分子标记和辐射技术在小麦-长穗偃麦草抗赤霉病易位系创建中的应用

为了打破小麦抗赤霉病育种种质资源狭窄的局限,丰富抗赤霉病遗传材料,本研究通过对中国春-长穗偃麦草二体异代换系DS7E/7A与扬麦16杂交后代进行辐射诱变,以产生小麦-长穗偃麦草易位系选择群体,并结合赤霉病抗性鉴定和长穗偃麦草染色体特异分子标记辅助选择,最终获得了5个小麦-长穗偃麦草抗赤霉病易位单株,创建了一条有效获得小麦-长穗偃麦草抗赤霉病易位系的技术路线。小麦-长穗偃麦草抗赤霉病易位系的成功创建不仅为小麦抗赤霉病育种提供了重要的中间材料,也将为小麦近缘种的抗赤霉病研究和利用提供理论与实践参考。     

小麦-长穗偃麦草矮秆种质系的鉴定及遗传分析

矮源是进行小麦矮化育种的基础。本研究对2个小偃麦矮秆种质系31505-1和31505-2进行了分子鉴定和遗传分析。结果表明,31505-1和31505-2是2个不同的矮秆小偃麦易位系,31505-1中易位的偃麦草染色体片段位于2D染色体;对矮秆小偃麦种质系与不同株高材料杂交后代的株高和节间长度进行了分析,发现2个种质系的后代致矮率可达16%~23%,其株高的降低主要由节间长度的变化引起的,其中倒2节间与株高的变化相关性最高。本研究对拓宽小麦矮秆种质资源基础具有一定意义。     

小麦-中间偃麦草抗条锈病渗入系的分子细胞学鉴定

小麦品系CH5383是源于中间偃麦草(Thinopyrum intermedium)的兼抗多种小麦病害的新种质。为明确其抗性来源和外源DNA片段的渗入位置,采用基因组原位杂交(GISH)和荧光原位杂交(FISH)对CH5383进行分析,GISH分析未发现外源信号,FISH结果观察到CH5383的3BL染色体端部与对照小麦(Triticum aestivum)品种中国春相比有明显的重组信号,初步推断CH5383染色体3BL端部可能有中间偃麦草DNA片段插入。用135对PLUG(PCR-based landmark unique gene)标记对CH5383、中国春和多个近缘物种进行扩增分析,发现位于3B染色体长臂端部的引物TNAC1383,能在CH5383和中间偃麦草中扩增出大约1 300 bp的特异DNA产物。从而进一步证实,CH5383是一个小麦-中间偃麦草小片段渗入系,携带抗条锈病基因的外源中间偃麦草DNA渗入片段位于3B染色体端部0.81-1.00区段。CH5383可以作为优异的小麦抗病育种新种质加以利用。     

矮秆早熟小偃麦种质山农0057-2的选育与鉴定

利用普通小麦(Triticum aestivum)品种烟农15与中间偃麦草(Thinopyrum intermedium)杂交、回交和多代自交,从BC3F6中选育出一个矮秆、早熟新种质山农0057-2.综合应用形态学、细胞学、生物化学、分子生物学等方法对其进行鉴定.结果表明,山农0057-2平均株高64.2 cm,较烟农15降低14.6 cm;抽穗期和开花期均比烟农15提前4～5 d.其根尖染色体数目为2n=42,花粉母细胞减数分裂中期Ⅰ(PMC M Ⅰ)染色体构型为2n=0.24 Ⅰ+20.88 Ⅱ;它与烟农15的杂种F1在PMC M Ⅰ有80.49%的细胞形成21个二价体,未观察到多价体.高分子量麦谷蛋白亚基的SDS-PAGE鉴定结果表明,山农0057-2含有1条中间偃麦草的特异带;从202对SSR引物中筛选出2对引物(Xgwm234-5A/5BS和BARC172-7DL)能在山农0057-2中扩增出不同的中间偃麦草特异带,分别标记为Xgwm234300和BARC172400.山农0057-2是一个含有中间偃麦草染色体(片段)的种质材料,具有矮秆、早熟等优点,在小麦育种中具有重要的利用价值.     

