中国狗牙根[Cynodon dactylon (L.) Pers.]耐寒性及其变化规律

将49份具有代表性的我国狗牙根〔Cynodondactylon(L.)Pers.〕种源的离体叶片进行模拟低温处理,用电导法测其电导率,将电导率拟合Logistic方程,计算出狗牙根各种源叶片的半致死温度(LT50)。回归分析的结果表明:各种源的LT50与其所在的经纬度呈显著的线性关系,线性回归方程分别为Y=-31.3797 0.1478X和Y=-10.7982-0.1420X。依据LT50的变化,可将这49份狗牙根种源分为3大类,即低温敏感型(LT50≥-10℃)、过渡型(-18℃相似文献   

坪用狗牙根(Cynodon spp.)优良品种(选系)的抗寒性初步鉴定

以狗牙根属(CynodonRich.)的18个优良品种(选系)为试验材料,以我国草坪生产上广泛应用的普通狗牙根〔C.dactylon(L.)Pers.〕品种'Common'和杂交狗牙根(C.dactylon×C.transvaalensis)品种'Tifdwarf'与'Tifway'为对照,用电解质渗透法进行了抗寒性的初步鉴定。结果表明:与对照'Common'相比,除'OKc95 1'的LT50与'Common'接近,其他的普通狗牙根品种(选系)的LT50均低于对照,尤其是C174的LT50为-5.2℃,比对照低4.6℃;杂交狗牙根中,与'Tifdwarf'和'Tifway'相比,'TifgreenⅡ'、'TifwayⅡ'和'Midfield'3品种的LT50显著低于对照,其LT50分别是-7.5℃、-8.8℃和-6.0℃,'Tifeagle'、'Tifsport'和'Tiflawn'的LT50则都高于两个对照品种。     

湖南四种尾矿环境下的狗牙根遗传多样性的RAPD分析

选择湖南4种有代表性的有色金属尾矿地所生长的野生狗牙根作为研究对象,并以正常生境下的野生狗牙根作为对照,采用RAPD技术分析了这些特别环境下的狗牙根的遗传多样性。17条10个核苷酸长的引物用于PCR扩增,共得到432条DNA带。检测位点160个,其中多态位点134个,占83.75%。各个类群间的Jaccard相似系数平均为0.4475±0.0806,遗传距离平均为0.3825±0.0712。结果显示生长于这些不同尾矿环境下的狗牙根种群在遗传本质上均产生了明显的分化,完全可以根据其尾矿基质的不同而划分为不同的生态型或品种,甚至可能处理为新的变种。狗牙根种群具有丰富的遗传多样性,作为先锋植物可为尾矿的复垦提供更多的品种选择。     

野生狗牙根种质遗传多样性的SRAP研究

采用SRAP分子标记技术, 对采自中国四川、重庆、贵州、西藏四省区的32份野生狗牙根(Cynodon dactylon)材料进行遗传多样性分析, 获得下述结果：(1)用14对引物组合共得到132条多态性条带, 平均每对引物扩增出9.4条多态带, 多态性位点百分率为79.8%, 材料间的遗传相似系数范围在0.591到0.957之间, 平均GS值为0.759, 这些结果说明, 供试野生狗牙根具有较为丰富的遗传多样性; (2)对所有材料进行聚类分析, 可聚为4类, 大部分来自相同或相似生态地理环境的材料聚为一类, 表明供试材料的聚类和其生态地理环境间有一定的相关性; (3)基于Shannon多样性指数估算了6个狗牙根生态地理类群内和类群间的遗传分化, 发现类群内遗传变异占总变异的65.56%, 而类群间遗传变异占总变异的34.44%; (4)对各生态地理类群基于Nei氏无偏估计的遗传一致度的聚类分析表明, 各生态地理类群间的遗传分化与其所处的生态地理环境具有一定的相关性。     

狗牙根与非洲狗牙根形态鉴别性状的筛选

对10个狗牙根〔Cynodon dactylon(L.)Pers.〕和2个非洲狗牙根(C.transvaalensis Burtt-Davy)种源的13个外部形态性状进行了实地观测和统计分析。结果表明,与狗牙根相比,非洲狗牙根的叶片宽度较窄,穗支数较少,小穗较长,节间直径较细,穗支长度较短,差异显著;非洲狗牙根的叶片、葡匐茎及柱头的颜色与狗牙根有明显不同,因此,叶片宽度、节间直径、穗支数、穗支长度、小穗长度、叶片色泽、匍匐茎色泽和柱头色泽8个外部形态性状可作为鉴别这2个种的形态学指标。     

