Differential Radiation Response Amongst Proliferating Epithelial Cells

Tissue irradiation results in both reproductive and histologically evident cell death. the correlation between these is poor. Irrespective of dose and fraction sterilized, many cells behave as if unirradiated (cell cycle and maturation activity). the fraction of histologically observable dead cells is usually less than 0.1, with most in the intestine being positioned in the presumptive stem cell region. the data strongly suggest different epithelial sub-populations with differing radioresponses. These may be the stem and differentiated proliferative cells.     

蒙古栎林种内和种间竞争研究

蒙古栎（Quercus mongolica Fischer ex Ledebour）林是东北地区常见的典型森林类型之一。以黑龙江中央站黑嘴松鸡国家级自然保护区面积为1 hm²的蒙古栎林固定样地为研究对象，采用固定样圆法确定了竞争范围，并利用Hegyi竞争指数分析了蒙古栎林的种内和种间竞争状态。研究结果表明：蒙古栎的种内和种间竞争强度分别占总竞争强度的28.08%和71.92%，说明了蒙古栎的种内竞争强度小，竞争压力主要来自于种间。白桦（Betula platyphylla Suk.）、黑桦（Betula dahurica Pall.）、兴安落叶松（Larix gmelinii（Ruprecht）Kuzeneva）数量较多，个体高大，对蒙古栎的竞争压力较大。蒙古栎种内和种间竞争强度的顺序为：白桦 > 蒙古栎 > 黑桦 > 兴安落叶松 > 山杨（Populus davidiana Dode） > 紫椴（Tilia amurensis Rupr.） > 大黄柳（Salix raddeana Laksch.）。蒙古栎的胸径与整个林分、伴生树种以及蒙古栎种内的竞争强度成幂函数关系，随着对象木胸径增大，3种竞争强度均减小。当蒙古栎胸径小于20 cm时，竞争强度较大；当胸径大于20 cm时，蒙古栎所受的竞争压力较小，并趋于稳定，通过所得的模型可以很好地预测出蒙古栎种内和种间的竞争强度。     

猕猴桃种间及种内杂交亲和性研究

以3个种的9个猕猴桃品种为试材,通过培养法比较它们的花粉活力,用荧光显微镜观察猕猴桃种间与种内杂交亲和性,并统计其亲和指数及坐果率,为猕猴桃的杂交育种以及最佳授粉树的选配提供依据.结果表明:猕猴桃花粉活力在种间表现为美味猕猴桃＞中华猕猴桃＞狗枣猕猴桃;中华猕猴桃和美味猕猴桃种间和种内杂交组合的柱头识别反应快,花粉在柱头粘附多、生长快且萌发率高、亲和性较强且坐果率较高,而用狗枣猕猴桃与中华猕猴桃和美味猕猴桃种间杂交的花粉在柱头上萌发生长发育缓慢,其亲和性弱,平均坐果率仅为19.81%;30个杂交组合中亲和指数最高的是'金阳'×'金阳'雄株,亲和指数为960.33,坐果率为95.56%,最低的是'狗枣'×'金阳'雄株,亲和指数201.60,坐果率为12.22%.研究发现,猕猴桃的种间亲和性小于种内亲和性,同种内不同品种间的亲和性与坐果率也不同.     

沙地云杉种内、种间竞争的研究

根据调查资料,采用Ｈｅｇｙｉ提出的单木竞争指数模型ＣＩ＝∑Ｎｊ＝１（Ｄｊ／Ｄｉ）１Ｌｉｊ对内蒙古白音敖包自然保护区的沙地云杉种内、种间的竞争强度进行定量分析。结果表明：沙地云杉种内竞争强度随着林木径级的增大而逐渐减小;种内竞争和种间竞争的强度顺序为：山杨＞沙地云杉种内＞白桦＞家榆。竞争强度与对象木的胸高直径服从幂函数关系ＣＩ＝ＡＤ－Ｂ,当沙地云杉胸高直径达到４０ｃｍ以上时,竞争强度变化很小。利用模型预测了沙地云杉种内、种间的竞争强度。说明Ｈｅｇｙｉ的单木竞争模型可为种内、种间竞争指数的研究提供可适用的数量指标。     

