葡萄属植物花粉形态的研究

利用扫描电子显微镜对葡萄属Vitis L．37个类群(包括32种、1亚种和4变种)以及其近缘属麝香 葡萄属Muscadinia(Planch．)Small一种植物的花粉进行了观察,结果表明,葡萄属植物的花粉形态特征 在区别并鉴定属下的种类时有较大价值,但对种以上的分类以及研究系统演化无多大意义。葡萄属植 物的花粉形态特征可以分为4类：(1)花粉粒扁球形或圆球形(P/E值为O.97-1.08),沟较宽,可见被有 较密颗粒状突起的沟膜,属于该类的有紫葛V．coignetiae Pull．ex Planch．;(2)花粉粒长球形至近长圆球 形(P/E值为1.25～1.76),沟较宽,可见有较疏颗粒状突起的沟膜,该类型包括了庐山葡萄V．hui Cheng 等共10种1亚种3变种;(3)花粉粒长圆球形(P/E值为1.87～2.1),沟边缘紧靠合呈直线状,但在赤道 轴萌发孔处沟边缘分开呈菱形,该类型有秋葡萄V．romanetii Roman du Caill．ex Planch．和锈毛刺葡萄V． davidii(Roman du Caill．)Foex．var．ferruginea Merr．et Chun等1种1变种;(4)花粉粒长球形或超长球形 (P/E值为1.30～2.0),沟边缘紧靠成直线状,麝香葡萄Muscadinia rotundifolia(Michx .)Small等21种的花粉属于此类型。     

铝胁迫对青杨雌雄幼苗生理生态特征的影响

以青杨雌雄幼苗为对象,研究铝胁迫(Al³⁺浓度为216 mg·kg^-1)下其生理生态特征及光合作用的差异.结果表明：铝胁迫下,青杨幼苗的丙二醛和可溶性蛋白含量显著增加(P<0.001),且雄株的丙二醛显著低于雌株,而可溶性蛋白显著高于雌株;雄株过氧化物酶活性显著增加、超氧化物歧化酶活性显著降低,而雌株无显著变化;雌雄幼苗的光合速率显著降低(P=0.001),雌株的蒸腾速率显著下降(P=0.007)、瞬时水分利用效率显著增加,而雄株均无显著变化;雌株幼苗的叶绿素a含量、总叶绿素含量和叶绿素a/b值显著降低,而雄株的叶绿素a/b值显著高于雌株;雌株的比叶面积显著降低、雄株的比叶面积显著增加,而叶和茎的干物质量无显著变化.与雌株相比,青杨雄株的可溶性蛋白含量、抗氧化酶活性、叶绿素含量和光合速率较高,其抗逆性更强.     

阿拉善荒漠驼蹄瓣属7种植物的花粉形态研究

用扫描电镜对阿拉善荒漠驼蹄瓣属(ZygophyllumL.)7种植物的花粉形态特征进行了观察分析.结果表明,在扫描电镜下,每种植物花粉粒的表面纹饰、萌发孔类型等性状符合驼蹄瓣属的主要特征;而花粉粒的大小、P/E值等细微特征存在明显差异.     

雌雄异株树种黄连木种群性比及空间分布

研究了100m×140m固定样地内黄连木种群的性比格局和空间分布。结果表明,调查样地中dbh≥4cm的黄连木植株共有2116株,其中包括526株雌树,1200株雄树,性别未确定植株390株。黄连木性比(雄/雌=2.28)显著偏雄(P0.001)。雌树和雄树平均胸径分别为7.34和7.81cm,雄树胸径显著大于雌树胸径(P0.05)。黄连木幼树、雌树和雄树均呈显著聚集性分布。黄连木幼树与雌树、幼树与雄树均在较小尺度上表现为相互吸引;雌树与雄树则在空间上相互排斥,即雌树与雄树存在空间分离现象;黄连木不同大小以及不同性别植株之间主要表现为相互排斥。     

