白杨派树种亲缘关系的RAPD分析

运用RAPD技术对白杨派中7个树种和3个人工杂交种共计50个无性系的亲缘关系进行分析.结果表明:筛选出的26条随机引物共扩增产生222条谱带,其中200条为多态性谱带,多态性带达90.09%,且种间遗传变异大于种内无性系间的遗传变异.聚类分析结果显示,参试的50个材料可分为2大类:第一类由山杨、响叶杨、河北杨组成;第二类由毛白杨、银毛杨、84K杨、银白杨、银灰杨、新疆杨和银新杨组成;3个人工杂交种与白杨亚派树种的亲缘关系较近;人工杂交种银毛杨与84K杨间亲缘关系最近.     

利用RAPD标记构建响叶杨和银白杨分子标记连锁图谱

利用ＲＡＰＤ标记响叶杨（ Ｐｏｐｕｌｕｓ ａｄｅｎｏｐｏｄａ Ｍａｘｉｍ ．） ×银白杨（ Ｐ． ａｌｂａ Ｌ．） 的Ｆ１ 群体,按照拟测交的作图策略,分别构建了响叶杨和银白杨的分子标记连锁图谱。实验过程中对６００ 个随机的寡核苷酸引物进行了重复筛选,共选出１２８ 个引物用于作图群体的随机扩增,选择符合１∶１ 分离的拟测交位点。作图群体大小为８２ 个单株（ 包括双亲） 。结果获得了３２６ 个拟测交分离位点和７ 个３∶１ 分离位点。拟测交位点中有２３８ 个位点来源于银白杨,有８８个位点来源于响叶杨。经偏分离检测,用于银白杨作图的位点共计２１２ 个（２６ 个位点偏分离） ,用于响叶杨作图的位点共计７８ 个（１０ 个位点偏分离） 。利用多点连锁分析,银白杨中有１８９ 个连锁标记构成了２０ 个不同的连锁群（４个以上标记）,６ 个三连体和１６ 个连锁对,连锁标记覆盖的总图距为２４０２ ．４ ｃＭ（ｃｅｎｔｉｍｏｒｇａｎ） 。而响叶杨有４１ 个连锁标记分属于１２ 个不同的连锁群（２ 个以上标记） ,标记覆盖的总图距为４７９ ．４ ｃＭ。获得了中等密度的银白杨连锁图谱和响叶杨图谱的一个连锁框架     

山杨杂种无性系的SSR分子标记遗传多样性

采用5对SSR引物对52个山杨杂种无性系进行了遗传多样性检测,结果表明在研究的5个位点上SSR标记多态位点百分率为100%,平均等位基因数为4.4个,有效等位基因数最多的位点是PTR7,最少的位点为PTR12;欧美山杨杂种的遗传多样性最丰富,相比之下,中美山杨杂种遗传变异最低;聚类分析表明,在一定的遗传距离基础上,欧美山杨杂种和欧洲山杨首先聚为一类,然后又与中美山杨杂种聚类,最后是中国山杨。研究表明来自芬欧美山杨杂种具有较高的遗传多样性,这对我国山杨遗传资源的扩大,以及未来山杨杂交育种,杂种优势的利用都是重要的。     

毛白杨CCoAOMT cDNA片段的克隆与转基因杨木质素含量的调控

用RT_PCR方法从毛白杨 (PopulustomentosaCarr.)中克隆了CCoAOMT基因的cDNA片段 ,并对其序列进行了分析。Northern杂交表明该基因在毛白杨正在木质化的次生木质部高水平表达 ,且与木质化进程同步。构建了该基因反义表达载体 ,根癌土壤杆菌 (Agrobacteriumtumefaciens (SmithetTownsend)Conn)介导转化杂交杨 (欧洲山杨×银白杨 ,P .tremula×P .alba)。采用PCR、PCR_Southern及Southern杂交对获得的转基因植株进行分子检测 ,并测定移栽 5～ 6个月的转基因植株的Klason木质素含量 ,其中一个转基因株系的Klason木质素含量比未转基因对照杨树下降 17.9%。结果表明利用反义RNA技术对杨树CCoAOMT基因的表达可以降低转基因植株的木质素含量 ,达到改善其造纸性能的目的     

