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关键词： 植物   生殖   花   雄性不育   S位点特异蛋白   离体受精  

摘要： 简介了成花的网状系统模型的建立、花器官分化的基因控制模型、基因工程方法构建雄性不育、自交不亲和的Ｓ位点编码产物的性质、性细胞研究及离体显微操作等方面的研究动态和进展。

关键词： 植物受精   有性繁殖   被子植物   双受精   受精生物学  

摘要： 今年是被子植物双受精现象发现一百周年。一百年前的这个重大发现,早已在大学和中学的生物学课本中成为普及知识了。它的意义,在于双受精是植物界进化到被子植物这一最高层次所出现的独特现象,而在生物界的其它所有类群中均只有卵的受精而无中央细胞的受精;还在于双受精的第二产物胚乳对胚胎发育、种子形成与后代有重要作用,加之人类赖以生存的粮食也主要来源于胚乳。

关键词： 永瓣藤   卫矛科   珍稀特有植物   生物学特性  

摘要： 本文研究了我国珍稀特有植物永瓣藤（Ｍｏｎｉｍｏｐｅｔａｌｕｍｃｈｉｎｅｎｓｅ）的自然环境、地理分布、群落学特点、外部形态、内部结构特征、生长发育及其开花结实特性，为其种质保存和保护生物学研究提供基础资料。

关键词： 理化逆境因子   植物   抗寒性   诱导   分子基础  

摘要： 简要综述了非低温理化逆境因子诱导植物抗寒性的普遍性及其分子生物学基础，抗寒相关基因的表达与调控，以及植物抗寒性的遗传改良等方面的研究进展。

关键词： 碳素同化作用   绿色植物   光合作用   二氧化碳同化   植物生物学   自养植物   异养植物  

摘要： 在各类《植物生理学》的考试中，经常会碰到这类考题：（1）简述植物碳素同化作用概念、类型及其进化顺序。（2）绿色植物光合作用的CO2同化途径包括哪几类？试比较其异同。（3）植物碳素同化作用包括哪几类？等，从考试结果看，此类题考生得分并不高，有不少考生答不完整，甚至有的答错，究其原因主要在于把植物的碳素同化作用与绿色植物光合作用中的CO2同化途径混为一谈所致。据此，以下将这两种概念的区别和联系加以讨论。1自养植物与异养植物碳素是植物的必需营养元素之一，碳素营养是植物的生命基础。其一，因植物体的干物质中有90％是有机化合物，而有机化合物都含有碳素（约占有机化合物重量的45％），碳素是植物体内含量较多的一种元素；其二，碳原子是组成所有有机化合物的主要骨架，好像建筑物的栋梁支柱一样。碳原子与其他元素有各种不同形式的结合，因此决定了这些化合物的多样性。根据植物碳素营养方式的不同可将植物分为两类，即自养植物和异养植物。自养植物指能利用无机碳化物（CO2）作营养来合成有机物并能将其供给自身生长发育需要的植物。如绝大多数高等植物和少数微生物（如硫细菌、铁细菌、氢细菌、硝化细菌等）。异养植物指只能利用现成的有机物作营养以维持自身...

关键词： heathland   ericoid mycorrhiza   nitrogen mobilization   necromass   protease   chitinase  

