粗山羊草间杂交及抗条锈病新基因遗传分析和分子标记

粗山羊草是小麦野生近缘属种,是D基因组的供体,蕴含大量的抗病资源,是进行小麦遗传改良的重要资源.选取条锈病免疫材料Y206和高度感病材料Y121杂交后代进行遗传分析和抗病性鉴定.从粗山羊草[Aegilops tauschii(Coss.)Schmal]Y206中鉴定出1个显性抗小麦条锈病基因,暂定名为YrY206.并利用SSR分子标记对该抗病基因标记定位,应用分离群体分组法(Bulked segregant analysis,BSA)筛选到Wmc11a、Xgwm71c、Xgwm161和xgwm183标记,与该基因之间的遗传距离分别为4.0 cM、3.3 cM、1.5 cM和9.3 cM.根据连锁标记所在小麦微卫星图谱的位置,YrY206被定位在3DS染色体上,可能是一个新的抗小麦条锈病基因.图2表2参22     

镉对小麦根尖细胞的遗传损伤效应

为了研究重金属镉对小麦是否产生细胞毒性和遗传毒性效应,采用不同浓度镉对小麦根尖处理24、48、72 h,统计有丝分裂指数、微核率及染色体畸变率.结果表明,1 μmol·L-1镉可提高小麦根尖细胞有丝分裂指数,但随镉处理浓度的提高和处理时间的延长,有丝分裂指数逐步下降;4个时期相比,镉对有丝分裂前期和中期的影响较小.微核率随着镉处理浓度的提高而增加,但浓度过高时,微核率随着镉处理时间的延长反而有所降低.此外,染色体畸变率也逐步上升,且随镉浓度的增加和处理时间的延长,其作用效果急剧加大,呈现明显的剂量-效应、时间-效应关系.说明镉可引起小麦根尖细胞有丝分裂抑制和染色体损伤,具有明显的遗传毒性.     

青稞B-hordein基因表达载体构建及对小麦的遗传转化

利用从具有特殊B-hordein亚基组成的青藏高原青稞材料中克隆的B-hordein编码基因(SL60)和小麦高分子量谷蛋白亚基胚乳特异表达启动子PGlu1Dx构建了真核表达载体pCB2007-SL60.通过农杆菌介导对普通小麦进行遗传转化,共获得227株再生植株,经PCR鉴定和转化片段测序验证,最终获得5株阳性植株.研究为进一步分析B-hordein基因在小麦背景中的遗传和表达,以及对小麦加工特性的影响奠定了基础.图5表2参21     

不同DNA分子标记在云杉属植物遗传多样性研究中的应用

综述国内外近20a来在DNA分子水平上埘云杉属植物遗传多样性的研究进展，简述用RELP、RAPD、SCAR、AFLP、SSR、EST、STS以及SNP标记对于云杉属核DNA、线粒体DNA、叶绿体DNA和rDNA多态性进行的研究以及在云杉属品种鉴定、遗传作图、遗传多样性、进化及分子生态学研究中的应用，参85     

海拔及细胞质背景对水稻测交群体遗传分化的影响

温度是导致水稻（Oryza sativa L.）遗传分化的一个重要环境因素,而海拔是导致环境温度差异的一个重要的地理因素。水稻的雄配子即花粉粒的活性极易受环境温度的影响。研究用来自云南2 670 m海拔的粳稻地方品种小麻谷与具籼稻细胞质背景的籼粳交后代品系南34正反交产生的F1,然后将其分布种植在海拔高低相差达1 800 m的4个海拔点并与育性稳定的1个滇Ⅰ型细胞质不育系杂交产生了8个测交群体,用SSR标记检测发现海拔因素和细胞质背景都对测交群体的遗传分化产生了影响。结果表明：同一海拔产生的正反交群体（合系42A//小麻谷/南34）间的遗传多样性具有比较明显的差异。正交组合F1（小麻谷×南34）在1 860 m的海拔产生的群体的遗传多样性最高,在1 600 m的海拔产生的群体的遗传多样性最低。在反交组合F1产生的群体中,群体的遗传多样性随产生群体海拔（400 m海拔除外）的升高而降低。利用Nei′s遗传距离评价各群体间的遗传分化,正反交组合F1产生测交群体间的遗传分化均高于同一组合在不同海拔下产生的测交群体之间的遗传分化,同一组合在4个海拔产生的测交群体间的遗传分化总体趋势是随海拔差异的增加而增大。研究证实了环境温度差异及细胞质背景导致F1产生的雄配子基因型发生选择,导致雄配子基因型的遗传比例偏离孟德尔规律,影响其后代群体的遗传多样性和遗传分化。     

