异,野生资源与粉甘之间鲜果肉或茎的SOD活性差异不显著。     

利用橡胶幼态无性系芽条进行芽接

用增殖圃扩繁的橡胶树幼态无性系芽条进行籽苗和幼嫩小苗芽接试验.结果表明,增殖圃幼态无性系芽条的芽接成活率明显高于常规绿色芽条,且抽芽的直径较大.虽经过连续多次取用芽条,但仍可保持较高的芽接成活率和芽条的幼态特征,是目前解决籽苗和幼嫩小苗芽接幼态芽条短缺、常规绿色芽条芽接成活率不稳定的一种有效方法.     

Coppicing experiments on the spread and control of cocoa swollen shoot virus in Ghana

A coppicing technique was used to assess the incidence of latent and missed infection around 76 outbreaks of cocoa swollen shoot disease found during routine surveys of cocoa farms in Ghana. When all apparently healthy trees were coppiced within at least 27 m of trees found with symptoms, some failed to regenerate, with overall mortalities of 15% and 19% in progenies of Upper Amazon and West African Amelonado parentage, respectively. Many of the regenerating shoots developed stem and/or leaf symptoms of swollen shoot disease within 3 years of coppicing. There were great differences between sites, with overall incidences of infection of 21% and 16% in the Amazon and Amelonado plantings, respectively. The infections revealed by coppicing were not usually grouped closely around trees originally found with symptoms. Gradients of infection were seldom evident and the overall incidence of infection within 3 m of the initial outbreak areas (17%) was little greater than that beyond (14%). The original inspections of the standing trees detected only c. 12% and 18% of all the infected trees present at the Amazon and Amelonado sites, respectively. These results emphasize the limitations of routine inspections in determining the true incidence of infection. They have an important bearing on the conduct and effectiveness of the eradication measures adopted in Ghana and are discussed in relation to the future policy for limiting spread.     

柚木离体快速繁殖技术

从优良柚木林段选取3~4a生优良单株,从中选取无病虫害的幼嫩侧芽,经表面消毒后接种到无菌培养基上,侧芽萌发率达70%~80%。切取新芽进行增殖,30~40d为一周期,增殖系数为2~3倍。当侧芽增殖到足够数量时,转移到生根培养基上,生根率超过80%~90%。植株移栽成活率达80%~90%。几个月后植株便可种植到大田。      

少核‘年桔’的辐射育种研究

用60Co-γ射线4、6、8 kR辐射‘年桔’秋梢芽条,嫁接成活率分别为68.4%、41.3%和16.5%,对照成活率为93.2%。通过连续2 a的果实调查分析,获得少核性状稳定、综合性状优良的突变体4个,平均单果种子含量3.3～6.6粒,极显著低于对照的17.6粒。少核‘年桔’突变体的花粉生活力在45.5%～68.8%,发芽率在11.8%～16.7%,均分别极显著低于对照的97.3%和54.1%,说明少核‘年桔’少核的主要原因是花粉败育。     

Dormant season foliar sprays of broad-spectrum insecticides: An effective component of integrated management for Diaphorina citri (Hemiptera: Psyllidae) in citrus orchards

Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a global pest of citrus and vector of Candidatus Liberibacter, a bacteria that causes huanglongbing or greening, a devastating disease of citrus. Mature citrus trees are dormant in winter and produce most new shoots in spring, followed by sporadic canopy growth in summer and fall. Young shoots are required for oviposition and nymphal development, but adults can survive and overwinter on hardened leaves. Surviving adults reproduce in spring shoots and their progeny are probably responsible for a large portion of disease spread as they disperse to search for food. Therefore, foliar sprays of broad-spectrum insecticides applied to mature trees in winter were evaluated in a commercial citrus orchard as tactic to reduce pest populations and insecticide use in spring and summer when beneficial insects are most active. A single spray of chlorpyrifos (2.8 kg a.i. ha⁻¹) in January 2007 reduced adult psyllids an average of 10-fold over six months compared to untreated trees. The following year, differences with the untreated control averaged 15-fold for over five months following a single spray of chlorpyrifos, fenpropathrin (0.34 kg a.i. ha⁻¹), or oxamyl (1.12 kg a.i. ha⁻¹) applied in January. Spiders, lacewings and ladybeetles were equally abundant during the growing season in both treated and untreated trees both years (P = 0.05). Thus foliar sprays of broad-spectrum insecticides before spring growth suppressed D. citri for five to six months, with no detectible impact on key natural enemies. This tactic has been widely adopted to control the psyllid in Florida, in some cases area-wide. Additional sprays during the growing season should be based on scouting and targeted at adults before anticipated new flush.     

Effect of Girdling at Various Positions of ‘Huang Zhi Xiang’ Tea Tree (<Emphasis Type="Italic">Camellia sinensis</Emphasis>) on the Contents of Catechins and Starch in Fresh Leaf

The contents of starch and catechins in the fresh leaf of 'Huang Zhi Xiang' Oolong tea trees girdled at the bottom, middle (on the big branches) and top (on the small branches) were determined. The study demonstrated that the starch contents from girdled trees were significantly higher (p<0.05) than that from non-girdled ones. Furthermore, the contents of (-)-epicatechin (EC), (-)-epigallocatechin (EGC), total catechins (TC) and simple catechins (SC) from girdled trees were significantly higher (p<0.05) than those from non-girdled ones. Especially, the contents of (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and catechin gallate (CG) from girdled at the middle were also significantly higher (p<0.05) than those from the non-girdled. The starch contents were negatively correlated with the contents of (-)-gallocatechin (GC), EC, SC, TC and EGC, while positively correlated with the contents of EGCG and CG in fresh shoots.