野生桂花繁育系统的观察和研究

对湖南省浏阳市周洛村桂花峡、福建省长汀县官坊村石峰寨东北坡和南坡、浙江省龙泉市供村及张公桥和毛圩村6个野生桂花〔Osmanthus fragrans(Thunb.)Lour.〕居群中桂花单株的性别比例进行了统计,并对单性雄株和两性株的花部雌蕊形态、花粉粒数量和外部形态及花粉在柱头上的萌发情况进行了观察和比较。结果显示:6个居群中雄性比率差异较大(0～0.62),平均值接近0.5;其中,石峰寨东北坡和南坡居群的雄性比率最大(0.62),张公桥居群的雄性比率最小。两性株花的雌蕊发育正常,而单性雄株的花具有退化雌蕊的痕迹。不同居群及个体间每个花药的花粉粒数量存在一定差异,且单性雄株每个花药的花粉粒数量多于两性株,但差异均不显著(P>0.05)。单性雄株和两性株的花粉粒形态一致,花粉粒均为长椭圆形、极轴长16μm、具三沟和网状雕纹型表面纹饰;花粉均具有较高活力且均能在柱头上萌发。结合对木犀属(Osmanthus Lour.)其他种类的观察结果认为:桂花的繁育系统应属功能性的雄全异株,这种繁育系统可能为两性同体与雌雄异株间的过渡类型,在木犀属的其他种类中也能观察到雄全异株的存在。     

猕猴桃属花粉形态及其系统学意义

由于天然种间杂交,猕猴桃属Actinidia Lindl.的分类存在着组间界限不清、近缘种之间很难区分的问题。本文试图通过对该属不同组、系的植物花粉及种间杂交后代花粉的扫描电镜观察,探讨该属物种的系统学关系。在扫描电镜下观察了猕猴桃属植物21种、 6变种和4个不同种间杂交F1代植株的花粉,描述了它们的花粉形态,并根据花粉形态特征建立了相应的检索表。研究结果表明：（1）猕猴桃属的花粉形状主要以长球形至近球形为主,变异较小,而花粉粒大小和外壁纹饰的种间差异较大。（2）多数迁地保护物种的花粉粒以三孔沟为主,不同于以前报道的以三拟孔沟为主,原因可能是花粉样本采集地的环境不一样,以及野外的广泛杂交造成的。（3）种间杂交后代花粉空瘪,无授粉能力,是由于所采用亲本植株染色体的倍性不同,后代不能产生正常花粉所致。（4）人工选育雄株花粉外壁纹饰较野生雄株花粉的精细,这种花粉外壁纹饰变小的特征可能有利于雌雄异株植物的授粉受精。这一现象值得进一步探讨。（5）雄株花粉大小与其雌株果实大小之间有一定相关性,这一现象有助于杂交后代的早期筛选。     

野生及栽培盾叶薯蓣（Dioscorea zingiberensis）的性别特征观察

对野生和栽培盾叶薯蓣(Dioscorea zingiberensis C. H. Wright)的性别特征及变异状况进行了观察,并对栽培盾叶薯蓣母根状茎和子根状茎萌发植株的性别特征进行了比较.观察结果显示,在湖北武当山6个样地717株野生盾叶薯蓣中共有155株开花植株,其中雌株、雄株和雌雄同株分别有60、94和1株,雌雄株比例1 ∶ 1～1 ∶ 3,平均雌雄株比例1 ∶ 1.57,每个根状茎一般具有1支缠绕茎.2004年至2006年的观察结果显示,2004年153株栽培盾叶薯蓣基株中雄株、雌株和雌雄同株分别有78、62和13株;2005年存活的基株中雌株和雄株数量明显减少,雌雄同株数量大幅增加,雄株、雌株和雌雄同株分别有35、19和88株;2006年成活的137株基株中有80株开花,其中雄株、雌株和雌雄同株分别有38、9和33株,雌株和雌雄同株数量大幅下降.随栽培年限的增加,每个基株的缠绕茎数由1～2支增加至5～6支.栽培过程中盾叶薯蓣的性别有较大幅度变异,雄株和雌株多数转变为雌雄同株,反向转变却较少,雄株和雌株间相互转变也较少.2005年存活并开花的基株中共有100株发生变异,在2006年有13株返变回原性别,有26株保持了2005年变异的性别,有11株变异为另一种性别;雄株、雌株和雌雄同株3年的总变异率分别达到80.77%、100.00%和46.14%.子根状茎萌发植株的性别与母根状茎有较大差异,总变异率达到约50%,其中母根状茎为雄性的其子根状茎萌发植株的性别总变异率最高(59.09%).研究结果表明,野生盾叶薯蓣可能以有性繁殖为主要繁殖方式,性系统简单清晰;栽培盾叶薯蓣复杂的性系统及大幅度的性别变异可能是由外部环境因子的影响造成的.     