Response of Black-Capped Chickadees to House Finch Mycoplasma gallisepticum

Tests for the presence of pathogen DNA or antibodies are routinely used to survey for current or past infections. In diseases that emerge following a host jump estimates of infection rate might be under- or overestimated. We here examine whether observed rates of infection are biased for a non-focal host species in a model system. The bacterium Mycoplasma gallisepticum is a widespread pathogen in house finches (Haemorhous mexicanus), a fringillid finch, but an unknown proportion of individuals of other songbird species are also infected. Our goal is to determine the extent to which detection of M. gallisepticum DNA or antibodies against the bacteria in a non-fringillid bird species is over- or underestimated using black-capped chickadees Poecile atricapillus, a species in which antibodies against M. gallisepticum are frequently detected in free-living individuals. After keeping black-capped chickadees in captivity for 12 weeks, during which period the birds remained negative for M. gallisepticum, four were inoculated with M. gallisepticum and four were sham inoculated in both eyes to serve as negative controls. Simultaneously we inoculated six house finches with the same isolate of M. gallisepticum as a positive control. All inoculated birds of both species developed infections detectable by qPCR in the conjunctiva. For the 6 weeks following inoculation we detected antibodies in all M. gallisepticum-inoculated house finches but in only three of the four M. gallisepticum-inoculated black-capped chickadees. All house finches developed severe eye lesions but none of the black-capped chickadees did. Modeling the Rapid Plate Agglutination test results of black-capped chickadees shows that the rate of false-positive tests would be not more than 3.2%, while the estimated rate of false negatives is 55%. We conclude that the proportion of wild-caught individuals in which we detect M. gallisepticum-specific antibodies using Rapid Plate Agglutination is, if anything, substantially underestimated.     

皮下盘菌属种内及种间遗传多样性的ISSR分子标记

对皮下盘菌属（Hypoderma）4种23个菌株进行了ISSR分析。结果表明,被试材料ISSR标记多态性好,8个引物共扩增出131个条带,其中126条（占9618％）具有多态性。经欧氏最短距离中的类平均法聚类,得到各菌株之间的ISSR标记的遗传相似性系数（GS）变异范围为0．30—0．82,23个菌株可聚为6类。通过ISSR分析结果与表型性状的比较和分析,明确了悬钩子皮下盘菌种内遗传差异体现在子囊果大小、形状及埋生深度、唇特征、侧丝顶端形状、子囊和子囊孢子形状及大小,以及寄主、着生部位和分布区域方面;皮下盘菌属的种间差异主要表现在子囊果、唇、侧丝、子囊及分生孢子器等部分形态学特征、寄主及着生部位方面。     

Interspecific Response to Playback of Bird Song

Responses to bird song have usually only been studied at the intraspecific level. I experimentally tested whether playback of the song of the black wheatear Oenanthe leucura in an area in S Spain resulted in responses from conspecifics as well as heterospecific birds by comparing the numbers of individuals singing before and after playback. The number of singing male black wheatears increased considerably, but also the number of singing males of five other passerine species increased significantly. The heterospecific response to playback may be due (1) to interspecific territoriality, (2) to black wheatear song signalling the absence of predators, or (3) to heterospecifics confusing the species-identity of the singer. The second alternative is considered more likely, since an ecologically wide array of species increased their song rate following playback. The conspicuous dawn (and dusk) chorus of bird song may be augmented by social facilitation due to the singing of conspecifics as well as heterospecifics.     