小偃麦渗入系抗条锈性评价及细胞学鉴定

为将中间偃麦草的抗条锈病基因导入小麦,以八倍体小偃麦TAI7047为桥梁亲本,与普通小麦杂交、回交,结合细胞学鉴定选育抗条锈病小麦-异源渗入系;并通过人工接种在温室和田间病圃对育成的82份渗入系进行了连续2年的苗期、成株期抗病性鉴定筛选。筛选到38份免疫我国优势小种CYR32、CYR33和新小种v26;45份免疫CYR32、CYR33小种;51份免疫CYR32;48份免疫CYR33;52份免疫v26。且它们的抗性均来自中间偃麦草。对随机选取的3份抗病渗入系及其与中国春小麦的杂交F1进行了染色体计数和配对分析。结果表明,它们的染色体数目均为2n=42,且3个测试材料及其与中国春杂种F1的平均配对构型分别为2n=0.26I+20.79II+0.05III和2n=0.37I+20.68II+0.09III。说明小偃麦抗病渗入系具有与普通小麦相似的染色体结构和规则的配对构型,为小麦抗病育种提供了新抗源。     

利用甲基磺酸乙酯(EMS)诱导小麦-华山新麦草染色体易位的研究

小麦(Triticum aestivum)种质24-3-1是通过染色体工程手段获得的一个高抗条锈病的小麦-华山新麦草二体异附加系。为了提高其遗传稳定性,促进华山新麦草(Psathyrostachys huashanica)优异基因的有效利用,对24-3-1进行甲基磺酸乙酯(ethylmethylsulfone,EMS)化学处理来诱导易位系。本研究利用细胞学和基因组原位杂交(genomic in situ hybridization,GISH)对其M2进行鉴定和易位系的筛选,并分析了不同EMS浓度对小麦-华山新麦草染色体易位的诱导效应。结果显示,在930个M2单株中共检测出了61个含有小麦-华山新麦草易位染色体的植株,易位频率为6.56%。其中7个单株检测出含有1条易位染色体,5个单株检测出含有1条易位染色体+1条华山新麦草染色体,20个单株检测出含有2条易位染色体,3个单株检测出含有3条易位染色体,26个单株检测出含有4条易位染色体。根尖细胞学观察和基因组原位杂交证明,含有2条易位染色体的单株为小麦-华山新麦草易位系;含有4条易位染色体的单株为小麦-华山新麦草易位-易位附加系。1.0%EMS为诱导小麦-华山新麦草染色体易位的最适浓度。本研究不仅为小麦特殊遗传材料的建立提供了重要的基因资源,同时也为小麦育种提供了新的种质。     

小麦抗黄矮病遗传育种研究进展

黄矮病是小麦的一种主要病毒病,感染小麦后发展迅猛,造成小麦严重减产,成为一个世界性难题.本文论证了全球小麦抗黄矮病育种的重要性;阐明了目前已将外源抗黄矮病基因导入小麦,逐步培育出一系列抗病种质材料,为抗黄矮病育种奠定了良好基础;明确了几个重要的黄矮病抗源以及不同抗性基因具有一定的遗传差异;指出抗黄矮病育种的成就并提出未来的研究方向.     

辐照花粉对小麦与中间偃麦草杂交及其胚胎发育的影响

用γ射线辐照中间偃麦草散粉期的穗,用其花粉授予普通小麦“J-11”和“中国春”,研究不同剂量辐照花粉对普通小麦与中间偃麦草杂交结实率、杂交种子含胚率、杂种幼胚培养和杂种幼苗获得率的影响。结果表明,5~9Gy低剂量γ射线略提高了中国春×中间偃麦草的结实率,表现出低剂量辐射的刺激效应,但对J-11×中间偃麦草却未表现出刺激效应。所有剂量的辐射对杂种幼胚均有伤害作用,杂交种子含胚率、杂种幼胚成苗率随剂量增加而下降。30Gy处理时有12.9%~14.5%的杂种幼胚发育成了植株,但该剂量应用到小麦中难以获得后代。在50~100Gy高剂量γ射线处理杂交种子胚发育不良,通过幼胚培养未能得到植株。将花粉辐照技术与幼胚拯救技术、花药培养技术有效结合,可以快速获得突变体,提高诱变育种效率。     