鱼类远缘杂交正反交杂种胚胎发育差异的细胞遗传学分析

本文报道了鲤(Cyprinus carpio)×鲢(Hypophthalmichthys molitrix)、鲫(Carassiusauratus)×鲢、白鲫(Carassius auratus cuvieri)×鲢和鲢×鲤、鲢×鲫、鲢×白鲫的正反交试验。在鲤×鲢、鲫×鲢和白鲫×鲢3个正交组中,胚胎发育基本正常,尽管孵出的鱼苗绝大多数生命力弱,但孵化率都在50％左右;而在鲢×鲤、鲢×鲫和鲢×白鲫3个反交组中,胚胎发育均为畸形,不能孵化出苗。 胚胎发育细胞遗传学分析表明,鲤×鲢、鲫×鲢和白鲫×鲢的杂种胚胎几乎都是整倍体,而鲢×鲤、鲢×鲫×鲢×白鲫的杂种胚胎基本上是非整倍体,染色体数变化较大。这些正反交杂种胚胎发育的显著差异可能与其亲本物种间的基因组大小有关。文中还分析讨论了这些正反交差异与天然多倍体物种以及胚胎发育速度的相关性,认为天然多倍体物种可能具有一些不同于普通二倍体物种协调外源基因组的能力。     

中国部分杨属植物的染色体数目

对中国杨属Populus L. 5组14种(银白杨P. alba L.、河北杨P. hopeiensis Hu & Chow、毛白杨P. tomentosa Carr.、欧洲山杨P. tremula L.、小叶杨P. simonii Carr.、辽杨P. maximowiczii Henry、大青杨 P. ussuriensis Kom. 、青杨P. cathayana Rehd.、小青杨P. pseudo-simonii Kitag.、香杨P. koreana Rehd.、毛果杨P. trichocarpa Torr. & Grog.、大叶杨P. lasiocarpa Oliv.、欧洲黑杨P. nigra L.、胡杨P. euphratica Oliv.),3变种(新疆杨P. alba L. var. pyramidalis Bge.、箭秆杨P. nigra L. var. thevestina Bean.、钻天杨P. nigra L. var. italica (moench.) Koehne),3杂交种(小钻杨P.×xiaozhuanica W. Y. Hsu & Liang、北京杨P.×beijingensis W. Y. Hsu、加杨P.×canadensis Moench、晚花杨P.×canadensis Moench cv. “serotina” 、沙兰杨P.×canadensis Moench cv. “Sacrau 79”和意大利214杨P.×canadensis Moench cv. “I-214”)进行了染色体计数。发现白杨组的毛白杨P. tomentosa Carr. 、 黑杨组的沙兰杨P. ×canadensis Moench cv. “Sacrau 79”和意大利214杨P. × canadensis Moench cv. “I-214”为三倍体(2n=3x=57),其余均为二倍体(2n=2x=38)。     

鲢的远缘杂交子代和人工三倍体的同工酶表达

用聚丙烯酰胺梯度凝胶电泳分析了鲢♀×鳙♂、鲢♀×团头鲂♂的二倍体和异源三倍体杂种,以及同源三倍体鲢及其亲本种的８种蛋白质和同工酶的表型。二倍体杂交子代的基因表达是多样的,这些多样的表达可能与双亲的这些蛋白质和同工酶的表型差异有关。如与二倍体杂交子代相比,鲢×鳙异源三倍体的肌肉蛋白和血清蛋白有效一致的表型,此外在两种异源三倍体中ＥＳＴ和ＭＤＨ同工酶的表型接近母本,这些结果表明异源三倍体由于增加了一套     

RAPD鉴定栽培稻与野生稻体细胞杂种

利用随机引物扩增DNA(RAPD)技术,对栽培稻和野生稻原生质体融合获得的体 细胞杂种进行了鉴定。证实了它们包含有双亲的基因组成分。但来自双亲的基因组成分并不是对等的。一些体细胞杂种含有一个亲本更多的基因组成分,而另一些相反。利用RAPD数据和聚类图讨论了体细胞杂种和双亲的亲缘关系。     