西南地区野生狗牙根种质资源的SSR与AFLP联合分析

为了制定科学的资源保护策略、促进其开发利用以及新品种的选育,对西南地区55份野生狗牙根材料,联合采用 SSR 和 AFLP 方法分析其遗传多样性.通过进行引物筛选,筛选出有效引物组合18对和11对;SSR 和 AFLP 扩增总条带353和626条,多态性条带267和592条,平均每对引物扩增出多态性条带19．61和53．83条,多态性位点百分率为75．10％和94．57％.聚类分析表明 GS＝0．806时,可将所有供试材料分成6个组群,当 GS＝0．82时,可将第 VI 个组群分成4个小组,当 GS＝0．836时,第 VI 组群中第3小组的14个材料分为3个组群基于 Shannon 多样性指数,类群内的遗传变异占总变异的67．41％,类群间的遗传变异占总变异的32．59％.基于 Nei 氏无偏估计的遗传一致度的聚类分析表明,各生态地理类群间的遗传分化与其所处的生态地理环境具有一定的相关性.通过两种标记的相关性分析,表明 SSR 和 AFLP 标记之间具有显著的相关性,而且相关性较高,证明供试材料的聚类和其生态地理环境间有一定的相关性;采用 SSR 和 AFLP 两种联合分析,结果会更加合理和有效.     

基于SRAP和TRAP标记的河北野生狗牙根种质遗传多样性分析

以SRAP和TRAP 2种标记技术对36份狗牙根材料的遗传多样性及亲缘关系进行了分析,其中包含34份河北省野生狗牙根种质资源。分别由238对SRAP和85对TRAP引物组合中筛选获得具有多态性的SRAP和TRAP引物组合各10对,PCR扩增总条带分别为186和161条,多态性条带156和132条,平均每对引物扩增出多态性条带各15.6和13.2条,多态性位点比率分别为83.4%和81.0%。2种标记合并进行聚类分析,所有供试的36份狗牙根材料遗传相似系数GS=0.519~0.983,平均为0.7。当GS=0.68时,可将36份供试材料分为4个类群。本研究结果表明河北野生狗牙根种质资源存在较丰富的遗传多样性,可为种质资源保护和选育优良狗牙根新品种提供科学依据。     

护坡卫士狗牙根

狗牙根(Cynodon dactylon)是禾本科狗牙根属植物,广泛分布于我国黄河流域和南方各省区,具有绿化、护坡、饲草等多种用途。 黄河自河南省郑州桃花峪到山东垦利县的下游河段,河长786公里。这段河段的特点是水势平缓,河道宽浅散乱,泥沙淤积,河床逐年升高,河道滩面一     

狗牙根花序发育过程的形态学观察

对狗牙根(Cynodon dactylon‘C299’)花序发育过程中的形态学变化进行了观察。结果表明,‘C299’花序的整个发育过程可分为8个阶段,即营养生长期、穗轴发生期、苞叶原基分化期、小穗原基分化期、小穗分化期、小花分化期、颖片和内外稃发育期及花药和柱头形成期。其中,穗轴发生期(直立茎上有6~9片叶)是抑制花序形成和决定种子产量的关键时期。     

不同地理种群狗牙根耐寒性研究

低温是狗牙根冬季生长的主要限制因素,越来越引起草业工作者的重视.以收集于我国不同地理种群的野生狗牙根为试验材料,探讨低温对不同种群狗牙根草坪质量和生理反应的影响,为抗寒栽培和耐冷育种提供理论和实践支持.结果表明:起源于高纬度狗牙根耐寒性最强,低纬度最差.起源纬度与狗牙根的耐寒性、可溶性糖含量、可溶性蛋白含量具有极显著的相关性,与过氧化氢酶(CAT)和过氧化物酶(POD)活性具有显著的相关性,而与草坪质量、超氧化物岐化酶(SOD)活性、丙二醛(MDA)含量、叶绿素a、叶绿素b以及叶绿素含量的相关性不显著.     

悬钩子属植物的RAPD分析

用RAPD标记技术对13个黑莓（blackberry）、树莓（raspberry）品种和5个野生悬钩子种类（Rubus spp．）的26个居群的遗传多样性进行了分析。用15个寡聚核苷酸随机引物共扩增出条带131条,其中多态性条带118条,占扩增条带总数的90％,表明悬钩子属植物种间和品种间存在丰富的遗传多样性。通过聚类分析可将供试的26个居群分为4组,其中A组有粗叶悬钩子（R．alceaefolius Poir．）、山莓（R．corchorifolius L．）、插田泡（R．coreanus Miq．）、掌叶覆盆子（R．chingii Hu）、‘威廉姆特’、‘托拉咪’、‘泰勒’、‘金克维’、‘布里斯托’、‘宝森’7号、‘布莱兹’及其实生苗、‘基奥瓦’、‘萨尼’、‘黑布特’等15个居群;B组包括‘宝森’1号～‘宝森’6号和‘马林’、‘乔克多’等8个居群;C组包括‘赫尔’和‘切斯特’的2个居群;D组仅有蓬藁（R．hirsutus Thunb．）1种。这一聚类结果与传统形态学分类结果基本吻合。     

AFLP analysis of Cynodon dactylon (L.) Pers. var. dactylon genetic variation.

