干细胞技术在地方猪种质资源保护中的应用前景

我国是养猪大国,拥有全球1/3猪种质资源。但近年来,我国地方品种猪养殖量急剧减少,部分品种几近灭绝,地方猪种遗传资源多样性遭受严重破坏,优质基因不断流失。如何有效保护和保存这些优良种质资源是非常紧迫和关键的问题。目前猪种质资源保护包括原位保存、精液和胚胎冷冻保存、DNA文库保种和体细胞冷冻保存等,但都存在一定局限性。干细胞是一类可以自我更新并具有分化潜能的细胞群体,它不仅能分化成不同类型的细胞,还可以通过分裂维持自身群体稳定。在小鼠和猪等动物上,利用干细胞已成功获得健康后代。最近,以干细胞研究为引领的种质资源保护新浪潮正在兴起,干细胞技术将成为我国地方猪种质资源保护的新手段。     

中国野生稻资源考察、鉴定和保存概况

本综述了我国野生稻种质资源的考察收集、农艺性状鉴定、编目、繁种、入库保存等情况。到目前为止,我国收集了野生稻种资源近万份,编目7324份,种子入国家种质库长期保存5599份,种茎进国家野生稻圃长期保存8933份,显示出我国野生稻资源丰富的遗传多样性,并得到较完善的保存。介绍了鉴定选出的一批具有优良性状的种质资源。作还提出加强野生稻资源保护和研究的6点建议。     

超低温保存植物种质资源的新途径——小滴玻璃化法

超低温保存是一种安全、有效的种质资源保存途径,可长期保存种质资源。小滴玻璃化法是在滴冻法和玻璃化法上基础上发展起来的用于植物种质资源保存的新技术。本文综述了该方法的技术概念、主要优点、基本程序、应用前景及国内外研究现状。     

植物种质资源超低温保存现状及其研究进展

本文根据联合国粮农组织2010年发布的世界各国的《第二份世界粮食和农业植物遗传资源现状报告以及有关国际会议和相关文献资料,从超低温保存材料类型、基本程序、方法技术、理论基础、影响因素、保存费用、保存策略和保存现状、实际应用等方面综述了全球植物种质资源超低温保存现状及其研究进展,展望了植物种质资源超低温保存技术的应用前景,旨在加强非正常型种子植物种质资源的安全长期保存。文章最后分析了我国存在的差距,提出了今后努力方向和发展的建议。     

中国作物种质资源安全保存理论与实践

我国是作物种质资源大国,目前已经收集保存了340种作物,保存资源总量达50万份,如何确保安全保存是种质资源管理的首要课题。自"九五"以来,系统地开展了作物种质资源安全保存理论与技术的研究,揭示了种质活力丧失存在关键节点及其生物学机制;明确了发芽率低于关键节点后进行更新,会导致群体遗传完整性降低;提出了种质安全保存寿命的概念,以及延长安全保存寿命的关键因素。研发了种质活力监测预警、繁殖更新与离体保存等关键技术,制定了种质资源入库圃保存、监测预警、繁殖更新、离体保存和设施建设等技术规程,创建了中国作物种质资源安全保存技术体系。该体系应用于全国作物种质资源的保存实践,最大程度延长种质安全保存寿命,并监测预警出需更新的种质,避免因活力和遗传完整性丧失而导致种质资源得而复失,为实现我国作物种质资源长久安全保存提供了有力保障。     

中国甘薯种质资源研究现状及发展战略

中国保存的甘薯种质资源约2000份,绝大部分进行了抗性鉴定评价及营养成分含量测定。甘薯种质资源的保存方式有田间种质圃和试管苗库。作为种质利用的资源材料有地方品种、引进品种、育成品种(系)、突变体和近缘野生种等。根据我国甘薯种质资源研究现状,本提出了未来研究重点,包括调整资源收集重点、建立完整的资源保存体系、深入开展鉴定评价、建立核心种质库、进行种质创新等。     

香石竹种质离体保存研究进展

香石竹是世界四大切花之一,具有重要的观赏价值。其种质资源主要依靠田间种质圃和离体库进行保存。离体保存包括试管苗保存和超低温保存,这两种方法作为田间种质圃保存的补充可以分别对种质资源进行短中期和长期保存。本文对香石竹离体保存的相关研究进行了概括总结,旨在为香石竹种质资源的保存提供参考。     

