辐射诱变板栗新品种——农大1号高产稳产性状分析

农大1号由阳山油板栗枝条用快中子辐射诱变育成。具早热、矮化和一苞多籽等丰产稳产优良经济性状.成熟期8月底～9月上旬;VM_3八年生平均树高3.3m,冠幅2.7m,平均株产2.8kg,最高株产10.7kg.果实品质优良,性状稳定.1991年通过省级成果鉴定,已推广100hm~2.     

A novel phenotype for Laron dwarfism in miniature Bos indicus cattle suggests that the expression of growth hormone receptor 1A in liver is required for normal growth

Mutations within the growth hormone receptor (GHR) gene that lead to an inactivated or truncated GHR protein cause abnormal growth and small adult size in a variety of species (Laron dwarfism). We studied a line of miniature Bos indicus cattle that have phenotypic (small mature size) and endocrine (increased blood growth hormone and decreased blood insulin-like growth factor-I concentrations) similarities to Laron dwarfs. Liver mRNA from miniature and control cattle was used to amplify a cDNA within the coding region of the GHR. The miniature cattle had GHR mRNA size (determined by Northern blot) and cDNA sequence that were similar to control cattle and, therefore, were unlike most Laron dwarf genotypes in which the GHR gene is mutated. Amounts of mRNA from liver as well as muscle (superficial neck and longissimus) were analyzed by ribonuclease protection assay for IGF-I, total GHR, GHR 1A (inducible, liver-specific GHR mRNA), and GHR 1B (constitutive GHR mRNA). Four control and five miniature bulls were tested. As expected, liver IGF-I mRNA was decreased in the miniature cattle (approximately 12% of control; P < 0.01). The amount of the total GHR as well as GHR 1A mRNA were also decreased in liver (17% and 19% of control, respectively; P < 0.01). Other GHR mRNA, including GHR 1B mRNA, were similar for miniature and control cattle. In muscle, there was a tendency (P < 0.10) for decreased IGF-I mRNA and increased GHR mRNA in miniature compared with control cattle. In summary, a novel phenotype for Laron dwarfism in Bos indicus cattle was associated with underexpression of GHR 1A mRNA, but not other GHR mRNA variants in liver. In addition to decreased GHR 1A mRNA, the miniature cattle had decreased liver IGF-I mRNA. Full expression of GHR 1A in liver, therefore, may be required for full liver IGF-I expression and normal growth.     

赤霉素反应敏感型和不敏感型谷子矮秆突变体的鉴定

采用赤霉素点滴法（苗期）浸渍法（芽期）以及喷洒法（拔节期）对３种谷子矮杆突变体的赤霉素反应敏感性进行了研究,结果表明矮宁黄和６２３Ｃ属赤霉素反应敏感型,它们苗期的叶片和叶鞘及拔节期的节间均可随外加赤霉素而显著伸长,达到正常株（苗）高,ＣＨ８４１１３则属于赤霉素反应不敏感型,多种赤霉素（ＧＡ１,ＧＡ３,ＧＡ７,ＧＡ９）处理均不能其株（苗）高恢复正常,用ＥＬＩＳＡＣ地３各矮秆突变体和正常品种伸长敏感期     

Insulin-like growth factor type-1 receptor down-regulation associated with dwarfism in Holstein calves

Perturbations in endocrine functions can impact normal growth. Endocrine traits were studied in three dwarf calves exhibiting retarded but proportionate growth and four phenotypically normal half-siblings, sired by the same bull, and four unrelated control calves. Plasma 3,5,3'-triiodothyronine and thyroxine concentrations in dwarfs and half-siblings were in the physiological range and responded normally to injected thyroid-releasing hormone. Plasma glucagon concentrations were different (dwarfs, controls>half-siblings; P<0.05). Plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin concentrations in the three groups during an 8-h period were similar, but integrated GH concentrations (areas under concentration curves) were different (dwarfs>controls, P<0.02; half-siblings>controls, P=0.08). Responses of GH to xylazine and to a GH-releasing-factor analogue were similar in dwarfs and half-siblings. Relative gene expression of IGF-1, IGF-2, GH receptor (GHR), insulin receptor, IGF-1 type-1 and -2 receptors (IGF-1R, IGF-2R), and IGF binding proteins were measured in liver and anconeus muscle. GHR mRNA levels were different in liver (dwarfs相似文献   

