浅析砖茶的降氟措施

砖茶氟含量较高，长期饮用影响人们的身体健康，降低砖茶的氟含量势在必行。本文简要介绍了从优化栽培条件、培养低氟品种、原料的选择、加工工艺、吸附剂、饮茶习惯等方面着手，采取相应的措施，降低砖茶的氟含量。     

砖茶初制过程中品质的形成与氟含量变化

以1芽6、7叶新梢为原料制作砖茶，并对初制各个工序的主要生化成分含量和含氟量进行了分析。结果表明，在初制工序中，含水量、水浸出物、蔡多酚与儿茶素、叶绿素含量均呈下降趋势，氨基酸含量在渥堆的过程略有上升，但是在干燥的过程明显下降，与可溶性糖的变化规律相似。茶黄素（TF）含量逐渐增加，茶红素（TR）与茶褐素（TB）变化不规律性。氟含量在整个初制过程中变化不大，表明初制过程对含氟量影响不大。感官审评结果表明，所用原料制作砖茶品质优于传统砖茶。     

绿茶的香气

煎茶(Sen—Cha)是日本最欢迎的绿茶。这种茶外形卷曲,由嫩的芽叶,通过蒸、揉和烘干过程制成的。制造过程开始阶段,通过蒸能保持鲜叶的绿色。日本九洲地区生产釜炒茶(Kamairi-Cha),采用类似于中国炒青绿茶制造方法。日本和其它一些亚洲国家,绿茶有很多种类和等级。每种绿茶的香气差异很大,感官评茶人员根据它能准确的评定出茶季,制造过程,甚至能辩别出茶树生长的地理位置。     

不同做形加工方式对烘青绿茶品质的影响

本研究以金萱、英红九号、青心1号、红叶1号四个品种的一芽一叶鲜叶为原料加工烘青绿茶,以碾压和揉捻两种方式进行,比较两种方式对烘青绿茶主要理化品质的影响。研究结果表明,茶多酚、氨基酸、咖啡碱、可溶性糖及水浸出物含量揉捻方式比碾压方式更高,但是理化指标含量均差异不显著。感官审评的结果表明,碾压方式得到的分数均高于揉捻方式,两种加工方式加工的烘青绿茶差异主要在茶叶外形上。综合品质结果认为,碾压加工方式在茶叶外形上优于传统揉捻加工方式,内在品质与传统揉捻方式相当。     

浅谈瓮安白茶的种植和加工

瓮安白茶是以珍稀茶树品种"白叶一号"的芽叶为原料,精细加工制作而成。为保证该茶的品质,在茶树种植、茶园管理及茶叶加工等多个环节都遵照有机茶的标准执行,并逐渐形成一套完整的生产工艺。     

梵净山野生茶与常规茶品质比较研究

本文以梵净山野生茶树与常规茶园鲜叶为原料加工成茶叶,进行感官品质、理化成分和香气成分对比分析,结果表明:感官品质常规茶的外形,汤色、叶底品质优于野生茶;野生茶水浸出物、可溶性糖含量相对较高,茶多酚、游离氨基酸、咖啡碱与常规茶差异不明显;野生茶与常规茶共检测出42种香气成分,野生茶醇类香气成分相对含量高于常规茶。总体来说,梵净山野生茶值得进行开发利用。     

良种茶树采摘加工信阳毛尖茶关键技术研究

信阳毛尖茶生产对茶树品种的基本要求是发芽早、芽叶绿色多茸毛,抗寒性强,在化学特性上要求茶多酚含量不超过25%,氨基酸含量高于3%,酚氨值小于7;按照“鲜叶采摘—鲜叶摊放—杀青—做形—干燥”工艺生产的信阳毛尖茶,其针型系列,主要是以采摘灌木型中、小叶良种茶树1芽1叶初展至1芽2叶的鲜叶生产,产品外形特征是色泽翠绿、外形圆细紧直、形似松针;而芽型系列,主要以小乔木型良种茶树的芽或1芽1叶初展的鲜叶生产,产品外形特征是外形似芽、形直、白毫满披。     