鲤和草鱼杂交四倍体及其回交三倍体草鱼杂种的研究

进行了兴国红鲤♀×草鱼♂的杂交,杂种一代染色体数为142—156,众数值为146—152,系染色体自动加倍的异源四倍体。其外形和习性接近母本,两性均能成熟,雌、雄鱼分别与草鱼进行了回交。以草鱼为母本,杂种一代为父本的回交子代全部为草鱼形,草食性。以杂种一代为母本,草鱼为父本的回交子代一部分象草鱼,一部分象鲤,但草鱼形子代成活率较低,两个回交组合的子代均为三倍体,染色体数98—100,众数值98。1983年获得的杂种一代♀×草鱼♂的鲤鱼形回交杂种,已于1986年性成熟,雌、雄鱼分别与草鱼再次回交,获得了二次回交杂种。测定了红鲤、草鱼、杂种一代及其与草鱼回交子代的乳酸脱氢酶和过氧化物酶的同工酶,它们各有不同的电泳图谱。     

大叶杨组组间杂交花粉－柱头相互作用的超微结构研究

以大叶杨为母本,分别与小叶杨、欧洲黑杨、响叶杨进行人工杂交,并以大叶杨×大叶杨为对照,观察其花粉与柱头相互作用的超微结构变化。结果表明,大叶杨柱头细胞在授粉前表现生理活跃,含丰富的细胞器,壁外被含分支通道的角质层。接受大叶杨及欧洲黑杨花粉的柱头细胞内部仍有丰富的细胞器,膜结构保存完好。接受小叶杨及响叶杨花粉的柱头细胞衰亡较快,授粉部位沉积厚的胼胝质,细胞内部液泡化,膜结构逐渐消失,细胞质电子密度加大。欧洲黑杨花粉行为与大叶杨花粉行为相似,花粉能迅速萌发,并以短管形式穿入柱头,异常行为罕见。小叶杨及响叶杨花粉萌发后只有半数花粉管能以短管形式进入柱头,其中部分管内沉积胼胝质,另半数花粉管在柱头上表现各种异常行为——扭曲、爬行、肿胀、提前破裂释放内容物及先端沉积胼胝质。由各种花粉在大叶杨柱头上的行为和大叶杨柱头对各种授粉的反应判断,与大叶杨杂交亲和力在柱头阶段表现由强至弱依次是欧洲黑杨、小叶杨、响叶杨。     

Study on Origin of Populus tomentosa Carr.

This study analyzed five varieties of P. tomentosa and their putative parents, P. alba, P. davidiana, P. adenopoda and P. tremula by RAPD and artificial cross. Of 78 bands revealed by 13 arbitrary primers selected, 58 (74.36%) bands were polymorphic among P. tomentosa and four putative parents. The RAPD statistical results showed the relationship between P. tomentosa and P. alba or P. adenopoda was closer than that between P. tomentosa and P. davidiana or P. tremula . There were higher similarity and lower genetic distance between P. tomentosa and P. alba or P. adenopoda than that between P. tomentosa and the other two putative parents. The results from UPGMA, Fitch margoliash phylogenetic dendrogram were similar. In addition, artificial hybrids including reciprocal cross between P. alba and P. adenopoda were used to compare with five varieties of P. tomentosa . And those hybrids between P. alba as female and P. adenopoda as male were closer to P. tomentosa than those from reciprocal cross. The results demonstrated that P. tomentosa was a natural hybrid between P. alba as female parent and P. adenopoda as male parent.     

Preliminary interspecific genetic maps of the populus genome constructed from RAPD markers.

