俄罗斯蜜蜂保种群的遗传标识码:基因组微卫星标记谱图

俄罗斯蜜蜂是欧洲人大约在十九世纪中期向俄罗斯符拉迪沃斯托克及其周边海冰边疆(即俄罗斯远东地区)移居时带入的西方蜜蜂;欧洲黑蜂在欧洲向东方向的地理分布极限地域是位于俄罗斯西部平原(欧洲部分)与东部高原、山地(亚洲部分)之间的乌拉尔山脉,即俄罗斯中部地区。为了初步揭示俄罗斯蜜蜂与欧洲黑蜂之间的遗传关系,本研究通过聚合酶链反应体外扩增基因组微卫星标记的方法,对俄罗斯远东地区采样点的俄罗斯蜜蜂(俄罗斯当地人称之为俄罗斯远东黑蜂)和俄罗斯中部地区采样点的欧洲黑蜂(俄罗斯当地人称之为俄罗斯中部蜜蜂)进行了比对分析。聚丙烯酰胺凝胶电泳的结果显示,绝大多数蜜蜂样本在11个基因组微卫星位点均出现等位序列条带,两种蜜蜂样本的等位序列条带数构成了各自特有的基因组微卫星DNA等位序列标记谱图。这提示,俄罗斯蜜蜂样本的基因组微卫星DNA等位序列标记谱图作为俄罗斯蜜蜂保种群的遗传标识码,很可能具有特异性(相对于欧洲黑蜂样本的基因组微卫星DNA等位序列标记谱图)。

Genetic Analysis and Linkage Mapping in a Resource Pig Population Using Microsatellite Markers

The use of markers and linkage map construction are important for QTL mapping in pigs. In this article, the genetic characteristics were studied and the linkage map was constructed in a pig resource population including 214 individuals by typing 39 microsatellite marker loci on Sus scrofa chromosomes, SSC4, SSC6, SSC7, SSC8, and SSC13. Results indicated that the average allele number, the average observed beterozygosity （Ho）, and the average polymorphism information content （PIC） in F1 and F2 population were 3.2, 0.528, 0.463 and 3.2, 0.496, 0.447, respectively. In the pig resource population, the average informative meiosis （IM） was 217.4 （44-316）, and the average linkage map length between the two sexes on the five chromosomes were 172.3 cM （SSC4）, 168.7 cM （SSC6）, 191.7 cM （SSC7）, 197.3 cM （SSC8）, and 178.3 cM （SSC13）. The orders of microsatellite marker loci in the linkage maps were identical to, but the length was greater than, those of USDA-MARC reference map. The results of this research showed the genetic relationship and genetic characteristics of the microsatellite markers in the pig resource family population, and the linkage map could be used to for QTL mapping in the subsequent study.

Genetic Diversity Analysis and Fingerprint Construction of Major Mango Cultivars in China

[Objective] The genetic diversity of major mango cultivars in China was analyzed by using SSR markers, and their fingerprints were constructed so as to provide theoretical basis for germplasm innovation and breeding of mango. [Method] With 115 pairs of SSR primers, genetic diversity analysis and cluster analysis were performed for 30 mango cultivars, among which the genetic relationships were analyzed. [Result] Total 64 pairs of polymorphic primers were screened out from the 115 pairs of primers, and total 343 bands were amplified from the 30 cultivars with 73.2% of polymorphic bands. On average, 3.9 allelic loci were detected for each pair of primers with genetic diversity index of 0.5, Shannon＇s diversity index of 1.00 and polymorphism information content of 0.49, indicating higher genetic diversity. The cluster analysis showed that the 30 major cultivars could be classified into four categories. The first category included 14 cultivars; the second category included 11 cultivars, most of which were introduced from abroad; the third category included 4 cultivars, Le., Miansan, Parayinda, Baiyu and Hongxiangya： the fourth category included only one cultivar Maqiesu.By using 7 pairs of SSR markers, i.e., M42, M49, M54, M55, M96, M99 and M103, digital fingerprints were constructed for the 30 mango cultivars. [Conclusion] The 30 mango cultivars present more complex genomic genetics and abundant genetic information, and they have higher genetic diversity.

Indication of Genetic Linkage Map for Sunflower(Helianthus annuus L.) by SSR Markers

In order to investigate the possibility and efficiency of exogenous gene spread in nature and potential ecological risk of transgenic rice, as well as analyze the effect of exogenous Bt gene insertion on ecological fitness of transgenic rice plants, a experiment was carried out with three insect-resistant Bt transgenic rice cultivars Bt63, R1 and R2 and one conventional rice line 11-838 as experimental materials, the insect-resistant transgenic and non-transgenic rice plants were inter- cropped pair-wisely under high and low insect-infestation pressures, and the vegeta- tive growth, seed-setting and the resistance to rice stem borers were compared be- tween transgenic and non-transgenic lines. According to the experimental results, both the tiller number and fresh weight of Bt transgenic rice plants under low insect- infestation pressure showed no significant differences compared with the control, but the plant height, spike length and spike weight were all lower than those of non- transgenic rice plant, and Bt63 and R2 were significantly different compared with the control. On the contrary, under high insect-infestation pressure, the tiller number, spike length and spike weight of three Bt transgenic rice cultivars were significantly higher than those of the control, while the plant height showed different fitness ef- fects among various transgenic rice cultivars, which might be related to the charac- teristics of the receptive cultivars. The individual filled grain number and 1 000-grain weight of three transgenic rice cultivars showed no significant difference compared with the control under two different insect-infestation pressures, suggesting that the effect of exogenous Bt gene on seed setting was not significant. Under insect-infes- tation pressure, the resistance of three Bt transgenic rice cultivars against rice stem borer was significantly superior to non-transgenic rice, indicating that the effect of exogenous Bt gene on insect resistance of receptive plants was distinctly. Further- more, experimental results showed that the fitness cost of Bt transgenic rice was rel- atively low, which implied that exogenous Bt gene in insect-resistant transgenic rice might escape under certain environmental conditions, but this risk was very low.

