蓝粒小麦4Ag染色体的显微分离与鉴定

本研究采用显微分离技术从蓝粒小麦(Triticum aestivum L.(2n=6x=42)×Thinopyrum ponticum Liu &Wang(2n=10x=70))根尖细胞中期分裂相中分离出具有4Ag染色体形态特征的单条染色体,对分离后的细胞进行原位杂交(FISH),结果显示细胞中所剩的和显微分离到的单条染色体均为4Ag染色体.利用Sau3A接头介导的PCR方法对分离出的单条4Ag染色体进行体外扩增,扩增的DNA片段大小约为200～2 000 bp,主要集中在250～750 bp之间.以DIG-dUTP标记的蓝粒基因组DNA为探针,与该扩增产物进行Southern杂交,结果表明显微分离出的染色体得到了有效的扩增.利用该分离染色体的PCR扩增产物为探针,对蓝粒小麦进行原位杂交,证明显微分离的染色体体外扩增片段确实来源于4Ag染色体.本研究拓宽了染色体显微分离的范围,为构建4Ag染色体文库和克隆位于该染色体上的重要农艺性状基因提供了新途径.     

巴西橡胶树第9染色体的显微分离及微克隆文库的构建

橡胶是我国的重要的战略物资,深入研究橡胶树基因组具有重要意义。本实验以巴西橡胶树(Hevea brasiliensis)热研7-33-97幼叶为材料,采用酶解去壁低渗法制片,玻璃针显微分离法成功分离出橡胶树单染色体。单染色体经蛋白酶消化、Sau3A核酸内切酶酶切和两轮LA-PCR(接头连接PCR)扩增。得到250~2000bp之间的DNA片段,通过Southernblot对单染色体产物进行验证,结果表明扩增片段与巴西橡胶树基因组DNA之间有同源性。从而说明单染色体DNA已被成功的扩增。采用荧光原位杂交技术(fluorescence insitu hybridization,FISH)验证分离出的是第9号染色体,构建了橡胶树第9号染色体微克隆文库。克隆片段长度在300~1200bp,平均为650bp左右,文库包含48000个克隆,空载率为1%。本研究从巴西橡胶树单染色体入手,运用单染色体微分离、微克隆技术,构建了巴西橡胶树单染色微克隆文库,为橡胶树基因组研究提供了新的思路与方法,为更好地开展橡胶树分子辅助育种提供技术方法。     

大孔树脂分离纯化柚皮黄酮的研究

该文以总黄酮含量和总黄酮回收率为考察指标，研究了大孔树脂分离纯化柚皮黄酮的工艺。结果表明：AB-8型树脂对柚皮总黄酮有较好的吸附分离性能，是分离纯化柚皮黄酮的适宜大孔树脂；AB-8型大孔树脂分离纯化柚皮黄酮的最佳工艺条件为：柱体积为160 mL，柚皮提取物上样量为62.5 mg/mL(以湿树脂体积计)，先用pH 4的水淋洗，再用30%的乙醇洗脱，洗脱剂用量为2.5～3倍湿树脂体积。AB-8大孔树脂按上述确定的吸附洗脱条件可重复使用3次。柚皮黄酮经上述工艺纯化后总黄酮含量达到39.67%，总黄酮回收率为62.48%。对经AB-8大孔树脂纯化后的柚皮黄酮进行高效液相色谱(HPLC)分析发现，柚皮黄酮主要为黄酮甙类。     

小麦染色体显微切割和微克隆方法的建立及HMW—GS1Dx5亚基基因克隆

在Ｃ－分带识别普通小麦钢８２－１２２染色体长臂的基础上，通过染色体显微切割和微克隆技术切割１Ｄ染色体，并通过ＰＣＲ扩增得到高分子量麦谷蛋白１Ｄｘ５亚基基因片段，序列分析证明其正确性。这一方法的建立为获得新基因特异性探针打下基础。     

染色体显微切割两种体外扩增方法的比较

以处一数分裂中期１的水稻三体花粉母细胞为材料,对额外染色体进行了显微分离,通过两种体外扩增方法,即接头引物ＰＣＲＩｌｉｎｋｅｒ－ａｄａｐｔｏｒ－ＰＣＲ,ＬＡ－ＰＣＲ）和简并寡聚核苷酸引物ＰＣＲ（ｄｅｇｅｎｅｒａｔｅｄ－ｏｌｉｇｏｎｕｃｌｅｏｔｉｄｅ－ｐｒｉｍｅｄ－ＰＣＲ,ＤＯＰ－ＰＣＲ）,研究了这两种ＰＣＲ方法在本研究所采用的微分离染色体体外扩增中的优缺点,认为两种方法都可以有效地体外扩增,但扩增     