吉林长白山夏季开花植物花粉形态研究及其古环境意义

应用光学显微镜对长白山地区122种(含4变种)夏季常见的开花植物花粉形态进行观察和研究,结果表明:花粉粒以近球形和长球形为主,分别占41.8%和33.6%,其它还有球形、扁球形、超长球形、超扁球形、花粉块。花粉粒中P/E值最大的为朝鲜当归(Angelica gigas Nakai)2.12,最小的为柳兰(Epilobium angustifolium L.)0.82;最大的花粉为北锦葵(直径118μm),最小的为落新妇(12.5×10.3μm)。花粉萌发孔以3孔沟和3沟为主,分别占41.8%和14.6%,还有少量的为散孔、3孔、6沟、4孔、单沟、3(-4)孔沟、4沟等类型。外壁纹饰有6种,主要有细网状(50%)和刺状(22.1%),其他还有颗粒状、粗网状、条纹状、条纹-穿孔。本文还对同科不同属、同属不同种、同种不同地区的花粉形态进行了讨论,研究结果为长白山地区沉积花粉的准确鉴定提供鉴别指南和标准对照图谱,为第四纪地层花粉的研究提供现代孢粉学资料。     

河北省平原地区常见伴人植物花粉形态研究

应用光学显微镜对河北省常见的28种伴人植物花粉形态进行了观察和研究。结果表明:花粉粒呈球形(近球形)的花粉22种、长球形5种、扁球形1种;P/E值最大的花粉为紫花地丁(Viola yedoensis Makino)1.59,最小的为苦菜[Ixeris chinensis(Thunb.)Nakai]0.84;最大的花粉为田旋花(Convolvulus arvensis L.),最小的为黄鹌菜[Youngia japonica(L.)DC.Prodr.];花粉的萌发孔主要有单孔、散孔、3—4孔、3沟、3孔沟、3—4孔沟和5—7沟等7种类型;其外壁纹饰主要包括网状、瘤状、具刺和颗粒状等4种类型。该研究为地层中伴人植物花粉的鉴定提供了标准图谱和相关信息,为了解古人类的活动、研究古代伴人植物生态学以及人类活动对环境的影响提供了现代孢粉学依据。     

