荒漠草原短花针茅表型性状对模拟绵羊采食的可塑性响应

为探讨短花针茅(Stipa breviflora)表型性状对模拟绵羊采食的可塑性响应,本研究设置对照(CK)、刈割(C)、模拟绵羊采食(CS)三个处理,测定短花针茅叶长、叶宽、单叶面积等11个表型性状,分析其不同处理下的差异性及可塑性。结果表明：与对照相比,刈割显著增加了短花针茅的比叶面积(P<0.05),模拟绵羊采食显著增加了短花针茅的单叶面积、比叶面积和株丛茎,显著降低了单叶质量、比叶质量和地上生物量(P <0.05);地上生物量、单叶质量和比叶质量是对刈割和模拟绵羊采食响应的敏感性状;单叶面积、平均叶长,株高及株丛径是对刈割和模拟绵羊采食响应的惰性性状;短花针茅地上生物量与分蘖数、单叶质量、比叶质量及株丛径呈极显著正相关(P<0.01),与株高呈显著正相关(P <0.05)。由此可见,短花针茅在模拟绵羊采食下产生的可塑性是其生存繁殖的重要反应机制之一。     

陆地棉遗传距离与杂种F_1、F_2产量及杂种优势的相关分析

 用两年田间试验数据和RAPD、ISSR与SSR分子标记,估算出36个陆地棉品种间的分子标记遗传距离为0.0701～0.4255,平均0.2844;表型遗传距离2.18～12.60,平均7.04;两者的相关系数为0.3350。双列杂交配置的28个F1和28个F2杂种群体,3个环境试验综合鉴定的F1与F2单株铃数、铃重、籽棉产量、衣分和皮棉产量间的相关系数分别为0.8035、0.8877、0.7135、0.9640和0.8956;F1、F2籽棉产量、皮棉产量的杂种优势平均数分别为13.62％、16.31％和7.90％、9.02％;F1、F2杂种间籽棉产量、皮棉产量杂种优势的相关系数分别为0.3689和0.3787。表型遗传距离、分子标记遗传距离与F1、F2产量性状表现及杂种优势之间的相关程度偏低,试验材料的选择也直接影响着它们之间的相关。     

营养生长期持续高温处理对玉米叶片转录组及生化指标的影响

以玉米杂交种郑单958和登海605为材料,通过转录组测序分析玉米营养生长期叶片受热胁迫后基因差异表达、基因功能富集和KEGG通路富集,使用微量法和HPLC法分析叶片中相关生化指标的变化。结果表明,高温胁迫会降低光合作用关键酶二磷酸核酮糖羧化酶(Rubisco)和三羧酸循环限速酶柠檬酸合酶(CS)的活力,升高丙二醛(MDA)、脱落酸(ABA)和赤霉素(GA₃)的含量,降低水杨酸(SA)的含量。与常温对照比,玉米营养生长期叶片受热胁迫后,两个品种4个比较组合累计检测到16 996个差异表达的基因,共同差异表达的基因有1 160个。光合作用、细胞代谢、叶绿体膜和质体膜等相关基因的表达会响应热胁迫。     

Evaluation of phenotypic markers in full genome sequences of avian influenza isolates from California

We evaluated phenotypic markers in full-genome sequences of avian influenza isolates to identify avian strains with increased potential for transmission and pathogenicity in mammals. Of 149 markers examined, 67 were positive in the consensus sequences from 206 avian isolates. Analysis of deep sequencing data in a subset of 24 isolates revealed that 344 subpopulations occurred at marker positions. Markers in subpopulations were significantly more likely to be negative (258/344) than positive (86/344), but nearly all of the marker-positive subpopulations (78/86) were associated with marker-negative consensus sequences. Our analysis revealed significant variation in important markers among avian isolates, and showed that consensus sequences do not fully convey an isolate's potential for increased transmissibility and pathogenicity in mammals.     

平贝母不同表现类型的总生物碱含量测定

目的确定平贝母不同表现类型是否在总生物碱含量上存在差别,为其育种做准备。方法超声法提取总生物碱,比色法测定含量。结果平贝母常见的绿茎绿叶品系的总生物碱含量为0.1703%,另2种品系——紫茎紫叶、紫茎绿叶分别为0.1807%、0.1830%。结论不同平贝母表现类型在总生物碱含量上没在显著差异,需要转向对其他性状进行分析。     

果树资源遗传多样性研究进展

遗传多样性研究对于维护物种稳定、有效保护和开发利用物种资源具有重要意义。本文从表型水平、染色体水平、等位酶水平、DNA水平介绍了果树资源多样性的研究现状,分析了不同研究方法的优缺点,指出只有将各种方法综合运用,才能更为全面科学地了解和掌握果树资源的遗传多样性。     

