小麦主要经济性状遗传参数的分析

小麦主要经济性状大多属数量性状,是受 微效多基因控制的。为了探索小麦常用亲本配 制组合时各主要经济性状的遗传变异规律,于 1980年选用了江苏、浙江两省普遍采用的UP 301、泰山1号、908、早白、白壳早、短秆早6 个品种作为杂交亲本,研究并分析了主要经济 性状的遗传参数,为有效地选配亲本,提高育种 成效,提供一些理论依据。     

小麦主要经济性状遗传参数的分析1)

小麦主要经济性状大多属数量性状，是受 微效多基因控制的。为了探索小麦常用亲本配 制组合时各主要经济性状的遗传变异规律，于 1980年选用了江苏、浙江两省普遍采用的UP 301、泰山1号、908、早白、白壳早、短秆早6 个品种作为杂交亲本，研究并分析了主要经济 性状的遗传参数，为有效地选配亲本，提高育种 成效，提供一些理论依据。     

冬小麦杂种后代(F_1、F_2)早熟性遗传的初步分析

通过试验说明,小麦的早熟性属数量性状。用生育期不同的亲本杂交,F_1抽穗期介于双亲之间,并倾向早熟亲本;F_1杂种的平均优势为-14.2％;F_2的抽穗期呈连续变异,并出现超亲遗传现象。小麦抽穗期的遗传力较高,平均为63.76％。F_1的抽穗期与双亲抽穗期的平均值具有明显的相关性,r=0.767,回归系数为0.715。生育期不同的亲本对杂种后代有较大的影响。一般组合受“早亲”的影响较大,但也不能忽视“晚亲”的制约作用。不同亲本早熟性的遗传传递力不同。在育种工作中应注意早熟亲本的选择。根据早熟性遗传规律,可以“早中选早”,也可以“晚中选早”,在杂种的早期世代选择早熟的类型是有效的。     

陕西关中地区杂种小麦强优势组合优势型研究

选用在陕西关中地区表现优良且某一农艺性状表现突出的11个冬小麦品种(系),根据农艺性状分为大粒型、多穗型、穗重型和中间型4类,组成6种NCII杂交组合模式,研究不同组合模式的杂种优势,探讨根据农艺性状划分杂种小麦亲本优势型在杂种小麦强优势组合选配中的应用.结果表明:在所组配的6种组合模式中,以大粒×多穗型组合模式表现突出,其杂种优势、超亲优势和超标优势均明显高于其它组合,分别达到了59.9%、37.1%和22.5%,因此,依据杂种小麦亲本农艺性状进行亲本优势型划分可以作为杂种小麦亲本选配的依据之一.在陕西关中地区以大粒×多穗型为杂种小麦强优势组合组配模式.     

小麦灌浆特性的遗传研究Ⅰ.遗传模型及基因效应

利用8个小麦品种双列杂交的F~1|及其亲本, 按Hayman分析法研究了小麦籽粒灌浆特性的遗传规律。结果表明,小麦籽粒灌浆特性符合加性-显性遗传模型。基因作用以加性效应为主,呈部分显性。籽粒灌浆期的显性方向指向增效,籽粒灌浆速率的显性方向指向减效。所有性状均有较高的狭义遗传力h^2|~N|=0.71-0.93,可在杂种早代选择。     

高粱穗部主要性状的配合力分析

以4个高粱不育系13163A、1358A、128A和407A,以及6个恢复系9.1R、213R、272R、381R、矮182R和早21R为试验材料,按照不完全双列杂交设计(NCII),对其F1的穗部主要性状进行配合力分析。结果表明:亲本穗部主要性状存在显著的遗传差异,主要表现为加性基因效应遗传的性状有:穗长、一级枝梗数、二级枝梗数、穗粒数;狭义遗传力大小顺序分别为:二级枝梗数一级枝梗数穗长穗粒数穗粒重千粒重。不同亲本的一般配合力(GCA)和特殊配合力(SCA)在不同穗部性状间存在较大差异。不育系407A和恢复系早21R、9.1R是综合性状较好的亲本材料,利用它们可组配出产量较高的杂交组合。恢复系272R组配的杂交种具有穗粒数较多、千粒重较小的特点,能满足市场上对小粒高粱的需求。深入分析高粱杂交亲本穗部主要性状表现,有利于对亲本材料的进一步了解和利用。     