不同矮杆大豆品种的耐密性研究

为了明确合理的矮杆密植大豆群体结构,为实现大豆超高产育种目标奠定理论基础。以4个不同基因型矮杆大豆品种为试验材料,设置了8个不同的密度梯度,调查分析产量相关性状,筛选最适宜的种植密度。结果表明,随着密度的递增,株高表现为逐渐增加;单株荚数及粒数则表现为逐渐下降;产量呈现先增加后减少的趋势;倒伏率在达到一定密度时出现急剧上升。‘吉密豆1号’、‘吉密豆2号’、‘吉密豆3号’、‘吉密豆4号’的最佳种植密度分别为40万株/hm ²、37.5万株/hm ²、40万株/hm ²和56万株/hm ²,产量分别可达4199.2 kg/hm ²、3282.3 kg/hm ²、3410.1 kg/hm ²和3313.4 kg/hm ²。因此,合理的增加种植密度,可进一步挖掘矮杆耐密型大豆的高产潜力。     

矮化型八倍体小偃麦的选育

矮化型八倍体小偃麦“TAI7044”是以天蓝偃麦草(Agropyron glaucum)作父本，春小麦品种“晋春7号”作母本杂交，并采用冬小麦品种“21124”回交克服其属间杂种的不育性，经过连续9年选育而成。细胞学观察结果表明，它的体细胞染色体数目2n=56的植株占77.3%，花粉母细胞减数分裂中期Ⅰ2n=28Ⅱ的细胞占59.95%，其染色体构型为1.43 Ⅰ+27.48Ⅱ+0.09Ⅲ+0.04Ⅳ。同工酶电泳结果表明，它的酯酶比双亲(普通小麦和天蓝偃麦草)多出5条新生酶带，同时又缺少双亲分别具有的3条酶带,进一步证明了利用外源种质与小麦遗传背景之间相互作用产生新性状的可能性。     

籼稻矮源遗传研究——论双桂、丛桂等品种矮生性的遗传性质

本试验研究了双桂1号、双桂36号和丛桂226等半矮生性品种的株高遗传。结果表明,其半矮生性受二对基因互补作用的控制,基因型为sd-1 sd-1 dg(t)dg(t),sd-1和dg(t)分别渊源于矮仔占和桂阳矮1号。研究证明,“丛生快长型”籼稻育种是我国籼稻育种矮源利用的新发展。     

油菜素甾醇对植物矮化作用的研究进展

阐述了油菜素甾醇的合成途径及其对植物生长、代谢、形态建成等的影响。重点介绍了油菜素甾醇对植物矮化作用的研究进展。并探讨了油菜素甾醇今后的研究方向。     

PP_(333)、GA_3和BA对马铃薯试管苗生长调节作用的研究

针对马铃薯试管苗在继代培养中,苗生长细长、瘦弱和叶嫩黄等现象,在培养马铃薯的培养基中附加不同浓度的生长调节剂PP_(333)(mg/1,单位下同)、GA_3、BA、GA_3+BA、PP_(333)+GA_3、PP_(333)+BA和PP_(333)+GA_3+BA等进行培养壮苗的试验.加入PP_(333)各处理对试管苗的高、茎粗和增绿效应明显,但高浓度的PP_(333)对试管苗生长过于抑制;加GA_3对PP_(333)有拮抗作用.适宜浓度的PP_(333)+GA_3+BA能培养壮苗,并促进侧芽分化,增加叶面积、叶绿素含量和干物质的累积.各处理对马铃薯试管苗的抑制生长效应为PP_(333)>PP_(333)+BA>PP_(333)+GA_3>PP_(333)+GA_3+BA>BA>GA_3>GA_3+BA;生理效应和移栽苗成活率的顺序为PP_(333)+GA_3+BA>PP_(333)+GA_3>GA_3+BA>PP_(333)+BA>GA_3>BA>PP_(333).     

籼稻矮源遗传研究——论80-7010的性质及新矮源的利用

对13份籼稻矮生和半矮生材料的基因等位性及遗传效应的研究表明:源于美洲的卡尔155和T480/57及我国云南省的矮麻谷和云南大粒等的半矮生基因同属于sd_1;源于印度尼西亚的印尼水田谷受多基因控制;我国四川省的一支腊和衍生于广东省桂阳矮1号杂交后代的80-7010则与sd_1非等位。七十年代以来,广东省的“丛化育种”直接或间接有效地利用了源于桂阳矮1号的新矮源种质,从而进一步丰富了我国南方稻区籼稻育种的遗传基础、本研究判定的这个新矮源基因暂定为dg(t)。