Evaluation of seedling and adult plant resistance in European wheat cultivars to Australian isolates of <Emphasis Type="Italic">Puccinia striiformis</Emphasis> f. sp. <Emphasis Type="Italic">tritici</Emphasis>

A set of 105 European wheat cultivars was assessed for seedling resistance and adult plant resistance (APR) to stripe (yellow) rust in greenhouse and field tests with selected Australian isolates of Puccinia striiformis f. sp. tritici (Pst). Twelve cultivars were susceptible to all pathotypes, and among the remainder, 11 designated seedling genes (Yr1, Yr3, Yr4, Yr6, Yr7, Yr9, Yr17, Yr27, Yr32, YrHVII and YrSP) and a range of unidentified seedling resistances were detected either singly or in combination. The identity of seedling resistance in 43 cultivars could not be determined with the available Pst pathotypes, and it is considered possible that at least some of these may carry uncharacterised seedling resistance genes. The gene Yr9 occurred with the highest frequency, present in 19 cultivars (18%), followed by Yr17, present in 10 cultivars (10%). Twenty four cultivars lacked seedling resistance that was effective against the pathotype used in field nurseries, and all but two of these displayed very high levels of APR. While the genetic identity of this APR is currently unknown, it is potentially a very useful source of resistance to Pst. Genetic studies are now needed to characterise this resistance to expedite its use in efforts to breed for resistance to stripe rust. Colin R. Wellings seconded from NSW Department of Primary Industries.     

水稻几个披垂叶突变体的表型研究及其遗传分析

随着水稻功能基因组学的发展,水稻突变体已成为研究相关基因功能与表达的良好实验材料。同时,水稻突变体还可以为当今水稻常规育种和分子育种提供新的种质资源。本文主要阐述了几个水稻披垂叶突变体在株型、株高、穗粒数、结实率、千粒重等方面的特征特性,并分析了它们在与正常植株杂交后F1、F2群体表现。研究表明,突变体与野生型正常植株杂交的F1代在经济学性状和生物学性状上均表现出超亲优势,而在F2群体中表现出有规则的分离,3个突变体中披垂叶性状均为隐性基因控制。在突变体材料MR304中,控制披垂性状的为2对隐性基因,其中1对为主效基因。在突变体材料MR168和MR312中,控制披垂性状的均为单隐性基因。     

267份青藏高原青稞种质材料的表型多样性分析

为了解青藏高原地区青稞种质材料的表型变异和遗传多样性,为育种亲本选配提供参考,对267份青稞种质的10个质量性状和9个数量性状,采用模糊数学的方法进行数量遗传和群体遗传学分析。结果表明:10个质量性状的Shannon-weaver多样性指数变幅为0.03~1.41,平均值为0.54,粒色和穗密度多样性较为丰富;9个数量性状在品种间的遗传差异均达到极显著水平,变异系数为2.84%~42.22%,多样性指数变幅为1.84~2.09,平均值为2.03,表型多样性十分丰富。9个数量性状的相关性分析显示,大多数性状间存在显著或极显著正相关或负相关关系。经主成分分析将相关变量转化为穗粒数因子、粒质量因子、分蘖和穗长因子、株高因子和籽粒体积质量因子等5个特征根,代表全部9个考察性状的89.05%的表型变异;聚类分析可将供试材料划分为4个类群,第Ⅰ类群多为青稞育成品系,主要为矮秆、高分蘖和密穗型材料。第Ⅱ类群主要是青稞地方品种,主要为中高秆、多分蘖和小穗型材料,其产量较低。第Ⅲ类群主要为高秆、分蘖力适中,中穗大粒型材料,产量适中。第Ⅳ类群主要为中高秆、低分蘖、大穗多粒型品种,产量较高。研究认为青藏高原青稞种质资源具有丰富的遗传多样性,尤其是地方品种可作为宝贵的遗传资源在今后的育种工作中加以利用。     

大丽花花型群体表型性状遗传多样性研究

本文以4个花型群体84个优良大丽花品种为试材,对大丽花7个表型性状的遗传多样性进行分析。结果表明：大丽花不同花型群体间在茎粗、叶长、叶宽、花径和花梗长性状上差异显著,在株高和叶柄长性状上差异不显著;巨大花型的在叶长、叶宽和叶柄长性状上分化明显,其它花型的叶分化不明显,4个花型群体间在花径和花梗长性状上分化均明显;花径在大花型中与株高、茎粗呈极显著负相关,小花型中与叶柄长显著正相关;4个花型群体内叶长与叶宽均呈极显著正相关,同一花型群体内,不同性状相关程度有所差异。