Agrobacterium tumefaciens-mediated Transformation of CryⅠA(b) gene to Trichoderma harzianum

In this study, Cry ⅠA(b) gene was successfully transferred into the biocontrol fungus Trichoderma harzianum with an efficiency of 60-180 transformants per 10^6 spores by using Agrobacterium tumefaciens-mediated transformation. Putative transformants were analyzed to test the presence of Cry ⅠA(b) gene by Southern blot. Most transformants contained a single T-DNA copy. RT-PCR analysis showed that the Cry ⅠA(b) gene was transcribed. Antifungal activities and insecticidal activities of the transformants were examined. There was no obvious difference in antifungal activities between the transformants and their wild strains. The modified mortalities of the transformants T1 and T2 were 69.57% and 91.30%, respectively. The tranformation system mediated by A. tumefaciens proved to be a powerful tool for the filamentous fungi transformation and functional genomic study with its high transformation frequency, simplicity of T-DNA integration, and genetic stability of transformants.     

基于SSR分子标记的广西极小种群野生植物长叶苏铁遗传多样性分析

了解广西区内的国家一级重点保护植物长叶苏铁（Cycas dolichophylla K.D.Hill）的遗传多样性和变异特征对广西长叶苏铁的保护和管理有着重要意义。本研究利用筛选出的6对稳定性好的SSR引物对分别来自广西百色市田阳县梅茶镇（PL）、德保县那甲镇（NL）和德保县城关镇（QH）的3个长叶苏铁种群的遗传多样性和变异特征进行分析。结果表明：6对引物中,高度多态性引物（GZST055、GZST065、GZST088）和低度多态性引物（GZST002、GZST013、GZST019）各占50%。广西长叶苏铁3个种群的平均观测等位基因为2.833,平均有效等位基因为2.005,平均Shannon信息指数为0.657,平均观测杂合度为0.259,平均期望杂合度为0.359。群体的遗传分化系数为0.049,说明群体间遗传分化小,且群体内遗传变异占所有遗传变异的97%,3个种群的基因交流频繁且遗传背景相互混杂。总体来看,广西长叶苏铁遗传多样性水平较低,而德保县那甲镇（NL）种群的遗传多样性相对最高,应将该种群作为重点保护单元进行保护。本研究还对广西长叶苏铁资源保护工作提出了建议和对策。     

微生物学名词

微生物microorganism个体难以用肉眼观察的一切微小生物之统称。微生物学microbiology研究微生物形态结构、生理生化、遗传变异、生态分布和分类进化等生命活动规律,以及与其他生物和环境相互关系的学科。细菌学bacteriology研究细菌等原核生物的形态结构、生理生化、遗传变异、生态分布、分类和进化等生命活动规律,及其在人类生产与生活中应用的微生物学分支学科。     

DNA标记技术在动物遗传育种中的应用

文中对几种ＤＮＡ标记技术在动物遗传育种领域应用的研究进展作了系统阐述。     

ISSR和ITS标记在白木香遗传变异研究中的应用

采用简单序列重复区间（ISSR）扩增技术和核糖体RNA基因（rDNA）转录间隔区（ITS）序列分析技术,对不同地区白木香的遗传变异、亲缘关系及分子鉴定进行研究.ISSR分析显示,筛选出的7条ISSR引物可扩增出80条DNA条带,其中多态性条带的比例是60.0%,白木香9个居群之间的遗传距离是0.0733-0.4213.ITS序列分析显示,白木香种内的9个居群中共有6个变异位点,种内遗传距离为0.0000-0.0110.两种标记得到的聚类图不一致,但大致趋势相同,都可以将白木香及其近缘种聚在不同的种群中,说明ISSR标记和ITS序列分析均可有效揭示白木香的遗传变异及亲缘关系.     

