适于玉米杂交种纯度鉴定的SSR核心引物的确定

为了确定一套适于玉米杂交种纯度鉴定的核心SSR引物,利用10个SSR引物对420份已知玉米(Zea mays)杂交种进行DNA指纹分析。综合考虑多态性和杂合率两个指标,确定bnlg161和bnlg1450为玉米杂交种纯度鉴定的首选核心引物,利用这两个引物进行筛选,412个品种(占98%)能够找到具有杂合带型的鉴定引物,确定5个引物bnlg439、bnlg125、umc2105、umc1705和bnlg1792为玉米杂交种纯度鉴定的备选核心引物。研究了纯度鉴定所用特异引物的选择,将特异引物分为两类:第一类是利用单个引物检测,某品种的基因型仅出现1次,将该引物作为该品种在特定品种范围内的特异引物,在420个品种中,累计29个品种具有第一类特异引物,其中umc1705和bnlg1450作为特异引物的次数最多,均为8个,phi072和phi065没有作为特异引物;第二类是根据引物基因频率表,将预测基因型频率低于2.40E-03(即1/420)的基因型作为特异基因型,除了phi072和bnlg161外,其它8个引物均可能成为具有特定基因型品种的第二类特异引物。利用推荐的7个纯度鉴定用核心引物可进一步筛选每个玉米杂交种的双亲互补型引物,建立了已知玉米杂交种的纯度鉴定DNA指纹图谱。     

SSR分子标记鉴定玉米杂交种纯度的研究及应用综述

从玉米基因组DNA提取、引物的筛选、PCR反应体系优化、部分推广玉米品种纯度鉴定引物信息等方面综述了SSR分子标记在玉米杂交种纯度鉴定方面的研究及应用。     

应用SSR分子标记鉴定甜瓜杂交种纯度

以甜瓜(Cucumis meio L.)杂交一代品种东方蜜1号、东方蜜2号及其亲本和7个同母异父的杂交组合为实验材料,利用SSR标记对甜瓜杂交种纯度进行了快速鉴定.结果表明,应用筛选得到的12对东方蜜1号SSR特异性引物及3对东方蜜2号SSR特异性引物可快速准确地鉴定出杂交种中混杂的母本自交系种子,且鉴定结果与大田鉴定结果基本一致.利用SSR引物组合MS48 MS60和MS4 MS20分别可以把东方蜜1号、东方蜜2号与其各自亲本及同母异父的7个杂交组合完全区分开.应用SSR引物组合的方法不仅能够有效地检测出混杂在杂交种中的母本自交系种子,也能检测出其它不明来源花粉所导致的生物性混杂,提高了甜瓜杂交种纯度检测结果的准确度.     

甘蓝型油菜秦优10号杂交种纯度鉴定的SSR引物筛选

为了建立一套快速可靠的油菜杂交种纯度的鉴定方法,本文以秦优10号及其亲本、杂种ZZH2为试验材料,对前人开发的2对SSR引物（7号引物,9号引物）进行了再次筛选。结果显示,7号引物不但能很好地区别出混入杂交种中的亲本,还能将杂交种子的同母异父组合种子从杂交种中分离出来,能够用于鉴别秦优10号杂交种子的真伪;9号引物能区分出杂交种和母本,但不能区分开杂交种和父本。同时,本试验利用人工制成的秦优10号杂交种标准样（纯度为100%）以及7份大田鉴定不同纯度梯度的杂交种子对7号引物鉴定结果的准确性进行了验证,鉴定结果与大田鉴定结果基本一致。本文结果将为鉴定秦优10号杂交种纯度提供更准确的技术资料。     

应用SSR分子标记鉴定甜瓜杂交种纯度的研究

摘要：本文以两个甜瓜杂交一代品种“东方蜜1号”、“东方蜜2号”及其亲本和若干同母异父的杂交组合为实验材料,利用SSR标记对甜瓜杂交种纯度快速鉴定的方法进行了研究。结果表明：SSR标记在甜瓜杂交种及亲本间具有较高的多态性,利用筛选出的SSR引物能够快速准确的区分出杂交种中混杂的母本自交系种子,对3批杂交种纯度的快速鉴定结果与大田鉴定结果一致。但是,利用筛选出的单一SSR引物不能完全区分开杂交种和与其同母异父的供试杂交组合,而用不同的引物组合能够将杂交种与大多数供试杂交组合区分开,但对于个别与杂交种遗传背景十分接近的杂交组合仍不能区分开。     