滁菊染色体核型的微变异

以安徽滁州地区特有的药食两用植物资源——滁菊(Dendranthema morifolium Ramat.‘Chuju’)为试材,采用根尖细胞压片技术进行染色体计数及核型分析,并与引种到外地的滁菊种进行比较。结果表明:滁菊种的染色体数目为2n=54,染色体基数x=9,为异源六倍体植物,其核型公式为2n=6x=54=42m+12sm(4SAT),核型类型为2A型,第10和21号染色体上均有1对随体,最长与最短染色体长度比为1.99,臂比>2的染色体比例为18.51%。与已公布的引种到外地的滁菊核型进行比较分析发现,引种后的滁菊较原生境滁菊染色体核型发生了微变异,表现在具随体染色体数量由4条减为2条,染色体多态性更为丰富,提示滁菊染色体核型与其生态环境有着密切的关系。     

细胞非对称分裂与姐妹染色体非随机分离研究进展

细胞非对称分裂与染色体非随机分离一直是生命科学研究领域的热点,细胞非对称分裂包含形态学非对称分裂与功能性非对称分裂,对于生命世代延续与维持个体组织功能完整意义重大.近年来,在生殖细胞与干细胞研究领域,对于细胞非对称分裂现象的研究取得了一些新的进展,这些进展有助于理解和认识细胞非对称分裂的形成及其调控机制.哺乳动物卵母细胞成熟过程中非对称分裂(形成较大体积的卵子和较小体积的极体)是形态学非均等分裂的代表;而损伤所诱发的干细胞的增殖则是细胞功能性非对称分裂的代表,这一过程所产生的两个后代细胞尽管形态近似,但是具有不同的命运与功能,一个留在原来微环境中继续维持干细胞特性,另外一个则分化成为功能性细胞,替代坏损细胞的功能.细胞在形态学与功能性的非均等分裂,其根源都是细胞核物质的选择性分离.果蝇(Drosophilamelanogaster)的精巢组织可在体外进行活体显微观察,能够对精原干细胞的细胞非对称分裂与姐妹染色体分离的实时观察研究,近年来细胞非对称分裂与姐妹染色体分离的研究结果主要来自果蝇.本文结合近年来关于果蝇精原干细胞的姐妹染色体的非对称分离的研究,对细胞非对称分离的假说、研究手段及其可能的调控机制等进行回顾总结,希望能为该领域的未来发展提供一些思路与借鉴.     

入侵杂草假高粱的染色体变异及核型分析

对入侵杂草假高粱(Sorghum halepenseL.)的根尖细胞进行染色体计数及核型分析,同时与二倍体高粱(SorghumL.)作比较。结果表明:供试材料假高粱的染色体数目为2n=34,染色体基数x=17,与原产地同物种(x=10)相比,发生了染色体数目变异,其核型公式为2n=2x=34=24m(2SAT)+10sm,为异源四倍体植物,核型类型为2B型,第15号染色体上有一对随体,最长与最短染色体长度比为2.30,臂比>2的染色体比例为18%,核型不对称系数为60.02%。与核型为2A型的高粱相比,二者的染色体数不成倍性关系,表明该假高粱种可能是由入侵种假高粱和禾本科其他植物通过远缘杂交形成的新变种。     

广西斜纹夜蛾核型多角体病毒的分离鉴定

从广西部分地区采集到自然罹病死亡的疑似具有病毒症状的斜纹夜蛾幼虫，对其进行病毒的分离鉴定。用研磨病虫尸体得到的浆液，经分离纯化后感染连续人工饲养至第三代的健康斜纹夜蛾三龄幼虫，部分样品能诱发病毒病症状。经差速离心的提纯物，在相差显微镜下观察到外形不规则的颗粒，进一步在电镜下观察到菱形、五边型、六边形、近似圆形等形状的多角体。用依据SpltNFV DNA的egt基因保守序列设计的引物，对多角体中提取的DNA进行PCR扩增，得到了与预期一致的380bp片段。经测序分析，该PCR片段与Splt NPV egt基因在核苷酸水平上的同源性为99．4％，演绎的氨基酸水平上的同源性为100％。进一步对采自广西16个地域的疑似具有病毒症状的200份斜纹夜蛾幼虫样本进行PCR扩增，其中6个地域的62份样本呈PCR阳性，这表明，广西斜纹夜蛾自然种群中存在着SpltNPV的流行。     

