小麦—黑麦—中间偃麦草三属杂种F1及其花粉植株的细胞遗传学研究

２个小麦－黑麦－中间偃麦草三属杂种Ｆ１的减数分裂行为复杂,中期Ｉ染色体平均每细胞构型为１９．５３Ｉ＋１３．４７ＩＩ＋０．７０ＩＩＩ＋０．０６１Ⅴ和１９．９９Ｉ＋１３．４２ＩＩ＋０．６５ＩＩＩ和０．０４１Ⅴ＋０．０１Ⅴ,后期Ｉ染色体分配不平衡,单价体并不一定排列在赤道板上,产生各种类型的异常四分体。１８株花粉植株染色体组成类型多样,在２个花粉植株中分别观察到端体和等臂染色体。单倍体花粉植株中期Ｉ染色     

赖草属植物的遗传学研究与利用

赖草属植物具有广泛的适应性和丰富的抗逆性,作为麦类作物的重要基因资源愈来愈受到人们的重视。介绍了赖草属植物的种类及分布,分析了赖草属植物的优良特性及潜在利用价值,探讨了赖草属植物的核型、染色体带型及分子细胞遗传学研究,重点论述了赖草属植物在小麦遗传改良中的应用．阐明挖掘利用小麦近缘野生植物是未来小麦品种改良的有效途径。     

小麦与黑麦属间杂种的染色体自然加倍的研究

分别以小麦属６个种的变种或品种共９个供试材料为母本,２个黑麦种为父本进行杂交,只有Ｓｔｅｗａｒｔｄｕｒｕｍ小麦与２个黑麦种杂交后,才得到Ｆ１种子,说明染色体的自然加倍需要一定的遗传背景,对这２个Ｆ１代花粉母细胞减数发裂所形成配子的观察表明,配子形成途径的不同,使Ｆ２出现了双二倍体和部分双二倍体的差异。     

小麦-黑麦小片段易位系的分子细胞遗传学分析

为选育具有经济价值的带有黑麦R染色体组小片段的小麦-黑麦育种基础材料,对小麦-黑麦5R/5A×6R/6A代换系杂交后代的8份高代材料6-30、6-31、7-1、7-9、7-13、7-21、7-22和7-28进行形态学、细胞学观察,及SSR分析和GISH检测。结果表明,8个品系田间生长整齐、育性正常,具有大穗、多小穗,抗白粉病、叶锈病等优良性状;对其中2个品系7-1和7-9进行花粉母细胞减数分裂观察,发现大多数细胞染色体构型为2n=21Ⅱ,具有良好的遗传稳定性;选择黑麦R染色体通用引物及5R、6R染色体上的微卫星引物共8对,对8个品系进行SSR分析,结果表明8个品系都有黑麦5R或6R染色体片段的导入,进一步进行GISH检测,发现5个品系6-31、7-1、7-13、7-21、7-22都存在黑麦杂交信号,为小麦-黑麦小片段易位系。本研究综合多种手段鉴定的8份材料皆为小麦-黑麦小片段易位系,在育种上具有利用价值。     

小麦改良的可利用资源：黑麦抗病基因

黑麦(Secale cereale)蕴藏着丰富的抗病基因,是改良小麦抗性的重要资源,黑麦抗病基因的导入一直是小麦育种的重要研究课题。本文综述了黑麦抗病基因的染色体定位、分子标记研究和含黑麦抗病基因的小麦种质资源在我国小麦育种中的应用,对应用中存在的问题进行了分析,并对今后的研究方向进行了展望。     

应用RAPD标记分析黑麦属品种的遗传多样性

四川农业大学小麦研究所侯永翠、郑有良、魏育明等研究人员对黑麦遗传多样性课题作了研究。他们采用随机扩增多态性DNA(RAPD)标记 ,对黑麦属 (SecaleL) 7个品种共 1 2份材料进行了遗传多样性检测 ,发现被检测材料间RAPD标记多态性较高 ,在 4 0个随机引物中 ,有 2 5个引物约占整个的 6 2 .5 %的扩增产物具有多态性。这 2 5个中共扩增出 1 6 7条带 ,其中 89条带约占 5 3.2 %具有多态性 ,每个引物可扩增出 1～ 1 0条多态性带 ,平均为 3～ 6条。RAPD标记遗传距离GD变异范围为 0 .1 382～ 0 .4 5 1 2 ,平均为 0 .2 71 2。通过聚类分析表…     

鹅观草x黑麦杂种F，的形态及细胞遗传学研究

以鹅观草作母本,黑麦作父本进行杂交,采用杂种幼胚培养技术,首次成功地获得了F,杂种。杂种 穗形呈双亲的中间类型,完全雄性不育。花粉母细胞减数分裂中期I平均染色体配对构型为：27.011+ 0.4711＋0.01111,后期I形成大量的落后染色体以及发生不均等的两极分裂和多极分裂,进而形成多 分体。花粉粒发育过程中出现不同数目的微核。     

悬钩子属植物资源及其利用

悬钩子属Rubus L.植物资源丰富,分布广泛,我国已发表201种98变种,种类之多仅次于北美中心,在分布上自西向东,自南而北有逐渐减少的趋势,西南部为分布中心,利用上有果用和药用两个主要途径,本文在进行国内资源考察的基础上,回顾了国内外悬钩子属植物的利用历史及其栽培化进程,并提出了我国野生悬钩子属植物中具有圈在果用潜力的11个种,本属许多种类是生态适应性很强的地被植物,从保护环境的角度出发,其在水土保持和美化环境方面的价值也值得注意。     

Genetic co-regulation of galactose and melibiose utilization in Saccharomyces.