氟化氢熏气和喷施防护剂对小麦应激乙烯产生的影响

应用开顶式熏气装置,研究了ＨＦ熏气对小麦叶片细胞质膜透性和ＭＤＡ（丙二醛）含量的影响,以及ＨＦ熏气和氟污染防护剂抗坏血酸（Ｖｃ）对小麦体内应激乙烯产生的影响,结果表明,小麦接触ＨＦ气体时细胞质膜透性增大,ＭＤＡ含量升高,体内乙烯量增加,增加幅度与ＨＦ的作用剂量有关,喷施防护剂Ｖｃ也引起乙烯量增加,Ｖｃ和ＨＦ在诱导乙烯生成上有协同效应,推测乙烯的增生可能是植物对环境变化的防御性反应。     

3种微量元素对小麦生长发育及产量和品质的影响研究进展

综述了锌、铁、硒3种微量元素对小麦生长发育、产量及品质影响的研究进展,对造成小麦中微量元素含量差异的原因进行了深入分析.土壤中微量元素的植物有效性、元素间的相互影响、小麦品种的基因型差异、栽培管理措施等因素都会导致小麦籽粒中微量元素含量变化.研究基因型差异并筛选富含微量元素的功能性营养小麦品种成为今后小麦遗传育种的一项重要工作.     

五氯苯酚的生态毒性效应及其遗传毒性

为评价环境内分泌干扰物——五氯苯酚对土壤生态系统动植物的生态毒性效应,检测了五氯苯酚对8种作物种子的萌发和根伸长的抑制作用以及对赤子爱胜蚓(Eisenia fetida)的急性毒性作用;并运用小麦根尖细胞微核实验和赤子爱胜蚓体细胞核的彗星实验,检测了五氯苯酚的遗传毒性效应.结果表明,五氯苯酚在一定浓度范围内对作物种子的...     

四川省部分豆科植物根瘤菌的遗传多样性

从四川省豆科植物鸡眼草属、合欢属、豇豆属、葛属、金合欢、杭子梢分离获得了103株根瘤菌,采用AFLP、BOXAIR-PCR研究了这些菌株的遗传多样性.结果表明,分离自四川省豆科植物6个属的根瘤菌存在明显的遗传多样性,AFLP分析中,全部供试菌株的相似性为21%,全部供试菌株可分为26个AFLP遗传群;BOXAIR-PCR聚类分析结果表明,103个菌株分在70%相似性水平处,供试菌株被分为18个BOX遗传群.除部分菌株外,多数根瘤菌按宿主类型聚群,同一宿主而地理来源不同的根瘤菌分布于不同的遗传群,表明宿主和地理环境对根瘤菌具有深刻影响.图3表1参9     

土霉素对小麦毒性效应的品种间差异

为了研究土霉素对小麦毒性效应的品种间差异,收集了63个小麦品种,根据土霉素对小麦种根影响的试验结果,从中筛选出对土霉素耐性相差最大的两个小麦品种,探讨了土霉素对这两个小麦品种叶片叶绿素含量的影响.结果表明:1)小麦对土霉素的耐性存在品种间差异,在供试的63个小麦品种中,核优1号对土霉素最敏感,而烟农21对土霉素最不敏感,二者的EC50值分别为1.25和54.21mg·L-1;2)土霉素处理能够显著降低小麦叶片叶绿素a、叶绿素b以及总叶绿素的含量,其中对土霉素敏感品种核优1号的抑制显著高于不敏感品种烟农21;3)就同一品种而言,土霉素胁迫条件下,叶片叶绿素a的降低程度明显高于叶绿素b,叶片叶绿素a/b的比值显著降低.土霉素对敏感品种核优1号叶绿素a/b比值的影响显著弱于不敏感品种烟农21.     

