Aneuploids of perennial ryegrass (Lolium perenne)     

B. S. Ahloowalia 《Euphytica》1982,31(1):103-111

Summary Aneuploid plants of perennial ryegrass (Lolium perenne L.) with 2n=15 to 30 chromosomes were obtained by crossing a near-triploid (2n=3x+1=22) with a diploid or on open-pollination with diploids and tetraploids. Aneuploids occurred with a frequency of 83% in near triploid × diploid progeny and 92% on open-pollination with diploid and tetraploid plants. Aneuploid plants with 15 to 18 chromosomes resembled diploids in morphology and those with 19 to 30 chromosomes were akin to tetraploids. Meiotic studies suggested that most aneuploid plants resulted from transmission of aneuploid egg cells (n=8 to 23). Aneuploid plants with 2n=27 to 30 chromosomes in the progeny of 22×14 cross originated from unreduced egg cells. Plants with 19 to 21 chromosomes were recovered only by immature seed culture. Aneuploid plants with 26 to 30 chromosomes and triploids (2n=21) had higher pollen fertility and bigger seeds than plants with 15 to 22 chromosomes.  相似文献   

利用SSR鉴定普通小麦-多枝赖草二体异附加系 Line24中外源染色体同源群的归属     

郭光艳  李瑞芬  张敬原  葛荣朝  赵茂林  沈银柱  黄占景 《华北农学报》2004,19(4):14-17

用227对小麦微卫星引物进行PCR扩增，76对可在多枝赖草和耐黄矮病的普通小麦-多枝赖草二体异附加系Line24的小麦亲本中国春、丰抗13间检测到多态性。和多枝赖草相同而与Line24其他小麦亲本不同的扩增带。在这76对引物中，发现有4对引物能从Line24中扩增出进一步用Line24和普通小麦杂交得到的7个不同的单体异附加系进行验证，也得到同样的结果，说明这4对微卫星引物扩增出的特异带可以作为Line24中多枝赖草染色体的分子标记。根据这4对引物各自对应的微卫星标记位点在小麦染色体上的位置，说明Line24中附加的一对多枝赖草染色体是第3，5，6和7部分同源群多枝赖草染色体相互易位形成的。  相似文献   

自私遗传元件     

靳忠英  彭正松 《广西农业生物科学》2007,26(1):88-93

自私遗传元件(SGEs)采用对自身有利的方式进行传递,它们在生物中广泛存在,在生物进化中具有不可替代的重要作用。SGEs被认为是生物基因组的重要部分,它们以低拷贝数长期稳定地寄生在宿主及其基因组中。SGEs的种类很多,所熟知的有转座元件、Wolbachia、B染色体、减数分裂驱动元件、限制-修饰系统和Medea基因等。为了加强自身的传播,这些元件通过许多方法操控宿主配子发生过程或宿主生殖,如诱导减数分裂驱动或胞质不亲和性和雌性化、雄性致死或雄性不育等。它们对宿主的调控和宿主基因组对这种调控的反应可能暗含着性别决定的进化、物种形成等重要机制。本文对SGEs的种类及其作用的研究进展进行了综述。  相似文献   

Trait inheritance,fertility, and genomic relationships of some n = 9 Brassica species     

Shahryar F. Kianian  Carlos F. Quiros 《Genetic Resources and Crop Evolution》1992,39(3):165-175

Summary Karyotypic differences among n = 9 Brassica species, as well as the inheritance of some morphological characteristics, are reported. Annual habit, anthocyanin pigmentation in leaf and stem, enlarged stem, glossy foliage, dark green foliage, white flower and leaf pubescence were all expressed as dominant characteristics and in most cases were determined by one or two genes. 172 intra- and interspecific hybrids of the species belonging to the Brassica oleracea cytodeme were analyzed for fertility and meiotic chromosome behavior. B. alboglabra, B. bourgeaui, B. cretica spp. cretica, B. montana and B. oleracea produced fertile interspecific hybrids, indicating that geographical isolation is the only barrier to gene exchange. Interspecific hybrids generated from crosses of B. incana, B. insularis and B. rupestris to other n = 9 species were semi-sterile. This was shown to be associated with abnormal meiotic behavior. The former two species, when crossed, produced fully fertile hybrids. Therefore, three different karyotypes are identified among the n = 9 Brassica species. Frequent changes in the genome of the species belonging to the Brassica oleracea cytodeme could have led to the formation of accessory chromosomes present in certain accessions.  相似文献   

拟水狼蛛染色体的初步观察     

彭宇  胡萃  赵敬钊 《浙江大学学报(农业与生命科学版)》1998,(3)

以附肢形成之前的蜘蛛胚胎细胞为材料,经秋水仙素处理、纸渗、固定、制片及染色,对拟水狼蛛的体细胞染色体进行了初步观察．结果表明：拟水狼蛛的染色体数为：雄性２ｎ＝２６,雌性２ｎ＝２８,性别决定机制为Ｘ１Ｘ２Ｏ．Ｃ－带分析表明,所有染色体都为端着丝粒染色体,端部有特异性染色质存在．  相似文献   