We have constructed RAPD-based linkage maps for an interspecific cross between two species of the genus Populus (P. adenopoda and P. alba), based on a double pseudo-test-cross strategy. Of a total of 360 polymorphic fragments scored, 290 showed a test-cross configuration, corresponding to DNA polymorphisms heterozygous in one parent and null in the other. In the female parent, P. adenopoda, 82 markers were grouped in 19 different linkage groups (553 cM), whereas in the male parent P. alba, 197 markers established a much more complete framework map with an observed genome length of 2300 cM covering 87% of the total P. alba genome. The larger number of test-cross markers detected for the P. alba parent than for the P. adenopoda parent might be due to a higher level of heterozygosity in the former than in the latter. In this study, we detected only a small percentage (2%) of the intercross dominant markers heterozygous in both parents and segregating 3:1 in the progeny. The further focus in this mapping study should be on the identification of more intercross markers, to align the two parent-specific maps into a consensus map for mapping important genes causing species differentiation during long evolutionary divergences.     

The Crossability of Triticum aestivum with Tetraploid Hordeum bulbosum

In order to study the crossability of wheat with H. bulbosum a series of wheat varieties from various sources and their F1 hybrids as well as tetraploid H. bulbosum from different countries were used as parents in this experiment. The main results of the experiment are showed as follows: 1. Twenty-one wheat varieties from Europe, West Asia, America, China, Australia etc. 11 countries and regions respectively as famele parents were crossed with four tetraploid H. bulbosum from Hungary, USSR, Canada and Germany. The seed set percentages in the intergeneric cross combinations ranged from 0.00% to 49.93%. Statistical analysis revealed that there were significant differences between the seed set percentages of wheat varieties. The crossability, with H. bulbosum might differed in different varieties of wheat from same country. 2. Various F1 hybrids resulting from 13 and 26 intervarietal cross combinations of wheat and their parents were crossed with H. bulbosum from Hungary and USSR respectively in different years. The mean seed set percentages of F1 hybrids, their male and female parents were 26.53%, 15.38%, 20.30% and 39.1%, 34.8%, 26.7% respectively. The results indicated that when some wheat varieties having poor-crossability with H. bulbosum were hybridized with other varieties especially with those varieties having high- crossability, the crossability of their F, hybrids probably had higher crossability than their parents having poor-crossability. Six F1 hybrids of wheat obtained from six com- binations of reciprocal crosses, in which the completely non-crossable varieties Hope, Xiao- Bai-Mang and high-crossable varieties Chinese Spring, Fortunate were used as male or female parent alternately, were crossed as female parents with H. bulbosum. All of 6 F1 hybrids were crossable and gave the percentage of seed set from 7.00% to 42.57%, although they ought to carry the dominant Kr genes responsible for non-crossability, which were passed on to F1 hybrids by non-crossable varieties, the parent Hope or Xiao-Bai- Mang. Clearly that is due to the gene interaction between female and male parents. Be- sides Kr loci in wheat, probably other genes can influence the crossability. 3. There were significant differences between clones of H. bulbosum in the crossa- bilities with wheat. In conclusion F1 hybrids of wheat have higher crossability with H. bulbosum than their parents having poor-crossability. This could be advantageous for exploitation of this technique. By selecting even more efficient clones of H. bulbosum and improving embryo culture techniques, the H. bulbosum technique will be used in wheat breeding program- mes probably.     

小麦杂交种与亲本发育早期种子的基因表达差异及其与杂种优势关系的初步研究

为深入探讨小麦杂种优势形成的分子机理,选取3个冬小麦品种(系)为一组亲本,3个为另一组亲本,配制了正反交18个杂交组合,以授粉后6d的杂交和自交种子为材料,应用mRNA差异显示技术(DDRT—PCR)研究了小麦杂交当代种子与其亲本自交种子基因的表达差异,并与杂种优势进行相关分析。为降低DDRT—PCR技术假阳性的不利影响,对每个引物组合均作了两次PCR扩增,在处理数据时,仅统计能重复出现的条带。结果发现：杂交种和亲本之间的基因表达模式有8类共15种：(1)单亲沉默型(2种),(2)单亲一致型(2种),(3)正交或反交沉默型(2种),(4)正交或反交特异型(2种),(5)正交或反交单亲一致型(4种),(6)杂交种特异型(1种),(7)双亲共沉默型(1种),(8)表达一致型(1种)。分析发现,小麦杂交种和亲本间存在显著的表达差异。在差异表达类型中,杂交种特异型和双亲共沉默型比例最低。对上述15种表达模式与杂种优势进行相关分析,结果表明,表达一致型与各产量性状杂种优势之间的相关均不显著,说明杂种优势是由某些有表达差异的基因造成。9个产量性状均能检测到一种以上与其显著或极显著相关的基因表达模式,有些性状受正负相关效应的共同影响;沉默型(包括单亲沉默型、正交或反交沉默型和双亲共沉默型)和正交或反交单亲一致型在杂种优势形成中发挥重要作用。这些研究表明,在种子发育早期,基因的差异表达与杂种优势形成之间可能存在较为复杂的关系。     

