首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
泡桐无性系苗期叶部性状的主成分分析   总被引:2,自引:0,他引:2  
经对15个泡桐无性系苗期叶部性状的主成分分析表明:叶大小和叶形状是泡桐无性系苗期叶部性状差异的主要因素,作为主成分可代表叶部信息量的87%。因而在苗期选择时可作为主要参考因子。  相似文献   

2.
泡桐优良无性系相关选择的研究   总被引:2,自引:0,他引:2  
以10年生的泡桐无性系测定林的研究材料,通过相关遗传力的通径分析表明:叶部性状与泡桐无性系的材积、胸径、树高的生长有着密切关系。叶面积大、叶干重小、叶柄短、叶基凹入较深是材积和胸径速生的标志;叶面积小,叶柄较长、叶基较宽是树高速生的标志。  相似文献   

3.
泡桐无性系数量性状的遗传分析和指数选择研究   总被引:3,自引:0,他引:3  
以10年的泡桐无性系为材料,对包括材积、胸径、树高以内的8个主要数量性状进行了遗传参数分析,并在相关分析的基础上通过指数选择法,分别对材积、胸径、树高进行了选择指数研究。结果表明:材积的遗传变异系数较大,胸径、叶基宽中等,树高、叶干重等最小。遗传力以材积、胸径、叶柄长最高,叶干重、叶面积、叶基凹入、叶基宽中等,树高最低。多性状选择指数优于单一性状。根据材积、胸径、树高的选择指数,选出了2个材积,胸  相似文献   

4.
羊草种群无性系生长格局的研究   总被引:37,自引:0,他引:37  
  相似文献   

5.
苦楝在我国分布广泛,具有丰富的遗传变异性。为进一步做好苦楝种源筛选和良种选育工作,该文对不同产地苦楝实生苗生长性状和各阶段的生长特点进行了比较分析,初步揭示了苦楝苗期生长规律。以15个产地的1年生实生苗为试材,对苗高、地径、复叶生长及生物量积累等生长性状进行了观测分析,并用Logistics方程对生长节律进行了拟合。结果表明:(1)不同产地苦楝苗高、地径生长差异均达显著水平,根生物量、茎生物量及复叶相关性状差异均达极显著性水平;(2)苗高和地径生长均呈现慢-快-慢的S型生长规律,且均存在2次生长高峰,与苗高生长高峰出现时间相比,地径生长高峰出现时间较晚;(3)Logistic拟合方程的R2为0.976~0.994,均达到极显著相关水平,说明可用Logistic方程拟合苦楝的生长节律;(4)总体上地径速生期较苗高速生期长20~30 d,北方产地苗高和地径进入速生期和结束速生期的时间均早于南方产地,速生期苗高和地径累积生长量均超过总生长量的60%;(5)各生长指标均与纬度负相关,苗高、生物量及复叶面积与经度正相关,其他指标与经度负相关。综上结果表明,苦楝为全期生长型树种,各生长性状在产地间达显著差异水平,生长受纬度和经度双重控制,以纬度控制为主。  相似文献   

6.
应用Eberhart的性状值回归参数b_i及S_(di)~2、Tai的结构模型参数和,Ecovalence(W)值等参数,对泡桐品种多点试验林8个无性系生长量的基因型稳定性和生长适应性进行了分析。并结合生产力对各无性系进行了综合评定。结果表明:选出的8112-3和8112-1属速生、稳定、适应性强的无性系;8112-4和7606-6属于速生但不稳定的无性系,只适宜于较好的环境条件。经聚类分析将采用的8个参数明显地归为三类,类间相互独立,可分别用于评价基因型的生产力、遗传稳定性和适应性。  相似文献   

7.
羊草种群无性系生长格局的研究   总被引:4,自引:0,他引:4       下载免费PDF全文
 本文根据野外实测数据和采用数学分析方法,在研究羊草种群无性系营养扩散和生长过程的基础上,建立了符合描述羊草种群无性系生长格局的相关随机走动模型和简单扩散模型。对模型进行检验,结果表明,所建模型可以定量地描述羊草种群无性系的生长格局。  相似文献   

8.
本研究以随机过程理论为基础,应用数理方法,在分期播种的基础上,提出了一个受遗传特性控制的水稻各生物学参量自然生长趋势的数学模型。并进行了重复验证,得到了不同生育时段各生物学参量的生长速度(一阶导数)和生长速度的变化率(二阶导数),揭示了水稻生长的基本规律。并结合实测资料,通过相关分析,得到影响各生物学参量的关键气象因子,将水稻生长的研究建立在定量的基础上,有利于更加合理地采用各项高产栽培和农田管理措施。  相似文献   