磷素营养对春小麦抗旱性的影响

在盆栽条件下研究了磷素营养与春小麦抗旱性之间的关系结果表明：施用磷肥由于对根系生长的促进,明显改善了春小麦的水分供应状况,同时,增加了束缚水含量,提高了膜稳定性和叶片耐脱水能力,且由于提高了渗透调节能力,维持了生长过程的正常进行,明显提高了春小麦的生物量和籽粒产量．虽然气孔导度的增大增加了作物的耗水,但由于施磷对失水的促进小于对产量的促进作用,因而明显提高了春小麦的水分利用效率综合分析表明：施磷可明显改善春小麦的抗旱性．     

土壤中腐殖酸对外源农用稀土生物可利用性的影响

采用盆栽实验方法,研究了腐殖酸对稀土元素在土壤-植物体系中的迁移、富集和生物可利用性的影响,结果表明,在试验土壤红壤中,稀土元素主要富集在小麦根部,加入低浓度的腐殖酸后,促进了小麦对稀土元素的吸收：而高浓度的腐殖酸则抑制小麦对稀土元素的吸收,腐殖酸浓度过高时,对小麦生长产生毒害作用,同时发现,小麦中叶绿素含量与小麦中稀土含量存在相关关系。     

汞胁迫对小麦幼苗抗氧化酶活性的影响

通过营养液培养实验,研究了小麦幼苗在遭受汞胁迫后,地上部及根系抗氧化酶活性的变化．试验表明:小麦幼苗受到汞胁迫后,地上部及根系的超氧化物歧化酶(ＳＯＤ)的活性均显著增加,过氧化氢酶(ＣＡＴ) 的活性也比对照有所增强,但不如ＳＯＤ酶变化迅速,表明ＳＯＤ酶活性是小麦幼苗遭受汞胁迫时比较敏感的生物标记物．但是,小麦幼苗地上部及根系的丙二醛(ＭＤＡ) 含量仍均比对照显著升高,表明小麦幼苗的膜系统受到了一定程度的破坏．试验同时还反映出,汞胁迫对小麦幼苗根系的影响强于对地上部的影响．     

The Role of Hybrid Vigor in the Replacement of Pecos Pupfish by Its Hybrids with Sheepshead Minnow

Abstract:  Many species are jeopardized by hybridization and genetic introgression with closely related species. Unfortunately, the mechanisms that promote or retard gene flow between divergent populations are little studied and poorly understood. Like many imperiled fish species, the Pecos pupfish ( Cyprinodon pecosensis ) is threatened with replacement by its hybrids with a close congener. We examined swimming performance and growth rate of hybrid pupfish to determine the role of hybrid vigor in the genetic homogenization of C. pecosensis by its hybrids with sheepshead minnow ( C. variegatus ). The F1 hybrids, backcross hybrids, and purebred C. variegatus displayed greater swimming endurance than purebred C. pecosensis . In addition, F1 hybrids and C. variegatus grew more rapidly than C. pecosensis . The ecological superiority of hybrids probably promoted their rapid spread through and beyond the historic range of C. pecosensis . These results indicate that eradication of hybrids and restoration of C. pecosensis to its native range is unlikely. Extinction of unique species via genetic homogenization can result from human activities that increase gene flow between historically fragmented populations; conservation managers must weigh the potential for such a catastrophe against the presumed benefits of increased interpopulation gene flow. This example illustrates how, after hybridization has occurred, conflict may arise between formerly complementary conservation goals.     

用幼苗法指示污泥和土壤中重金属的植物有效性

利用小麦幼苗与黑麦幼苗研究了污泥和土壤中重金属的植物有效性,并对二者进行了比较。结果表明, 在两种污灌区土壤、四种污泥以及一种污泥施用于两种清洁土壤中,黑麦和小麦测定的Cd,Pb,Cu,Zn,Ni五种重金属有效性的顺序,以及有效性大小的数量级上是一致的;除了在污泥中,二者的茎Pb,Ni及根Zn相关不显著,以及在Lou土中施用污泥后,两种植物各部位相关不好外,在污泥及污泥施于赤红壤各处理中黑麦与小麦相关均匀为极显著。上述结果表明,应用小麦幼苗可以替代黑麦幼苗指标土壤中重金属的植物有效性,但同时也应考虑不同植物间的差异。     

Synthesis of Li-doped bismuth oxide nanoplates,Co nanoparticles modification,and good photocatalytic activity toward organic pollutants

Abstract

Lithium-doped bismuth oxide nanoplates with the thickness of 50–150?nm and tetragonal bismuth oxide, monoclinic lithium bismuthate phases have been synthesized via a simple hydrothermal process using lithium acetate and sodium bismuthate as the raw materials. Cobalt nanoparticles modified lithium-doped bismuth oxide nanoplates hybrids were obtained by an in situ photo-deposition route. The cobalt nanoparticles-modified nanoplates hybrids display significantly enhanced photocatalytic activity toward gentian violet compared with the nanoplates. Gentian violet solution can be totally degraded by the hybrids within 60?min under ultraviolet–visible light irradiation. The superior photocatalytic activity of the cobalt nanoparticles modified nanoplates hybrids originates from the superior charge transfer capacity and the energy band structure of the hybrids. The excellent photocatalytic performance makes the cobalt nanoparticles modified nanoplates hybrids a promising candidate as the photocatalyst for wastewater treatment.     

