分子标记在啤酒花种质资源研究中的应用

该论文利用分子生物学中常用的DNA分子标记对世界各地现存的野生和栽培的啤酒花种质资源遗传多样性研究的应用进展做一综述。通过查阅和研读20世纪90年代以来发表的各类文献进行归纳总结。发现DNA分子标记相比形态学标记和细胞学标记具有结果准确、稳定的特点,常用的分子标记技术有RAPD、RFLP、ISSR、SSR、AFLP、EST等;研究发现北美洲的啤酒花遗传多样性要高于欧洲的啤酒花,基因变异程度也相对较高;野生啤酒花的基因序列具有丰富的基因多样性,可在分子杂交遗传育种中作为一个种质去改善栽培品种的某些不良性状。因此,利用分子标记研究啤酒花的遗传多样性将对啤酒花的优良育种提供理论指导和技术支持,目前较为理想的技术是SSR和AFLP。     

SSR分子标记在荔枝上的研究进展

SSR作为第二代基于PCR的一种新型DNA分子遗传标记,数量丰富、多态性高、重复性好、分布于整个基因组、特异位点扩增、发生频率高、共显性遗传等,在果树育种中具有极大的应用价值和开发潜力.本文主要简述了SSR标记的原理和特点,并从分子指纹图谱构建、种质资源的遗传多样性分析、核心种质的发掘、品种鉴定、分子标记辅助育种、遗传图谱构建与基因定位等多方面介绍了近年来SSR技术在荔枝上的应用现状及前景.     

鲤饲料转化率性状的QTL 定位及遗传效应分析

数量性状(QTL)定位是实现分子标记辅助育种、基因选择和定位、培育新品种及加快性状遗传研究进展的重要手段。饲料转化率是鲤鱼的重要经济性状和遗传改良的主要目标, 而通过QTL 定位获得与饲料转化率性状紧密连锁的分子标记以及相关基因是遗传育种的重要工具。研究利用SNP、SSR、EST-SSR 等分子标记构建鲤鱼(Cyprinus carpio L.)遗传连锁图谱并对重要经济性状进行QTL 定位。选用174 个SSR 标记、41 个EST-SSR 标记、345 个SNP 标记对德国镜鲤F2 代群体68 个个体进行基因型检测, 用JoinMap4.0 软件包构建鲤鱼遗传连锁图谱。再用MapQTL5.0 的区间作图法(Interval mapping, IM)和多QTL 区间定位法(MQMMapping, MQM)对饲料转化率性状进行QTL 区间检测, 通过置换实验(1000 次重复)确定连锁群显著性水平阈值。结果显示, 在对饲料转化率性状的多QTL 区间定位中, 共检测到15 个QTLs 区间, 分布在9 个连锁群上, 解释表型变异范围为17.70%—52.20%, 解释表型变异最大的QTLs 区间在第48 连锁群上, 为52.20%。HLJE314-SNP0919(LG25)区间标记覆盖的图距最小, 为0.164 cM; 最大的是HLJ1439-HLJ1438(LG39)区间,覆盖图距为24.922 cM。其中区间HLJ1439-HLJ1438、HLJ922 -SNP0711 解释表型变异均超过50.00%, 可能是影响饲料转化率性状的主效QTLs 区间。与饲料转化率相关的15 个QTLs 的加性效应方向并不一致, 有3个区间具有负向加性效应, 平均为?0.027; 12 个正向加性效应, 平均值为0.06。研究检测出的与鲤鱼饲料转化率性状相关的QTL 位点可为鲤鱼分子标记辅助育种和更进一步的QTL 精细定位打下基础。       

豌豆遗传图谱构建及QTL定位研究进展

豌豆的许多性状是多基因控制的数量性状,QTL定位就是以分子标记技术为工具、以遗传连锁图谱为基础、利用分子标记与QTL之间的连锁关系确定控制数量性状的基因在基因组中的位置.本文对QTL定位原理、方法进行了简单介绍;对豌豆遗传图谱构建及主要性状,如产量、品质、抗病性等QTL定位、遗传效应分析等方面的研究进行综述;对目前基于QTL豌豆分子标记育种存在的问题、应用前景进行了探讨.     