Cynodon dactylon (L.) Pers. var. dactylon (common bermudagrass) is geographically widely distributed between about lat 45 degrees N and lat 45 degrees S, penetrating to about lat 53 degrees N in Europe. The extensive variation of morphological and adaptive characteristics of the taxon is substantially documented, but information is lacking on DNA molecular variation in geographically disparate forms. Accordingly, this study was conducted to assess molecular genetic variation and genetic relatedness among 28 C. dactylon var. dactylon accessions originating from 11 countries on 4 continents (Africa, Asia, Australia, and Europe). A fluorescence-labeled amplified fragment length polymorphism (AFLP) DNA profiling method was used to detect the genetic diversity and relatedness. On the basis of 443 polymorphic AFLP fragments from 8 primer combinations, the accessions were grouped into clusters and subclusters associating with their geographic origins. Genetic similarity coefficients (SC) for the 28 accessions ranged from 0.53 to 0.98. Accessions originating from Africa, Australia, Asia, and Europe formed major groupings as indicated by cluster and principal coordinate analysis. Accessions from Australia and Asia, though separately clustered, were relatively closely related and most distantly related to accessions of European origin. African accessions formed two distant clusters and had the greatest variation in genetic relatedness relative to accessions from other geographic regions. Sampling the full extent of genetic variation in C. dactylon var. dactylon would require extensive germplasm collection in the major geographic regions of its distributional range.     

The small-scale pattern of Cynodon dactylon in Mediterranean pastures

The abundance of Cynodon dactylon was recorded in 50 plots presenting different geomorphological conditions and along a transect of 16 500 2×2 cm contiguous quadrats within a small basin 330 m in length, in the granite pediment of the Sierra de Guadarrama (Central Spain). Soil analyses were undertaken on samples from the 50 plots and the soil information matrix obtained was analysed using Principal Components Analysis and Discriminant Analysis. Results showed that in the Mediterranean pastures Cynodon dactylon was restricted to deep, well developed soils with relatively high values of cations, conductivity and organic matter, and could be used as an indicator of such soil conditions in these grasslands. The spatial pattern of the species was analysed using New Local Variances which revealed the existence of a small-scale pattern, ranging from 8 to 18 cm, present at all levels of the analysis. The size of small-scale patterns was positively correlated with species abundance and was interpreted as a relation between plant vigour and favourable soil conditions.I would like to thank Professor González Bernáldez for his interest and encouragement.     

茶园黑刺粉虱(Aleurocanthus spiniferus)种群的RAPD多样性

用RAPD技术对华东地区7个茶园的黑刺粉虱种群进行遗传结构分析。从40个随机引物中筛选出9条具特异性的引物,扩增出248条长度约为200～2000bp的DNA条带,其中199条多态性条带,多态性为80．24％。经Popgene软件分析,黑刺粉虱种群平均水平的多态位点百分比（P砚）为48．33％,Nei＇s基因多样性（HE）为0．2910,Shannon＇s多态性信息指数（日）为0．4442,表明黑刺粉虱种群遗传多样性丰富;各种群问遗传分化程度（Gst）较高,达0．3749,其中PPL以福建武夷山区的九龙山种群（JLS）最高,达77．42％,其次为安徽九华山种群（JHS）的65．73％;而且两种群的HE,H等遗传指标均较高。以NTSYSpc软件包,基于Nei＇s遗传距离对昆虫个体进行UPGMA和NJ法聚类分析,构建分子系统树,并进行多维标度分析（MDS）。系统树显示：同一种群的个体优先聚类,遗传相似度高的种群依次聚类。多维标度分析也显示：浙江杭州、富阳和绍兴3种群集中分布,安徽宣城种群靠近该3种群;而九华山种群则与武夷山区的九龙山种群聚拢;福建金山种群独立成簇。多维标度分析与聚类分析结果一致。认为粉虱种群间的遗传距离与地理距离之间存在相关性;两个山地种群的多样性有别于其它种群,是因为山地环境和气候引起粉虱适应性的生态地理分化。     

不同化学型樟树的RAPD分析

用RAPD标记技术分析了30个不同化学型樟树〔Cinnamomum camphora(L.)Presl〕样本的遗传关系。14个引物共扩增出170个位点,其中多态位点161个,多态性位点百分率达94.71%,特异位点有15个。聚类结果显示,当λ=13时,30个樟树样本被分为4类,即芳樟型(主成分为芳樟醇)、脑樟型(主成分为樟脑)、桉樟型(主成分为1,8-桉叶油素)和黄樟型(主成分为黄樟醇),表明不同化学型樟树样本间的遗传关系与其叶精油的主成分有一定的相关性。     