青杨雌雄叶片气孔分布及气体交换的异质性差异

利用网格和二维成图的方法对青杨雌雄叶片各区域的气孔分布及气体交换特性进行了测定.结果表明:1)除气孔密度(SD)外,雌雄植株在气孔长度(SL)、宽度(SW)和比值(SR)方面具有显著差异(P=0.000,P=0.000和P=0.002).雌株的SL和SW分别比雄株的高51.86%和67.06%,而SR则比雄株的低11.46%.从雌株和雄株的叶面分布来看,SD均为叶中>叶尖>叶基,SL均为叶尖>叶中>叶基,SW的最小值同在叶基部,但最大值分别在叶中和叶尖部.雌株的SR表现为叶基>叶尖>叶中,雄株却正好相反.2)在净光合速率(Pn)上雌株明显低于雄株.雌株的Pn叶基最低(Pn值介于2.00～3.00?μmol m-2 s-1),叶尖最高(Pn值介于8.00～9.00?μmol m-2 s-1),总体上表现出沿叶基到叶尖逐渐增大的趋势.雄株的Pn在叶面的分布也有差异,但总体规律不明显.3)从叶面各区间的气体交换来看,雌株的蒸腾速率(Tr)和气孔导度(Gs)变化不大,雄株的Tr和Gs呈现叶尖和叶中部高于叶基部的明显趋势.雌株的胞间CO2浓度(Ci)为叶基>叶中>叶尖,气孔限制值(Ls)与此相反.而雄株的Ci在叶面的变化较大,Ls呈现沿叶尖至叶基方向逐步上升的趋势.上述结果表明,青杨雌雄叶片在气孔分布及气体交换特性上不仅存在显著的性别差异,而且具有明显的叶面区域异质性.     

A study on pollen morphology of the genus Vitis L.

The pollen grains of 32 species, 1 subspecies and 4 varieties of Vitis and 1 species of Muscadinia were scanned with Hitachi S-800 scanning electron microscope and described in the present paper. In Vitis, the pollen morphology is found to be valuable for the identification of species, though it is of little significance in supraspecific classification and systematic consideration. The ornamentation of Vitis could be divided into four types: ( 1 ) The pollen grains are oblate or rarely spheroidal (P/E =0.97 ～ 1.08) in shape, with colpi wide enough to show dense granulae inside. The pollen grains of V. coignetiae Pull. Ex Planch. belong to this type. (2) The pollen grains are prolate to subprolate (P/E = 1.25 ～ 1.76 ), with sparse granulae within the colpi. This type includes l0 species, 1 subspecies and 3 varieties, such as V. hui Cheng etc. (3) The pollen grains of V. romanetii Roman du Caill. ex Planch. and V. davidii (Roman du Caill. ) Foex. var. ferruginea Merr. et Chun are prolate (P/E= 1.87 ～ 2.1), with colpi narrow and linear-shaped, but rhombic in the equational region. (4) The pollen grains are prolate or perprolate (P/E= 1.30 ～ 2. 0), with narrow and linear-shaped colpi. The species with this type of pollen grains are Muscadiniarotundifolia (Michx.) Small and 20 species of Vitis.     

贵州喀斯特山区野生葡萄实生苗抗旱机理研究

以4份2生年喀斯特山区野生葡萄实生苗为试材,通过塑料大棚盆栽试验研究了自然干旱胁迫下野生葡萄幼苗的外观形态特性和生理指标变化规律,探讨其抗旱性及其抗旱机理.结果表明;(1)4份野生葡萄的抗旱性存在明显差异,以葛藟葡萄'小七孔-3'的抗旱性最强,毛葡萄'天河潭-2'的最差.(2)干旱胁迫期间,'小七孔-3'的1级旱害症状出现时间比'天河潭-2'晚12d,且旱害指数始终小于其他3份种质.(3)抗旱性强的野生葡萄叶片相对含水量、可溶性蛋白含量高于抗旱性差的株系,而其叶片水分饱和亏、细胞膜透性、丙二醛(MDA)含量变化则相反,且材料间差异随着干旱程度的增强而增加;(4)野生葡萄叶片相对含水量与其旱害指数间呈极显著负相关,而其水分饱和亏、相对电导率、丙二醛含量与旱害指数间呈极显著正相关;细胞膜脂过氧化产物丙二醛含量增加是导致葡萄旱害的首要因素.研究发现,在干旱胁迫下,抗旱性强的野生葡萄叶片膜系统稳定,水分散失较少,细胞电解质外渗较低,渗透调节物质可溶性蛋白含量增加,从而维持了正常的生理代谢活动.     