同源四倍体黄花菜减数分裂行为及其育性的探讨   总被引：20，自引：0，他引：20  

李爱华  何立珍 《湖南农业大学学报(自然科学版)》1998,24(1):14-17

为探讨四源四倍体黄花茶部分不育和结实率低的原因,以同源四倍体黄花菜新品系ＨＡＣ－大花长嘴子花为材料,观察其花粉母细胞减数分裂行为。结果表明：在减数分裂不同时期出现异常现象,双线期和终变期见到四价体,三价体,二价体,单价体;中期Ⅰ,后期Ｉ和末期Ｉ均出现落后染色体,后期Ｉ见到染色体桥和断片  相似文献   

利用AFLP方法筛选中华绒螯蟹性别相关标记     

吕慧锋  江学慧  邱高峰 《上海海洋大学学报》2012,21(5):650-655

利用AFLP(amplified fragment length polymorphism)技术筛选中华绒螯蟹性别相关标记,共使用192对引物组合检测中华绒螯蟹雌、雄和雌雄混合3个基因组池的多态性,共扩增出5 376条多态性条带,平均每对引物组合扩增出28条多态性条带,获得88条雌雄差异条带。利用雌雄各10个个体再次进行AFLP验证,共62条差异条带具有性别差异,包括两种情况:(1)有49条条带在雌性的4～6个个体中存在,在雄性全部个体中缺失;(2)有13条条带在雄性4～6个个体中存在,在所有的雌性个体中缺失;其余的26条没有性别差异性。差异条带经回收、克隆、测序,结果发现有些条带包含多个序列,共得到77条DNA序列,其中31条序列与鸟类、两栖类和哺乳类等脊椎动物性染色体DNA部分片段具有同源性,相似区间在22～212 bp不等,其中6条DNA序列与命中序列之间具有生物学相关性。设计特异性的引物在基因组中检测,没有获得性别特异SCAR标记。  相似文献   

秋水仙素对肇东苜蓿根尖细胞染色体的影响     

曹惠美  张月学  刘凤歧  唐凤兰  韩微波  刘杰淋  朱瑞芬 《黑龙江农业科学》2012,(5):121-124

为了探究秋水仙素对肇东苜蓿根尖细胞染色体的影响,利用不同浓度的秋水仙素(0.01%、0.05%、0.10%、0.15%和0.20%)以及处理时间(12、24、36和48h)分别对肇东苜蓿根尖细胞进行诱导,观察肇东苜蓿根尖细胞染色体、细胞中期分裂指数和细胞加倍指数的变化。结果表明:秋水仙素诱导了肇东苜蓿根尖细胞染色体的变异,细胞内染色体加倍,数目不等(32、64及128条);在时间与浓度互作方面,秋水仙素溶液浓度为0.15%时处理肇东苜蓿根尖12h,使细胞中期分裂指数达到最大值18.51%;利用浓度为0.10%的秋水仙素处理24h,细胞加倍指数达到最高值11.57%。  相似文献   

2种制备黄河鲤鱼染色体方法的比较及条件优化   总被引：1，自引：0，他引：1  

陈建军  潘春梅  常重杰 《甘肃农业大学学报》2012,47(1):41-44,48

以黄河鲤鱼为材料,采用体外肾细胞培养及空气干燥法制作染色体标本,通过对不同培养时间,不同秋水仙素处理时间获得的染色体分裂指数的比对,以期获得最佳的染色体制备条件.结果表明:在秋水仙素浓度及处理时间一定时,培养时间3d后分裂指数最高,为1.46%,且分裂相在前3d逐渐增多,第4d开始减少;同时发现,在培养时间一定时,秋水仙素处理时间为2h时分裂指数最高,为1.49%.因此认为最佳染色体制备条件为:培养时间3d,秋水仙素处理2h;与传统的体内注射PHA短期培养法制备的染色体标本相比,体外肾细胞培养法制备的标本背景清晰,染色后形态可辨,且染色体分散良好,彼此间没有交联,放大后染色体的测量较易完成,可以进行核型分析.  相似文献   

Meiotic chromosome preparation techniques of pollen mother cells for laser micro-dissection in <Emphasis Type="Italic">Populus</Emphasis> spp.     

Hong-yan Yang  Jun Wang  Xiang-yang Kang 《中国林学(英文版)》2010,12(2):74-78

In order to isolate meiotic chromosomes of Populus species meiotic chromosome preparation techniques of pollen mother cells for laser micro-dissection were studied. Pollen mother cells at diakinesis of Populus canadensis Moench were used as samples. Two methods were used to prepare meiotic chromosomes: in the first, cell suspensions were dropped on polyethylene-naphthalate or polyester membrane slides which had just been incubated at –20°C; in the second method, cell suspensions were also dropped on polyethylene-naphthalate or polyester membrane slides, but spread with the aid of high temperatures. The cells did not completely spread by the first method and chromosomes at diakinesis could not be individually distinguished. In contrast, well-spread diakinesis chromosomes were obtained by the second method, where chromosomes, connected with their nucleolus, were successfully isolated with the laser micro-dissection system. As well, we discuss the prospect of applications of laser micro-dissection in cytogenetics and molecular genetics in Populus species.  相似文献