Chromosome Number in Cynodon dactylon in Relation to Ecological Conditions

Populations of Cynodon dactylon (L.) Pers. were collected fromthree habitat types (roadsides, lawns and paddy-fields) withineach of five climatic regions (arid, dry, intermediate, wetand hill country) in Sri Lanka. Further populations were collectedfrom forests and grasslands in the hill country. Most populations contained only tetraploid plants (2n = 36),but populations from roadsides and lawns in the wet region,and from forests in the hill country, contained only diploidplants (2n = 18). Populations from paddy-fields in the wet regioncontained both tetraploid and diploid plants. No triploid plantswere found in any environment, despite the fact that C. dactylonpredominantly reproduces vegetatively by both stolons and rhizomes.Soil acidity seems to be the main factor determining the distributionof the two cytotypes.Copyright 1995, 1999 Academic Press Cynodon dactylon (L.) Pers., chromosome number, ecology, habitat, climatic region     

基于RAPD标记的薄荷属(Mentha L.)植物亲缘关系分析

应用RAPD标记方法分析了薄荷属(Mentha L. )7个种38个种源间的遗传多样性,并采用UPGMA聚类分析方法探讨了38个种源间的亲缘关系.结果表明,用20条随机引物从38个种源的总DNA中共扩增出111条带,其中多态性条带91条,多态性条带百分率达81.98%,表明薄荷属植物种间和种内存在丰富的遗传多样性.聚类分析结果表明,在遗传相似系数0.43 处,供试的38个种源被分为2大类,其中第1大类包含日本薄荷(M. arvensis L. )、灰薄荷(M. vagans Boriss. )、留兰香(M. spicata L. )、皱叶留兰香(M. crispata Schrad. ex Willd. )、椒样薄荷(M.×piperita L. )和薄荷(M. haplocalyx Briq. )的37个种源,第2大类仅包含唇萼薄荷(M. pulegium L. )1个种源.在遗传相似系数0.74处,38个种源被分为6组:A组仅包含日本薄荷1个种源;B组包含灰薄荷的4个种源;C组包含留兰香的2个种源和皱叶留兰香的6个种源;D组包含椒样薄荷的5个种源和留兰香的2个种源;E组包含薄荷的17个种源;F组仅包含唇萼薄荷1个种源.在遗传相似系数0.83处,B组、C组、D组和E组可各自进一步划分为不同的亚组.研究结果显示,基于RAPD标记分析的聚类分析结果与传统形态学分类结果基本相吻合;同一种类来源相同或相近的种源聚在一起,说明薄荷属植物种内的遗传关系与地理分布和环境差异有一定的相关性.     

Genetic analysis of Canarium album in different areas of China by improved RAPD and ISSR

To lay the foundation of the classification of Canarium album (C. album), and C. album from Terminalia Chebula (T. chebula) in different areas of China, improved RAPD and ISSR analysis were performed to analyze polymorphism and genetic relationship. Ten samples were collected from different locations in China. A total of 221 fragments were detected by improved RAPD, out of which polymorphic fragments accounted for 82.3% with average amplification bands of 10.05 per primer. ISSR markers revealed a total of 147 alleles, where polymorphic fragments accounted for 83.5%, with average amplification bands of 7.35 per primer. The sizes of fragments ranged from 200 to 2500 bp and from 150 to 2000 bp in RAPD and ISSR markers, respectively. The similarity coefficient ranged from 0.46 to 0.86 with RAPD markers and 0.36 to 0.89 with ISSR markers. The results indicated that improved RAPD and ISSR methods are useful for genetic diversity study of C. album. Thus, this study provides us the theoretical basis for the breeding and classification of C. album in South and Southwest China.     

Physiological responses of bermudagrass (Cynodon dactylon) to submergence

A split-plot design was used to study the physiological responses of anti-oxidative enzymes and carbohydrate contents of bermudagrass to different durations (0, 3, 7, 15, 30, 60, 90, 120 and 150 days) and depths of submergence (0, 1, 5 and 15 m). The results suggest that submergence caused a higher production of malondialdehyde and more significant changes in the different submerged treatments. The activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and glutathione reductase (GR) in roots increased with the increase of the durations and depths of submergence, implying an integrated pathway involving CAT, SOD, POD, GR and APX for protection against the detrimental effects of activated oxygen species under submergence. Total soluble carbohydrate and starch contents of shoots and roots decreased with the increase of the depth and duration of submergence, but remained at relatively high level at the end of the study, showing quiescence is one of the major strategies of bermudagrass under the stress of submergence. The results suggest that bermudagrass can endure long-term and deep submergence by balancing between the formation and detoxification of activated oxygen species, lowering metabolism and reserving high amounts of carbohydrate.