云南杂交玉米SSR标记核心引物的筛选及多样性分析

为降低合成引物成本,加快杂交玉米品种鉴定进程,筛选适用于云南玉米杂交种SSR标记鉴定的核心引物.本研究用玉米SSR标记鉴定规程中推荐的40对SSR引物对12个杂交玉米品种DNA进行扩增,筛选出多态性高、扩增效果好、稳定性好的20对引物,推荐其作为云南玉米杂交种特异性鉴定的核心 引物.并用筛选的核心引物对云南220个杂交...     

近红外光谱技术定量分析玉米杂交种纯度

摘要：应用近红外光谱分析技术结合定量偏最小二乘法对先玉335杂交种纯度进行了定量分析,将不同年份和来源的杂交种和其母本种子粉碎后混合,按0.5%的梯度获得纯度80～100%范围内的样本123份（每梯度按年份和来源设置3个重复）后采集光谱。结果表明：采用散射校正预处理,4 000～8 000 cm-1光谱范围时建模效果较适宜（建模集∶检验集=3∶1）,建模集内部交叉决定系数达96.06%,校正标准差1.18%,平均相对误差1.03%;检验集的决定系数均达到95.02%,校正标准差1.28%,平均相对误差1.12%。采用不同比例的建模样品和检验样品时,建模集和检验集的决定系数均在94%以上,证明了近红外光谱技术定量测定玉米杂交种纯度的可行性以及所建模型的稳定性。     

DHPLC技术鉴定玉米杂交种真实性及纯度

变性高效液相色谱(denaturing high-performance liquid chromatography, DHPLC)技术可用于检测玉米(Zea mays)品种的单核苷酸多态性(single nucleotide polymorphism,SNP)和插入/缺失(Insertion/Deletion,InDel)的多态性遗传标记.为验证DHPLC技术在玉米分子标记分析中应用的可行性和可靠性,本研究基于公共数据库中的玉米基因信息,筛选2条DNA序列作为目标分析片段,利用DHPLC技术平台对10份玉米杂交种及其亲本进行检测.2条目标分析片段的DHPLC分析结果显示,玉米杂交种产生的DHPLC谱图具有多态性,基于Amp Ⅰ片段,10份玉米杂交种产生3类DHPLC图谱,基于AmpⅡ片段,可产生7种图谱类型,不同类型的DHPLC图谱在峰的数量和峰的保留时间上存在明显差异.测序结果显示DHPLC谱型与基因型一一对应,即使只有一个碱基差异的两种基因型样本,也将产生不同峰型特征的DHPLC图谱.10份玉米杂交种中,除3份杂交种的两条目标片段的DHPLC峰型均一致以外,其余7份杂交种相互之间至少存在一个DHPLC谱型的差异从而可以获得有效区分.实验结果也显示所有杂交种均与其亲本混合样本的DHPLC图谱一致.利用该特征,可以认为通过比对玉米杂交种子和育种亲本混合样本的DHPLC图谱峰型,实现对杂交种子真实性和纯度的鉴定.DHPLC分辨率高、快速、操作简单、安全等优点,将是杂交玉米种子真伪和纯度快速鉴定的有效手段.     

应用RAPD技术快速进行西瓜杂交种纯度鉴定的研究

本研究建立了简单,快速提取西瓜半粒种子ＤＮＡ方法,并简化了适合西瓜的ＲＡＰＤ－ＰＣＲ分析程序。对“无籽京欣一号”西瓜种子纯度开展了分子鉴定研究,找到了一个随机引物ＯＰＰ－０１,用它扩增的ＯＰＰ－０１／５６４只在父本与杂交种上出现,母本不出现,本文还针对ＲＡＰＤ技术在西瓜杂交种纯度鉴定上实际应用的可能性进行了讨论。     

