Morphological variation in the short-tailed fruit bat (Carollia) in Ecuador,with comments on the practical and philosophical aspects of boundaries among species     

Pablo JARRÍN-V.  Cristina FLORES  Janeth SALCEDO 《Integrative zoology》2010,5(3):226-240

The mechanisms for the morphological delimitation of species in Carollia remain poorly understood. This is the first study to assess variation in size and shape from strictly geometric terms. Both factors are assessed by statistical perspectives of distribution, overlap and relative distances. Despite its overlap, the size of the skull seems to be the most influential character for the discrimination of species, with shape playing a much smaller role. The smallest species seems to be the most distinct in shape, not only in terms of distance among centroids in morphometric space, but also in the overall trend and direction of variation. Contrary to previous studies, sexual dimorphism is not given by size but by distinct shapes of the skull. Characters such as the shape of the maxilla, previously described qualitatively as discrete with sharp boundaries, appear to be truly continuous with fuzzy borders among species. Because morphometric space is a gamut of continuous variation and overlap, the taxonomic error rate for size characters seems to be substantial for the medium-sized species (Carollia brevicauda Schinz, 1821), with approximately 30–40% of individuals erroneously assigned to a different species after a jackknifed discriminant function. This taxonomic error is higher for shape characters. Morphological, systematic and ecological consequences of the observed patterns of shape and size variation are commented within the context of previously proposed arguments and hypotheses.  相似文献   

干旱对不同地力水平、不同品种小麦生育性状及产量的影响     

鞠赋红  孙萍  吴霭霞 《青岛农业大学学报(自然科学版)》2000,17(4):287-289

在相同的水分条件下 ,对不同地力水平、不同品种小麦的生育性状及产量进行比较。研究结果表明 ,小麦品种 9350 31在高肥力条件下表现突出 ,鲁麦 2 1适应性广 ,在中、低肥力地块上表现最佳  相似文献   

萝卜肉质根产量与主要性状相关及通径分析   总被引：1，自引：0，他引：1  

戴希尧  任喜波  李娜 《北方园艺》2009,(6)

试验运用相关及通径分析,对萝卜杂交组合的株高、展开度、外露长、叶重、叶片长、叶片宽、叶片数、根长、根粗9个相关农艺性状与肉质根产量进行了分析。结果表明,萝卜杂交组合单根重与其相关性状的直接通径系数是：株高-0.3176、展开度0.3338、外露长0.7369、叶重-0.1175、叶片数0.0626、叶片宽-0.1773、叶片长0.0267、根长0.4839、根粗0.4420。外露长〉根长〉叶重〉株高〉展开度〉根粗〉叶片长〉叶柄长〉叶片数〉叶片宽〉叶柄宽。  相似文献   

为害小麦新害虫——显脉污灯蛾Spilarctia bisecta Leech (Lepidoptera: Arctiidae)          下载免费PDF全文

秦杨  余金珂  刘怀  王梓英 《植物保护》2024,50(1):347-355

小麦是我国三大粮食作物之一, 其在生产过程中受到多种害虫为害;在调查重庆市潼南区小麦病虫害过程中新发现一种鳞翅目害虫为害小麦, 对其进行形态学及细胞色素氧化酶Ⅰ亚基(cytochrome oxidase Ⅰ, COⅠ)基因序列鉴定, 确定其为显脉污灯蛾Spilarctia bisecta Leech。污灯蛾属中有多种为害农作物的害虫, 但显脉污灯蛾在中国还未有为害小麦的确切报道, 这一发现提醒我们应当注意小麦和其他禾本科作物上的潜在害虫。  相似文献   

论期刊中繁体字、异体字的错误使用问题     

张海英 《湖南农业大学学报(自然科学版)》2008,(4)

简化字已推行了五十多年,但被简化了的繁体字、异体字却频频出现在各种简体版的出版物特别是学术期刊中,导致期刊用字极不规范。以随机抽取的数种期刊为例,具体分析了其中被错误使用的繁体字、异体字,并简单讨论了错误使用的原因,提出了改变这种繁简乱用的混乱状况的建议。  相似文献   