烤烟主要性状配合力和相关性研究

选用7个烤烟品种作亲本,采用Griffing方法I,利用7×7完全双列杂交,对烤烟产量、产值、上等烟比例、均价和级指等主要经济性状配合力和相关性进行研究,结果表明:各农艺性状和经济性状的遗传特性同时受基因加性效应、非加性效应以及反交效应的共同作用.从经济性状来看,以红花大金元和云烟317作亲本之一,特别是红花大金元作母本配制的杂交组合优势较强.以净叶黄作为亲本之一配制的杂交组合没有优势,显示出各组合的产量、产值等经济性状较低.     

T型细胞质的杂交小麦的杂种优势及配合力的初步研究

利用提莫菲维细胞质（Triticum timopheevi) 获得杂交小麦（下简称T质杂交小麦）是目前国 内外杂交小麦利用的主要研究内容之一。近年 来有关T质杂交小麦优势表现的报道较多,但 对于亲本性状之间的配合力及其对形成优势的 作用研究甚少。     

普通小麦×硬粒小麦杂种性状与细胞遗传

本工作以硬粒小麦2个品种与普通小麦6个品种,通过正反交,探讨五倍体杂种性状与细胞遗传。观察到:亲本组合对杂交当代的结实率与后代性状遗传均有影响;杂种性状分离非常复杂,经常出现小麦其他种类型;培育条件对某些性状的形成,亦有作用;以及性状遗传与染色体数目、接合、行为有一定相关性。     

多子房性状应用于杂种小麦的研究Ⅰ.多子房性状基因和细胞质效应

利用单体分析和多亲本常规杂交 ,研究了小麦多子房性状基因遗传传递规律和细胞质效应。结果表明 :小麦多子房性状有显、隐性两种基因类别 ,均位于 6B染色体 ;粘果山羊草和偏凸山羊草细胞质对 F1杂合显性多子房性状具有抑制表达作用。多子房小麦对 K、Ven型不育系有着不同程度的育性恢复能力 ,恢复度变幅为 4.82 %～ 48.67%。     

Characterization of silver-stained nucleolus organizer regions (Ag-NORs) in 16 inbred strains of the Norway rat, Rattus norvegicus

Silver-stained nucleolus organizer regions (Ag-NORs) in metaphase chromosomes of cultured fibroblasts were compared among 16 inbred strains of the Norway rat, Rattus norvegicus. Ag-NORs were located at the secondary constrictions or juxtacentromeric regions of the short arms of chromosomes 3, 11, and 12. The frequency and relative size of Ag-NORs were found to be strain-specific, providing a genetic marker system useful for characterization of inbred strains. While considerable cell-to-cell variation was observed within a given strain, the strain-specific pattern of Ag-NORs was shown to be consistent in cultured and noncultured cells obtained from different tissues of embryos, newborns, and adults, as well as in successively cultured cells examined up to the 10th subculture generation. The patterns of Ag-NORs in F1 hybrids made between some of the inbred strains were in general agreement with those expected from the parental strains; some unexpected patterns were noted in F1 hybrids of a particular cross, suggesting the possible existence of nucleolar interactions in such interstrain hybrids, although this has to be confirmed.     

Deoxycytidine reverses the suppression of nucleolar organizer regions' activity caused by BrdU

Summary In this article we report that 5-bromodeoxyuridine (BrdU) significantly suppresses the nucleolar organizer regions (NORs) activity of Chinese hamster cells (both dipliod cells and cell line Wg3-h) (P<0.001). One of the most obvious characteristics of the suppression is a significant decrease in the total number of the Ag-NORs per cell rather than in a frequency variation of the associated Ag-NORs. The decrease in the Ag-NORs number is mainly because of the decrease in number of chromosomes bearing 2 Ag-NORs. The degree of the suppression increases with increase in BrdU concentration in the culture medium. There is a close relationship between the suppression and the BrdU-treatment time, i.e. for a given concentration of the BrdU, the longer the BrdU-treatment time, the stronger the suppression. When the BrdU-treated cells are transferred into BrdU-free medium and allowed to grow in it for another 30 h, NORs activity can be restored. Therefore, the suppression of NORs activity may be due to BrdU toxicity. When deoxycytidine (dC) is added into medium containing 30 g/ml of BrdU, the total number of both the Ag-NORs and the chromosomes bearing Ag-NORs per cell increases to the level of untreated cells. Our results thus indicate that the addition of dC reverses the suppression of the NORs activity caused by BrdU.     