甜菜种质资源遗传多样性研究与利用

通过多年对中国甜菜种质资源搜集、整理、繁种、鉴定及编目入库等方面进行科技攻关研究,弄清了目前我国甜菜中期库保存种质资源源遗传多样性的丰富程度,根据对已经编目入国家种质长期库的1382份甜菜种质资源材料的主要经济性状鉴定试验结果,证实了我国甜菜种质资源的块根产量、含糖率和产糖量均以西北生态区最高,华北生态区次之,东北生态区最低,同时其变异幅度也比较大。由此表明我国甜菜不同生态区保存的甜菜种质资源材料具有相当高的异质性和丰富的遗传基础,这将有利于推动我国甜菜科研及育种事业的可持续发展。     

离体保存技术在无性繁殖蔬菜种质资源保存中的应用

概述了无性繁殖蔬菜种质资源的重要性及保存现状、离体保存技术及其国内外研究进展,着重介绍了我国无性繁殖蔬菜种质资源离体保存技术的研究进展和应用情况,展望了离体保存技术在无性繁殖蔬菜种质保存中的应用前景。     

我国苹果属资源现代分布调查初报

种质资源是农业生物资源的重要组成部分。我国是苹果属植物的起源演化中心之一,加强我国苹果种质资源调查与收集,可以丰富我国苹果资源保存的多样性。国家果树种质苹果圃于2005-2016年开展了我国西北、华北、西南、东北和华东苹果属植物集中分布地区的调查和收集,旨在进一步摸清家底,扩展我国苹果属种质资源的保存类型和数量,为保护利用及科学研究提供基础资料。调查结果表明:我国苹果属种质资源类型多样,分布广泛,新收集资源621份,西北、西南和东北地区的苹果野生种资源丰富,地方品种少量分布;华北地区以地方品种为主,野生种类型较少。目前野生资源集中分布面积逐年减少,由先前的大范围散落分布逐渐转变为小面积集中分布;地方品种面临的问题较多,砍伐频发,流失严重。以连续11年的苹果属种质资源调查为依据,提出苹果资源收集保存面临的问题,并提出建议。     

猪PRLR和RBP4基因多态性与产仔性能的关系

采用PCR-RFLP方法, 对莱芜黑猪、鲁莱黑猪、里岔黑猪、鲁烟白猪、新沂蒙黑猪5个山东地方/培育猪种和大约克夏、长白、杜洛克3个引进猪种共8个猪种323头繁殖母猪进行PRLR和RBP4基因的多态性检测, 并采用最小二乘法分析其对产仔数影响的遗传效应。结果表明: 两个基因位点在8个猪种的测定群体中均存在多态性, 但山东地方/培育猪种与引进猪种间在基因型频率上存在较大差异。PRLR和RBP4基因对产仔数性状有显著影响(P<0.05), AA均为优良基因型。对于PRLR基因, 山东地方/培育猪种内AA基因型母猪的总产仔数和活产仔数比BB基因型母猪平均多产1.03头和0.89头, 引进猪种中AA基因型母猪比BB基因型母猪平均多产分别为1.26头和1.11头。对于RBP4基因, 山东地方/培育猪种内AA基因型母猪的总产仔数和活产仔数比BB基因型母猪平均多产0.59头和0.51头, 引进猪种中AA基因型母猪比BB基因型母猪平均多产分别为0.72头和0.64头     

Genetic diversity of autochthonous pig breeds analyzed by microsatellite markers and mitochondrial DNA D-loop sequence polymorphism

The evaluation of the genetic structure of autochthonous pig breeds is very important for conservation of local pig breeds and preservation of diversity. In this study, 18 microsatellite loci were used to detect genetic relationship between autochthonous pig breeds [Black Slavonian (BS), Turopolje pig (TP), and Croatian wild boar] and to determine phylogenetic relationship among Croatian autochthonous pig breeds and certain Asian and European pigs using the mitochondrial DNA (mtDNA) D-loop sequence polymorphism. Relatively high degree of genetic variation was found between the observed populations. The analysis of mtDNA showed that haplotypes of the studied pig populations are different from the other European and Chinese haplotypes. BS pigs showed some similarities with Mangalitsa and Duroc breeds. The genetic distances of TP can be explained by high degree of inbreeding during the past century. Despite the European origin of Croatian pig breeds with some impact of Chinese breeds in the past, the results of present study show that genetic diversity is still pronounced within investigated breeds. Furthermore, the genetic diversity is even more pronounced between Croatian breeds and other European and Chinese pig breeds. Thus, conservation of Croatian pig breeds will contribute to overall genetic diversity preservation of pig breeds.     

