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101.
D. Crouzillat E. Lerceteau V. Petiard J. Morera H. Rodriguez D. Walker W. Phillips C. Ronning R. Schnell J. Osei P. Fritz 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(1-2):205-214
A genetic linkage map of Theobroma cacao (cocoa) has been constructed from 131 backcross trees derived from a cross between a single tree of the variety Catongo and an F1 tree from the cross of Catongo by Pound 12. The map comprises 138 markers: 104 RAPD loci, 32 RFLP loci and two morphologic loci. Ten linkage groups were found which cover 1068 centimorgans (cM). Only six (4%) molecular-marker loci show a significant deviation from the expected 11 segregation ratio.The average distance between two adjacent markers is 8.3 cM. The final genome-size estimates based on two-point linkage data ranged from 1078 to 1112 cM for the cocoa genome. This backcross progeny segregates for two apparently single gene loci controlling (1) anthocyanidin synthesis (Anth) in seeds, leaves and flowers and (2) self-compatibility (Autoc). The Anth locus was found to be 25 cM from Autoc and two molecular markers co-segregate with Anth. The genetic linkage map was used to localize QTLs for early flowering, trunk diameter, jorquette height and ovule number in the BC1 generation using both single-point ANOVA and interval mapping. A minimum number of 2–4 QTLs (P<0.01) involved in the genetic expression of the traits studied was detected. Coincident map locations of a QTL for jorquette height and trunk diameter suggests the possibility of pleiotropic effects in cocoa for these traits. The combined estimated effects of the different mapped QTLs explained between 11.2% and 25.8% of the phenotypic variance observed in the BC1 population. 相似文献
102.
V. H. Beaumont J. Mantet T. R. Rocheford J. M. Widholm 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(4):606-612
The F2 generations from two maize crosses were used to compare the ability of RAPD and RFLP marker systems to create a genetic linkage map. Both RFLPs and RAPDs were shown to provide Mendelian-type markers. Most of the RFLPs (80%) could be placed with a good level of certainty (LOD>4) on the genetic linkage map. However, because of their dominant nature, only between 37% and 59% of the RAPDs could be placed with such a LOD score. The use of combined data from RFLPs and RAPDs increases the level of information provided by RAPDs and allows the creation of a combined RFLP/RAPD genetic linkage map. Thus, the RAPD technique was found to be a powerful method to provide improved probes coverage on a previously created RFLP map and to locate markers linked to chromosomal regions of interest. 相似文献
103.
Yeehn Yeeh Soon Suk Kang Hye Gi Chung Mun Su Chung Myong Gi Chung 《Journal of plant research》1996,109(2):161-168
Vitex rotundifolia L.f. is a woody perennial and has sexual and asexual modes of reproduction. Allozyme study was conducted on 550 plants in
13 Korean populations. The levels of genetic variability and divergence within and among populations, respectively, are considerably
lower and higher than the mean values for woody plants with similar life history tralts. Mean percentage of polymorphic loci
(P
P), mean number of alleles per locus (A
P), and mean genetic diversity (He
P) within populations ofV. rotundifolia were: 16.7%, 1.21, and 0.047. On average, about 79% of the total variation inV. rotundifolia was common to all populations (meanG
ST=0.208). In addition, significant differences in allele frequencies among populations were found in all polymorphic loci examined
(P<0.001). On the other hand, levels of genotypic diversity within and among populations were moderate. About 44% (18/41) of
multilocus genotypes were “local genotypes” (genotypes occurring in only one population), whereas only one “widespread genotype”
(genotypes occurring in more than 75% of the populations) were detected. The mean number of multilocus genotypes per population
(G) and mean genotypic diversity index (D
G) were 8.4 and 0.74, respectively. Most common multilocus genotypes found in populations were homozygous for five polymorphic
loci. The abundance of ramets of these genets is responsible for the low levels of expected heterozygosity within populations.
The results indicate that clonal reproduction may act as an enhancer of genetic drift by reducing effective size of local
populations ofV. rotundifolia. 相似文献
104.
The existence of parentally imprinted gene expression in the somatic tissues of mammals and plants can be explained by a theory of intragenomic genetic conflict, which is a logical extension of classical parent-offspring conflict theory. This theory unites conceptually the phenomena of autosomal imprinting and X-chromosome inactivation. We argue that recent experimental studies of X-chromosome inactivation and andro-genetic development address previously published predictions of the conflict theory, and we discuss possible explanations for the occurrence of random X-inactivation in the somatic tissues of eutherians. © 1995 Wiley-Liss, Inc. 相似文献
105.