小麦-顶芒山羊草2M染色体系的鉴定与评价

为了研究小麦-顶芒山羊草新种质材料的染色体组构成及开发其在育种中的利用价值,本研究利用分子标记和荧光原位杂交对小麦-顶芒山羊草杂交新种质进行鉴定,并通过小麦主要病害生理小种接种和农艺性状调查等方法对鉴定的材料进行综合评价。分子标记和原位杂交结果显示,所鉴定材料分别为小麦-顶芒山羊草2M附加系、2M(2D)代换系、2AS-2ML.2MS易位系和2DS-2ML.2MS易位系;抗病性鉴定结果表明,含2M染色体的材料均高抗小麦条锈病,其小麦亲本则高感条锈病,表明2M染色体上可能含有抗条锈病新基因;农艺性状调查分析结果表明,2M染色质导入小麦,可影响其小穗数、穗粒数和穗粒重等产量性状。因此,在创制和利用抗条锈病的小麦-顶芒山羊草2M染色体小片段易位系时,应加强对上述农艺性状的考察,并利用当前主栽品种进行回交改良。本研究鉴定出的抗条锈病小麦-顶芒山羊草2M染色体系丰富了小麦抗病基因库,为小麦育种提供了新抗源。     

利用小麦微卫星引物建立偃麦草Ee染色体组特异SSR标记

选用40对小麦SSR引物对17份偃麦草(Thinopyrum sp．)、2份小麦(Triticum aestivum)材料进行了PCR扩增分析，从中筛选到引物Xgwm325能在不同偃麦草材料中扩增出4条长度分别为1400、440、120和100bp的特异DNA片段，可以作为偃麦草种质的特异SSR标记。利用小麦-二倍体长穗偃麦草(Th.elongatum)异代换系和异附加系对引物Xgwm325进行了扩增鉴定，结果只有100bp左右的片段出现在长穗偃麦草所有E^e组染色体上，该片段可以作为E^e染色体组的特异SSR标记。     

抗大麦黄矮病小麦新品系选育及其RAPD分子验证

利用辐射与外源DNA花粉管导入技术相结合的方法 ,选出了抗大麦黄矮病(BYDV)的小麦新品系龙辐 97K1 0 99。经多年自然发病和两年接毒蚜鉴定 ,该品系不仅高产 ,而且抗大麦黄矮病。RAPD分子验证表明 ,在所用的 75个随机引物中只有OPF15 具有多态性。OPF15 的扩增产物在 880bp、650bp和 50 0bp处出现 3条供体与龙辐 97K1 0 99共有的特异谱带。可以认为这些谱带与大麦黄矮病抗性有关     

辐射外源DNA导入小麦诱变效果的研究——后代品系籽粒贮藏蛋白分析和大麦黄矮病抗性鉴定

通过花粉管通道法将受照射的中 5DNA(小偃麦异源 8倍体 ,抗大麦黄矮病 )导入到受体小麦新克旱 9,在D3～D5 代获得了稳定的 5 4个品系。对其籽粒醇溶蛋白和麦谷蛋白进行电泳出现 3种变异类型 :第 1种类型为新谱带的出现或原有谱带的丢失 ;第 2种类型为供体谱带的出现 ;第 3种类型为谱带强度 (深或浅 )发生变化。根据农艺性状和籽粒贮藏蛋白电泳结果 ,精选 2 0份进行毒蚜接种 ,鉴定大麦黄矮病抗性 ,其中有 7个品系中抗黄矮病 ;1个品系 (97K1 0 77)高抗黄矮病。可初步认为供体中 5的抗大麦黄矮病基因已转化成功     

Evaluation of Chinese Triticeae for resistance to Barley Yellow Dwarf Virus (BYDV)

