橡胶草可作为产胶研究的模式植物     

庄玉粉  郭秀丽  刘进平 《热带作物学报》2015,35(9):4-8

以尾细桉9个无性系叶片为外植体进行叶片离体培养和植株再生研究。结果表明,TDZ对尾细桉的再生诱导起着明显的促进作用,9个尾细桉无性系都获得了植株诱导再生,再生过程中不同的无性系呈现出不同的TDZ响应浓度,TDZ浓度在0.005～0.010 mg/L时获得较高的再生效率。不同无性系之间的再生率呈现出明显的差异,其中无性系YL2获得了最高达69.2%的植株再生效率,且每个外植体平均芽数超过10个。TDZ浓度对YL2的再生起到显著性影响,0.050 mg/L时再生效率最高,可以进行下一步的遗传转化研究。  相似文献   

Models for predicting tree and stand development on larch plantations in Hallormsstaður,Iceland     

A. Pesonen  K. Eerikäinen  M. Maltamo  T. Tahvanainen 《New Forests》2009,37(1):63-83

The aim was to model the growth of Siberian larch (Larix sibirica Ledeb.) and Russian larch (Larix sukaczewii Dyl., syn. L. sibirica var. sukaczewii) plantations in Hallormsstaeur, Iceland. The field inventory was carried out in eastern Iceland in June 2006. Models were constructed for predicting dominant height, total tree height and 5-year diameter increment. Several linear and non-linear forms of models were tested in preliminary analyses to find the equations that fitted the modelled characteristics best. Due to the spatially hierarchical correlation structure of the data (stands, plots and trees), the assumption of non-correlated error terms did not hold. Therefore, a random parameter modelling approach was adopted using mixed models when the estimates obtained for the random effects were statistically significant. The variance estimates for the random effects can be further used to calibrate the models. The models generated here performed well with independent test data and were consistent with the forest growth theory. They can be used to evaluate site quality and to estimate the growth and yield of larch stands in eastern Iceland in connection with forest planning.  相似文献   

Spatially discriminating Russian wheat aphid induced plant stress from other wheat stressing factors   总被引：1，自引：0，他引：1  

Georges F. Backoulou  Norman C. ElliottKristopher Giles  Mpho PhoofoloVasile Catana  Mustafa MirikJerry Michels 《Computers and Electronics in Agriculture》2011,78(2):123-129

The Russian wheat aphid (RWA) Diuraphis noxia (Mordvilko) is a major pest of winter wheat and barley in the United States. RWA induces stress to the wheat crop by damaging plant foliage, lowering the greenness of plants, and affecting productivity. The utilization of multispectral remote sensing is effective at detecting plant stress in agricultural crops. Stress to wheat plants detected in fields can be caused by several factors that can vary spatially in their presence and intensity across a field. Stress can result from factors such as nutrient deficiency, drought, diseases, and pests that can occur individually or collectively. The present study investigated the potential of using spatial pattern metrics derived from multispectral images in combination with topographic and edaphic variables to identify a set of variables to differentiate the stress induced by RWA from other stress causing factors. A discriminant function analysis was applied to 15 discriminating variables. A set of 13 variables were retained to develop a model to differentiate the three types of stress. Overall, 97 percent of patches of stress used to validate the model were correctly categorized. Stressed patches caused by RWA were 98 percent correctly classified, patches caused by drought were 94 percent correctly classified, and patches caused by agronomic conditions were 99 correctly classified. It is possible to discriminate stress induced by RWA from other stress causing factors in multispectral data when spatial attributes of the stress causing factors are incorporated in the analysis.  相似文献   

Typology of historical sources and the reconstruction of long‐term historical changes of riverine fish: a case study of the Austrian Danube and northern Russian rivers     

Gertrud Haidvogl  Dmitry Lajus  Didier Pont  Martin Schmid  Mathias Jungwirth  Julia Lajus 《Ecology of Freshwater Fish》2014,23(4):498-515

Historical data are widely used in river ecology to define reference conditions or to investigate the evolution of aquatic systems. Most studies rely on printed documents from the 19th century, thus missing pre‐industrial states and human impacts. This article discusses historical sources that can be used to reconstruct the development of riverine fish communities from the Late Middle Ages until the mid‐20th century. Based on the studies of the Austrian Danube and northern Russian rivers, we propose a classification scheme of printed and archival sources and describe their fish ecological contents. Five types of sources were identified using the origin of sources as the first criterion: (i) early scientific surveys, (ii) fishery sources, (iii) fish trading sources, (iv) fish consumption sources and (v) cultural representations of fish. Except for early scientific surveys, all these sources were produced within economic and administrative contexts. They did not aim to report about historical fish communities, but do contain information about commercial fish and their exploitation. All historical data need further analysis for a fish ecological interpretation. Three case studies from the investigated Austrian and Russian rivers demonstrate the use of different source types and underline the necessity for a combination of different sources and a methodology combining different disciplinary approaches. Using a large variety of historical sources to reconstruct the development of past fish ecological conditions can support future river management by going beyond the usual approach of static historical reference conditions.  相似文献   