Matched Counter-singing Signals Escalation of Aggression in Black-capped Chickadees (Parus atricapillus)

Black-capped chickadees (Parus atricapillus) have the ability to shift their songs up and down over a wide range of absolute frequencies. Males can shift their songs over 465 ± 52.9 (SE) Hz. During the dawn chorus, males shift their songs by 80 Hz or more every 41 ± 8.8 (SE) songs, but it appears that males can sing at any frequency within their range. Frequency shifting may allow males to match counter-sing with rival males; that is, to switch song output to match that of a rival. During simultaneously recorded dawn choruses, however, there was no correlation over time in the frequency of neighbouring males' songs, nor was there a correlation over time in the size of shifts between their songs. Moreover, males did not match the frequencies of songs presented on a played-back tape at the edge of their territories during the dawn chorus. Matching was observed during some bouts of counter-singing between males. In these cases, matched counter-singing was highly associated with escalation of the conflict. We suggest that frequency matching in this species may be a graded signal that allows the singer to direct aggression towards a particular rival.     

散斑壳属部分种内及近似种间的RAPD分析

从100个随机引物中选取重复性好、条带清晰的随机引物分别对针叶树和阔叶树上的34个散斑壳(Lophodermiumspp.)菌株进行RAPD-PCR扩增反应,RAPD分析结果与表型性状表现出良好的一致性,从而表明RAPD技术可以较好的应用于散斑壳属种内及近似种间亲缘关系的分析。通过RAPD分析结果与表型性状的比较和分析,明确了部分表型性状在散斑壳属近似种区分方面的重要性。     

珙桐群落种内与种间竞争研究

采用Hegyi的单木竞争指数模型对卧龙自然保护区的珙桐群落种内与种间竞争强度进行定量分析,并讨论了不同竞争强度下珙桐的形态变化。结果表明：珙桐受到的竞争强度随着林木径级的增大而逐渐减小,珙桐种内竞争较之与其伴生树种间的竞争剧烈;在群体水平上,珙桐种内与种间竞争强度顺序为：珙桐种内〉汶川钓樟〉野核桃〉灯台树〉光叶珙桐〉白楠〉总状山矾〉五裂槭〉稠李〉蛮青冈;竞争强度和对象木胸径的关系服从幂函数关系（CI=AD^-B）,当珙桐的胸径达到30cm以上时,竞争强度变化很小,所得的模型能很好的预测珙桐种内与种间的竞争强度;不同竞争强度下,珙桐主干各层的逐级分枝率（R1：2）、分枝角度、平均枝长和当年生枝条长都有一定的差异,其中下层的分枝角度、平均枝长和当年生枝条长对邻体竞争表现出极强的可塑性。说明珙桐通过自身形态变化,提高了对资源的利用能力,增强了对不同生境的适应性。     

Intraspecific and Interspecific Competition in Davidia involucrata (Davidiaceae) Community

Davidia involucrata was a rare valuable and endangered plant in China. In order to study neighborhood competition effects, the intraspecific and interspecific competion intensity in Davidia involucrata community in Wolong Nature Reserve was analyzed quantitatively by using Hegyi individual tree competition index model. And the morphological characteristics of Davidia involucrata were investigated under different neighborhood competition intensity . The results showed that the competition intensity in Davidia involucrata decreased gradually with the increasing of forest tree diameter class and the intraspecific competition in Davidia involucrata was more intensive than interspecific competition. The order of the intraspecific and interspecific competition intensity at the community level was: intraspecific > Lindira pulcherrima > Juglanscathayensis> Cornus controversa > Davidia involucrata var. vilmoriniana > Phoebe neurantha >Symplocos botryantha Franch>Acer oliverianum > Prunus branchypoda > Cyclobalanopsis oxyodon . The relationship between competition intensity and individual growth of objective tree closely followed the following equation: CI = AD^{- B} . The change in competition intensity is very small when the diameter of the objective tree reaches 30 cm . The model can stimulate and predict the intraspecific and interspecific competition efficiently. The morphology of Davidia involucrata , such as stepwise bifurcation ratio 1∶2, branching angle, average branch and current-year branch lenghth of the main stem in different strata , was modified under differentcompetition intensity. The plasticity of substrate branching angle , substrate average branch length and substrate currentyearbranch length was very obvious in response to different neighborhood competion intensity. That suggests Davidia involucrata can improve its capacity to explore the resource and adapt to different habitats through morphological changes .     