Genetic characterization of asymmetric reciprocal hybridization between the flatfishes <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis> and <Emphasis Type="Italic">Paralichthys dentatus</Emphasis>

Interspecific reciprocal crosses between the two flatfishes Paralichthys olivaceus and P. dentatus yielded hybrids with different viabilities. Specifically, the hybrids of P. olivaceus female and P. dentatus male (HI) were found to be viable, while the reciprocal hybrids from P. dentatus female and P. olivaceus male (HII) were completely inviable. All the HII individuals showed morphological deformities and died before first feeding. The chromosome analysis showed that HI individuals had the same chromosome number as parents. However, two chromosomes were missing in HII offspring indicating that the latter were aneuploids. Genomic inheritance from the parents to F₁ progeny was also examined by amplified fragment length polymorphism (AFLP) analyses, and the results showed differences between reciprocal hybrids. Almost all AFLP bands (97.71%) observed in parents were passed on to HI individuals. In contrast, only 86.64% of the AFLP bands from parents were scored in HII individuals. Frequency of lost parental bands was thus significantly higher in HII than that in HI and intraspecific crosses, which was probably associated with chromosomal elimination. In addition, higher segregation distortions were found in hybrids than in controls, although these differences were not significant. The present study indicates that chromosomal elimination and loss of AFLP loci occurred in inviable HII individuals, while such genomic changes were not found in viable HI individuals. Possible implications of such difference on genomic changes for asymmetric viability in reciprocal hybrids are discussed.     

RAPD Linkage Mapping in a Populus adenopoda×P. alba F1 Family

Random amplified polymorphic DNAs(RAPDs) were used to construct linkage maps of the parents of a Populus adenopoda Maxim. x P. alba L. Fl family. A set of 620 random oligonucleotide primers were screened and 128 primers were selected to generate RAPD markers within a sample of 80 Fl progenies. A total of 333 segregating loci [ (326( 1:1 ) ,7(3:1 ) ] were identified. Among the 326 1:1 segregating loci (238 loci from P. adenopoda and 88 loci from P. dba),36 loci (26 loci in P. adenopoda and 10 loci in P. dba) were found distorted from the normal 1:1 ratio. Altogether 290 loci segregating 1:1 (testcross configuration) were used to construct parent-specific linkage maps,212 for P. alba and 78 for P. adenopoda. The resulting linkage maps consisted of 189 marker loci in 20 groups (four or more loci per group), 6 triples and 16 pairs for P. dba, which cover the map distance about 2 402.4 cM, and 41 linked marker loci for P. adenopoda which cover map distance about 479.4 cM. Further study is warranted to locate some important quantitative trait loci (QTLs) based on the maps.     

Clonality and spatial genetic structure in Populus x canescens and its sympatric backcross parent P. alba in a Central European hybrid zone.