马尾松纸浆材优良家系的选择

对福建三明和仙游两个试验点9年生的马尾松自由授粉子代试验林进行调查研究，结果表明：不同家系在树高、胸径、材积生长性状上存在极显差异，这些差异主要是由遗传因素制约；在木材基本密度、木材化学组分、木材纤维形态上也存在较大的差异。以单株纤维素产量为主要指标，从参试的105个家系中各选出10个纸浆材优良家系。从三明点选出W00249、W00251等10个纸浆材优良家系，其平均单株纤维素产量达10.718kg，树高、胸径、材积的平均值分别为9.55m、12.4cm和0.05848^3,分别大于福建省马尾松速生丰产林标准的50.39%、93.75%和173．91％；从仙游点选出W00307、W00335等10个纸浆材优良家系，其平均单株纤维素产量为8．240kg，树高、胸径、材积的平均值分别为7.34m、11.4cm和0.04172m^3，分别大于福建省马尾松速生丰产林标准的52.92%、132.65%和210.65%，增产效果极为显。     

闽楠优树子代测定林生长性状差异及聚类分析

调查分析福建省永安国有林场8个种源43个家系的8 a生闽楠优树子代测定林.结果表明:不同家系间胸径、树高、材积等性状生长差异极显著.平均胸径6.14 cm,变异系数23.35%;平均树高4.98 m,变异系数21.16%;平均材积0.009 1 m3,变异系数60.11%.不同家系胸径、树高、材积的遗传力分别是86.32%,96.23%,88.84%.对胸径、树高、材积进行系统聚类分析、综合排序,开展闽楠优良家系选择.入选家系按排序分别为NP606,NP617,NP607,NP602,Sx04,Yp602,NP608,NP601,入选的优良家系可用作闽楠育种群体和无性繁殖材料.     

美洲黑杨新无性系干形性状遗传变异初步研究

对９ 年生美洲黑杨新无性系的圆满度、弯曲度、利用率、节子数和树皮厚度等５ 个干形性状进行了调查,并对各性状的遗传变异进行初步研究。结果表明,调查的５ 个干形性状在杨树无性系间变异十分显著;各性状的遗传力较高（０４３８ ０ ～０７７５ ３） ,干形高度受遗传控制;弯曲度、节子数及树皮厚度等３ 性状遗传变异系数较大,圆满度和利用率２ 性状变异系数较小;杨木单板利用率的高低与树干弯曲度和树皮厚度遗传上有密切的关系,但与节子数相关不密切。同时利用指数分析法对杨树新无性系干形的优劣进行了综合评价。     

基于细胞色素b序列的罗非鱼选育群体遗传变异分析

对吉富品系尼罗罗非鱼(Oreochromis niloticus)不同世代选育群体细胞色素b序列进行测定和分析,45个样本经重排比较后获得1 064 bp的同源序列.共检测到161个变异位点,占分析位点数的15.13%.同源序列中多态位点比例随着选育世代数的累进,呈现出降低的趋势,F_0、F_6、F_7、F_8、F_9代分别为14.38%、13.47%、13.38%、10.24%、9.49%.核苷酸多样性指数也呈现出同样的降低趋势,F_0、F_6、F_7、F_8、F_9代分别为0.065 47、0.049 05、0.048 81、0.036 19、0.033 81.本研究结果表明,新吉富罗非鱼仍保持了一定程度的遗传变异水平,新吉富罗非鱼逐步趋于纯化.     

RAPD analysis of genetic variability among Stylosanthes guianenesis accessions of resistant and susceptible to the stylo anthracnose

Stylosanthes guianenesis Sw. is an important tropical forage legume grown and utilized in the tropics and the subtropics of South China. Anthracnose, caused by Colletotrichum gloeosporioides (Penz.) Sacc., is a major constraint to the extensive use of Stylosanthes. Forty-five accessions of S. guianensis were assessed with RAPD for genetic diversity and for resistance to anthracnose. RAPD analysis was performed using twenty primers screened from 200 arbitrary oligonucleotides, and a 71.5% level of polymorphism was found. The dendrogram obtained with unweighted pair group method of averages (UPGMA) based on the RAPD data showed genetic similarity from 50% to 94% among all stylo accessions, and fourteen clusters were defined at 66.5% genetic similarity. Two strains of C. gloeosporioides from stylo in China were used for anthracnose resistance screening. All plant accessions showed variation in the reaction to two strains and the correlation of resistance had a value of 0.904. Multiple correspondence analysis displayed a random distribution of the resistance or susceptibility response with respect to the genetic diversity measured by RAPD analysis except one group. Mean distance was also calculated to determine the diversity within clusters. From our results, the RAPD analysis is an effective and efficient technique of providing quantitative estimates of genetic similarity among stylo accessions.