红松天然林种内和种间竞争关系的研究

基于穆棱林业局3块红松天然林标准地调查数据,采用竞争区域动态半径的概念确定了林分中有效竞争木,并利用Hegyi竞争指数对红松天然林的种内、种间竞争强度进行了定量分析。研究结果表明：红松的种内和种间竞争强度分别占总竞争强度的18.0%和82.0%,说明红松天然林种内竞争小,主要竞争来自种间。色木、云杉、冷杉林木个体高大,数量较多,在群落中占据一定优势,对红松的竞争压力较大。红松对象木胸径与竞争指数之间呈幂函数关系,随着红松胸径的增大,受到的竞争强度逐渐减小。当红松胸径小于25 cm时,所受到的竞争压力较大;当胸径大于25 cm时,竞争指数较小,并维持稳定。     

舟山群岛红楠林种内和种间竞争研究

红楠（Machilus thunbergii）林是浙江沿海地区典型森林类型之一,研究竞争强度的动态变化规律及红楠种群的生态适应机制,对舟山群岛常绿阔叶林的保护与可持续利用具有重要意义。利用Hegyi单木竞争指数模型,对舟山桃花岛次生林优势种红楠的种内和种间竞争强度进行定量分析。结果表明：红楠3种类型的竞争强度均随对象木胸径的增大而逐渐减小,小径级的红楠承受的竞争压力较大;红楠的种内和种间竞争强度分别占总竞争强度的44.55%和55.45%,两者大致相等,说明其受到的种内和种间竞争压力均衡;落叶树种的平均竞争指数大,常绿树种的平均竞争指数小,使红楠受压的主要树种是朴树和枫香树;红楠种内和种间竞争强度的顺序为：红楠种内 > 朴树 > 枫香树 > 椿叶花椒 > 柘 > 梾木 > 化香树 > 赛山梅 > 黄檀 > 日本珊瑚树 > 天仙果等;3种类型的竞争强度与对象木胸径均呈显著负相关,且服从幂函数关系CI=AD^-B,当红楠胸径达到20 cm以上时,竞争强度变化很小,利用所得的预测模型能很好地预测红楠种内和种间竞争强度。当红楠胸径小于20 cm时,应对其进行抚育管理以提高红楠成活率和促进植被恢复。     

入侵植物北美车前和野胡萝卜种内及种间的化感作用

当前入侵植物种类和入侵范围均日益扩大,而多种入侵植物共同入侵同一生境的概率也逐渐增加。为探讨这些入侵植物种内和种间的化感作用以及化感作用对其竞争能力的影响,本研究以北美车前(Plantago virgica)和野胡萝卜(Daucus carota)为例,采用室内生物学测定法,分析了2种植物不同器官(根、茎或花序轴、叶)、不同浓度(CK、0.005、0.01和0.05 g·mL^-1)的水浸提液培养对其自身和对方种子萌发和幼苗生长的影响。结果表明,浸提液浓度对2种入侵植物种子萌发和幼苗生长的影响最大,且浓度、器官及物种之间存在显著交互作用。2物种各器官各浓度浸提液对二者种子萌发总体表现为抑制;中低浓度浸提液对同种植物幼苗生长有一定促进作用;高浓度浸提液尤其是野胡萝卜叶浸提液对二者种子萌发与幼苗生长均有显著抑制作用。综合化感效应指数表明,浸提液浓度越高抑制作用越强,地上部分化感效应强于地下,且野胡萝卜对北美车前的种间化感作用最强。由此可见,种内和种间化感作用是入侵植物在相同入侵地相互竞争的重要方式。     

