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关键词： 长苞铁杉   铁杉属   生物学特性   保护措施  

摘要： 长苞铁杉（ＴｓｕｇａＩｏｎｇｉｂｒａｃｔｅａｔａ）属松科铁杉属，长苞铁杉组（Ｓｅｃｔ．ＨｅｏｐｅｎｃｅＫｅｎｇｅｔＫｅｎｇｆ．），为我国特有树种；现正处在濒危状态，已被列为国家三级保护植物。本文比较系统地综述了长苞铁杉的生物学特性，包括其外部形态、内部结构、染色体核型、地理分布、生长特性及材性、生态学和群落特性等。关于长苞铁杉的分类位置，一直争论不休。作者在比较了各种分类观点后，根据上述特性的分析结果，支持建立长苞铁杉属（Ｎｏｔｈｏｔｓｕｇａ）的主张。最后，文章分析了可能引起长苞铁杉濒危的原因，并提出了两点保护措施。

关键词： 抗病性基因   植物生物学   真菌感染   N基因   保护植物   拟南芥   烟草花叶病病毒   抗性蛋白   伯克利分校   基因导入  

摘要： 表面上,似乎是九月在延长,但对于植物生物学家来说,却好象今年的圣诞节提早了三个月到来。美国加州大学伯克利分校的二个研究小组发现了二种不同的抗病性基因,有可能揭示作物抗病毒、细菌和真菌感染的秘密。 这二个基因是N基因和RPS2基因。前者是首次分离的,可使作物抵抗烟草花叶病病毒;后者发现于芥子植物拟南芥(Arabidopsis thaliana),它可使植物抵抗丁香假单[胞]菌(Pseudomonas syringae)。

关键词： 高等植物   自交不亲和性   分子生物学  

摘要： 自交不亲和性是大多数高等植物防止近亲繁殖的一种遗传屏障。它涉及受精时雄配子（花粉）和雌蕊之间的相互作用。目前，已经分离获得了编码控制雌蕊自交不亲和性的Ｓ基因。在孢子体型自交不亲和的芸苔属中，雌蕊Ｓ基因编码Ｓ位点糖蛋白（ＳＬＧ）和Ｓ受体激酶（ＳＲＫ）。它们可能与磷酸化和去磷酸化参与了的某种信号传递有关，最后导致自交花粉生长的抑制。在配子分配体型自交不亲和的茄科中，雌蕊Ｓ位点糖蛋白为一种核糖核酸酶，称为Ｓ－核酸酶（Ｓ－ＲＮａｓｅ）。自交不亲和反应与Ｓ－核酸酶引起的花粉管ＲＮＡ降解有关，并且可能通过花粉管特异性地摄入Ｓ－核酸酶或者花粉管内存在的特异性的核酸酶抑制剂的作用，达到对自交花粉生长的抑制。另外，从配子体型自交不亲和的罂粟中，分离到了与芸台属和茄科不同的雌蕊Ｓ基因，其作用机理可能与Ｃａ＋＋参与的信号传递有关。

关键词： 植物   短命植物   种子生物学   适应   生态学特性  

摘要： 卷果涩芥（ＭａｌｃｐｌｍｉａｓｃｏｒｐｉｏｉｄｅＳ）、四齿芥（Ｔｅｔｒａｃｍｅｑｕａｄｒｉｃｏｒｎｉｓ）、长齿四齿芥（Ｔ．ｒｅｃｕｒｖａｔａ）和狭果鹤虱（Ｌａｐｐｕｌａｓｅｍｉｇｌｏｂｒａ）为新疆北部常见的四种短命植物。本文从种子生物学、发育节律、株形和植株寿命等方面研究它们与生存环境的协调与适应。

关键词： 植物细胞   扫描显微镜   共焦显微镜   Southern   镭射   电子显微镜   植物生物学   三维图象   遗传性缺陷   成象系统  

摘要： 在1993年Southern Association of Agricural Scientists年会上发表的一篇论文中,Southern Branch of the American Society of Agronomy的***,***,V.T.