Summary Barley Yellow Dwarf Virus (BYDV) is recognised as a major pathological constraint to cereal production in northern China and several widespread epidemics have been reported. The host range of BYDV includes not only cereals but many grasses. The indigenous Triticeae of northern China have likely been exposed to significant disease pressure from BYDV and therefore may be a potential source of BYDV resistance for cereal improvement. A wide range of Triticeae accessions collected over three expeditions in northern China were evaluated for resistance to BYDV. Seedlings were artificially inoculated and virus levels then assayed by ELISA. Resistance and immunity to BYDV were found to be widely distributed among the seven genera of Triticeae included in the screening. A high proportion of resistant and immune accessions was found in the genera Hordeum, Leymus, Elymus and Elytrigia. The wide range of reaction types to BYDV found within many species, and even between accessions of some species, indicates that natural selection for BYDV resistance may have been relatively recent in the Chinese Triticeae. A high proportion of resistance and/or immunity was found in Xinjiang compared to the general distribution. From the Chinese Triticeae tested the Leymus species may be the most appropriate material to initiate transfer of BYDV resistance to wheat.     

Nutrient solution nitrogen form and barley yellow dwarf virus disease tolerance in oat and wheat

Abstract

The form of nutrient solution nitrogen (either NH₄‐N or NO₃‐N or mixtures of the two) provided to plants influences the severity of many crop diseases. This greenhouse study was conducted to determine how growth, grain yield, and yield components of oat (Avena sativa L.) and wheat (Triticum aestivum L.) plants given nutrient solutions containing different ratios of NO₃‐N to NH₄‐N would react to barley yellow dwarf virus (BYDV) infection. Fifteen‐day‐old seedlings (2nd leaf stage) were either infected with BYDV (PAV strain) or left uninfected. Nutrient solution treatments (started 19 d after germination) provided three ratios of NO₃‐N to NH₄‐N (100% NO₃, 50:50 NH₄:NO₃, or 100% NH₄) for a 30‐d period, after which plant height and tillers plant^?1 were measured. Oat and wheat plants given NH₄ had fewer tillers than plants given the other nutrient solution treatments. BYDV‐infected oat and wheat plants were shorter than uninfected plants. All pots then received NO₃ nutrient solution until plant maturity, after which days to anthesis, primary tiller height, grain yield and yield components were measured. In the NH₄ nutrient solution treatments, BYDV infection significantly reduced individual kernel weight in oat and primary tiller height in wheat. These same measures were not significantly affected by BYDV infection in the NO₃ or NH₄NO₃ nutrient solution treatments. There were no other significant nutrient solution by BYDV infection interactions for any other dependent variable measured. Nutrient solution treatments had no significant effect on grain yield, but BYDV infection reduced grain yield by 45% in oat and 46% in wheat. In conclusion, nutrient solution N form interacted with BYDV infection to alter disease tolerance in oat (kernel weight) and wheat (primary tiller height), but these alterations had no effect in ameliorating grain yield loss caused by BYDV disease.     

玉米辐射诱变后代M4选系配合力效应分析

以经60Coγ射线处理选育得到的M4代诱变系及其基础材料R08和48-2为被测系,与玉米骨干自交系不完全双列杂交,分析主要农艺经济性状的配合力效应。结果表明:基础材料经辐射诱变后各性状的配合力产生了不同程度的变化;R08的诱变系11和17与48-2的诱变系26和31,其产量性状一般配合力改良效果较好,是高产育种的良好材料,但株高和穗位高GCA偏大;48-2的诱变系23、25、28、29和30虽有利于缩短生育期、降低株高和穗位高,但产量性状GCA表现较差,有待进一步改良;诱变系24产量GCA表现一般,是缩短生育期、降低株高和穗位高的理想材料;其余诱变系各具特点,需在育种实践中有针对性地改良和利用。     

