龙眼SRAP反应体系的建立和优化

采用分步优化的方法对影响龙眼SRAP-PCR反应的模板DNA用量、Mg2+浓度、dNTP浓度、引物浓度、TagDNA聚合酶用量等进行了研究。确立了适合龙眼SRAP分析的反应体系,即体系总体积25μl,包含1×PCR Buffer ,Mg2+ 2.0mmol/L,dNTPs 0.5 mmol/L,引物0.3μmol/L,模板DNA 10ng, TaqDNA聚合酶1.5 U。结果表明,该体系能很好地满足龙眼基因组SRAP扩增的要求,SRAP标记应用于龙眼遗传研究是可行的。     

SRAP标记技术及其在蔬菜作物遗传多样性分析中的应用

SRAP标记技术是基于内含子、启动子3’端含AATT核心和开放阅读框的编码区富含GC的序列规律进行随机扩增而获得DNA多态性的。由于不同的生物个体其基因组的内含子、启动子与外显子的间隔长度不同,因而扩增出的DNA指纹图谱也就产生了多态性。SRAP标记是近年来发展起来的一种DNA多态性分子标记, 以其操作简便快速、成本低、可信度高、易于测序等特点倍受关注。在短短的几年时间内,此标记已在马铃薯、水稻、苹果、柑橘类果树、樱桃、梅子、油菜、大蒜、芹菜和棉花等植物中实验应用,显示出良好的应用效果。本文综述了SRAP标记技术原理特点和在蔬菜遗传多样性研究领域初步应用情况。     

桃SRAP体系的优化及与SSR在桃品种鉴定上的比较

为确立的桃10 μL SRAP反应体系,以桃部分品种为试材,采用均匀设计,对SRAP-PCR反应体系中Taq DNA聚合酶、模板DNA、dNTPs、Mg2+、引物5个组分的浓度进行优化.结果表明,桃10 μL的SRAP反应体系的最佳组分包括2 U Taq DNA聚合酶、50 ng模板DNA、0.6 mmol/L dNTPs、0.25 μmol/L引物、2.0 μL 10×PCR Buffer+Mg2+.利用所确立的体系对其他部分桃种质进行扩增的结果清晰可靠,多态性好.并且利用随机挑选的SRAP引物和SSR引物分别区分鉴定8种桃种质,发现SRAP用5对可以将桃种质区分开,而SSR用13对才区分开,说明在桃品种鉴定上SRAP比SSR更省时方便,而且操作相对简单,适用性强.     

A practical method for almond cultivar identification and parental analysis using simple sequence repeat markers

Early and accurate identification of almond [Prunus dulcis (Mill.) D.A. Webb] cultivars is critical to commercial growers and nurseries. Previously published simple sequence repeat loci were examined for their ability to distinguish commonly grown almond cultivars. Twelve highly polymorphic loci were selected for their ability to uniquely identify a set of 18 almond cultivars commonly grown in California, many of which are closely related. These markers also allow an accurate assessment of parent/progeny relationships among cultivars. This system can reliably identify at an early stage of development all major California almond cultivars in current production.     

Mapping QTLs for pre-harvest sprouting traits in the spring wheat cross ‘RL4452/AC Domain’

Pre-harvest sprouting (PHS) in spring wheat (Triticum aestivum L.) is a major downgrading factors for grain producers and can significantly reduce end-use quality. PHS resistance is a complex trait influenced by genotype, environment and plant morphological factors. A population of 185 doubled haploid (DH) lines from the spring wheat cross ‘RL4452/AC Domain’ were used as the mapping population to detect quantitative trait loci (QTLs) associated with three PHS traits, germination index (GI), sprouting index (SI) and falling number (FN). Six major QTLs linked with PHS traits were mapped on bread wheat chromosomes 3A, 3D, 4A (2 loci), 4B and 7D. ‘AC Domain’ alleles contributed to PHS resistance on 3A, 4A (locus-2) and 4B, and ‘RL4452’ alleles contributed resistance on 3D, 4A (locus-1) and 7D. QTLs detected on chromosome 4B controlling FN (QFN.crc-4B), GI (QGI.crc-4B) and SI (QSI.crc-4B) were coincident, and explained the largest amount of phenotypic variation in FN (22%), GI (67%) and SI (26%), respectively.     

