Genetic diversity in European perennial ryegrass cultivars investigated with RAPD markers

Perennial ryegrass (Lolium perenne L.) is the most important grass species for temperate grassland agriculture. The genetic relationship and distance among cultivars is largely unknown but of great interest for breeding programmes. The objectives of this study were to (i) investigate the molecular variation and structure of population cultivars, (ii) describe the relationship among cultivars in terms of the modified Rogers’ distance, and (iii) determine the minimum sample size required for characterization of cultivars of L. perenne using random amplified polymorphic DNA (RAPD) markers. A total of 22 ryegrass cultivars, mainly of European origin, were investigated with RAPD markers. The minimum sample size required for the characterization of cultivars was about 20 individuals per population. An analysis of molecular variance (AMOVA) revealed a much larger genetic variation within cultivars (66%) than between them (34%).     

The high and low molecular weight glutenin subunit polymorphism of Algerian durum wheat landraces and old cultivars

The high molecular weight (HMW) and B‐zone low molecular weight (B‐LMW) glutenin subunit composition of 45 Algerian durum wheat (Triticum turgidum L. var. durum) landraces and old cultivars were examined by sodium‐dodecyl‐sulphate polyacrylamide gel electrophoresis (SDS‐PAGE). Nine accessions were heterogeneous and presented two or three genotypes. All together, 33 glutenin patterns were detected, including 12 for HMW and 15 for B‐LMW glutenin subunits. Twenty‐four different alleles were identified for the five glutenin loci studied, Glu‐A1 (3), Glu‐B1 (6), Glu‐A3 (8), Glu‐B3 (5) and Glu‐B2 (2). Five new alleles were found, three at Glu‐A3 and two at Glu‐B3. At the Glu‐1 loci, the Glu‐A1c‐Glu‐B1e allelic composition was predominant (31%). For the B‐LMW glutenins, the most common allelic composition was Glu‐A3a‐Glu‐B3a‐Glu‐B2a (36%). The collection analysed shows a high percentage of glutenin alleles and allele combinations related to high gluten strength, together with some others that have not been tested so far. This information could be useful to select local varieties with improved quality and also as a source of genes to develop new lines when breeding for quality.     

粳稻育成品种种子耐贮性的SSR关联分析

旨在发掘粳稻育成品种中与种子耐贮性相关联的优异等位变异和携带优异等位变异的载体材料。利用太湖流域和黑龙江省粳稻育成品种构成的群体为实验材料,调查了100 个品种种子耐贮性指数,利用259 对SSR标记对基因组进行扫描,采用Structure 软件进行群体分析,根据GLM(general linear model)方法对标记与耐贮藏性状进行关联分析;并以携带无效等位基因(null allele)材料的表型均值作为对照,鉴别出携带优异等位变异的载体材料。（1）太湖流域粳稻育成品种的耐贮藏能力、遗传多样性高于黑龙江省;（2）与种子耐贮性关联的标记总计有71 个,与苗高关联的SSR标记有17 个,贡献率最大的是RM6811(50.54%),增加表型效应值最大的等位变异是RM5753-215,载体材料为‘台粳16 号选紫’;与根长关联的SSR 标记有26 个,贡献率最大的是RM5753(49.3%),增加表型效应值最大的等位变异是RM5753-207,载体材料为‘垦稻12 号’;与干重关联的SSR 标记有28 个,贡献率最大的是RM5340(50.49%)和M24481 (50.51%),增加表型效应值最大的等位变异是RM180-101,载体材料为‘连粳4号’。     

国内部分新品种对大豆花叶病毒抗性的鉴定

对2004-2006年度参加国家或部分省(市)区域试验的193个新选育的大豆品种进行了针对大豆花叶病毒主要流行株系SC-3和SC-7的抗性鉴定。结果表明:中作119、东大2号、中作017020、中作00-683、03鉴31等20个品种对2个株系都表现为抗侵染,约占参试品种总数10%;铁豆37、东大4号、铁96001-7、密选2号、东大7号等36个品种对SC-3株系表现为抗侵染,占参试品种总数的19%;晋遗46号、徐9302-186、晋遗39号、石豆412 4个大豆品种对SC-7株系表现为抗侵染,占参试品种总数的2%。除此之外,鲁9594-3、浙4074、中作J4015,汾豆72等品种虽然对2个株系表现为系统感染,但病情指数相对较低,表明这些品种对于大豆花叶病毒的扩展有一定抗性。这些不同类型的抗性品种既可用于大豆生产,也可作为抗源用于抗病新品种选育和与抗性相关的研究。     