The phylogeny of Chinese indigenous pig breeds inferred from microsatellite markers

A genetic study of 32 local Chinese, three foreign pig breeds [Duroc (DU), Landrace and Yorkshire], and two types of wild boar (Hainan and Dongbei wild boar) based on 34 microsatellite loci was carried out to clarify the phylogeny of Chinese indigenous pig breeds. The allele frequencies, effective numbers of alleles, and the average heterozygosity within populations were calculated. The results showed that the genetic variability of the Lingao pig was the largest, while the Jiaxing pig was the lowest. The greatest distance between domestic pigs was found between Shanggao and DU pig and the shortest was found between Wuzhishan and Lingao pig, respectively. A neighbour-joining tree constructed from Modified Cavalli-Sforza genetic distances divided Chinese pigs into two clusters; four subclusters were also identified. Our results only partly agree with the traditional types of classification and also provide a new relationship among Chinese local pig breeds. Our data also confirmed that Chinese pig breeds have a different origin from European/American breeds and can be utilized in programmes that aim to maintain Chinese indigenous pig breeds.     

Genetic Diversity of Yunnan Local Pig Breeds Inferred from Blood Protein Electrophoresis

Protein electrophoresis was used to examine theblood protein polymorphism in Yunnan local pig breeds,i.e., the Saba pig, Dahe pig, and Diannan small-ear pigbreeds. Of 38 genetic loci surveyed, 9 were found to be polymorphic. The percentage ofpolymorphic loci (P) varies from 0.1875 to 0.2121, andthe mean individual heterozygosity (H) varies from0.0712 to 0.1027 in three pig breeds. The resultsindicate that blood protein polymorphism in Yunnan pigbreeds is high. Yunnan local pig breeds have a wealth ofgenetic diversity at the level of blood proteins.     

西部地区主要猪种和野猪H-FABP基因分子标记

利用PCR-RFLP(Hinf I、Hae Ⅲ和Msp I 3种限制性内切酶)分子标记技术,检测了杜洛克猪、长白猪、大白猪、内江猪、荣昌猪、汉江黑猪、汉中白猪、八眉猪和野猪共计265头猪H-FABP基因5′-上游区和第二内含子区的遗传变异,并利用最小二乘模型分析了H-FABP基因对猪肌内脂肪含量的遗传效应。结果表明：（1）在Hinf I-RFLP位点上,上述品种和野猪均存在多态性,其中大白猪、八眉猪、汉江黑猪、汉中白猪和野猪表现为低度多态,杜洛克、长白猪、内江猪和荣昌猪为中度多态;除汉江黑猪（P<0.05）和野猪（P<0.01）外,其他猪种基因频率和基因型频率都处于Hardy-Weinderg平衡状态（P>0.05）;而在Hae Ⅲ-RFLP和Msp I-RFLP位点上,仅内江猪、荣昌猪、汉江黑猪和八眉猪为单态;（2）9种基因型对肌内脂肪（IMF）含量的影响,HH>Hh>hh,DD相似文献   

猪MyoG基因的PCR-RFLP多态性分析

以杜洛克、长白、大约克、南昌白、二花脸、梅山猪、玉山黑猪、乐平花猪、金华两头乌及上高两头乌等中外10个猪种共计561头猪为研究材料,采用3对引物（PCR1、PCR2、PCR3）分别扩增猪肌细胞生成素（MyoG）基因的不同区域,扩增产物经限制性核酸内切酶MspⅠ酶切后发现：（1）在PCR1 MspⅠ-RFLP位点上,外来品种杜洛克、长白、大约克及培育品种南昌白中极大多数个体表现为AA型,个别为BB型;而6个中国地方猪种除乐平花猪外均以BB型居多。（2）在PCR2 MspⅠ-RFLP位点上,6个中国地方猪种除一头玉山黑猪表现为MN型外,其余均为MM型;而外来品种以NN型占大多数,培育品种南昌白更趋向于外来品种。（3）在PCR3 MspⅠ-RFLP位点上,所有猪种均可得到扩增产物,但无MspⅠ酶切位点。（4）在梅山猪及与其亲缘关系较近的二花脸猪中,没有发现Soumillion等(1997)报道的梅山猪特异性MspⅠ多态性酶切位点。     