中国野生毛葡萄芪合成酶基因克隆及表达分析

采用RT-PCR技术克隆中国野生毛葡萄‘丹凤-2’芪合成酶基因,命名为VqDSTS1,并进行序列及表达模式分析.结果表明:VqDSTS1基因cDNA编码区全长为1 179bp,GenBank登录号为JQ342086,编码392个氨基酸;氨基酸序列分析表明,VqDSTS1含有芪合成酶基因家簇的特征识别序列‘IPNSAGAIAGN’和‘GVLFGFG-PGLT’;序列比对显示,VqDSTS1与其他葡萄种质的芪合成酶氨基酸序列一致性在95.2%～98.7%之间;半定量RT-PCR分析表明,VqDSTS1受白粉病诱导表达,呈双峰模式.为进一步研究中国野生毛葡萄‘丹凤-2’芪合成酶基因家族的表达及功能分析提供了基础.     

野生毛葡萄远缘杂交后代离体培养研究

以MS、1/2MS、GS三种培养基为基本培养基,以及在1/2MS培养基上分别附加6-BA 1.0mg/L+IAA 0.1mg/L和6-BA 1.0mg/L+NAA 0.1mg/L两组植物生长调节剂,对野生毛葡萄及其远缘杂交种后代213、741、196、296、B₂等6个品种(种类)进行茎段腋芽萌发离体培养试验。结果表明:1/2MS培养基为基本培养基最适宜茎段腋芽的诱导萌发;NAA对毛葡萄及其杂交种后代的萌芽生长影响明显,若单独使用,对绝大多数品种的茎段腋芽萌发有明显的抑制作用,与IAA交替使用,则对茎段腋芽萌发有促进作用。     

The arrest of development of abortive reproductive organs in the unisexual flower of<Emphasis Type="Italic"> Vitis vinifera</Emphasis> ssp.<Emphasis Type="Italic"> silvestris</Emphasis>

During the first stages of development, flowers of most dioecious species are hermaphroditic, with their transition to unisexual flowers being the result of the developmental arrest of one set of reproductive organs. In this work, we describe the development of male and female flowers of the dioecious wild grape species Vitis vinifera ssp. silvestris through scanning electron microscopy analysis and cytological observations, focusing our attention on the transition from bisexual to unisexual development. We divide floral development of the wild grape into eight stages. Differences between male and female flowers appear first at stage 6, when the style and stigma start to differentiate in female but not in male flowers. Cytological analysis of the slowly growing abortive pistil of male flowers shows that megagametophyte formation is, surprisingly, not inhibited. Instead of pistil abortion in the male flower, sexual determination is accomplished through programmed death of external nucellus cells and some layers of integumentary cells. Sterility of male structures in female flowers follows a different pattern, with microspore abnormalities evident from the time of their release from the tetrad. Sterile microspores and pollen grains in female flowers display an abnormal round shape, lacking colpi and possessing uniformly thickened cell walls that impede germination.     

雌雄异株葡萄的性别鉴定研究

通过扫描电镜观察花粉的形态;分析叶片超氧化物歧化酶同工酶(SOD);RAPD分析基因组DNA多态性,来鉴别葡萄的性别。结果表明：葡萄雌雄株的花粉形态存在着较大的差异;在本实验条件下葡萄雌雄株叶片SOD同工酶谱带一致;一些引物的RAPD产物间存在着多态性,在葡萄雌雄株的基因组DNA序列中存在着碱基排列顺序的差异。实验指出,花粉形态和基因组DNA的多态性分析是进行性别鉴定的有效方法。     

Genetic transformation of a fruit-specific,highly expressed stilbene synthase gene from Chinese wild Vitis quinquangularis

Planta - The stilbene synthase gene VqSTS6, from Chinese wild type Vitis quinquangularis accession Danfeng-2, increases the resveratrol content and pathogen resistance of transgenic plants of V....     