9.
利用田间实验和统计分析方法,研究了毛泡桐[Paulownia tomentosa(Thunb.)Steud.]与白花泡桐[P.fortunei(Seem.)Hemsl.]正反交F1无性系自然接干性状的遗传变异。结果表明,供试的11个F1无性系的22个自然接干性状具有广泛而明显的遗传变异和变异差异,其中接干高、全干高、接干材积、全干材积、接干材秽全干材积、通直度和丛枝病等级是变异最大的7个自然接干性状(CV〉30);在6个正交F1无性系间和5个反交F1无性系间,绝大多数自然接干性状的差异达极显著水平;在毛泡桐与白花泡桐正交F1无性系和反交F1无性系间,22个自然接干性状均存在极显著差异。  相似文献   

10.
中国马褂木不同种源苗期生长规律研究   总被引:2,自引:0,他引:2  
对中国马褂木6个种源(云南金平、浙江安吉、福建武夷山、贵州黎平、广西全州、江西庐山)一年生实生苗的苗高生长规律进行研究。结果表明:(1)各种源在苗高生长上存在着极显著的差异。(2)利用logistic曲线拟合其苗高生长方程,发现各种源苗高生长均呈现明显的"慢—快—慢"的"S"型生长节律。(3)利用有序样本聚类分析将苗木生长划分为幼苗期、生长前期、速生期、生长后期4个阶段,福建武夷山种源最早进入速生期,且持续时间最长,江西庐山种源最晚进入速生期,且持续时间最短。速生期苗高净生长量占总生长量最大的是浙江安吉种源,达56.05%;第二是福建武夷山;最小的是江西庐山种源,只有34.29%。(4)依据苗高和地径两个性状的聚类分析把6个种源分成三大类,第一类是全州种源,苗高生长表现最好;第二类是金平、安吉、武夷山、黎平种源;第三类是庐山种源。  相似文献   

11.
邱胜荣 《生态学报》2020,40(3):1015-1020
中国自然保护区建设已由数量扩张型进入质量效益型的新阶段,运用自然保护区统计年鉴数据,基于logistic模型,借助R语言,对自然保护区发展上限进行了估算。同时,运用高等数据曲线曲率求导方法,对发展阶段进行划分,对持续时长和增长速度进行了测算。结果表明:①面积理论饱和值为15470.00万hm2;②将自然保护区发展历程分为缓慢起步期(1956—1989年)、快速发展期(1990—2008年)和稳定完善期(2009—至今);③目前则处于稳定完善期,面积已渐近饱和值,数量仍在小幅度增加。希望本研究结果能为自然保护区主管部门制定管理政策、规划以及整合组建以国家公园为主体的自然保护地体系提供参考。  相似文献   

12.
不同产地木荷优树无性系生长和开花性状的分析   总被引:4,自引:0,他引:4  
为比较不同产地木荷(Schima superba Gardn.et Champ.)优树无性系的生长性状(包括树高、胸径、冠幅和一级侧枝数)和开花性状(包括开花物候期和花朵数量)的遗传差异,采用方差分析、相关性分析和聚类分析方法,对来源于福建建瓯和连城、浙江庆元及龙泉和遂昌、江西上犹的22个木荷优树无性系的生长和开花性状进行了综合分析。结果表明:供试木荷无性系的树高、胸径、冠幅和一级侧枝数的的变异系数为19%~32%,始花时段、盛花时段、末花时段和花朵数量的变异系数为37%~73%,表明不同无性系生长和开花性状的变异较大。除木荷无性系一级侧枝数产地间的变异未达到显著水平外,其他生长和开花性状产地间和产地内的变异均达到显著或极显著水平。各生长和开花性状的无性系重复力为0.41~0.94,显示遗传控制程度中等偏强。无性系的树高、胸径和冠幅与花期的相关性均不显著,但与花朵数量呈显著或极显著正相关;来自较低纬度的无性系始花期最早,来自较高纬度或海拔的无性系始花期最晚。聚类分析结果显示:22个木荷无性系可聚为4个类型,类型1和类型4分别包含5个和7个无性系,这2类无性系的树高、胸径、冠幅和花朵数量总体上高于群体均值,生长表现优良、花朵数量较多,且类型4包含的无性系产地纬度较低、开花日期较早;类型2包含8个无性系,生长表现一般、花朵数量较少;类型3包含2个无性系,生长表现优良、花朵数量低于群体均值。研究结果显示:依据产地的纬度和海拔可初步判定木荷无性系的花期,可为木荷杂交育种亲本的选配和种子园建园过程中无性系的配置提供科学依据和理论基础。  相似文献   