利用InDel标记鉴定大白菜杂交种豫新四号种子纯度

InDel(insertion deletion length polymorphism)是基于基因组测序的第三代分子标记,已在一些作物的遗传研究中得到运用。本研究以大白菜(Brassica rapa L.ssp.pekinensis)杂交种豫新四号及其亲本和8个同父异母、同母异父的杂交组合为实验材料,利用InDel标记和引物组合方法对大白菜杂交种纯度进行了快速鉴定。结果表明,从104对InDel引物中筛选到3对(BrID10667、BrID90107和BrID90147)在豫新四号及其亲本间表现多态性且带型清晰稳定,这3对InDel引物对两批杂交种进行检测,第一批材料所测纯度全部为98.00%。第二批材料所测纯度分别为:100.00%、98.30%和99.10%,与田间鉴定结果 100.00%的纯度高度一致,吻合度达99.13%。利用筛选出来的3对特异性InDel引物分别对豫新四号及其4个同母异父和4个同父异母的杂交组合进行InDel分析,没有一对引物能够将豫新四号以及其4个同母异父和4个同父异母杂交组合同时区分开来。然而在这3对引物中引物BrID90107和BrID10667退火温度相同均为55℃,但是各自扩增产物位置不同,应用引物组合BrID90107和BrID10667就可以将豫新四号与其亲本及4个同父异母和4个同母异父的杂交组合完全区分开。实验结果显示,InDel标记可以快速、准确、经济地鉴定大白菜杂交种纯度,同时证明,利用引物组合的方法可以更有效地鉴别大白菜杂交种子中的生物学混杂,表明InDel标记技术在大白菜杂交种纯度室内快速检测中具有广泛的应用前景。     

Earthworm primers for DNA-based gut content analysis and their cross-reactivity in a multi-species system

Specific primers can be used in polymerase chain reactions (PCR) to amplify prey DNA from the gut content of generalist predators at high specificity and sensitivity. A prerequisite for applying this approach to field studies, however, is to confirm that primers are actually targeting specific prey species or prey groups and do not produce false positive results by amplifying DNA either from predator species or from the wide range of potential alternative prey found under natural conditions. Here, we report on a new group-specific primer pair for earthworms designed from cytochrome oxidase c subunit 1 (COI) sequences of 11 earthworm species found in Central Europe that can be used to detect consumption of earthworms by invertebrate predators. Besides inter-specific also considerable intra-specific variation was found for COI sequences among most of the earthworm species. We, therefore, combined a universal forward primer with an earthworm-specific reverse primer which amplified a 523 bp product from all 11 species tested. Earthworm DNA amplification was also successful in the presence of excess DNA of a predator species. The primer pair was tested against 82 non-target invertebrate species commonly found in the same habitats, including potential prey for generalist predators and predators themselves. The earthworm primer was highly specific: only one of the non-target species showed a product of similar length as the earthworms, whereas PCR with 12 non-target species produced amplicons whose length differed from that of earthworms. We conclude that the new primer will be a useful tool to investigate the role earthworms play as a food resource in soil food-webs. Moreover, we suggest that future studies utilizing DNA-based approaches for prey detection should select non-target species for cross-reactivity tests according to their abundance and importance rather than choosing representatives of taxonomic units; this will help validate the results achieved using species- or group-specific primers and guarantee their meaningful ecological interpretation.     

Effect of seaweed sap as foliar spray on growth and yield of hybrid maize

Seaweeds are important marine renewable resources. Use of seaweeds as fertilizers has allowed for substitution in place of conventional synthetic fertilizers. This study was conducted to examine the effect of seaweed liquid extract (SLE) on growth, yield, and nutrient uptake by hybrid maize. The experiments were conducted in ZARS, Vishweshwaraiah Canal farm, Mandya (Karnataka, India) during the rabi season of 2011–2013 to study the effect of foliar applications of Kappaphycus alvarezii (K sap) and Gracilaria edulis (G sap) sap on growth and yield response of hybrid maize “NAH 1137”. Three foliar sprays of both saps were applied at the rate of 2.5, 5.0, 7.5, 10, and 15.0% (v/v) along with water spray as a control at different stages of the crop. It was found that grain yield increased significantly by 18.54% and 26.04% for plants receiving 10% concentrations of both K. alvarezii and G. edulis sap respectively, over control. The increase in yield was attributed to increase in the number of rows in cob, cob length, and 100 grain weight. This investigation concludes that application of both the saps at 10% increased the nutrient uptake, grain, and stover yield over control.     