QTL Mapping for Weight Traits on Chromosome 3 in Liangshan Semi-fine Wool Sheep

By using Windows QTL Cartographer v2.5 software, QTLs for five weight traits of Liangshan semi-fine wool sheep were detected based on nine microsatellite markers on chromosome 3. According to the results, ① in reference family 191, the QTL affecting weaning weight was detected at 110.01 cM with an additive effect of 6.860, explaining 29.3% of the phenotypic variance; ② in reference family 190, the QTL affecting weaning daily gain was detected at 227.41 cM with an additive effect of 0.013, explaining 1.7% of the phenotypic variance; ③there was no QTL affect- ing birth weight, 1.5-year weight and 2.5-year weight of Liangshan semi-fine wool sheep.

A genetic linkage map of marine shrimp Penaeus (Fenneropenaeus) chinensis based on AFLP, SSR, and RAPD markers

The Chinese shrimp Penaeus (Fenneropaeneus) chinensis is an important species in marine fishery and aquaculture in China. A female Chinese shrimp Penaeus (Fenneropaeneus) chinensis was captured from west coast of the Korean peninsula and mated with a "Yellow Sea No. 1" male to produce the first filial generation (F1) 100 F2 full-sib progeny from brother-sister crosses between F1 families was used for the mapping study. A genetic linkage map of the Chinese shrimp was constructed, based on 354 markers, including 300 amplified fragment length polymorphism (AFLP) markers, 42 microsatellite (SSR) markers, and 12 randomly amplified polymorphism (RAPD) markers. Forty-seven linkage groups (LGs) were identified. The total map length was 4 580.5 cM, with an average spacing of 11.3 cM, covering 75.8% of the estimated genome size. The construction of this genetic linkage map was part of a genetic breeding program. This linkage map will contribute to the discovery of genes and quantitative trait loci (QTLs) in Chinese shrimp.

Molecular Identification and Cultivar Fingerprints of Prunus persica (L.) Batsch Germplasms

[Objective] The aim was to study the molecular identification and cultivar fingerprints of Prunus persica (L.) Batsch germplasms.[Method] Sixty peach genotypes,representing China common local cultivars and European samples were screened by microsatellites (simple sequence repeats,SSRs) and Inter-Simple Sequence Repeat (ISSR) markers.[Result] 26 reproducible bands were amplified by Nine SSR primers,and 24 of which were polymorphic; 236 bands were amplified by 30 ISSR primers,and 113 of which were polymorphic.31 genotypes were discriminated with 1-3 distinct polymorphic bands generated from the primers ISSR and SSR.Seven cultivar-specific ISSR fragments and two SSR unique alleles obtained from this study were available to be converted into Sequence Characterized Amplified Region (SCAR) markers.The genetic similarity coefficient (GS) estimated from these molecular data averaged were 0.939 (ranged from 0.856 to 0.983) for ISSR and 0.646 (ranged from 0.240 to 1.000) for SSR,respectively.The combined grouping association indicated that most local Chinese peach cultivars and exotic accessions were clustered together.This could be related to the mode of introduction and maintenance of the peach cultivars involving limited foundation germplasm,exchange of cultivars between plantations,and periodic development of new recombinant cultivars following sexual reproduction.[Conclusion] The results obtained in this work would help to improve the conservation,molecular identification and management of peach germplasm in breeding.

A Microsatellite Genetic Linkage Map of Black Rockfish(Sebastes schlegeli)

Ovoviviparous black rockfish(Sebastes schlegeli) is an important marine fish species for aquaculture and fisheries in China. Genetic information of this species is scarce because of the lack of microsatellite markers. In this study, a large number of microsatellite markers of black rockfish were isolated by constructing microsatellite-enriched libraries. Female- and male-specific genetic linkage maps were constructed using 435 microsatellite markers genotyped in a full-sib family of the fish species. The female linkage map contained 140 microsatellite markers, in which 23 linkage groups had a total genetic length of 1334.1 c M and average inter-marker space of 13.3 c M. The male linkage map contained 156 microsatellite markers, in which 25 linkage groups had a total genetic length of 1359.6 c M and average inter-marker distance of 12.4 c M. The genome coverage of the female and male linkage maps was 68.6% and 69.3%, respectively. The female-to-male ratio of the recombination rate was approximately 1.07:1 in adjacent microsatellite markers. This paper presents the first genetic linkage map of microsatellites in black rockfish. The collection of polymorphic markers and sex-specific linkage maps of black rockfish could be useful for further investigations on parental assignment, population genetics, quantitative trait loci mapping, and marker-assisted selection in related breeding programs.