西北牡丹品种瓣基色斑形态的初步研究

西北牡丹品种群是中国牡丹栽培品种中极富特色的品种群,所有品种的花瓣基部都有色斑。实地调查中发现,这些色斑在位置、大小、颜色、形状等方面存在丰富的变异,现结合文献资料,对这些变异进行整理分析。色斑的位置有基部和离基2种情况;颜色以棕红色、紫红色、棕色、黑紫色等紫黑色系居多;色斑的大小按其高度占花瓣的高度比例可分为特大型、大型、中型和小型4种;形状有卵形、椭圆形、圆形等10种。对色斑的描述可按照颜色、大小、形状的顺序。此外色斑透背与否及雄蕊瓣化瓣上的白色条纹等都有很大的变化,这些特点极大地提升了西北牡丹品种花朵的观赏性。     

基于信息熵理论的模糊综合评价方法及其在棉花区试中的应用

为提高对区域试验参试品种评价的科学性和合理性,采用模糊数学和信息熵理论,提出了作物品种模糊熵权综合评价方法。该法利用作物品种区试的综合性状指标,建立相应的评价指标矩阵,然后借助信息论中的熵权理论,利用各评价指标的变异程度计算权重,实现品种的综合评价。最后结合棉花区试资料,介绍了该法的应用,验证了其可行性和有效性。     

中国北方冬麦区主栽品种醇溶蛋白组成的遗传演变分析

用改良的pH3.2A-PAGE技术分析了我国北方冬麦区建国后不同时期的51个主栽品种和21个骨干亲本的醇溶蛋白组成及其遗传演化规律.结果表明,供试主栽品种具有丰富的醇溶蛋白变异类型,是今后小麦育种的重要物质基础.本实验材料共分离出72种醇溶蛋白组分,供试主栽品种含有其全部组分,其单品种谱带数目在21～41之间,品种间各类蛋白组     

豇豆始花节位遗传分析

为明确豇豆始花节位的遗传规律,应用数量性状的主基因+多基因遗传模型6世代联合分析方法,调查豇豆杂交组合‘Ju08-10’ב丰豇10号’的6个世代始花节位。利用南京农业大学章元明教授提供的植物主基因+多基因遗传分析软件,计算最适合的遗传模型及相应的遗传参数。结果显示,‘Ju08-10’ב丰豇10号’杂交组合的始花节位遗传符合加性-显性-上位性多基因模型,无主基因存在,F2群体多基因遗传率为71.64%,环境方差占表现型方差的比例为28.36%,说明豇豆始花节位是多基因控制的数量性状,始花节位易受环境因素的影响,早熟性(较低的始花节位)可以通过杂交后代选择实现,但定向选择会有较好的效果。     

国外引进盆栽芍药品种在杭州的生长观测及筛选

以从荷兰引进的8个盆栽芍药品种为试验材料,中国传统盆栽品种‘大富贵’为参照材料,对9个芍药品种在杭州盆栽2年的株高、分株数、开花数、成活率等数量指标运用隶属函数法进行分析,结合绿叶期、茎秆直立性和花型等性状指标进行综合评价。结果表明:9个芍药品种连续2年多在杭州夏季高温高湿气候条件下盆栽的成活率为100%;‘Kiev’、‘Dublin’、‘Oslo’和‘Athens’的株型紧凑、茎秆粗壮、成花率高、绿叶期长、生长健壮,可作为江南地区盆栽芍药的优良品种进行推广。     

Inheritance of N2 fixation efficiency in cowpea

Summary Host plant genetics of N₂ fixation in the cowpea (Vigna unguiculata (L.) Walp.) — Rhizobium symbiosis was investigated in the field with a mixed strain inoculum and in the greenhouse with a single strain inoculum. Five cowpea genotypes, including H-Brown Crowder and L-Bush Purple Hull, were used to generate populations for genetic studies. Diallel analysis for general combining ability (GCA), specific combining ability (SCA) and reciprocal effects was carried out for the N₂ fixation variables nitrogenase activity, nodule number, nodule weight, and top dry weight, in the field study. Generation mean analysis and heritability estimates were performed on the greenhouse population which included P₁ (H-Brown Crowder), P₂ (L-Bush Purple Hull), F₁, F₁. F₂, BC₁, and BC₂. Positive and significant correlations were observed between nitrogenase activity and both nodule weight and nodule number. Correlation coefficients between top dry weight and the other 3 variables were not significant. Estimates of SCA were highly significant for all variables except top dry weight, while those of GCA were significant only for nodule weight. Generation mean analysis revealed that additive gene action was more prominent than dominance and interallelic gene action for nodule number and nitrogenase activity, while the opposite was true for nodule weight and top dry weight. Narrow sense heritability estimates were moderately high for nodule number (0.55) and nitrogenase activity (0.62), and low for nodule weight (0.39) and top dry weight (0.17).Texas Agricultural Experiment Station Technical Article 20385. Research supported in part by a grant under USAID PASA AG/TAB 610-9-76 (USDA-CSRS-701-15-59).