关键词： CONIFER   SOMATIC EMBRYOGENESIS   SPRUCE   CYTOSKELETON   ENDOCYTOSIS  

摘要： Embryogenic cultures have been produced for a wide range of conifers and current methods developed for spruce permit the maturation of high quality embryos that can be desiccated and then germinated to form plantlets. Embryogenic suspensions consisting of immature embryos are an excellent source of regenerable protoplasts. This review considers examples of applications of embryogenic suspension cultures for basic studies in three areas of plant cell biology, a) Immunofluorescence studies of microtubules in mitotic spruce cells reveal focused spindle poles at prophase and anaphase, suggesting the presence of microtubule organizing centers (MTOCs). Antibodies known to recognize animal MTOCs do not stain the polar regions but do stain developing kinetochores. b) Embryo-derived protoplasts regenerate directly to somatic embryos. Fluorescence studies of the cytoskeleton in freshly derived protoplasts reveal random cortical microtubules and a fine network of actin filaments. During culture, protoplasts change shape and develop transverse cortical microtubule arrays. Embryonal cells of newly formed embryos possess distinctive arrays of cortical microtubules and networks of fine actin filaments while suspensor cells are characterized by transverse cortical microtubules and longitudinal actin cables. c) Transmission electron microscope studies of endocytosis in spruce protoplasts reveal an endocytotic pathway similar to that described previously for soybean. Uptake results are confirmed using high pressure freeze fixation instead of conventional chemical fixation.

关键词： AMARYLLIDACEAE   ANDRENIDAE   BEHAVIORAL THERMOREGULATION   ECTOTHERMY   FLORAL MICROCLIMATE   FLOWER DURATION   FORAGING BEHAVIOR   PHENOLOGY   POLLEN LIMITATION   POLLINATION   SOUTHERN SPAIN   THERMAL BIOLOGY   THORACIC TEMPERATURE  

摘要： Abiotic factors may constrain the functioning of species interactions such as plant-pollinator mutualisms. I investigated how thermal environment affects the interaction between the early-blooming daffodil, Narcissus longispathus (Amaryllidaceae) and its major bee pollinator (Andrena bicolor;Andrenidae), focusing simultaneously on plant and pollinator sides of the interaction. I studied fruit and seed set, flower duration, and the intrafloral thermal environment of N. longispathus, and the thermal biology, foraging behavior, and thermoregulatory ability of A. bicolor over a 6-yr period in southeastern Spain. N. longispathus flowers from February to April, when unsuitable weather often limits pollinator activity, yet most flowers are successfully pollinated in all years and sites. Fruit set was weakly pollen limited, but among flowers setting fruit the proportion of ovules developing into seeds was not. Individual flowers lasted for 17 d on average, remaining functional during this period. On sunny days, the air inside N. longispathus flowers was significantly warmer than outside. Mean temperature excess inside flowers was as high as 8 degrees C, and was positively related to solar irradiance. Within flowers, air temperature was highest around the anthers;this intrafloral gradient was consistent with variation among perianth parts in radiation transmittance. Andrena bicolor foraged in N. longispathus flowering patches only on sunny days with air temperature >12 degrees-13 degrees C, and foraging behavior and flower visitation rate were temperature dependent. Bees were able to fly at relatively low thoracic temperatures (T-th;range 22 degrees-31 degrees C) and this was essential for successfully foraging at N. longispathus. Under the range of irradiance and air temperature found at foraging sites, A. bicolor individuals inside flowers were able to reach T-th suitable for flight by passive means alone. Under laboratory conditions, A. bicolor was unable to raise or othe

关键词： 水稻花粉   特异基因   核糖核酸酶   烟草花粉   特异表达   表达调控  

关键词： 悬钩子属植物   树莓   蓬Lei   生物学特性  

摘要： 从形态学、解剖学、资源分布、营养生长节律,繁殖和种子生物学等方面对蓬LEI作了探讨,并进行了初步的栽培试验和果实成分的分析及加工试验,结果表明:蓬LEI分布广,资源丰富,适应性和抗逆性强,果实的食用价值较高,是浙江悬钩子属植物中具有引种、驯化、育种价值和开发利用前景的野生种之一.