Different quantitative trait loci for <Emphasis Type="Italic">Fusarium</Emphasis> resistance in wheat seedlings and adult stage in the Wuhan/Nyubai wheat population

Fusarium head blight (FHB), caused primarily by Fusarium graminearum (Schwabe), is an important wheat disease. In addition to head blight, F. graminearum also causes Fusarium seedling blight (FSB) and produces the mycotoxin deoxynivalenol (DON) in the grain. The objectives of this study were: (1) to compare the relationship between resistance of wheat lines to F. graminearum in the seedlings and spikes and (2) to determine whether the quantitative trait loci (QTL) for FSB were the same as QTLs for FHB resistance and DON level reported for the same population previously (Somers et al. 2003). There was no relationship between FSB infection and FHB index or DON content across the population. A single QTL on chromosome 5B that controlled FSB resistance was identified in the population; the marker WMC75 explained 13.8% of the phenotypic variation for FSB. This value implies that there may be other QTL with minor effects present, but they were not detected in the analysis. Such a QTL on chromosome 5B was not reported previously among the QTLs associated with FHB resistance and DON level in this population. However, because of recombination, some lines in the present study have Fusarium resistance for both seedling and head blight simultaneously. For example, DH line HC 450 had the highest level of resistance to FSB and FHB and was among the ten lines with lowest DON content. This line is a good candidate to be used as a parent for future crosses in breeding for Fusarium seedling resistance, together with breeding for head blight resistance. This approach may be effective in increasing overall plant resistance to Fusarium.     

小麦新品种济麦22抗白粉病基因的分子标记定位

为明确济麦22携带抗白粉病基因的染色体位置,利用济麦22与感病亲本中国春杂交,用小麦白粉菌(Blumeria graminis f. sp. tritici)强毒性小种E20对F₂抗、感分离群体和F_2:3家系进行抗病鉴定和遗传分析。结果表明,济麦22携带1个显性抗白粉病基因, 暂被命名为PmJM22。运用SSR和EST标记及分离群体分组分析法(bulked segregant analysis, BSA),将其定位在2BL染色体上,与4个SSR和5个EST标记间的连锁距离为7.7 cM (Xwmc149)到31.3 cM (Xbarc101)。通过分析2BL上其他抗白粉病基因的来源、染色体位置和抗性反应,认为PmJM22不同于Pm6、Pm26、Pm33和MlZec1。     

SRAP标记及其在林木遗传育种研究中的应用前景

相关序列多态性（SRAP）是近年发展起来一种基于PCR的新型DNA分子标记技术。该文介绍了SRAP的原理与方法,阐述了SRAP标记在植物遗传育种研究中的应用进展,展望了其在林木遗传育种上的应用前景。     

油松毛虫亚居群遗传结构的SSR分析

采用SSR分子标记技术对平泉县5个油松毛虫亚居群进行遗传多样性和遗传分化研究.结果显示:8对SSR引物对5个油松毛虫亚居群的扩增片段长度范围为78～430 bp,检测到的等位基因数为1～6个;种群总体水平多态位点比率P=87.50%,平均有效基因数A＝3.1250,平均期望杂合度He＝0.474 7,种群平均遗传距离为0.070 3～0.419 7;遗传分化度Fst=0.215 9,基因流Nm=0.908 1.由此可以得出在5个天然油松毛虫亚居群中,天然油松纯林居群内杂合度要比其他居群高;油松毛虫亚居群间已发生明显的遗传分化,基因交流较少,遗传漂变已经成为导致该物种种群分化的主要原因之一;油松毛虫亚居群遗传结构产生变异推测是由于常年化学防治和单一寄主植物造成的选择压力的影响.     

利用正交设计优化牡丹SRAP-PCR反应体系

利用正交设计L16(45对牡丹SRAP-PCR反应体系的五因素(Taq,Mg2+,模板DNA,dNTP,引物)在四个水平上进行优化试验,得出如下结论:各因素水平变化对PCR反应的影响从大到小依次为:Tap,引物,dNTPs,Mg2+,模板DNA;筛选出各反应因素的最佳水平,建立牡丹SRAP-PCR反应的最佳体系(25μL)为:Taq酶0.5 U,Mg2+2.0 mmol/L,模板DNA 50 ng,dNTF 0.2 mmol/L,引物0.30 μmol/L.这一优化系统的建立为今后利用SRAP标记技术对牡丹进行相关研究提供了帮助.