单核苷酸多态性与甜瓜抗枯萎病分子育种研究

目的:结合单核苷酸多态性标记技术,利用甜瓜本身的抗病性以解决新疆甜瓜病害问题。方法:对新疆甜瓜抗枯萎病基因Fom-2基因进行克隆分析,并根据Fom-2基因在不同抗性甜瓜亲本的单核苷酸多态性,设计检测SNP标记的PCR扩增引物,验证其多态性;并利用F2代分析该标记与筛选获得的甜瓜抗枯萎病基因连锁的SSR标记的遗传关系。结果:在抗病与感病甜瓜品种中均扩增获得PCR条带,试验中设计单核苷酸多态性分子标记在抗病品种为显性,与筛选的和抗枯萎病基因紧密连锁的共显性标记SSR430共分离。结论:不同抗性甜瓜品种均含有Fom-2基因或其高度同源序列,SNP显性标记和共显性标记SSR430均可用于甜瓜抗枯萎病分子标记辅助育种。     

分子育种与作物改良

所谓分子育种就是定向、有目的地对农作物品种的遗传进行改良和修饰。分子遗传学研究的不断深入为农作物的遗传改良提供了强有力的手段,特别是农作物质量性状和数量性状基因的标记、定位和克隆以及植物转基因方法的不断完善和成熟,展示了分子育种的诱人前景。１分子标记...     

分子标记在油茶研究中的应用

近年来,分子标记技术发展快速,其在油茶研究中的应用也越来越广泛。由于分子标记具有高效、可靠等诸多优点,它的快速发展为油茶开展遗传多样性分析、品种鉴定、优良基因定位、分子辅助育种、遗传图谱构建等方面研究提供了一条快速有效的途径。综述了RAPD、AFLP、SSR、ISSR和SRAP等几种分子标记在油茶研究中的应用,并在此基础上分析了分子标记在油茶研究中存在的问题和今后研究工作的重点。     

SSR分子标记在烟草研究中的应用进展

SSR分子标记技术作为最常用的分子标记技术之一,该标记技术重复性好,结果可靠,近年来在烟草遗传育种中展示了广阔的应用前景,是应用潜力较大的分子标记技术。介绍了SSR分子标记的原理及其分布特征,对其在烟草基因定位及分子标记辅助选择、种质资源研究、遗传图谱构建及种子纯度及真伪鉴定研究中的应用等方面进行了综述,并探讨了SSR分子标记技术在烟草遗传育种中的应用前景,以期为烟草SSR分子标记技术的研究提供参考。     

SSR分子标记在作物遗传育种中的应用

SSR(simple sequence repeat)是建立在PCR技术上的一种广泛应用的分子标记,具有含量丰富、多态性高、共显性等优点。本文简要介绍了SSR分子标记技术的原理和特点,重点介绍了SSR分子标记技术在作物遗传育种中的应用,主要在作物遗传多样性、基因定位、分子辅助标记、遗传图谱构建、品种鉴定和纯度鉴定等方面进行阐述。     

RAPD技术在植物遗传育种上的应用

RAPD技术以其快速、简便、高效等优点,已广泛应用于多个学科、领域。本文综述了RAPD技术在植物遗传育种上的应用,如遗传多样性研究、分子标记辅助育种、品种(杂种)真实性鉴定、基因定位、构建遗传图谱等。     

Barbels and related muscles in Mullidae (Perciformes) and Polymixiidae (Polymixiiformes)

Barbels of the Mullidae and Polymixiidae were observed osteologically and myologically. They were considered to be derived from branchiostegal rays. Four muscles, the extensor tentaculi, retractor tentaculi, and two sections of rotator tentaculi, were related to the barbels in both families. These muscles originate from almost all the hyoid bones in mullids, whereas they originate only from the ventral hypohyal and fifth branchiostegal ray in polymixiids. In addition, each muscle related to the barbel of the former is independent from others, but that of the latter is interconnected. These muscular differences indicate that the barbels occurring in the two families are nonhomologous. Received: August 27, 2000 / Revised: April 11, 2001/ Accepted: May 13, 2001     

侧柏雌球果及其胚珠的发育

Seed cone in Platycladus orientalis (L.) France consists of four or five pairs of decussate bracts. Usually, two pairs of the fertile bracts in the middle of the cone subtend six ovules, which initiate in an acropetal manner. Only one ovule presents on each of the upper fertile bract, while two ovules initiate from a common primordium in the axil of lower bracts. In Beijing, most female cones initiated in July. All parts of the cone formed before dormancy, which occurred during November to the next January. After pollination in March, bract morphology changed dramatically; intercalary growth of the bract base formed a conspicuous protuberance, in which inverted vascular system developed. Furthermore, ovules on different pairs of bracts initiated in an acropetal manner and two ovules in each lower fertile bract initiated from a common primordium, which was different from the basipetal initiation of ovules and independently formed single ovule as reported by Takaso in Calltris.     

