首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 359 毫秒
1.
苜蓿属植物有６０余种,染色体数可分为二倍,四倍体和六倍体。其中１年生二倍体有３２种,四倍体２种,１年生主要是自花授粉;多年生二倍体１３种,四倍体２种,有４个二倍体兼有四倍体,有１个四倍体兼有六倍体,多年生主要是异花授粉。１　二倍体、四倍体种群多年生二倍体、四倍体苜蓿染色体基数相同,二倍体２ｎ＝２ｘ＝１６,四倍体２ｎ＝４ｘ＝３２（见表１）［１］。表１　多年生苜蓿属二倍体、四倍体植物及其染色体数（２ｎ）种名中名染色体数种名中名染色体数Ｃａｒｓｔｉｅｎｓｉｓ卡斯廷苜蓿１６Ｒｕｐｅｓｔｒｉｓ岩苜蓿１６Ｃ…  相似文献   

2.
利用荧光原位杂交技术,在蒙古冰草染色体组上进行5S rDNA、45S rDNA以及重复序列pAs1 DNA序列的定位,通过荧光原位杂交信号的强弱、数量、位置进行蒙古冰草染色体的配对及核型分析。结果表明:蒙古冰草染色体组总长度为91.788μm,平均绝对长度为13.113μm,最长染色体与最短染色体的长度比值为1.446,具有2对随体,分别位于第2号染色体和第4号染色体的短臂上,没有臂比大于2∶1的染色体,核型不对称系数为56.96%,核型类型属于1A型,核型公式为2n=2x=14=10m(2SAT)+4sm(2SAT)。5S rDNA序列和45S rDNA序列分别位于第2号和第4号染色体的短臂上,有5对染色体两端都检测到明显的pAs1 DNA荧光信号,有2对染色体只有一端检测到明显的pAs1 DNA荧光信号。荧光原位杂交技术大大提高了染色体核型分析的可靠性,为冰草属内植物的分类和育种提供了细胞学依据。  相似文献   

3.
以桑的幼叶为材料,采用以酶解、火焰干燥,Giemsa染色为主要程序的染色体制片新方法,对桑属(Morus L.)9个种的25个品种以及5个未定种名的材料进行了染色体计数,其中二倍体19个、三倍体7个、四倍体1个、六倍体2个和单体(2n—1)1个。此外,还对不同倍性的间期核以及二倍体和三倍体在减数分裂过程中染色体的行为作了观察和比较。  相似文献   

4.
孙浩男  李明阳  刘冬云  王鑫  田琳  吴芳芳 《草地学报》2021,29(11):2477-2485
为了区分不同金鸡菊的种质,明确目前广为栽培的金鸡菊的染色体数目及核型特征,采用常规压片法,以60个不同的金鸡菊种质为材料,鉴定其根尖细胞的染色体数目,并选取其中18个籽播系材料进行染色体核型分析。结果表明：60个金鸡菊的染色体数目包括12个类型,染色体数目24~52不等,18个核型分析的材料全部为二倍体,染色体基数存在x=10,12,13,14四种。在6个材料中发现了随体,未发现B染色体,染色体类型包括s,sm,st三种。核型全部为2A,核型整体上较为对称,核型不对称系数为58.56%~64.93%,一年生类型的金鸡菊普遍进化程度更高。亲本复杂的染色体基数及染色体倍性是造成栽培金鸡菊染色体数目多变且产生大量非整倍体的主要原因。本研究从细胞学方面为金鸡菊的分类鉴定和杂交育种提供了理论参考。  相似文献   

5.
1.本文研究了四川省桑树品种资源163份材料染色体的倍数性,发现其中三倍体13个,四倍体2个,六倍体12个,八倍体1个,其余135个为二倍体。 2.在163份材料中,栽培型119个,野生型44个,栽培型中三倍体6个,其余113个皆为二倍体。野生型中三倍体7个,四倍体2个,六信体12个,八倍体1个。多倍体数占野生型总数的一半。表明野生型中有极为丰富的多倍体。 3.在已进行分类鉴定的104份材料中,分属桑树8个种。在不同种群中多倍体数量和倍性均有很大差异,华桑中发现二倍体,三倍体,四倍体,六倍体,八倍体,倍性丰富。在蒙桑和鬼桑中有六倍体,为首次报道。在园叶桑、鸡桑、白桑中有三倍体。 4.多倍体研究在研究桑树起源,分化,遗传育种上具有重要价值。四川省桑树野生资源中,倍性极为丰富,表明四川省在桑树起源研究上有重要地位。多倍体具有许多特殊优良性状。多倍体育种是现代桑树育种的重要方向。  相似文献   

