凡纳滨对虾全同胞家系的建立及生长比较

全同胞家系是遗传分析的重要材料。采用自然交配法建立了62个凡纳滨对虾第一代全同胞家系,对其中17个家系进行了比较研究。结果表明,各家系的孵化率、出苗率与雌性亲本的大小相关性不显著。17个家系中有7个家系显示生长优势,其大小顺序依次是A02＞A11＞A01＞A17＞A06＞A08＞A16;7个家系在40周内的生长速度较17个家系的平均值高23.2%。在所有家系中,A01、A02、A11等3个家系的体重显著大于其它家系（P＜0.05）,其平均生长速度较所有家系平均生长速度分别快25.5%、31.6%和31.0%。这3个家系的整齐度良好,在养殖中期的个体变异系数分别为11.58%、9.95%和8.48%,后期均小于5%,显示出优良的经济性状,为进一步选择培育凡纳滨对虾的快速生长新品系奠定了基础。     

Genetic stability analysis of introduced Betula pendula,Betula kirghisorum,and Betula pubescens families in saline-alkali soil of northeastern China

Approximately, 20% of arable land worldwide, as well as nearly half of irrigated land, is subjected to salt stress. Osmotic stress and ion toxicity due to saline soils cause low crop yields. In this study, we introduced 18 families of salt-tolerant birch (Betula pendula Roth., Betula kirghisorum Sav.-Ryczg., and Betula pubescens Ehrh) into five high-salinity locations in northeastern China and evaluated their survival abilities. We also analyzed variation and stability of genotype–environment interactions of the different families under an additive main effect and multiplicative interaction model. Survival rate analysis indicated that the introduced families were well adapted to the high-salinity environments, whereas native families died. Variation analysis revealed significant differences between location × family interaction mean values for height and basic stem diameter (BSD), suggesting that most genotypes responded differently to different sites. The heritability of tree height and BSD at different sites varied from 0.416 to 0.940, with the coefficient of phenotypic variation ranging from 9.88% to 35.53%. Stability analysis indicated that some families had high tree heights but were sensitive to environmental conditions, whereas others were resistant but had average tree heights. These results suggest that families should be bred in various habitats to assess growth under favorable and unfavorable environments.     

新疆阿尔泰地区白杨派3个树种半同胞家系子代遗传多样性分析

利用SSR分子标记技术,对采自新疆额尔齐斯河流域阿尔泰市哈巴河及北屯地区的白杨派3个树种银白杨、银灰杨、欧洲山杨的半同胞家系子代进行遗传多样性分析.结果表明:筛选12对SSR引物在90个样本中共检测到58个等位基因(A)、112种基因型,多态位点百分率是100％,Nei遗传多样性指数(h)平均为0.648 5,Shannon多样性指数平均为1.234.基因分化系数(Fst)为0.337 l,即在总的遗传变异中有33.71％的变异来自于不同树种之间,绝大部分存在于子代个体间.白杨派内种间分化程度较高,种间遗传距离为0.3863～1.869;银灰杨的遗传变异最大,而银白杨的遗传变异最小.     

高校家庭经济困难女生科学发展的现状调查与思考——以福建部分高校为例

高校家庭经济困难女生是一个特殊的学生群体。通过调查了解她们发展中面临的困扰，分析指出促进她们的科学发展，应改进经济资助，强化精神扶持；增进人际交往，提高社会化技能；以学习为先，素质拓展为重；加强心理援助，妥善干预。     

一球悬铃木优良家系的评选

对1999年引自美国的12个种源47个一球悬铃木半同胞家系子代进行了综合评定,在5个试验点分别筛选出了适应性强的优良家系.虽然对4、5年生的一球悬铃木进行选择的结果不尽相同,但诸如松江点的10、16,镇江点29、36等5个试验点的21个优良家系表现是相对稳定的,而14和36号家系则适应范围更广.5个试验点的优良家系多来...     

