10份偃麦草形态生物学特性及其坪用性研究

对5份新疆野生偃麦草(Er04、Er06、Er07、Er09、Er10)和5份引进的偃麦草(Er01、Er02、Er03、Er05、Er08)从生物学特性(生育期、形态特征)、坪用性(质地、盖度、颜色、均一性、绿色期等)及牧用性方面进行了研究.结果表明:供试材料在种内差异较大;Er04、Er07植株低矮、叶片较纤细柔软,坪用性好;Er05、Er10植株高大,叶片宽、叶量多、产草量高,牧用性好.通过聚类分析,初步将10份偃麦草分为3大类群,即草坪型(Er04、Er07)、草坪草牧草兼用型(Er01、Er02、Er03、Er06、Er08、Er09)和牧草型(Er05、Er10).     

Cytological Evaluation and Karyotype Analysis in Plant Germplasms of Elytrigia Desv

Elytrigia Desv.is widely distributed throughout the world and is represented with species of various levels of ploidy including diploids,tetraploids,hexaploids,octaploids,and decaploids.The distribution pattern of these ploidy levels,however,is not well-defined.In this study,the levels of ploidy for 64 accessions of Elytrigia from 25 countries were determined with microscopic procedures.The results showed that accessions of E.intermedia and E.repens were grouped into three distinct levels of ploidy including diploids,tetraploids and hexaploids.For E.elongata,E.pontica,and E.caespitosa,it was found that two ploidy levels presented,and only one ploidy level was in those of E.hybrid,E.pycnantha,E.pungens,E.juncea,and E.alatavica.Karyotype analysis indicated that the karyotype formula of diploid,tetraploid and hexaploid of E.intermedia was 2n=2x=14=6m+6sin+2st,2n=4x=28=2M+10m+16sm and 2n=6x=42=4M+18m+20sm,respectively.Furthermore,the karyotype formula of three germplasms in tetraploid of E.intermedia was 2n=4x=28=2M+10m+16sm,2n=4x=28=4M+22m(sat)+2sm and 2n=4x=28=4M+12m+12sm(sat),which were not completely uniform.Therefore,it could be suggested that the studies about chromosome constitution would be helpful for the detail understanding of the diversity of germplasm resource in Elytrigia and promoting the utilization in the crop molecular breeding.     

蕨菜组织培养的消毒方法比较

以蕨菜[Pteridium aquilinum (L.) Kuhn var.latiusculum(Desv.) Underw.ex Heller]粗壮、幼嫩的茎段为外植体实施组织培养,比较了不同的消毒步骤及洗刷处理对蕨菜茎段的消毒效果.结果表明,用柔软毛笔对蕨菜茎段表面洗刷1 min,再用75％的乙醇浸泡15s,接着用1.0 g/L的HgCl2溶液处理5min,取得了组织培养最佳的消毒效果,其污染率为15.0％,成活率达66.7％,是试验范围内效果最佳的消毒方法.     

小麦、偃麦草和小偃麦同工酶及蛋白质的比较研究

本文采用聚丙烯酰胺凝胶电泳法,比较分析了小麦、天蓝偃麦草和小偃麦的酶酯同工酶、过氧化物酶同工酶和可溶性蛋白质。结果表明,不同属的酶谱是不同的。小麦和天蓝偃麦草的同工酶和可溶性蛋白质具有属的特异性。小偃麦兼有小麦和天蓝偃麦草的酶带,是不同于小麦和天蓝偃麦草的八倍体新类型。5个小偃麦划分成两种不同的类型,中_1和中_2属于第一种类型,中_3、中_4和中_5属于第二种类型。酯畴同工酶和过氧化物酶同工酶可以做为研究种属间关系和分类的一项生化指标。     

猫尾射的组织培养

以猫尾射无菌播种苗(去除根部)为外殖体,对其愈伤组织诱导和分化及其不定芽增殖进行研究。结果表明,外殖体在MS＋6-BA 1.0 mg/L＋NAA 0.1 mg/L培养基上,愈伤组织诱导和分化的效果较好,愈伤诱导率为82.0%,分化率为74.5%;经不定芽增殖培养基MS＋6-BA 0.5 mg/L＋NAA 0.05 mg/L培养,不定芽增殖倍数为8.2,平均株高为4.7cm。组培苗在MS＋IBA 0.5 mg/L培养基上生根率达90%。生根苗移栽成活率达84%。     