6.
研究了秋水仙碱不同浓度(0.05%、0.2%、0.3%)、不同处理时间(1d、2d、3d)、种子不同萌芽阶段(芽长<0.5cm、1~2cm、>3cm)对二倍体鸭茅染色体加倍效果及生长发育的影响。结果表明,三个因素对诱变效果均有一定程度的影响,所有染色体加倍植株均为混倍体,即同一根尖细胞中二倍体和四倍体细胞共存;混倍体早期生长弱于二倍体,以后的生长发育及开花期形态特征二者几乎无差异。  相似文献   

7.
通过对24份来自不同地方的供试材料(苜蓿属18份、胡卢巴属6份)的根尖细胞染色体进行压片,采用染色体计数法初步了解供试材料的染色体数目、平均臂比值和平均着丝点指数,进一步了解苜蓿属和胡卢巴属亲缘关系。实验结果表明:苜蓿属18个材料中共检测出二倍体(2n=2x=16)和四倍体(2n=4x=32)的2个倍性水平;胡卢巴属6个材料均为二倍体,染色体组成为(2n=2x=16)。从染色体数目和倍性水平初步来看,胡卢巴属植物与苜蓿属的部分植物亲缘关系较近。聚类分析结果表明:胡卢巴属植物与苜蓿属的扁蓿豆材料亲缘关系较近,与苜蓿属的其它材料亲缘关系比较远。  相似文献   

8.
为了探明我国紫苏属（Perilla Linn.）植物的染色体特点,本研究采用常规压片法对我国紫苏属的28份材料的染色体核型进行分析研究。结果表明：供试的28份紫苏属材料,染色体基数均为x=20,其中3个为四倍体,2n=80,其余25份皆为二倍体,2n=40;28份材料中均有发现至少一个随体,染色体类型包含m,sm,st 3种,核型有2A,3A,2B,3B 4个类型,最长染色体/最短染色体值1.50~2.80,臂比大于2的染色体占染色体总数的百分比为10%~65%,核型不对称系数59.69%~68.52%;通过核型分析,回回苏和多倍体紫苏类型可能具有更高的进化地位,而野生紫苏与之相反。这些数据表明了我国紫苏属植物资源在细胞学方面具有较为丰富的多样性,同时本研究也对我国紫苏属植物的分类、鉴定等提供了理论参考。  相似文献   

9.
为了分析建昌马的Y染色体遗传多样性和父系起源进化,试验从建昌马公马(n=21)血液样本中提取基因组DNA,对马Y染色体上4个遗传标记位点(Y-25 345、Y-45 288、Y-45 701/977、Y-50 869)进行PCR扩增后直接测序,分析测序结果并定义马Y染色体单倍型。结果表明:在建昌马的1个遗传标记位点发现单核苷酸多态性(Y-50 869,T/A),共鉴定出2种单倍型,即CHT1和CHT2,其中CHT1单倍型占绝对优势,单倍型多样性为0.095±0.084,核苷酸多样性为0.000 36±0.000 32,Y染色体遗传多样性低。说明建昌马可能有2个父系起源。  相似文献   

10.
中国不同地区罂粟的核型比较   总被引：2，自引：0，他引：2  
为揭示不同地区生境条件下的罂粟生态型的染色体核型变化,利用普通压片法对来自中国5个省(市)的10份罂粟材料染色体数与核型进行了分析。结果表明,不同地区来源的罂粟材料可分为白花1号和白花2号2个生态型,染色体倍性均为二倍体,染色体数目为2n=2x=22条,染色体相对长度组成(IRL)为2L+3M2+5M1+1S;白花1号的核型公式是K(2n) =2x=22=18sm+4st,平均核型不对称系数(Ask)为72.04%,核型分类标准属于4A型;白花2号的核型公式是K(2n)=2x=22=16sm+6st,平均核型不对称系数为73.00%,核型分类标准属于4B型;不同地区的白花1号和白花2号的核型均为极不对称型,但核型发生了多样性变化。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
Tropical Animal Health and Production -  相似文献   

14.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

15.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

16.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

17.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

18.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

19.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

20.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号