13.
The Caribbean staghorn coral, Acropora cervicornis, was once a dominant habitat creating coral, but its populations have declined dramatically in recent decades. Numerous restoration efforts now utilize coral gardening techniques to cultivate this species, growing colonies on fixed structures or from line/suspended nurseries. Line nurseries have become increasingly popular because of their small footprint and ease of use, replacing fixed structures in many nurseries. To evaluate the efficacy of the line technique, this study evaluated growth, condition, and survivorship of A. cervicornis nursery colonies of three distinct genotypes grown via two line nursery techniques (suspended and direct line attachment [vertical]). Direct line attachment of nursery colonies resulted in poor survival (43%) and growth (9.5 ± 1.33 cm/year), whereas suspended culture had 100% survival and increased growth (61.1 ± 4.19 cm/year). Suspended culture had significantly reduced disease prevalence and prevented colony predation. Suspended coral growth was also comparable to a neighboring fixed structure nursery (55.2 ± 7.86 cm/year), and found to be as effective in propagating corals as fixed structures.  相似文献   

14.
甘肃省经济增长与环境压力关系动态变化的结构分解分析   总被引:1,自引:0,他引:1  
基于宏观环境经济学思想,建立了以污染物排放为表征的环境压力函数,并运用结构分解分析(SDA)模型,结合“修正后的Laspeyres方法”,构建了用于分析和解释“经济增长-环境压力”关系动态变化的驱动因子及其影响程度的方法,并分析了1990-2005年甘肃省经济增长与环境压力之间时序关系的变化趋势以及各驱动因素对时序关系变化的影响程度.结果表明:研究期间,甘肃省由污染物排放所产生的环境压力主要是由经济增长过程中产生的废气和工业固体废弃物所致,且环境压力在后期呈现出较快的增长趋势;人口因素对甘肃省环境压力变化的影响不大,经济增长因素对环境压力增大具有明显的正向效应,而技术因素则相对表现出抑制效应,但不足以抵消经济增长带来的正向效应,且经济增长和技术因素对环境压力的影响程度视不同类型污染物而有所差异.  相似文献   

15.
对23个雷公藤(Tripterygium wilfordii Hook.f.)优良无性系扦插苗的干物质积累量(全株及根干质量)及生长性状(平均枝数、地径、主藤长、平均藤径、平均藤长、平均根径和平均根长)进行了测定;在此基础上,采用典范相关分析法分析了其干物质积累量与生长性状间的相关性.结果表明:各无性系幼苗的根干质量占全株干质量的63%,其变异系数在所有指标中最大(54.67%),主藤长的变异系数次之,而平均根长的变异系数最小,表明各无性系间根干质量和主藤长的差异较大,可作为雷公藤优良无性系选优的基本指标.各无性系幼苗的干物质积累量与生长性状的第1对典范相关系数(0.964 9)达显著水平,且包含总相关信息的69.84%;在该对典型变量中,干物质积累量第1典型变量U1的X2变量(全株干质量)系数的绝对值最大(0.786 2),U1为主要描述优良无性系幼苗全株干质量的综合性状,随全株干质量升高U1明显下降;生长性状第1典型变量V1的Y4变量(平均藤径)和Y5变量(平均藤长)系数的绝对值最大(0.388 3),V1为描述优良无性系幼苗平均藤径和平均藤长的综合性状,随平均藤径的增加V1明显减小、而随平均藤长的增加V1明显增大.通过第1对典型变量的二维排序可将供试的23个无性系划分为3类,最优无性系为2、4、7、8、9、13和15.研究结果表明:平均藤径和平均藤长可以作为雷公藤生物量模型构建的评价指标.  相似文献   

16.
The Tagus estuary has long been subjected to several human activities and uses. Changes in the estuarine fish community were evaluated based on beam trawl surveys in 1978–1980 and 1994–1996. There was a decrease of abundance of many species that use the Tagus as a nursery, namely bib (Trisopterus luscus), five bearded rockling (Ciliata mustela), tub gurnard (Trigla lucerna), and flounder (Platichthys flesus), possibly due to reduction of the water quality. In 1994–1996, only sea bass (Dicentrarchus labrax), sole (Solea solea) and Solea senegalensis Kaup, 1858, were found within the nursery grounds, showing an irregular pattern of abundance. Condition and vacuity index were highly variable. The major problems affecting the fish community, namely pollution, fishery regulation and waterflow regulation, are discussed in relation to the management and conservation of this estuarine system.  相似文献   