摘要： In the 'F' horizons of acid mor-humus soils of heathland ecosystems, mycorrhizal roots of the dominant ericaceous species form a large fraction of the soil biomass. Rapid turnover of these roots provides the potential for recycling of substantial amounts of nitrogen contained in their fungal and plant components. Here, we first determine the amount of N in the biomass of ericoid roots growing in heathland and show it to constitute a large proportion of total soil N. In order to assess the accessibility of this N to ericaceous plants, experiments were then conducted using aseptically produced shoot and root necromass of Vaccinium macrocarpon Ait., the roots being grown with or without mycorrhizal colonization. These materials were provided as sole nitrogenous substrates in growth experiments using the ericoid mycorrhizal fungus Hymenoscyphus ericae (Read) Korf & Kernan in pure culture and V. macrocarpon in the mycorrhizal (M) or non-mycorrhizal (NM) condition as test organisms. The experiments were designed to test the hypothesis that the N contained in these substrates can be mobilized by the mycorrhizal endophyte. The ability of the endophyte to utilize the substrates was determined by measuring fungal yields and by assessing the presence of its extra-cellular protease and chitinase enzymes. Transfer of N to the host by the endophyte was determined through measurements of plant yield and tissue N contents. H. ericae produced a significantly greater yield on shoot and mycorrhizal root necromass than on non-mycorrhizal root necromass. The extra-cellular enzymes protease and chitinase were produced by the fungus when grown on the M root necromass. The fungus also transferred N to the host plant, up to 76%, of N contained in the substrate being found in M plants whereas less than 5% was present in their NM counterparts.

关键词： 饲料   植物性饲料   磷   植酸酶   利用率  

摘要： 常用植物性饲料中60～70％以上磷以植酸磷的形式存在,很难为单胃动物利用,饲粮中通常加入无机磷来满足动物对磷的需要。由于大量植酸磷不能为单胃动物消化利用,导致相当数量的磷由粪排泄,严重污染环境,尤其是世界上土地和水资源匮乏而牲畜饲养密度较大的地区。

关键词： 居群   遗传   进化   同工酶   等位酶  

摘要： 本文讨论了植物居群生物学的概念，同工酶分析在该学科中的应用和意义。认为同工酶分析是研究植物居群生物学的重要方法，它对推动该学科的发展具有十分重要的作用。

关键词： 2,4-D, (2,4-dichlorophenoxy)acetic acid   dicamba, (3,6-dichloro-2-methoxybenzoic acid)   glyphosate, N-(phosphonomethyl)glycine   picloram, (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid)   smooth brome, Bromus inermis Leyss. 'Rebound'   western wheatgrass, Pascopyrum smithii Rydb.'Rodan'   slender wheatgrass Elymus trachycaulus ssp. trachycaulus (Link) Gould ex Shinners 'Pryor'   pubescent wheatgrass Elytrigia intermedia (Host) Nevski 'Manska'   leafy spurge gall midge, Spurgia esulae   leafy spurge, Euphorbia esula L. #(3) EPHES   noxious weed   biocontrol   integrated pest management   grazing   cultural   chemical   EPHES  

摘要： Leafy spurge, a long-lived perennial, grows in many habitats, from floodplains to grasslands and mountain slopes. The plant emerges in early spring and produces showy, yellow bracts that appear in late May. The true flowers emerge in mid-June. The plant spreads by both seeds and roots and contains a white sticky latex that deters grazing by many animals. Dicamba, 2,4-D, glyphosate, and picloram have commonly been used to control leafy spurge. Picloram plus 2,4-D is frequently used for leafy spurge control in North Dakota. Ten insect species for leafy spurge biocontrol have been released in North Dakota;the most successful have been the flea beetles, Aphthona nigriscutis, A. czwalinae, and A. lacertosa. The leafy spurge gall midge (Spurgia esulae) has been most successful near wooded areas. Herbicides combined with either the leafy spurge flea beetles or gall midge have controlled leafy spurge better than either method used alone. Grazing with sheep or goats is a cost-effective method for controlling leafy spurge top growth in large infestations. Grazing combined with fall-applied picloram plus 2,4-D reduced leafy spurge density more rapidly and maintained control longer than either method used alone. Several grass species are competitive with leafy spurge including 'Rebound' smooth brome, 'Rodan' western wheatgrass, 'Pryor' slender wheatgrass, and 'Manska' pubescent wheatgrass. Cultivating twice each fall after harvest for 3 yr in cropland completely controlled leafy spurge. A successful long-term management program should be designed for specific situations and should include combinations of herbicides, insects, grazing, and/or seeding competitive species.