Actinobacterial Diversity in Hot Springs in Tengchong (China), Kamchatka (Russia), and Nevada (USA)

Actinobacterial diversity was investigated in three hot springs [Tengchong Frog Mouth (TFM) hot spring (in Tengchong, China), Kamchatka Robb Flag hot spring (in Kamchatka, Russia), and Nevada Boiling Spring (in Nevada, USA)], a Tengchong Frog Mouth hot spring-derived pond and a soil sample near the TFM hot spring. Culture-independent techniques were employed including denaturing gradient gel electrophoresis and actinobacterial 16S rRNA gene phylogenetic analysis. The three hot springs and the hot spring-derived pond had pH of 6.8 to 7.9 and temperature of 50 to 81°C. Actinobacteria were for the first time found to be very diverse in hot springs with temperature up to 81°C, indicating that they have an unexpected capability of adapting to hot spring environments. A total of 346 actinobacterial clones were obtained from the three hot springs, and these clones were identified as 31 RFLP types, falling into the Actinomycetales (only limit to the Frankineae suborder), the Rubrobacterales, uncultured Candidatus Microthrix, unclassified Actinobacteria, and uncultured Candidate Division OP10. Our data have implications for a better understanding of the distribution of Actinobacteria in hot springs.     

(153)Sm(3+) and (111)In(3+) DTPA derivatives with high hepatic specificity: in vivo and in vitro studies

Two DTPA derivatives, a mono-amide derivative containing an iodinated synthon, DTPA-IOPsp (L(1)) and the ligand DTPA(BOM)(3) (BOM=benzyloxymethyl) (L(2)), radiolabelled with (153)Sm(3+) and (111)In(3+), were studied as potential hepatospecific gamma scintigraphic agents. In vivo studies with Wistar rats show that the main excretory pathway for all the chelates studied is the hepatobiliary system. The complexes of L(2) show even greater hepatobiliary specificity than L(1), perhaps as a consequence of longer blood circulation times due to their strong affinity towards HSA. The (153)Sm(3+) chelates are also more hepatospecific than the corresponding (111)In(3+) chelates. The La(3+) and In(3+) chelates of L(1) and L(2) show some structural and dynamic differences in aqueous solution, as studied by (1)H NMR spectroscopy. While only two nona-coordinated isomers were observed for the La(3+) complexes with both ligands, its number is much larger in the In(3+) complexes, with both octa- and hepta-coordinated species (with unbound side arms), as well as structural isomers for each coordination number.     

Cultivar differences in boron uptake and distribution in celery (Apium graveolens), tomato (Lycopersicon esculentum) and wheat (Triticum aestivum)

Species and cultivar differences in boron (B) uptake at low B availability and tolerance to high external B are known for many species but mechanisms explaining such differences remain obscure. Here we contrast B uptake and distribution between two cultivars of tomato and celery that differ significantly in their susceptibility to B deficiency. The celery cultivar S48-54-1 and tomato cultivar Brittle are known to be more susceptible to B deficiency (inefficient) than the closely related cultivars Emerson Pascal and Rutgers (efficient), respectively. B uptake and distribution was also compared in two wheat lines differing in tolerance to B excess (Chinese Spring, sensitive and Lophopyrum Amphiploid, tolerant). Results showed that there is no significant difference in either the specific uptake rate (I_M) of ¹⁰B or the relative growth rate (RGR) between the efficient cultivar (Emerson Pascal) and less efficient cultivar (S48-54-1) of celery. However, the distribution of ¹⁰B among plant organs (leaves, stems and roots) of Emerson Pascal was different from S48-54-1. In Emerson Pascal more than 63% of accumulated B was present in the shoots while in S48-54-1 only 45% of accumulated B was present in shoots. In tomato plants, in addition to differences in B distribution among plant organs between the efficient (Rutgers) and less efficient (Brittle) cultivars, the specific uptake rate of ¹⁰B was significantly higher in the efficient cultivar. In wheat, the tolerant line (Amphiploid) took up less B than the less tolerant cultivar (Chinese Spring), and the pattern of B distribution among plant organs was different with a greater percentage of B found in roots of Chinese Spring compared to Amphiploid. Differences in sensitivity to B deficiency and excess amongst cultivars and species were a consequence of either reduced B uptake as in wheat (Amphiploid), a restriction in B translocation from roots to shoot as in celery (S48-54-1) or a combination of both process as in tomato (Brittle).     