葛叶复合红茶及其制作工艺研究

将葛叶和茶树芽叶,按春季2∶3质量比、夏季3∶2质量比进行复合,并应用自然萎凋→机械匀叶→热风萎凋→加压揉捻→振动解块→程控发酵→炒干滚形→电热制形→电磁固形→风选去杂→微波提香等工艺制作研究葛叶复合红茶及其加工方法。该工艺制成的葛叶复合红茶外形呈弯钩状,色泽乌润光亮,冲泡后汤色红黄清亮,不但含葛叶清香和红茶甜香,而且滋味鲜爽醇厚、回味甘甜,具有独特的葛茶品质风味,是一种大众化营养保健饮品。如此,不但加强了葛与茶植物资源高效利用,而且还可促进国家增税、企业增效、农民增收。     

不同原料对金花菌茶品质的影响

为促进金花菌茶产品的开发,通过人工接种金花菌发酵,分析比较不同茶类、不同绿茶原料对金花菌茶品质的影响。结果表明,不同茶类原料中以红茶发酵的金花菌茶感官品质最佳,菌香浓郁,绵滑感强,但内含物质含量以晒青发酵的最高;不同绿茶原料中以杀青揉捻叶发酵的金花菌茶品质最佳,汤色橙黄尚明,滋味浓醇绵滑,内含成分丰富。这说明在不同茶类中以红茶为原料更有利于金花菌茶感官品质的形成,晒青原料更有利于金花菌茶理化品质的形成,而以杀青揉捻叶为原料发酵金花菌茶更有利于降低生产成本。     

微型茯砖茶发花技术研究

对黑毛茶接种冠突散囊菌,压制为质量为5 g左右的圆柱形的茯砖茶,再发酵制作微型茯茶。采用单因素试验和正交试验,通过研究茶叶含水量、蒸制时间、渥堆温度及渥堆时间,筛选出合适的工艺条件,并确定制作微型茯茶的最佳工艺参数。结果表明:影响微型茯茶品质的环境因子依次为:含水率>渥堆温度>蒸制时间>渥堆时间,最优水平为含水率26%,蒸制时间10 min,渥堆温度70℃,渥堆时间2.0 h,在此条件下其发酵的茶叶汤色红艳透明、香气浓郁、滋味甜香醇和。     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Disease resistance in protected crops and mushrooms

Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office.     

Genetic constitution and diversity in four narrow endemic redwoods from the family Cupressaceae

The genetic constitution and diversity of four relictual redwoods are discussed in this review. These include monotypic genera of the family Cupressaceae: coast redwood (Sequoia sempervirens), giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides), and alerce (Fitzroya cupressoides). All four species are narrow endemics, share a number of common phenotypic traits, including red wood, and are threatened species. Fossil history suggests that the ancestors of redwoods probably originated during the Cretaceous and Tertiary periods and flourished thereafter for millions of years. Towards the end of the Tertiary period began their decline and struggle for existence that continued during the subsequent geologic upheavals and climate changes, until the survival of the present-day redwoods in the current restricted locations in the world (USA, China, and South America). Although two species, Sequoiadendron and Metasequoia, are diploids (2n = 22), and the other two are polyploids: Fitzroya a tetraploid (2n = 4x = 44), and Sequoia a hexaploid (2n = 6x = 66); they all share the same basic chromosome number x = 11. The genome size in the hexaploid Sequoia is one of the largest (31,500 MB) in the conifers, while the genome sizes of diploid Metasequoia and Sequoiadendron are about one-third (~10,000 MB) of Sequoia. Genetic diversity in the redwoods is lower than most other gymnosperms, except in Sequoia, which seems to rank near the upper quarter of the coniferous forest trees. Genomic research is sparse in the redwoods, and should be pursued for a better understanding of their genome structure, function, and adaptive genetic diversity.     