纽荷尔脐橙对建阳橘柚上柑橘衰退病毒分离株构成的影响

建阳橘柚兼具橘和柚的优良性状,为了解其携带的柑橘衰退病毒(CTV)分离株的分子特征及其传播到江西赣州对赣南脐橙产业的影响,将建阳橘柚(Citrus paradisi×C.reticulata)CTV分离株JY-5嫁接接种到赣南脐橙纽荷尔(C.sinensis)品种上,比较接种前后病毒外壳蛋白(cp)基因的HinfⅠRFLP和SSCP变化情况,实验结果表明,建阳橘柚上CTV分离株RFLP组群由接种前的单一组群变为混合组群,SSCP谱带数增加,在建阳橘柚上受抑制的CTV分离株在纽荷尔脐橙上能得到较好地增殖;同时接种前后分离株cp,p23和k17基因片段序列同源性及聚类分析表明,在建阳橘柚上的CTV分离株JY-5与其嫁接接种在纽荷尔脐橙上的JY-5R分离株并未在系统进化树上聚类在一起,表明两者不具有紧密的亲缘关系,结合RFLP和SSCP分析结果推测,JY-5R可能是在建阳橘柚上受抑制的分离株在纽荷尔脐橙上恢复了增殖。研究结果提示,建阳橘柚上的CTV分离株一旦传到赣南脐橙上,对赣南脐橙产业会带来一定的威胁。     

不同预处理对长寿沙田柚根尖染色体制片的影响

本研究采用0.1％秋水仙素、对二氯苯饱和水溶液、对二氯苯-α-溴萘混合液这3种常用于植物染色体预处理的药剂,研究了不同处理方式对长寿沙田柚根尖细胞染色体制片效果的影响.结果表明:利用对二氯苯-α-溴萘混合液预处理根尖12h效果最好,中期分裂指数高,染色体分散、清晰.     

不同预处理对长寿沙田柚根尖染色体制片的影响

本研究采用0.1%秋水仙素、对二氯苯饱和水溶液、对二氯苯-α-溴萘混合液这3种常用于植物染色体预处理的药剂,研究了不同处理方式对长寿沙田柚根尖细胞染色体制片效果的影响。结果表明:利用对二氯苯-α-溴萘混合液预处理根尖12h效果最好,中期分裂指数高,染色体分散、清晰。     

Volatile constituents of redblush grapefruit (Citrus paradisi) and pummelo (Citrus grandis) peel essential oils from Kenya

The volatile constituents of cold-pressed peel essential oils of redblush grapefruit (Citrus paradisi Macfadyen forma Redblush) and pummelo (Citrus grandis Osbeck) from the same locality in Kenya were determined by GC and GC-MS. A total of 67 and 52 compounds, amounting to 97.9 and 98.8% of the two oils, respectively, were identified. Monoterpene hydrocarbons constituted 93.3 and 97.5% in the oils, respectively, with limonene (91.1 and 94.8%), alpha-terpinene (1.3 and 1.8%), and alpha-pinene (0.5%) as the main compounds. Sesquiterpene hydrocarbons constituted 0.4% in each oil. The notable compounds were beta-caryophyllene, alpha-cubebene, and (E,E)-alpha-farnesene. Oxygenated compounds constituted 4.2 and 2.0% of the redblush grapefruit and pummelo oils, respectively, out of which carbonyl compounds (2.0 and 1.3%), alcohols (1.4 and 0.3%), and esters (0.7 and 0.4%) were the major groups. Heptyl acetate, octanal, decanal, citronellal, and (Z)-carvone were the main constituents (0.1-0.5%). Perillene, (E)-carveol, and perillyl acetate occurred in the redblush grapefruit but were absent from the pummelo oil. Nootkatone, alpha- and beta-sinensal, methyl-N-methylanthranilate, and (Z,E)-farnesol were prominent in both oils.     

Antioxidant content and free radical scavenging ability of fresh red pummelo [Citrus grandis (L.) Osbeck] juice and freeze-dried products

The antioxidative phytochemicals in various fruits and vegetables are widely recognized for their role in scavenging free radicals, which are involved in the etiology of many chronic diseases. Colored fruits are especially considered a quality trait that correlates with their nutritional values and health benefits. The specific aim of this study was to investigate the antioxidants in the juice and freeze-dried flesh and peel of red pummelo and their ability to scavenge free radicals and compare them with those in white pummelo juice. The total phenolic content of red pummelo juice extracted by methanol (8.3 mg/mL) was found to be significantly higher than that of white pummelo juice (5.6 mg/mL). The carotenoid content of red pummelo juice was also significantly higher than that in white pummelo juice. The contents of vitamin C and delta-tocopherol in red pummelo juice were 472 and 0.35 mug/mL, respectively. The ability of the antioxidants found in red pummelo juice to scavenge radicals were found by methanol extraction to approximate that of BHA and vitamin C with a rapid rate in a kinetic model. The ability of methanol extracts of freeze-dried peel and flesh from red pummelo to scavenge these radicals was 20-40% that of BHA and vitamin C effects. Fresh red pummelo juice is an excellent source of antioxidant compounds and exhibited great efficiency in scavenging different forms of free radicals including DPPH, superoxide anion, and hydrogen peroxide radicals.     