Bulb and Root Rot in Lily (Lilium longiflorum) and Onion (Allium cepa) in Israel

In the past 10 years, there has been a substantial increase in reports, from growers and extension personnel, on bulb and root rots in lily (Lilium longiflorum) in Israel. Rot in these plants, when grown as cut flowers, caused serious economic damage expressed in reduction in yield and quality. In lily, the fungal pathogens involved in the rot were characterized as binucleate Rhizoctonia AG‐A, Rhizoctonia solani, Pythium oligandrum, Fusarium proliferatum (white and purple isolates) and F. oxysporum, using morphological and molecular criteria. These fungi were the prevalent pathogens in diseased plants collected from commercial greenhouses. Pathogenicity trials were conducted on lily bulbs and onion seedlings under controlled conditions in a greenhouse to complete Koch's postulates. Disease symptoms on lily were most severe in treatments inoculated with binucleate Rhizoctonia AG‐A, P. oligandrum and F. proliferatum. Plant height was lower in the above treatments compared with the control plants. The least aggressive fungus was R. solani. In artificial inoculations of onion, seedling survival was significantly affected by all fungi. The most pathogenic fungus was F. proliferatum w and the least were isolates of F. oxysporum (II and III). All fungi were successfully re‐isolated from the inoculated plants.     

Cylicospirura species (Nematoda: Spirocercidae) and stomach nodules in cougars (Puma concolor) and bobcats (Lynx rufus) in Oregon

The stomachs and proximal duodena of 160 cougars (Puma concolor) and 17 bobcats (Lynx rufus), obtained throughout Oregon during 7 yr, were examined for Cylicospirura spp. and associated lesions. Prevalence in cougars was 73%, with a range in intensity of 1-562 worms. The mean diameter of nodules was 1.2 cm (SD=0.5), and many extended through the submucosa to the muscularis. About 83% of cougars had nodules; most nodules contained worms, but 14% of the smaller nodules (<0.2 cm) contained porcupine (Erethizon dorsatum) quills. A mean of 12.4 worms/nodule (SD=34.1) was observed, with a maximum of 340 worms/nodule. Prevalence in bobcats was 53%, with an intensity of 1-25 worms. About 65% of bobcats had nodules, which were slightly smaller than those in cougars but appeared to involve similar layers of gastrointestinal tissue. One to 25 Cylicospirura sp. were found in all but two small nodules in bobcats. Cougars killed for livestock damage or safety concerns had a significantly higher median worm intensity than did those that died of other causes. Also, the median worm intensity of older cougars was higher than that of younger lions. There were more males than females killed for livestock damage or safety concerns. The cylicospirurid from cougars was Cylicospirura subaequalis, and that of bobcats was Cylicospirura felineus. These two similar species were separated morphologically by differences in tooth and sex organ morphology. They were also differentiated by DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1). Worm sequences from cougars differed from those from bobcats by 11%, whereas essentially no difference was found among worms from the same host. Phylogenetic analysis showed that within the order Spirurida, both cylicospirurids were most closely related to Spirocerca lupi, based on this gene sequence.     

Birds and small mammals in kanuka (

Native kanuka (Kunzea ericoides) and adventive gorse (Ulex europaeus) stands aged 10-14 years, and not grazed by domestic stock, were studied near Nelson, New Zealand. The aim was to determine their use by introduced small mammals, and native and adventive birds, and the effects of these animals on seed rain and seedling dynamics as factors influencing vegetation succession. Seed traps were established where they could catch only bird-dispersed or wind-blown seed, and seedling emergence and growth were monitored. Bird abundance was estimated by five-minute bird counts, and small mammal abundance by trapping. The summed frequencies of all birds, and those likely to disperse seeds, were similar in kanuka and gorse. The endemic native bird species, bellbirds (Anthornis melanura) which are omnivorous, brown creepers (Mohoua novaeseelandiae) and grey warblers (Gerygone igata) which are insectivorous, were more frequent in kanuka than in gorse, while fantails (Rhipidura fuliginosa) were equally frequent in both stands. Non-endemic silvereyes (Zosterops lateralis) which are omnivorous were the most abundant seed-dispersing species, and they were significantly more frequent in gorse, as were adventive California quail (Callipepla californica) which are granivorous. Other small adventive granivores and omnivores were either more frequent in kanuka or gorse, or equally common in both stands. Ship rats (Rattus rattus) and possums (Trichosurus vulpecula) were in low numbers throughout. Mice (Mus domesticus) were more frequent in the gorse, probably because of the shelter offered by the dry gorse litter, and food supply, e.g. gorse seed. More seeds of native, fleshy-fruited shrubs fell in the kanuka, largely those of Coprosma spp. and Cyathodes juniperina, which grow in the kanuka. Seed species richness was similar in kanuka and gorse. In both cases, the seed rain appeared more influenced by the local seed source than by the different bird communities. In both kanuka and gorse, the relationship between seed rain and seedling numbers was close only for the most common fleshy-fruited species. Seedling emergence and survival was greater in gorse because of openings in the canopy, and the lower density of the introduced hares and rabbits. Overall, the different morphology and structure of the adventive gorse probably have the greatest influence in seedling dynamics, and ultimately on vegetation succession.