Establishment of a core collection for maize germplasm preserved in Chinese National Genebank using geographic distribution and characterization data

Since the 1980s, a large collection of maize has been preserved in the China National Genebank. To facilitate the evaluation and utilization of these valuable germplasm resources, a core collection was established. The collection was firstly divided into two groups, i.e. the landraces and inbred lines. The percentage of the original collection to be included in the core was given as 7% based on a previous study of sampling strategies in maize. Each group was sequentially stratified based on administrative provinces or regions and kernel types, and a clustering method was applied in further stratification. A logarithmic strategy was used to determine the number of entries in the core at each step. The process resulted in the maize core comprising 951 landraces and 242 inbred lines. Shannon-Weaver diversity index and means were used to validate the core. The core can be used effectively in further in-depth research and maize improvement.     

Screening and application of SSR markers related to seed storability traits in maize (Zea mays L.)

Genetic Resources and Crop Evolution - In this study, a maize F2:3 population and a population of RILs were constructed from a cross between Dong156 and Dong237, and SSR markers were then used to...     

Structural identification of dehydrotriferulic and dehydrotetraferulic acids isolated from insoluble maize bran fiber

Two new dehydrotriferulic acids and two dehydrotetraferulic acids were isolated from saponified maize bran insoluble fiber using size exclusion chromatography on Bio-Beads S-X3 followed by Sephadex LH-20 chromatography and semipreparative phenyl-hexyl reversed phase high-performance liquid chromatography. On the basis of UV spectroscopy, mass spectrometry, and one- and two-dimensional NMR experiments, the structures were identified as 8-5(noncyclic)/5-5-dehydrotriferulic acid, 8-8(tetrahydrofuran)/5-5-dehydrotriferulic acid, and 4-O-8/5-5/8-O-4-dehydrotetraferulic acid. The second tetramer was tentatively identified as 4-O-8/5-5/8-5(noncyclic)-dehydrotetraferulic acid. Compounds containing an 8-5(noncyclic)-coupled dimeric unit probably do not exist in planta but are formed from their phenylcoumaran precursors containing an 8-5(cyclic)-coupled dimeric unit during saponification. The presented dehydrotrimers are the first dehydrotriferulates that do not contain an 8-O-4-coupled dimeric unit. The ferulate dehydrotetramers that are reported for the first time are presumed, like the dimers and trimers, to cross-link polysaccharides in the plant. Because both tetramers contain a 5-5/8-O-4-dehydrotriferulate moiety, the predominant dehydrotrimer in maize bran, it is not possible to deduce whether tetramers are formed by coupling of a fourth unit to a preformed dehydrotriferulate or by 5-5-coupling of preformed 8-O-4- and 8-5-dehydrodiferulates. Nevertheless, such compounds document expanded roles for ferulates in cross-linking polysaccharides in plant cell walls.     