PPI1在裸鼠体内抑制人宫颈癌细胞HeLa生长的研究

探讨PPI1基因在裸鼠体内对人宫颈癌细胞生长的抑制作用。首先将稳定表达PPI1野生型和突变活化型基因的人宫颈癌细胞HeLa进行裸鼠体内致瘤,观察PPI1对肿瘤生长的影响;其次构建野生型HeLa细胞宫颈癌裸鼠模型,通过在体电脉冲技术,将PPI1野生型和突变活化型基因导入瘤体内进行基因治疗,观察裸鼠的存活情况;FACS分析移植瘤的细胞周期分布;免疫组化法检测移植瘤中的PPI1、cyclin B1、p53和p21的表达水平。在致瘤实验中,稳定表达PPI1突变活化型基因的HeLa细胞组的瘤结节生长缓慢,瘤结节明显小于对照组;在基因治疗实验中,PPI1突变活化型基因治疗组的裸鼠生存期明显延长,瘤组织中的肿瘤细胞呈现G2/M期停滞,cyclin B1和p21的表达水平明显增强,而突变型p53的表达明显减弱。PPI1活化型突变体对裸鼠HeLa移植瘤生长有明显的抑制作用。     

大豆2个种皮不完整突变体的形态特点与遗传分析

为揭示种皮不完整性遗传规律,发掘关键基因,本试验采用理化诱变剂处理不同大豆品种以创制种皮新突变体,并对其进行形态与遗传特性鉴定,其中从~(60)Co-γ射线辐照的科丰1号M_3株行发现种皮不完整突变体scd-KF,从甲基磺酸乙酯处理的南农1138-2 M_4株行发现突变体scd-NN。scd-KF突变体种皮开裂出现在种子成熟初期,种子背部纵向或横向开裂,程度与种子大小有关;scd-NN突变体种子发育早期种皮即受到影响,种子背部纵向开裂,2片子叶之间有明显裂缝,种子显著小于其野生型。遗传分析结果表明,scd-KF种皮不完整性状由单隐性基因控制,而scd-NN的突变性状在F_2符合15∶1的分离比例,可能由2对隐性基因控制。2个突变体杂交F_2植株的株高及单株荚数、粒数及每荚粒数低于正常种皮植株,但大部分性状未达到显著差异水平。本研究结果为深入揭示大豆种皮及种子发育提供了遗传材料与信息。     

Resistance to powdery mildew and barley yellow dwarf in perennial Triticeae species

Summary In a collaborative effort between the USDA-ARS and CAAS, 50 accessions each of perennial Triticeae held at the Forage and Range Research Laboratory, Logan, Utah, U.S.A. and the Institute of Crop Germplasm Resources, Beijing, People's Republic of China were exchanged. Eighty six and 85 accessions of these germplasms were screened for powdery mildew (caused by Erysiphe graminis DC) and barley yellow dwarf virus (BYDV) strain GPV, respectively. Fifty seven and 72 accessions had resistance to powdery mildew and BYDV, respectively. These materials are valuable genetic resources for breeding disease resistances in three of the major cereal crops — wheat, barley, and rye.Abbreviations BYDV barley yellow dwarf virus - ELISA enzyme-linked immunosorbent assay     

籼型温敏核不育水稻叶绿素突变体的诱变及其初步研究

用＾６０Ｃｏγ射线辐照籼型温敏核不育系２１７７Ｓ,获得了一批常见的叶绿素突变体。Ｍ２代按苗计,叶绿素总突变频率为０．２６２％,其中只有４．５０％可以存活并遗传,从中筛选出３３个综合性优良的灿型温敏核不育叶绿素突变系。经鉴定,这些叶绿素突变受基因控制,比较稳定,有的只在苗期表达并逐渐转为正常,有的则在全生育期表达。     

Isolation and characterization of a novel Arabidopsis thatiana mutant that requires a high concentration of boron

We isolated a novel Arabidopsis thaliana mutant line that requires high levels of boron (B) for normal growth. Line 8–21 was identified from ethyl methanesulfonate-mutagenized M2 population. When grown in medium containing 3 μm or less B in the form of boric acid, the fresh weights of aerial portions of the mutant were about a half of those of the wild type, but in that containing 300 μm B, the growth appeared normal. The mutant plants did not shown any difference in root growth from the wild-type plants in the range of B concentrations tested. When grown with 30 μm B, the B concentration in shoots of the line 8–21 was similar to that in the wild-type, suggesting that the mutant could not utilize B efficiently. Line 8–21 was not allelic to bor1-1 (Noguchi et al., Plant Physiol., 115, 901–906, 1997). A significant portion of F2 plants from the crosses between the wild-type and the mutant grew poorly on a low B media, suggesting segregation of the mutation.