新麦草愈伤组织多倍体诱导与倍性鉴定   总被引：1，自引：1，他引：0  

云岚  云锦凤  李俊琴  郑丽娜  赵韦  齐丽娜 《草业学报》2010,19(6):126-131

以新麦草幼胚形成的胚性愈伤组织为材料,在悬浮培养基中添加不同浓度秋水仙素和1.5%DMSO诱导愈伤组织染色体加倍,并对处理后的愈伤组织再生幼苗进行根尖染色体倍性鉴定。在25℃下用100mg/L秋水仙素和1.5%DMSO处理72h的愈伤组织再生植株,平均加倍细胞比例最大,为53.58%。比较分蘖期加倍幼苗与二倍体幼苗形态差异,结果除分蘖数无显著差异外,四倍体叶片长、宽均显著高于二倍体,与混倍体叶长差异不显著。四倍体新麦草叶片气孔保卫细胞长度比二倍体增加13.52%,差异显著。同时四倍体叶表皮气孔之间距离也显著大于二倍体,混倍体以上气孔特征介于四倍体与二倍体之间。  相似文献   

俄罗斯森林采伐管理制度研究与借鉴     

宿海颖  李智勇  包应爽 《林业资源管理》2010,(5)

通过对俄罗斯森林资源采伐管理的法律、法规与政策进行分析,深入了解俄罗斯森林采伐管理制度的内涵,并在此基础上借鉴其成功经验,对我国相关政策的建立提出了政策性建议。  相似文献   

土壤质地定名法及吸湿水与土壤粒级含量关系的研究     

潘瑞  刘树庆  宁国辉  杨志新 《北方园艺》2010,(16):25-29

利用卡庆斯基制、美国制、中国制3种土粒分级标准对张家口葡萄产区的30个采样点进行土壤质地命名,并通过对比分析得出中国制是该区最适的土壤质地分类方法。现对吸湿水含量与土壤各粒级微粒百分含量的关系做了探测性研究,得出吸湿水和土壤中小于0.01 mm的粒径含量之间拟合曲线方程为:Y=20.272e0.207x,可根据此方程应用卡庆斯基制确定土壤质地;吸湿水和土壤中1~0.05 mm0、.05~0.002 mm粒径含量的拟合曲线方程分别为:y=22.018x2-105.323x+156.381,y=-18.304x2+86.495x-49.536,又可根据这2个方程利用美国制确定土壤质地名称。这些为用简易方法鉴定土壤质地类型提供科学依据。  相似文献   

Allozyme diversity of Russian wildrye accessions     

Y. Yang  J. Han  J. D. Berdahl 《Plant Breeding》2008,127(5):480-484

Analysis of genetic diversity among plant accessions plays an important role in developing strategies for plant breeding and the conservation of genetic resources. Therefore, we sought to estimate the extent of genetic diversity present among and within 29 Russian wildrye accessions, which were collected from widespread geographic sites. We assessed the genetic diversity of eight enzymes found in 29 Russian wildrye accessions using vertical polyacrylamide gel electrophoresis. The genetic diversity of each accession was estimated from standard genetic parameters that included (1) the number of polymorphic loci; (2) the average number of alleles per locus; (3) the observed and expected heterozygosity. The eight enzymes were encoded by 13 putative loci and 46 alleles. Allozyme analyses revealed a large number of polymorphic loci among the 29 accessions and some of the accessions carry rare alleles and trace their origin to sites in Xinjiang, China, where Russian wildrye is indigenous. The accessions with rare alleles require additional evaluation to determine whether they possess unique phenotypic traits which would be useful in applied plant breeding.  相似文献   

中俄远东地区木材贸易问题与对策研究     

侯建筠  李剑泉  段新芳  陆文明  申伟  欧阳华  周宇 《林业科技》2008,33(1):64-67

目前,中国木材资源缺口基本保持在1.5亿m3左右,这部分主要靠进口木材来补充.中国木材的主要供应国俄罗斯鼓励发展国内木材深加工,特别是中国进口木材的主要供应地区俄远东已开始逐步限制原木出口.对此,本文分析了俄远东地区森林资源与木材生产状况,探讨了中俄远东木材贸易现状及其存在的主要问题,提出了未来中俄远东木材贸易的对策建议.  相似文献   

老芒麦种子发育过程中的生理生化变化   总被引：16，自引：2，他引：14  

韩建国  毛培胜  牛忠联 《草地学报》2000,8(4):237-244

在河北省承德市鱼儿山牧中国农业大学科技攻关实验站,以种植２年和３年的老芒麦为材料,研究种子发育过程中的生理化变化。结果表明,在老芒麦种子发育过程中含水量均呈先慢后快的阶段性下降,而干重则逐渐增加,种子在盛花期后２６～２７ｄ达到生理成熟,含水量为３９．０～４５．６％。可溶性粮含量随种子发育成熟逐渐减少,相反,淀粉含量则逐渐增加,生长素、赤霉素、脱落酸含量高峰在种子发育过程中出现的顺序不同。  相似文献