Resistance of genetically different common carp, Cyprinus carpio L., families against experimental bacterial challenge with Aeromonas hydrophila

The objective of this study was to determine the differences in disease resistance against artificial infection with Aeromonas hydrophila between genetically different common carp families. Four strains differing in their origin and breeding history were selected from the live gene bank of common carp maintained at the Research Institute for Fisheries, Aquaculture and Irrigation (HAKI, Szarvas, Hungary) to establish families with wide genetic background: Szarvas 15 (15), an inbred mirror line; Tata (T) scaly noble carp; Duna (D), a Hungarian wild carp and Amur (A), an East Asian wild carp. A diallele mating structure was used to allow the assessment of genetic variation within and between the tested 96 families for a variety of traits. The existing technologies of fertilization and incubation of carp eggs, as well as larval and fingerling rearing had been modified because of the large number of baseline populations. Two challenge trials of the 96 families of carp with Aeromonas hydrophila were done. The 10 most resistant and 10 most susceptible families to A. hydrophila were identified from these two challenges. The crosses that produced the most resistant families were mainly those having parents from Tata and Szarvas 15 domesticated strains, while the most susceptible families were from the wild strains Duna and Amur.     

Multigene Families of Powdery Mildew Resistance Genes in Locus Mla on Barley Chromosome 5

A review of data on powdery mildew resistance genes in the Mla locus of barley reveals that there are at least 12 clusters of genes present, each comprising one Mla gene and one or more closely linked, additional resistance genes. Tentative designations are listed for 16 additional resistance genes. Many sources of powdery mildew resistance in barley appear to harbour multigene families in the Mla region, not single ‘superior’genes.     

紫溪山大型真菌物种多样性研究

对紫溪山自然保护区大型真菌进行了较为细致的收集、鉴定,并对优势科、属,营养类型和利用价值进行了分析。结果显示紫溪山大型真菌有2门5纲12目49科135属291种。占优势的科有7个,占总科数的14．29％,包含166种,占总种数的57．06％;占优势的属（种数≥5的属）有10个,占总属数的7．41％,包含103种,占总种数的35．40％。按营养方式可以分为腐生、共生、寄生3个类型：腐生菌最多,有187种,占全部种数的64．26％;共生型有101种,占总种数的34．71％;寄生较少,仅有3种,占全部物种数量的1．03％。按照利用价值可分为食用、药用、毒菌3类：可食用的有184种,占总数的63．23％;可药用的有56种,占总数的19．24％;有毒菌27种,占总种数的9．28％。     

羊台山森林公园植物区系研究

据初步统计,羊台山森林公园共有野生维管植物162科512属829种,包括蕨类植物28科50属82种;裸子植物3科3属4种;被子植物131科459属753种。各分类群呈不均匀分布,科级,以单属科和寡属科(2~4属)的科数占绝对优势,合计占78.88%,属级植物分布类似。植物区系带有较明显的热带成分,表征科为粘木科、桑科、芸香科、大戟科、樟科、山茶科、杨梅科、山矾科、杜英科、冬青科、金缕梅科等,也夹杂着较多的世界广布成分。     

杂种落叶松优良家系选择研究

以8年生杂种落叶松21个处理为对象,对生长性状进行变异分析的结果显示:树高、胸径家系内存在较丰富的变异。其中,树高变异较大的前4个家系为日3×石51、兴5×兴9、兴9×日76-2、日5×长77-3,胸径变异较大的前4个家系为日3×石51、兴5×兴9、兴7×日77-2、兴9×日76-2。对比5年与8年生杂种落叶松生长性状变化的结果显示:兴6×和6、日11×兴2、日12×兴9这3个家系表现出较快的生长速度,年平均树高、胸径生长量较大。对杂种落叶松3次测量数据进行相关分析的结果显示:8年生树高、胸径与5年、6年生长性状均为正相关,且均达到显著水平。对8年生杂种落叶松树高、胸径数据进行方差分析的结果显示:生长性状杂种间差异达到显著水平。最终选择兴6×和6、兴7×日77-2、日11×兴2这3个家系为杂种落叶松优良家系,其平均树高与胸径遗传力分别为0.652、0.619,遗传增益分别为45.08%、39.97%。