Distribution,ecology and reproductive biology of wild tomatoes and related nightshades from the Atacama Desert region of northern Chile

Over the past 20 years, several expeditions were made to northern Chile to collect populations of wild tomatoes (Solanum chilense, S. peruvianum) and allied nightshades (S. lycopersicoides, S. sitiens), and obtain information about their geographic distribution, ecology and reproductive biology. Restricted mainly to drainages of the Andean and the coastal cordillera, populations are geographically fragmented. The two nightshade species are rare and threatened by human activities. Adaptation to extreme aridity and soil salinity are evident in S. chilense and S. sitiens (the latter exhibits several xerophytic traits not seen in the tomatoes) and to low temperatures in S. lycopersicoides and S. chilense. All tested accessions are self-incompatible, with the exception of one S. peruvianum population collected at the southern limit of its distribution. Several distinguishing reproductive traits—anther color, attachment, and dehiscence, pollen size, and flower scent—suggest S. sitiens and S. lycopersicoides attract different pollinators than S. chilense and S. peruvianum. The four Solanum spp. native or endemic to Chile provide a variety of novel traits which, through hybridization and introgression with cultivated tomato, could facilitate development of improved varieties, as well as research on a variety of basic topics, including plant-pollinator interactions, abiotic stress responses, and evolution of reproductive barriers.     

The induction in vitro of adventitious shoots in Rosa

Summary Adventitious shoots were formed on excised leaves, roots and callus of Rosa persica x xanthina and on excised leaves of R. laevigata and R. wichuraiana on culture media that included BAP and NAA as growth regulators. Shoots formed freely on freshly cultured callus of R. persica x xanthina but their production declined in successive cultures and ceased after twelve weeks. Transplantation to soil was improved by rooting plantlets in cellulose plugs in vitro and transferring plantlets to soil while still in the plugs.     

The exploration of genetic resources of Portuguese cabbage and kale for resistance to several Brassica diseases

Summary Twenty three accessions of nine Portuguese cabbage and kale land races from different geographic origins were tested at the seedling stage for resistance to several important brassica diseases. Resistance to downy mildew (Peronospora parasitica), expressed as necrosis of the cotyledon mesophyll, was found in all the accessions. Type A resistance to cabbage yellows (Fusarium oxysporum f. sp. conglutinans race 1) was present in most of the landraces. Resistance to clubroot (Plasmodiophora brassicae race 6) was found in one accession of the Portuguese tree kale. High resistance to blackleg (Leptosphaeria maculans) and white rust (Albuco candida) was not detected, although several accessions showed 20 to 30% of plants with intermediate expression of resistance. All Portuguese cole accessions were susceptible to blackrot (Xanthomonas campestris pv. campestris).     

Production and characterization of intergeneric diploid cybrids derived from symmetric fusion between Microcitrus papuana Swingle and sour orange (Citrus aurantium)

Plants were regenerated from intergeneric somatic hybridization between embryogenic protoplasts of Microcitrus papuana Swingle and leaf-derived protoplasts of sour orange (Citrus aurantium L.) via electrofusion. The regenerated plants were morphologically similar to the leaf parent in growth vigor, leaf and branch structure. FCM analysis showed that they were diploids. Simple-sequence-repeat (SSR) and cleaved-amplified-polymorphic-sequence(CAPS) were employed for hybridity characterization. SSR banding patterns of the regenerated plants were identical to the leaf parent, sour orange, indicating that they possessed nuclear component derived from sour orange. DNA amplification with chloroplast and mitochondrial universal primers, followed by restriction endonuclease digestion, revealed polymorphism between the fusion parents. Therefore, this method was used to determine the cytoplasmic compositions of the regenerated plants. Banding patterns for all the polymorphic primer/enzyme combinations of the regenerated plants were similar to those of the embryogenic parent, M. papuana, suggesting that only the cytoplasmic components derived from the embryogenic parent were present in the regenerated plants. FCM, SSR and CAPS demonstrated that intergeneric diploid cybrids have been successfully obtained by symmetric fusion. Related results concerning nuclear and cytoplasmic composition of previous diploid somatic hybrids and potential mechanism for regeneration of such kind of plants are discussed herein. This revised version was published online in July 2006 with corrections to the Cover Date.