The Effects of Inflorescence Size and Flower Position on Biomass and Temporal Sex Allocation in <Emphasis Type="Italic">Lobelia sessiliflora</Emphasis>

To test the prediction of sex allocation theory that plants or flowers high in resource status emphasize the female function, we explored the variation in both biomass (the number of pollen grains and ovules) and temporal (male and female durations) sex allocation among and within plants of protandrous Lobelia sessilifolia in relation to plant size and flower position within plants. Among plants, the mean number of pollen grains and ovules per flower of a plant increased with plant size, whereas the mean P/O ratio (number of pollen grains/number of ovules ratio) decreased with plant size. The mean male duration, the mean female duration, and the mean ratio of male duration/flower longevity per flower of a plant were not correlated with plant size. Thus, large plants emphasized female function in terms of biomass sex allocation, which is consistent with the prediction of size-dependent sex allocation theory. The results for temporal sex allocation, however were inconsistent with the theory. Within plants, the mean number of pollen grains and ovules per flower at each position decreased from lower to upper flowers (early to late blooming flowers) and that of the P/O ratio increased from lower to upper flowers. The mean male duration and the mean female duration per flower decreased from lower to upper flowers, whereas the mean ratio of male duration/flower longevity increased from lower to upper flowers. The population sex ratio changed from male-biased to female-biased. Thus, later blooming flowers emphasized the male function in terms of both biomass and temporal sex allocation, consistent with the sex allocation theory, regarding the change in the population sex ratio.     

Development of a novel recessive genetic male sterility system for hybrid seed production in maize and other cross‐pollinating crops

We have developed a novel hybridization platform that utilizes nuclear male sterility to produce hybrids in maize and other cross‐pollinating crops. A key component of this platform is a process termed Seed Production Technology (SPT). This process incorporates a transgenic SPT maintainer line capable of propagating nontransgenic nuclear male‐sterile lines for use as female parents in hybrid production. The maize SPT maintainer line is a homozygous recessive male sterile transformed with a SPT construct containing (i) a complementary wild‐type male fertility gene to restore fertility, (ii) an α‐amylase gene to disrupt pollination and (iii) a seed colour marker gene. The sporophytic wild‐type allele complements the recessive mutation, enabling the development of pollen grains, all of which carry the recessive allele but with only half carrying the SPT transgenes. Pollen grains with the SPT transgenes exhibit starch depletion resulting from expression of α‐amylase and are unable to germinate. Pollen grains that do not carry the SPT transgenes are nontransgenic and are able to fertilize homozygous mutant plants, resulting in nontransgenic male‐sterile progeny for use as female parents. Because transgenic SPT maintainer seeds express a red fluorescent protein, they can be detected and efficiently separated from seeds that do not contain the SPT transgenes by mechanical colour sorting. The SPT process has the potential to replace current approaches to pollen control in commercial maize hybrid seed production. It also has important applications for other cross‐pollinating crops where it can unlock the potential for greater hybrid productivity through expanding the parental germplasm pool.     

Types of pollen dispersal units in orchids,and their consequences for germination and fertilization

The various pollen dispersal units (PDU) found in orchids are discussed together with possible evolutionary trends and the consequences for germination and fertilization. Orchids with monad and tetrad pollen form more complex dispersal units by means of pollenkitt, elastoviscin, a callosic wall, common walls or a combination of these. Evolutionary trends include (1) from pollenkitt to elastoviscin; (2) from monad to tetrads and multiples of tetrads; (3) from partially dehydrated (<30 %) to partially hydrated (>30 %) pollen; and (4) from monad pollen to PDUs with many pollen grains. The biological consequences concern both male and female reproductive systems. Some features of the male side are present in all orchids irrespective of the pollen dispersal unit, whereas other characters are found only in orchids with pollinia; the same applies for the female counterpart. Pollen grains of orchids with pollinia germinate at least 24 h after pollination because the pollen grains/tetrads must swell and make space for the growth of pollen tubes.