三份偃麦草种质的染色体核型分析

选用产地来源不同的3份偃麦草的种子为试验材料,采用根尖压片法进行细胞染色体核型分析,旨在为其细胞学特性和演化趋势的研究奠定科学基础。结果表明,来源于俄罗斯列宁格勒的偃麦草种质ER044染色体数目为2n=6X=42,染色体相对长度组成为:4L+14M₂+20M₁+4S,核型公式为:K(2n)=6X=42=2M+32m+8sm。来源于阿富汗喀布尔的偃麦草种质ER058染色体数目为2n=6X=42,染色体相对长度组成为: 2L+20M₂+16M₁+4S,核型公式K(2n)=6X=42=30m+12sm(2sat)。采自于中国新疆的偃麦草种质ER132染色体数目为2n=6X=42,染色体相对长度组成为:4L+16M₂+16M₁+6S,核型公式为:K(2n)=6X=42=32m+8sm(4sat)+2st。3份偃麦草种质的染色体核型均属于“2B”类型。     

Variation in Elymus repens susceptibility to glyphosate

Continuous increase in glyphosate use in Sweden has caused concern about resistance development, not least in connection with the possible introduction of crops resistant to glyphosate. In Sweden, the main weed targeted by glyphosate is Elymus repens (L.) Gould. We sampled 69 clones of E. repens to assess the magnitude and geographical distribution of variation in susceptibility to glyphosate. Clones originated from four habitat types: intensively and extensively used arable lands, field vicinities and other habitats, including natural vegetation. Susceptibility varied greatly among clones with GR50 (50% of untreated growth reduction) spanning over at least one order of magnitude, 17–278 active ingredient ha^?1 in a pot experiment setting. There was a strong covariance between geographic and genetic distance, but there was no evidence of geographic or genetic differentiation in GR50. Nor did GR50 vary consistently between habitat types. We conclude that no indication of past selection was found towards the resistance to glyphosate in E. repens clones in Sweden. The great variability in susceptibility suggests that there might be a potential for such selection.     

猫尾射的组织培养

以猫尾射无菌播种苗（去除根部）为外殖体,对其愈伤组织诱导和分化及其不定芽增殖进行研究。结果表明,外殖体在MS＋6-BA 1.0 mg/L＋NAA 0.1 mg/L培养基上,愈伤组织诱导和分化的效果较好,愈伤诱导率为82.0%,分化率为74.5%;经不定芽增殖培养基MS＋6-BA 0.5 mg/L＋NAA 0.05 mg/L培养,不定芽增殖倍数为8.2,平均株高为4.7cm。组培苗在MS＋IBA0.5mg/L培养基上生根率达90%。生根苗移栽成活率达84%。     

小麦-中间偃麦草蓝粒代换系的创制与鉴定

小麦的蓝粒性状可作为表型标记用于小麦育种和遗传学研究,来自中间偃麦草的蓝粒种质材料尚鲜见报道。本研究通过八倍体小偃麦中5 (2n=8x=56, AABBDDXX)与中国春缺-四体系列材料杂交,在中5×N4BT4A和中5×N7BT7D杂交组合后代中获得了两份蓝粒材料,编号分别为Zh5-a2-1和Zh5-c13-2。利用细胞遗传学和分子标记方法对这两份蓝粒材料进行了染色体组成分析。以中间偃麦草基因组DNA为探针的GISH分析显示,这两份蓝粒材料的染色体数均为2n=42,包括40条小麦染色体和两条中间偃麦草染色体。利用重复序列探针pSc119.2和pAs1进行的FISH分析表明,Zh5-a2-1和Zh5-c13-2均为二体代换系,被代换的一对小麦染色体分别为4B和4D。通过用St、E~e和E~b基因组DNA作探针进行GISH分析,证明这两份蓝粒代换系中的中间偃麦草染色体均为St组染色体,但与中5中的中间偃麦草染色体比较发现这对St组染色体的短臂端部发生了缺失。利用二倍体长穗偃麦草E~e基因组的SNP标记分析证明,两份蓝粒代换系中的中间偃麦草染色体与长穗偃麦草的4E~e染色体同源,即Zh5-a2-1和Zh5-c13-2分别为4St(4B)和4St(4D)代换系,命名为SubZh5-4St(4B)和SubZh5-4St(4D)。同时说明,中间偃麦草的4St染色体上带有蓝粒基因。通过对450个小麦SSR标记进行筛选,获得了4个可跟踪鉴定4St染色体的特异SSR标记。研究结果可用于蓝粒小麦品种的培育和中间偃麦草蓝粒基因的遗传学研究。