猪前列腺素内过氧化物酶2(PTGS2)基因的遗传变异及其与繁殖性状相关性研究

前列腺素内过氧化物酶2是花生四烯酸合成前列腺素的限速酶,在包括排卵、受精、着床、分娩等一系列生殖过程中起着重要作用,因而编码该酶的基因是影响繁殖性状的重要候选基因。通过PCR—RFLP分析前列腺索内过氧化物酶2基因在15个中外不同繁殖性能猪种中的遗传变异,结果表明,不同类型中国地方猪种和外来商业猪种往此摹因位点上存在丰富的多态性,繁殖性能相埘较好的江海型、华北型和华中型猪种中A等位基因表现为优势等位基因,卡方检验显示其基因频率分布与西方商业猪种及繁殖性能较低的高原型藏猪和华南型猪种差异均极为显著（P〈0．001）。利用二花脸x杜洛克资源家系F2群体分析该基因与繁殖性状的相关性,在180头F2代母猪群体中,未能进一步证实该基凶位点对总产仔数、产活仔数和死胎数3个繁殖性状存在显著影响（P〉0．05）,但携带优势等位基因4的个体趋向于拥有较高的总产仔数、产活仔数和偏低的死胎数,鉴于该基因的重要作用,基于全基因序列的SNP扫描和大样本群体的相关性分析仍很有必要。     

Estimating the frequency of Asian cytochrome B haplotypes in standard European and local Spanish pig breeds

Mitochondrial DNA has been widely used to perform phylogenetic studies in different animal species. In pigs, genetic variability at the cytochrome B gene and the D-loop region has been used as a tool to dissect the genetic relationships between different breeds and populations. In this work, we analysed four SNP at the cytochrome B gene to infer the Asian (A1 and A2 haplotypes) or European (E1 and E2 haplotypes) origins of several European standard and local pig breeds. We found a mixture of Asian and European haplotypes in the Canarian Black pig (E1, A1 and A2), German Piétrain (E1, A1 and A2), Belgian Piétrain (E1, A1), Large White (E1 and A1) and Landrace (E1 and A1) breeds. In contrast, the Iberian (Guadyerbas, Ervideira, Caldeira, Campanario, Puebla and Torbiscal strains) and the Majorcan Black pig breeds only displayed the E1 haplotype. Our results show that the introgression of Chinese pig breeds affected most of the major European standard breeds, which harbour Asian haplotypes at diverse frequencies (15–56%). In contrast, isolated local Spanish breeds, such as the Iberian and Majorcan Black pig, only display European cytochrome B haplotypes, a feature that evidences that they were not crossed with other Chinese or European commercial populations. These findings illustrate how geographical confinement spared several local Spanish breeds from the extensive introgression event that took place during the 18th and 19th centuries in Europe.     

Genetic relationships among Vietnamese local pigs investigated using genome‐wide SNP markers

Vietnam is one of the most important countries for pig domestication, and a total of 26 local breeds have been reported. In the present study, genetic relationships among the various pig breeds were investigated using 90 samples collected from local pigs (15 breeds) in 15 distantly separated, distinct areas of the country and six samples from Landrace pigs in Hanoi as an out‐group of a common Western breed. All samples were genotyped using the Illumina Porcine SNP60 v2 Genotyping BeadChip. We used 15 160–15 217 SNPs that showed a high degree of polymorphism in the Vietnamese breeds for identifying genetic relationships among the Vietnamese breeds. Principal components analysis showed that most pigs indigenous to Vietnam formed clusters correlated with their original geographic locations. Some Vietnamese breeds formed a cluster that was genetically related to the Western breed Landrace, suggesting the possibility of crossbreeding. These findings will be useful for the conservation and management of Vietnamese local pig breeds.