甘蓝型黄籽油菜产量性状的遗传分析     

王瑞  李加纳  唐章林  谌利  张学昆 《勤云标准版测试》2004,(5)

利用加性-显性-母体的遗传模型,分析了7个不同遗传来源甘蓝型黄籽油菜品系所配制的完全双列杂交资料。结果表明,产量性状主要受加性和显性效应共同控制,环境对产量性状有一定的影响而母体效应影响很小。基因效应分析发现y4单株粒重有极显著的加性效应,y3×y4单株粒重有极显著的显性效应  相似文献   

两种不同穗型水稻的籽粒灌浆特性分析     

康丽丽  周鸿飞 《河南农业科学》2008,(4):29-32

以直、弯两种穗型水稻各1份材料为试材,通过剪叶与疏花措施,改变灌浆进程,研究了源库关系对水稻籽粒灌浆特性的影响。结果表明,不同穗型水稻籽粒灌浆进程可用Richards进行拟合,从而可以用朱庆森等提出的有关参数对灌浆特性进行解释。剪叶降低水稻籽粒的灌浆速度和终极生长量,导致结实率低,籽粒充实度差,千粒重小而减产,而疏花(剪穗)则相反。  相似文献   

Characterization, reference ranges and the influence of gender on morphological parameters of the endangered Catalonian donkey breed     

P. Folch  J. Jordana   《Journal of Equine Veterinary Science》1997,17(2):102-111

This study characterizes morphometrically a limitedsizepopulation in danger of extinction; the Catalonian donkey breed (Spain). Sixty-nine adult individuals of both genders, forty-four jennies and 25 stallions, were characterized and analyzed for twenty-six morphological measurements and twelve corporal indices by a univariate procedure. The population showed little sexual dimorphism, since only eight of twenty-six measures and one of twelve indices showed statistically significant differences for gender effect. The analysis of correlations between measures and obtained dendrograms allowed the identification of interactions between and within the different corporal regions (head, trunk and extremities). The important morphological variability degree (coefficients of variation) shown by individuals of the Catalonian donkey breed will be of great interest to further improve the population.  相似文献   

柱型苹果杂交后代不同株型枝叶及光合参数比较     

王鸣枭  刘政礼  文翠萍  刘蕾  王祎和  祝军  张玉刚 《青岛农业大学学报(自然科学版)》2017,(2):95-99

为了分析柱型苹果杂交后代群体不同株型的幼树在形态及生理上的差异,本文以柱型苹果"塔斯坎"、"特珍"与普通型苹果"富士"、"嘎啦"杂交的3个群体为试材,进行了枝条、叶片以及光合参数的比较.研究结果表明:3个杂交组合不同株型的表型存在很大差异,普通型植株节间长度分别是柱型植株的1.81、1.69和1.68倍,长粗比分别是柱型的1.62、1.59和1.57倍,成枝角度分别是柱型的2.07、1.89和1.93倍.柱型苹果植株容易形成大量短枝,短枝比例分别是普通型的1.57、1.85和1.83倍,普通型植株长枝较多,长枝比例分别是柱型植株的2.35、2.49和2.52倍.柱型苹果对光能的利用效率比普通型高,其叶面积指数分别是普通型的6.41、6.43和4.92倍.日周期中,柱型苹果树的净光合速率(Pn)、蒸腾速率(Tr)均高于普通型苹果树,二者均呈双峰曲线,在13:00-14:00之间有一段 "午休"现象.  相似文献   

桑椹浆瘿蚊的生物学特性及防治技术研究   总被引：1，自引：0，他引：1  

焦锋  韩明斋 《蚕业科学》1997,23(2):73-76

桑椹浆瘿蚊（ContariniamorulaeJiangnomennudum）是新发现的一种桑树害虫。在陕西关中地区年发生1代，以幼虫寄生于雌花子房内为害，5月中旬幼虫老熟后弹跳入土结茧越夏越冬。采用蛹期或幼虫入土期地面薄膜覆盖；或蛹期每公顷用40％甲基异柳磷乳油6kg或50％甲基对硫磷6.6kg拌适量干细土撒施于桑园土壤，有较好的防治效果。  相似文献