The gal3 mutation of Saccharomyces, which is associated with an impairment in the utilization of galactose, has been shown to be pleiotropic, causing similar impairments in the utilization of melibiose and maltose. Milibiose utilization and alpha-galactosidase production are directly controlled by the galactose regulatory elements i, c, and GAL4. The fermentation of maltose and the induction of alpha-glucosidase are regulated independently of the i, c, GAL4 system. The production of alpha-galactosidase and galactose-1-phosphate uridyl transferase is coordinate in galactokinaseless strains. Galactose serves as a nonmetabolized, gratuitous inducer of alpha-galactosidase in strains lacking the genes for one or more of the Leloir pathway enzymes.     

Genetic study on the physical properties of Coffea arabica L. wood

The physical characteristics of wood are not usually considered as selection criteria when breeding perennial species that are grown for their fruits or seeds. In the coffee tree, stem breakage during harvesting and lodging during the growth period are major defects in some cultivars. These defects are linked to certain physical and mechanical properties of the wood, such as density or rigidity, which can be characterized by a parameter used in the resistance of materials: the Modulus of Elasticity (MOE). Wood density and the longitudinal MOE were studied on the stems of coffee trees of the species Coffee arabica L., derived from a diallel mating design. The MOE was measured by an acoustic system based on an analysis of the vibrations produced by a blow to the end of a piece of wood of known geometry. The MOE obtained in that way, along with the density of coffee tree stem wood, displayed substantial heritability. A strong link between the average internode length and the yield cumulated over 4 years was detected. Wood density was also correlated to yield and wood elasticity. Classification of parents according to the wood characteristics of their progenies depended on their degree of introgression by the species C. canephora. These traits could therefore be used to measure introgression, possibly as predictors of traits of agronomic interest, and as target traits in the creation of tall C. arabica varieties.

Genetic study of a new color of the beet Beta vulgaris L.

A new genetic character of the beet Beta vulgaris L., named stem color, was described and studied genetically. This character was shown to be dominant and monogenically inherited. The first-year beet plants with the genotype Stc/_ have red leafstalks, weakly colored central rib, and colored storage root; however, the root itself is not colored. The second-year plants have a red-colored low third of the floral shoot. The plants with the genotype stc/stc are uncolored. The Stc gene was localized to the first linkage group at a distance of 17.5 ± 2.1% crossing over units from the gene B (Bolting), which controls the annual-perennial habit of beet.     

黄独遗传多样性研究

采用ISSR标记技术研究了我国14个黄独样品的遗传多样性.从55条简单重复序列引物中筛选出9条多态性引物,共扩增出70条带,其中67条多态性带,多态性比率为95.71%,平均每条引物扩增出7.8条带.黄独原变种内Nei s基因多样性(h)为0.294 9,有效等位基因数(Ne)为1.491 1,Shannon多样性指数(I)为0.444 8.种水平h为0.326 3,Ne为1.552 9,I为0.488 3.基因分化系数(Gst)为0.782 1,基因流(Nm)为0.139 3.聚类分析表明来自海南省和台湾省的样品与我国内陆的样品较早分离.据此可将来自我国内陆的样品分为5组.ISSR聚类分析基本上支持依据形态特征对黄独变种的划分.同时实验结果也表明,云南可能是黄独在我国的分化中心.     

Feeding value of alkali-treated whole rye (secale cereale L.) grain for lactating cows and its digestibility for sheep

Alkali-treated whole rye grain (35 g NaOH/kg grain) and rolled rye grain were given to cows in diets with $\text{concentrate}\text{roughage}$ ($\text{C}\text{R}$) ratios of 65:35 and 75:25. Alkali treatment tended to increase intake (by 13% for the 65:35 diet), but non-significantly. Milk yield and composition did not differ significantly among the four treatments.Alkali treatment of rye tended to increase the molar proportion of acetic acid and decrease that of propionic acid, although non-significantly.Apparent digestibility of dry matter, crude protein and energy, determined by the acid-insoluble ash (AIA) technique, did not differ significantly among treatments.In another trial, alkali treatment of rye grain for sheep resulted in no significant improvement in dry matter, energy or cellulose digestion, but alkali treatment of barley increased the digestibility of acid detergent fibre and cellulose. The present studies show a slight tendency for improvement with alkali treatment of whole rye grain, but further investigations are needed.     

曼陀罗药用价值的开发和利用

现代医学和临床研究表明,曼陀罗含有莨菪碱、东莨菪碱等多种生物活性物质,在生物医药领域的研究和应用中,具有广阔的前景。为了更好地开发利用这一药用植物资源,本文对其生物学特性,药用成分及开发利用现状等方面进行了综述,力求为相关研究提供参考。     

曼陀罗药用价值的开发和利用

现代医学和临床研究表明,曼陀罗含有莨菪碱、东莨菪碱等多种生物活性物质,在生物医药领域的研究和应用中,具有广阔的前景。为了更好地开发利用这一药用植物资源,本文对其生物学特性,药用成分及开发利用现状等方面进行了综述,力求为相关研究提供参考。