玉米/大豆和玉米/甘薯模式下玉米干物质积累与分配差异及氮肥的调控效应

【目的】西南山地玉米区是我国第三大玉米主产区,但单产比全国低近750 kg/hm2。由于该区特殊的气候条件,玉米以多熟间套种植为主,如何利用多熟种植中各作物的间套优势和茬口特性,寻求提高本区玉米产量的新途径,是农业科技工作者研究的热点。本文在四川的两个玉米主产区,通过四年的田间小区试验,对比研究了西南玉米主要的两种套作模式—玉米/大豆和玉米/甘薯模式下玉米干物质积累分配、转运差异及施氮量对其的调控效应,以探讨种植模式和氮肥管理的增产效应。【方法】2008年设置玉米/大豆和玉米/甘薯两个套种田间试验,分析比较两种模式玉米干物质积累、分配和转运的差异;2009 2010年在前一年的基础上分带轮作,即玉米分别种在大豆或甘薯茬上,分析套作和轮作效应对玉米干物质积累的影响;2011年,在前三年的基础上,采用小区套微区的方式,研究两种模式下不同施氮水平(N0、N90、N180、N270、N360)对玉米干物质积累和转运的调控。【结果】1)在玉米/大豆模式下,玉米干物质积累量从蜡熟期开始显著高于玉米/甘薯模式,茎鞘输出率也显著高于玉米/甘薯模式,最终产量增加2.4%3.2%,但差异未达显著水平;2)分带轮作后,从拔节期开始,玉米/大豆模式下玉米干物质积累量就显著高于玉米/甘薯模式,到成熟期两套种模式下玉米单株干物质积累两试验点平均相差达26.8 g,茎秆向籽粒的输出率和贡献率也显著高于玉米/甘薯模式,收获指数玉米/大豆模式平均较玉米/甘薯模式提高3.9%,最终玉米/大豆模式下玉米产量较玉米/甘薯模式增幅加大,两年两个试验点分别增加了7.4%和14.4%;3)氮肥对两种模式下玉米干物质积累分配和产量的调控效应显著,玉米/大豆模式下,玉米以施氮180kg/hm2处理,而玉米/甘薯模式下270 kg/hm2处理与同一模式下其他氮素水平相比,增加了光合产物的积累,提高了干物质增长速率,延长了灌浆持续天数,有利于茎鞘和叶片的干物质向籽粒转移,显著提高收获指数,进而提高玉米的增产潜能,玉米/大豆模式下低氮处理(0 180 kg/hm2)对玉米的增产效应比较明显,在高施氮水平(270360 kg/hm2)下两种模式间玉米产量差异不显著。【结论】西南丘陵旱地应选择玉米与大豆套作,采用分带轮作种植方式,既有利于提高玉米产量,又可避免大豆的连作障碍;且氮肥管理措施应因种植模式不同而有所差异,在中高等肥力条件下,与大豆套作玉米施氮180 kg/hm2,与甘薯套作施氮应提高至270 kg/hm2。     

低磷胁迫下磷高效玉米单交种的形态生理特性

以齐319耐低磷突变体为亲本组配的杂交组合SD-1、SD-2为供试材料,采用溶液培养方法研究了它们对磷的吸收、转运及植株体内磷的利用效率,进而确定在低磷胁迫下其对根系形态学和生理生化机制的适应性反应。结果表明,磷胁迫下(-P)与对照(SD-1-CK、SD-2-CK)相比SD-1、SD-2有较强的磷吸收能力和利用效率;SD-1、SD-2的根系干重、总根长、根总表面积、平均根尖数均明显增加,而平均直径减小;在与磷吸收效率有关的生理指标上,SD-1、SD-2具有更大的根总吸收面积、活跃吸收面积以及在磷吸收动力学上表现出较大的Imax和较低的Km、Cmin。因此认为,SD-1、SD-2对磷具有高的吸收效率是由于根系生长旺盛,根系吸收面积大、根系活力强和对磷亲和力高所致。     

土壤容重对玉米光合特性的影响及调控研究

以耕地棕壤为试验材料,采用盆栽方法,研究不同土壤容重对玉米光合指标(光合速率、气孔导度、胞间二氧化碳浓度)及叶绿素(a、b)的影响,并进一步研究了施用不同有机肥量及模拟不同耕作深度对玉米光合指标的调控效果。结果表明:不同容重处理之间对玉米叶绿素含量的影响拔节期前差异不显著,拔节期后达极显著差异(p<0.01),叶绿素含量在研究的生育期内始终增长。光合速率与容重、胞间二氧化碳浓度呈负相关,与气孔导度呈正相关。高容重土壤有机质调节至40～50 g kg-1即可以获得比较理想的效果;低容重的土壤有机质在研究含量范围内效果始终显著增长,有机质含量在15 g kg-1左右制约玉米生长,有机质含量应至少调节至3%以上。耕层厚度增加能提高所测定生理指标,但耕层厚度处理对叶绿素、光合指标影响不显著,当耕层厚度调节至30～40 cm时,各项指标增加基本达到限值,再增加耕层厚度作用不再明显。