Photosynthesis,Transpiration, and Water Use Efficiency of Caragana microphylla,C. intermedia,and C. korshinskii

In the order C. microphylla — C. intermedia — C. korshinskii, compensation irradiance, saturation irradiance, and optimum temperature for photosynthesis increased, net photosynthetic rate (P _N) at low irradiance and low temperature decreased, optimum air humidity decreased, and P _N at low air humidity increased. Daily cumulative value of P _N increased while daily cumulative value of transpiration (E) decreased, and hence water use efficiency (WUE =P _N/E) increased. Diurnal course of P _N of C. microphylla was a double-peak curve, but the second peak in the curves of C. intermedia and C. korshinskii was not visible. These physiological characteristics are biological basis for the geographical distribution of these three Caragana species, and are in relation to water conditions of their habitats and distinctiveness in leaf hair of plant.     

西藏蕨类植物增补(Ⅱ)

报道了8种蕨类植物为西藏新记录,并讨论了西藏蕨类植物的区系特点和分类问题.     

黑桦叶表皮形态及其化学成分分析研究

利用扫描电子显微镜对黑龙江、吉林、辽宁黑桦 (Betula davurica Pall) 的叶形态对生境的适应及其化学成分进行了比较分析.结果表明:不同地区的叶表皮细胞形状、数量、角质膜均表现出不同程度的适应环境特征.在微量元素的含量上也表现出不同的特征.     

西藏蕨类植物增补(II)(英文)

报道了 8种蕨类植物为西藏新记录 ,并讨论了西藏蕨类植物的区系特点和分类问题     

寒区不同海拔橘黄罂粟叶片结构特征的比较研究

橘黄罂粟(Papaver croceum Ldb.)采自乌鲁木齐河源区海拔3600m、2500m两种海拔高度,采用PEG和Epon-812两次包埋方法．在光学显微镜和扫描电子显微镜下叶片剖面结构进行了观察。结果显示：橘黄罂粟叶片既具有中生植物又兼有旱生和湿生植物的部分结构特征,其叶片厚度、表皮细胞外壁角质层表面、外角质层蜡质分泌物的有无、表皮细胞形状、气孔密度、气孔大小、维管束形态组成、CTR值、叶肉细胞叶绿体含量等性状特征,在不同生境的橘黄罂粟间呈现出明显差异;而表皮毛状附属器等性状则差异较小。数值分析叶结构各类性状以及不同性状状态的组合．显示出橘黄罂粟个体形态的多样性与生境的海拔高度相关,并以形态结构上的变化来适应寒区高山环境。     

墨兰组织培养植株的叶结构和生理特性

墨兰叶肉没有海绵组织和栅栏组织的分化,但在叶的不同部分的叶脉附近叶肉细胞有不同的形态变化。叶尖和叶中部中脉附近的叶肉细胞排列紧密。细胞明显伸长,似栅栏组织,叶基部中 叶肉细胞没有伸长,叶部叶绿体周径大,叶绿素含量高,光合速率亦较高,且Fv/Fm、φPSⅡ和qp均较叶的其他部分高。     

尖叶拟船叶藓居群叶形态变异的初步研究

对东桠特有濒危植物尖叶拟船叶藓4个地点9个居群叶的形态变异进行了初步观测,结果表明,7个形态指标除叶表外,叶的形状、叶细胞形状、叶基部反曲和宽窄程度、叶边缘的分化及齿的类型和数量、叶尖和中肋的相对长度等均存在一定程度的变异,尤其是后三者变异程度较大,在梵净山的4个居群中,随着海拔的上升,叶的宽度递减和长度递增,叶缘齿的数量递减,叶尖和叶中肋的相对长度却以中度海拔的居群较大。     

Immune response of male barn swallows in relation to parental effort, corticosterone plasma levels, and sexual ornamentation

Life-history theory posits trade-offs between fitness components. Reproduction negatively affects physiology and immune systemfunctioning, and the effect of this form of stress may be mediatedby glucocorticosteroids. We manipulated brood size of barnswallows (Hirundo rustica) to study the effect of stress arisingfrom reproductive effort on corticosterone levels of males.We also measured T-cell—mediated immunocompetence by intradermally injecting birds with phytohemagglutinin, whichis mitogenic to T-lymphocytes. The results confirmed the predictionof a negative effect of parental effort on lymphoproliferativeresponse. We found no covariation between immune response andcorticosterone levels. Males with long tails, an ornament currentlyunder directional sexual selection, had a relatively large T-cell response to the mitogen, consistent with models of parasite-mediated sexual selection predicting higher levels of immune defensein highly ornamented males. In addition, males with large sexualornaments had relatively low corticosterone levels at the endof the parental period. These results can be reconciled withthe hypothesis proposing a trade-off between parental activitiesand adaptive immunity and suggest that highly ornamented malesare less exposed or less susceptible to stress arising fromparental effort.     

水稻籼粳交DH群体花器性状的遗传分析

水稻花器性状是影响杂交稻制种异交结实率的重要因素之一。利用一个水稻籼粳交(窄叶青8号/京系17)来源的DH群体对水稻柱头外露率、花柱长、柱头长、柱头宽、花药长、花药宽、颖花长、颖花宽和颖花长宽比9个花器性状和穗抽出度进行遗传分析。不论性状在2个亲本间的差异显著与否,在DH群体中10个研究性状在基因型间的差异均达到极显著水平(P<0.01),并表现为连续变异和明显的超亲分离。除花药宽的遗传力较低(50%)、且估计的基因数多达13个之外,其余9个研究性状的遗传力均较高,为68%～93%,控制这些性状的基因数估计为7～10个。这些结果表明,10个研究性状均为受多基因控制的数量性状,其增效和减效基因在2个亲本中均有分布,通过基因重组可产生正向和负向两个方向的超亲基因型。除了柱头长、柱头宽和穗伸出度3个性状未发现有基因间的上位性互作外,其余7个性状均检测到显著的互补性互作。性状相关和通径分析的结果显示,与柱头外露率关系最密切的花器性状为柱头长、柱头宽和颖花长宽比,颖花长和颖花宽主要通过影响颖花长宽比来对柱头外露率产生影响。其次,与柱头外露率关系较密切的为花柱长。柱头外露率高的基因型通常表现为长柱头、长粒型和长花柱。花药长、花药宽与上述花器性状间的相关性较弱。在DH群体中,穗伸