水与“楚门文旦”生长发育和裂果的关系

为探索防止“楚门文旦”裂果的方法,分析了已取得的研究成果,和裂果的诸多相关因子指出果园气候异常,空气相对湿度和土壤持水量是影响裂果最明显的因素,防止文旦裂果的有效途径(特别对已种植的数万亩文旦园)是实施对文旦果园土壤水分和空气相对湿度的调控,以满足不同生长发育期对水分和湿度的合理需求。提出在现有深沟排灌的基础上增设微量喷灌,利用单片微处理机技术,建成最佳的给排水自动调节系统,具有明显的经济和社会效益。     

Juice quality of two new mandarin-like hybrids (Citrus clementina Hort. ex Tan x Citrus sinensis L. Osbeck) containing anthocyanins

Tacle and Clara [Monreal clementine (Citrus clementina Hort. ex Tan) x Tarocco orange (Citrus sinensis L. Osbeck)] are two new triploid citrus hybrids developed by the CRA-Istituto Sperimentale per l'Agrumicoltura (Acireale, Italy). The fruits are easy-peeling and juicy, have a pleasant taste like the Tarocco orange, and are sweet like the Monreal clementine. In addition, a distinctively attractive characteristic of these mandarin-like fruits is the red-pigmented flesh caused by the presence of anthocyanins. This study reports the juice quality attributes of fresh fruits harvested at different ripening stages and of cold-stored fruits kept for 104 days at 6+/-1 degrees C and 90-95% relative humidity. Physico-chemical analyses showed that the fresh-fruit juice yield ranged between 39 (Tacle) and 41% (Clara); these values were 11-14% lower after 104 days of storage. Vitamin C content in the Clara juice was decisively higher than that in the Tacle juice. Juice anthocyanins and other polyphenols increased during cold storage. These results show that low-temperature storage enhances the functional attributes of Tacle and Clara fruit juices.     

Juice components of a new pigmented citrus hybrid Citrus sinensis (L.) Osbeck x Citrus clementina Hort. ex Tan

Fruit juice of a new pigmented citrus hybrid named Omo-31 and those of its parents clementine cv. Oroval (Citrus clementina Hort. ex Tan.) and Moro orange [Citrus sinensis (L.) Osbeck] were analyzed during fruit maturation to determine juice yield, total soluble solids (TSS), total acidity (TA), TSS/TA ratio (classical parameters of quality), and potential health beneficial components, such as vitamin C, flavanones, anthocyanins, and phenolic acids. Results showed that juice yield, TA, TSS, and TSS/TA ratio values of Omo-31 were similar to those of the Moro orange. Vitamin C content of the new hybrid was slightly higher than that of clementine and lower than that of the Moro orange, but at maturity stage no differences were observed among the three genotypes. The phenolic compounds content of the new hybrid and those of the parents and their evolution during maturation were studied. At maturity stage the amount of anthocyanins, flavanones, and hydroxycinnamic acids in Omo-31 was found to be notably higher than those of the parents. The high level of antioxidant substances makes this new fruit important for its nutritional benefits.     

Ultrafiltration performance of heat-treated shamouti orange [Citrus sinensis (L.) Osbeck] juice.

During ultrafiltration of orange juice with inorganic membranes, heating of the juice prior to the filtration experiment resulted in a significant increase of the fouling indices. The effect of the irreversible fouling (Rif) was always high, whereas the reversible fouling (Rrf) depended on the treatment. It was clearly seen that fouling was reduced after pectin degradation, but the heat treatment applied to the juice before filtration still resulted in reduced fluxes. It is suggested that pectins and proteins that undergo flocculation/coagulation during the heat treatment tend to interact with the membrane-filtering layer and to cause reduction of permeation flux. To clean the membrane to restore its pure water flux, close to the initial one, a proteolitic enzyme detergent wash was needed.     

Characterization of the most odor-active volatiles of orange wine made from a Turkish cv. Kozan (Citrus sinensis L. Osbeck)

The aroma-active compounds of cv. Turkish Kozan orange wine were analyzed by sensory and instrumental analyses. Liquid-liquid extraction with dichloromethane was used for extraction of volatile components. According to sensory analysis, the aromatic extract obtained by liquid-liquid extraction was representative of orange wine odor. A total of 63 compounds were identified and quantified in orange wine. The results of the gas chromatography-olfactometry analysis showed that 35 odorous compounds were detected by the panelists. Of these, 28 aroma-active compounds were identified. Alcohols followed by terpenes and esters were the most abundant aroma-active compounds of the orange wine. Among these compounds, ethyl butanoate (fruity sweet), 3-methyl-1-pentanol (roasty), linalool (floral citrusy), gamma-butyrolactone (cheesy burnt sugar), 3-(methylthio)-propanol (boiled potato, rubber), geraniol (floral citrusy), and 2-phenylethanol (floral rose) were the most important contributors to the aroma of the orange wine because they were perceived by all eight panelists.