畜禽遗传资源系统保存的理论与模拟实验研究──I.畜禽遗传资源系统保存的理论分析 总被引:1,自引:1,他引:0
本文提出了畜禽遗传资源系统保存的概念、基本思想及其群体遗传结构变化的数学模型。该理论是将一定时空内某一畜种所拥有的全部基因作为保存对象,既将活体保存作为基本方法,又将其有机地与高新生物技术结合在一起;既追求系统地保存控制畜种特性的基因资源,又可达到保存地方品种的目的。在假定无世代重叠,群体内存在选择、突变、迁移,且考虑漂变效应的情况下,本文所构建的两个数学模型可分别用来描述一个座位上多个主基因频率或数量性状群体均数的动态变化。 相似文献
106.
一个恢复力受单基因控制的水稻CMS育性回复突变体 总被引:3,自引:0,他引:3
利用 ̄(60)Co-γ射线对具有印尼水田谷细胞质的籼稻细胞质雄性不育系Ⅱ-32A干种子进行诱变处理,获得了一育性回复突变体T24。育性基因未纯合的突变体分离出可育株和完全不育株,比例为3∶1;其与Ⅱ-32A和珍汕97A测交,F1代分离出1∶1的可育株和不育株。育性稳定株系与Ⅱ-32A和珍汕97A杂交,F2分离成3∶1的可育株和不育株。表明其育性回复是由一对基因显性突变所致。这一突变体对不育系的育性恢复机制不同于明恢63、20964等恢复系,后者表现为两对显性恢复基因作用。未观察到T24与亲本Ⅱ-32A除育性以外的其他性状的差异,因而两者构成育性恢复基因的近等基因系。本文还对不育系育性回复类型和T24的理论意义与育种价值进行了讨论。 相似文献
107.
Geneticdivergenceanalysiswasconductedbasedonperformanceof12quantitativetraitsin85sunflowerinbredlines,tostudyitseffectivenessinpredictingyieldheterosisofthe72hybridsfromthem.Resultsshowedthatlinearregressionmodelfittherelationshipbetweenheterosisofseedoilcontentandgeneticdistance,andquadraticregressionequationtherelationshipbetweengrainyieldheterosisandgeneticdistance,whichcanbeusedinpredictingheterosisfromtheparentperformances.Clusteranalysiswaseffectivetocertainextent,butitsutilizationshouldbelimited.Grainyieldandoilcontentcanbeimprovedsimutaneouslyaccordingtotherelationsbetweengeneticdivergenceandtheheterosisofthesetwotraits. 相似文献
108.
利用PCR方法对单纯疱疹病毒Ⅱ型糖蛋白D(HSV-2gD)基因进行了修饰,在其5'端删去约500bp的非编码区,仅保留ATG上游7个bp。将修饰后的HSV-2gD基因插入到带有痘苗病毒天坛株TK基因区段的痘苗表达质粒pJSA1175,置于痘苗病毒P7.5k早/晚期启动子控制下。将此重组质粒用脂质体Lipofectin方法转染已受野型TK ̄+痘苗病毒天坛株感染的TK ̄-143细胞,通过同源重组机制和标志基因LacZ产物的蓝斑显色作用,以及BudR试剂对TK表型的选择压力,筛选出整合有HSV-2gD基因的重组痘苗病毒。Southem杂交表明,HSV-2gD基因已正确地插入痘苗病毒TK基因区内;间接免疫荧光检测显示,HSV-2gD蛋白已得到有效表达,且主要分布于细胞膜。重组病毒免疫家兔可产生明显的抗HSV-2gD中和抗体。用重组病毒免疫小鼠,3周后可使94%(17/18)的小鼠对抗HSV-2的致死量攻击,表明重组病毒具有明显的免疫保护作用。 相似文献
109.
双列杂交法已广泛地应用于性状的遗传研究,但均局限于无非等位基因互作的性状.本文在前人研究的基础上提出了应用双列杂交F_1代加倍单倍体检验双基因互作模型适合性的方法,并对遗传参数的估算作了进一步的研究. 相似文献
110.
家鸡和原鸡的线粒体DNA多态性比较 总被引:17,自引:0,他引:17
本文运用11种限制性内切酶分析了家鸡(茶花鸡、尼西鸡、大理漾濞黄鸡)和原鸡共10只个体的线粒体DNA限制性片段长度多态性(RFLP),平均每个个检测到的片段为40条左右。但仅发现3种变异的限制性片制性格局,即StuI-B,Eca-I-b和RI-B.其中StuI-B和ScaI-B为首次报道,而且均为原鸡所物有,EcoRI-B则为大理漾濞黄鸡所特有。茶花鸡和尼西鸡拥有完全相同的限制性格局。经过计算,原 相似文献