被子植物生散斑壳属若干种内和种间亲缘关系RAPD分析

采用9个重复性好的随机引物对被子植物上的28个散斑壳属(Lophoderm iumChevall.)菌株进行RAPD-PCR扩增,通过RAPD分析结果结合表型性状的比较和分析,确定了子囊果埋生位置,子座、子囊、子囊孢子、侧丝等形态学特征以及寄主种类差异在该类菌物种水平分类上的重要性,另外产地不同等对种内遗传多样性产生一定影响。进一步明确了被子植物生散斑壳属一些种内和种间的亲缘关系。     

秦岭太白山巴山冷杉种内和种间竞争特性的研究

通过对不同方法的比较分析,提出了确定巴山冷杉(Abies fargesii)植株间竞争强度和竞争范围的新方法,并利用改进的方法研究了其种内和种间竞争强度。结果表明:随对象木胸径的增大,由于巴山冷杉种群自然稀疏过程中密度调节作用,植株距离增加,种内竞争强度降低;巴山冷杉主要分布于亚高山地段,群落内太白红杉(Larixchinensis)数量较多,胸径较大,种内与种间竞争关系顺序为:太白红杉-巴山冷杉>巴山冷杉-巴山冷杉>牛皮桦(Betula utilis)-巴山冷杉>其它树种-巴山冷杉;竞争强度和对象木胸径的关系服从幂函数关系(CI=AD-B),当巴山冷杉胸径达到25 cm以上时,种内和种间竞争强度变化较小。研究表明,改进的方法能很好地预测巴山冷杉种内和种间的竞争强度。     

杉木-观光木人工混交林种内和种间竞争研究

采用Hegyi单木竞争指数模型对杉木-观光木人工混交林种内、种间及全林分竞争强度进行定量研究。结果表明,以杉木为对象木时,3种不同类型的竞争强度均随着对象木个体的增大而减弱,并且除6~9 cm径级外,种内竞争均大于种间及全林分竞争;以观光木为对象木时,3种不同类型的竞争强度均随着对象木个体的增大而减弱,除18~21 cm与24~27 cm径级外,其种间竞争均大于种内及全林分竞争。利用对象木竞争强度与胸径关系进行预测的结果显示,杉木和观光木在胸径分别达到36和39 cm之前应进行密度控制措施。     

云杉属7个种针叶性状种间和种内变异分析

以沙坝国家云杉/落叶松良种基地苗圃的云杉属7个种(2007年移栽的欧洲云杉、西加云杉、红皮云杉、黑云杉、蓝云杉、白云杉和恩氏云杉)实生苗1 a针叶为对象,研究种间和种内针叶性状的遗传差异,为云杉苗期识别和进行适应性评价提供依据。结果表明:(1)云杉种间针叶长、宽、长/宽、鲜重、干重、冬季含水率差异达显著水平,且云杉针叶性状种间和种内都存在着丰富的遗传变异。(2)7个云杉种间针叶性状的变异系数从大到小依次为鲜重(47.65%)＞干重(40.94%)＞宽(24.98%)＞长(22.39%)＞长/宽(21.32%)＞冬季含水率(12.75%),鲜重的变异系数最大,冬季含水率是最稳定的性状。(3)种内白云杉的鲜重、干重的变异系数最大,分别为50.85%和38.01%,蓝云杉针叶冬季含水率变异系数最小,为2.11%。(4)针叶性状间除长/宽与鲜重、干重、冬季含水率不相关外,其余性状间呈极显著相关关系;除针叶长/宽与苗高、当年高生长量不相关外,其余针叶性状与树高、当年高生长量呈显著或极显著正相关关系。(5)种间针叶干重与针叶长、宽回归方程的决定系数在0.793～0.993间,根据针叶长指标将7个云杉种划分为3类,并可根据云杉针叶长、宽、长/宽、鲜重、干重、颜色和气孔带等性状进行苗期识别和选择。