17.
方杰  赵博光  杨振德  朱麟 《昆虫知识》2011,48(1):132-135
本文研究了不同的美洲黑杨无性系对分月扇舟蛾Clostera anastomosis L.幼虫生长的影响。结果表明,抗性水平不同的无性系影响分月扇舟蛾幼虫体重、相对生长率、食物利用率和转化率。抗性较强的89-3号无性系对幼虫的生长有抑制作用,幼虫取食后,其食物利用率和转化率在第2天有显著下降,但随后表现不明显;而感性较强的74-4号无性系有一定的促进作用,幼虫取食后,其食物利用率和转化率都显著提高。  相似文献   

18.
Summary Results of experiments with four poplar clones and various chemical fertilizers in a nursery in southern Greece are presented. At the end of the first growth period the heights of the four clones, without fertilizers, decreased in the order of I-214>I-262>cv. campeator > black poplar 1/64 with significant differences only between black poplar 1/64 and the rest of the clones.Of the fertilizer nutrients N, P, K and Mg only N improved heights of all clones significantly and especially of the clone I-214. One hundred and 200 kg of P fertilizer per ha had minimal or negative effect on height increase of all clones.Ammonium sulfate, ammonium nitrate and potassium nitrate all at 400 kg N per ha were found equally effective in improving height growth of the clone I-214 but ammonium nitrate is the N fertilizer of choice by its higher N content and relatively lower price.Ammonium nitrate at 200 kg N per ha, in two or three equal dosages, during the first growth period, June–July, gave the maximum height increase for two consecutive years of the clone I-214. Six hundred kgs, of N per ha reduced height increase of the same clone and increased losses of N, as NO3 , in drainage water.  相似文献   

19.
Nursery-reared primates do not experience psychological "maternal bonding" or immunological benefits of breast milk, so they are expected to be inferior to mother-raised monkeys in growth, health, survival, reproduction, and maternal abilities. Studies of nursery-reared monkeys support aspects of this prediction for infants deprived of social contact or raised in pairs. We present colony record data on 1,187 mother and 506 nursery-raised monkeys, 2-10 yr of age, living in mixed groups. We found no group differences in survival, growth, clinical treatments for disease or bite wounds, or pregnancy outcome and neonatal deaths. Nursery males given breeding opportunities produced an average of 24 offspring. In addition to 24-hr personnel present on every day of the year, we believe that three of our procedures account for differences between our results and other reports. Our infants received 1) intensive human handling, 2) daily social interaction in a playroom, and 3) success and failure experience during learning and cognitive testing. We do not advocate rearing primates without mothers, but we conclude that these procedures are sufficient for producing physical health and adaptive juvenile and adult social skills in nursery-raised monkeys.  相似文献   

20.
The effects of vesicular-arbuscular mycorrhizae inoculation on the growth of cacao seedlings (Theobroma cacao var. Ocumare 60) grown for 5 months in a nursery were studied. The effects of introduced VAM fungi (Glomus occultum, Acaulospora appendicula, Glomus manihotis, Acaulospora morrowae and Scutellospora pellucida) in soils treated with copper oxychloride or methyl bromide, were compared with the indigenous VAM and with their respective non-inoculated controls.Cacao seedlings responded well to indigenous VAM fungi, which included Scutellospora calospora as the dominant species, inducing increases significant in height, dry weight and foliar uptake of P, Cu and Zn in relation to the sterile control. G. occultum and A. appendicula increased the height of cacao seedlings but to an extent not yet statistically significant through the duration of the experiment. S. pellucida and A. appendicula doubled the phosphorus uptake of cacao seedlings. The methyl bromide sterilization induced the lowest Cu and Zn uptake in the cacao seedlings but this effect was ameliorated with VAM inoculation. Manifest deficiency symptoms were not observed in the treatments.Copper oxychloride treatment depressed growth to the same level as the sterile control although its residual effects did not kill VAM. It could change the competitive relations among the VAM species and in this case seemed to affect adversely the more efficient native fungi.The influence of the presence and long permanence of large cotyledons in cacao on the results obtained is discussed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号