Genetic Identification of Spotted Owls, Barred Owls, and Their Hybrids: Legal Implications of Hybrid Identity

Abstract:  Recent population expansion of Barred Owls (  Strix varia ) into western North America has led to concern that they may compete with and further harm the Northern Spotted Owl (  S. occidentalis caurina ), which is already listed as threatened under the U.S. Endangered Species Act (ESA). Because they hybridize, there is a legal need under the ESA for forensic identification of both species and their hybrids. We used mitochondrial control-region DNA and amplified fragment-length polymorphism (AFLP) analyses to assess maternal and biparental gene flow in this hybridization process. Mitochondrial DNA sequences (524 base pairs) indicated large divergence between Barred and Spotted Owls (13.9%). Further, the species formed two distinct clades with no signs of previous introgression. Fourteen diagnostic AFLP bands also indicated extensive divergence between the species, including markers differentiating them. Principal coordinate analyses and assignment tests clearly supported this differentiation. We found that hybrids had unique genetic combinations, including AFLP markers from both parental species, and identified known hybrids as well as potential hybrids with unclear taxonomic status. Our analyses corroborated the findings of extensive field studies that most hybrids genetically sampled resulted from crosses between female Barred Owls and male Spotted Owls. These genetic markers make it possible to clearly identify these species as well as hybrids and can now be used for research, conservation, and law enforcement. Several legal avenues may facilitate future conservation of Spotted Owls and other ESA-listed species that hybridize, including the ESA similarity-of-appearance clause (section 4[e]) and the Migratory Bird Treaty Act. The Migratory Bird Treaty Act appears to be the most useful route at this time.     

Genetically informed captive breeding of hybrids of an extinct species of Galapagos tortoise

Hybridization poses a major challenge for species conservation because it threatens both genetic integrity and adaptive potential. Yet, hybridization can occasionally offer unprecedented opportunity for species recovery if the genome of an extinct taxon is present among living hybrids such that selective breeding could recapture it. We explored the design elements for establishing a captive-breeding program for Galapagos tortoises (Chelonoidis spp.) built around individuals with admixed ancestry involving an extinct species. The target individuals were hybrids between the extinct species from Floreana Island, C. niger, and an extant species, C. becki, which were recently found in the endemic range of C. becki, from Wolf Volcano on Isabela Island. We combined genotypic data from 35 tortoises with high ancestry from C. niger with forward-in-time simulations to explore captive breeding strategies that maximized overall genetic diversity and ancestry from C. niger while accommodating resource constraints, species biology, and the urgency to return tortoises to Floreana Island for facilitating ecosystem restoration. Overall genetic diversity was maximized when in the simulation tortoises were organized in relatively small breeding groups. Substantial amounts of the C. niger genome were captured despite limited resources available for selectively breeding tortoises in captivity. Genetic diversity was maximized when captive-bred offspring were released to the wild rather than being used as additional breeders. Our results provide genetic-based and practical guidance on the inclusion of hybrids with genomic representation from extinct taxa into species restoration programs and informs the ongoing debate on the value of hybrids in biodiversity conservation.     

小麦籽实中蛋白质-Cd,Pb结合形态及其稳定性

在体外消化酶模拟条件下,对小麦籽实中Ｃｄ,Ｐｂ蛋白质结合体的稳定性进行了研究．结果表明:小麦籽实中存在的表观分子量为５４．５×１０３和５．５×１０３的蛋白质－Ｃｄ,Ｐｂ结合体,在体外胃蛋白酶和胰蛋白酶消化后,蛋白质结构发生变化．特别是分子量为５４．５×１０３的Ｃｄ,Ｐｂ－蛋白质结合体不稳定,容易被胰蛋白酶分解,变成分子量为５．５×１０３的稳定的Ｃｄ,Ｐｂ－蛋白质结合体或更小的多肽．     

土壤施加垃圾堆肥的允许负荷量

利用城市生活垃圾堆肥进行生菜、青菜、小麦三种作物的盆栽试验，并根据作物中金属元素Ｃｄ、Ｃｕ、Ｃｒ、Ｐｂ、Ａｓ的含量，探讨了三种土壤施加垃圾堆肥的效果及允许负荷量，结果表明：土壤消纳垃圾肥的潜力很大，但不同土壤类型对垃圾肥的负荷量有明显差异。