Spatial genetic structure (SGS) holds the key to understanding the role of clonality in hybrid persistence, but multilocus SGS in hybrid zones has rarely been quantified. Here, the aim was to fill this gap for natural hybrids between two diploid, ecologically divergent European tree species with mixed sexual/asexual reproduction, Populus alba and P. tremula. Nuclear microsatellites were used to quantify clonality, SGS, and historical gene dispersal distances in up to 407 trees from an extensive Central European hybrid zone including three subpopulation replicates. The focus was on P. x canescens and its backcross parent P. alba, as these two genotypic classes co-occur and interact directly. Sexual recombination in both taxa was more prominent than previously thought, but P. x canescens hybrids tended to build larger clones extending over larger areas than P. alba. The 3.4 times stronger SGS in the P. x canescens genet population was best explained by a combination of interspecific gene flow, assortative mating, and increased clonality in hybrids. Clonality potentially contributes to the maintenance of hybrid zones of P. alba and P. tremula in time and space. Both clonality and SGS need to be taken into account explicitly when designing population genomics studies of locus-specific effects in hybrid zones.     

甘蓝型油菜Ogura 雄性不育×白菜的回交杂种后代与亲本之间蕾期基因表达差异比较研究*

以甘蓝型油菜（Brassica napus L, AACC,2n＝38）Ogura细胞质雄性不育材料为母本,以不同白菜（B campestris ssp. chinensis Makino, AA, 2n＝20） 自交系‘新选一号’和‘矮脚黄’为父本进行杂交,获得了杂种F1、BC1、BC2代。利用cDNA-AFLP技术对两种材料的不同回交世代BC1、BC2代与其亲本在蕾期的基因表达进行分析。结果表明,两种白菜回交世代与其亲本的基因表达有明显差异,在质和量上都存在差异。基因表达模式有5类共7种：（1）单亲沉默型（2种）,（2）单亲一致型（2种）,（3）双亲共沉默型,（4）杂种特异型,（5）表达一致型。随着回交世代的增加,回交杂种和亲本的基因表达在单亲沉默型、双亲共沉默型呈增加趋势。而在母本一致型、父本一致型、杂交种特异型、表达一致型呈下降的趋势。两种白菜在F1、BC1、BC2 3个世代与回交亲本花蕾间的基因差异表达有15种类型,其中以在轮回亲本、F1、BC1、BC2中共同出现表达的带的比例最高。Abstract: Crosses between female parent of Ogura male sterility Brassica napus L. and male parents of B. campestris ssp. chinensis Makino were made and F1, BC1 and BC2 generations produced. Gene expression of two Chinese cabbage backcross hybrid BC1, BC2 and their parents at bud stage was analyzed by means of cDNA-AFLP technique. The results indicated that the patterns of gene expression differ significantly between BC1 and BC2 generations and their parents. There were many patterns of gene expression, including gene overexpression and gene silencing. Five patterns (seven kinds) of gene expression were observed, which include: (1) bands occurring in only one parent (two kinds); (2) bands observed in hybrids and one parent (two kinds); (3) bands occurring in only parents (one kind); (4) bands visualized in only hybrids (one kind); (5) bands observed in parents and hybrids (one kind). In accompany with the addition of backcross, the increase trend in backcross hybrids and their parents were described in the aspects of differential gene expression, bands expressed only in one parent and bands expressed only in both parents. The declined trend in backcross hybrids and their parents were observed in the aspects of bands expressed in both hybrids and one parent (two kinds), bands visualized in only hybrids and bands observed in parents and hybrid. Fifteen patterns of gene expression were observed in F1、BC1、BC2 and backcross parents. The percent of bands expressed in F1、BC1、BC2 and backcross was highest.     

萝卜-芥蓝杂种F1代创制及杂种鉴定

以萝卜为母本,以芥蓝为父本,采用人工去雄授粉的方法进行杂交,然后通过胚抢救（embryo rescue）得到F1代植株,并利用RAPD技术对杂种F1代幼苗进行了鉴定。RAPD鉴定结果表明：杂种表现出亲本的特异带或者亲本不具备的新谱带,有的还遗失了亲本的特异带或者共有带。     

萝卜-芥蓝杂种F_1代创制及杂种鉴定

以萝卜为母本,以芥蓝为父本,采用人工去雄授粉的方法进行杂交,然后通过胚抢救(embryo rescue)得到F1代植株,并利用RAPD技术对杂种F1代幼苗进行了鉴定.RAPD鉴定结果表明:杂种表现出亲本的特异带或者亲本不具备的新谱带,有的还遗失了亲本的特异带或者共有带.