Chromosome banding in salmonid fish: nucleolar organizer regions in Salmo and Salvelinus

Chromosome banding patterns obtained by silver staining (Ag-NORs) were analyzed in three species of Salmo (rainbow, brown trout, and Atlantic salmon) and three species of Salvelinus (brook trout, lake trout, and arctic char). In rainbow trout and Atlantic salmon the Ag-NORs were found at the secondary constrictions of a single chromosome pair, while in brown trout the Ag-NORs were found on the short arms of one or two of the two longest subtelocentric or acrocentric chromosome pairs. The location of the Ag-NORs was multichromosomal in the three Salvelinus species, occurring on one or both members of four to six different chromosome pairs in different individuals. The Ag-NOR sites were on the short arms of some acrocentric pairs and at the telomeres of other acrocentric pairs and one or two metacentric pairs. Chromomycin A3 positive bands were found at the same sites as the Ag-NORs in all species. In the species with multichromosomal location of Ag-NORs, polymorphisms in the size and location of the NORs were extremely common, so that almost every individual fish had a different pattern of Ag-NOR sites.     

宝兴泛树蛙不同地理居群的染色体多样性

本文分析了比较了宝兴泛树蛙四个地理居群的核型,Ｃ－带和Ａｇ－ＮＯＲｓ,结果表明它们有相同的２ｎ＝２６,ＮＦ＝５２,和相同的核型模式：５＋８。但是,它们彼此之间在ＳＭ数目和顺序,次缢痕或随体的位置以及银染的位置,Ｃ－带类型都有所不同。     

Silver-banded karyotypes of the rainbow trout and the brook trout and their hybrids: disappearance in allotriploids of Ag-NORs originated from the brook trout

Silver-banded karyotypes of the rainbow trout Salmo gairdneri, the brook trout Salvelinus fontinalis, and their hybrids were described. Diploid-type and triploid-type hybrids were obtained. Triploid-type hybrids had two maternal genomes of the rainbow trout and one paternal genome of the brook trout. The rainbow trout had one pair of M or SM with Ag-NORs near the satellite. In the brook trout, Ag-NORs were observed in four pairs of chromosomes, but each cell had different number of chromosomes with Ag-NORs. In all observed cells of triploid-type hybrids, Ag-NORs originated from the brook trout were not recognized, whereas those from the rainbow trout were found.     

中国五种高山锄足蟾的核型、Ag-NORs和C-带的研究

作者用核型、Ag-NORs和C-带,对分布于川、滇两省的二属(齿突蟾、齿蟾)五种(胸腺齿突蟾、圆疣齿突蟾、凉北齿蟾、秉志齿蟾、疣刺齿蟾)锄足蟾作了属间和种间关系的比较分析,并讨论了它们的核型演化机制。结果表明:(1)齿突蟾和齿蟾两属间在核型和带型上都有明显的差异,演化途径主要的可能是含有重复DNA染色体片段的相互易位或臂间倒位;(2)属内不同种之间带型无显著差异,但某些对应染色体对间,其相对长度和臂比值差异明显,十分可能是常染色质片段的易位和臂间倒位所致;(3)凉北齿蟾有染色体数目变异多态现象;(4)五种锄足蟾均未发现异形性染色体。     

Variation in the distribution of silver-staining nucleolar organizer regions on the chromosomes of the wild mouse, Mus musculus.

A silver staining method was used to analyze the distribution of nucleolar organizer regions (Ag-NORs) on chromosomes of 45 wild mice (Mus musculus). The four subspecies represented were M. m. musculus, M. m. molossinus, M. m. castaneus, and M. m. bactrianus. Ag-NORs were observed near the centromeric regions of 11 chromosomes (4, 8, 9, 10, 11, 12, 15, 16, 17, 18, and 19), indicating a preponderance of Ag-NORs on smaller chromosomes. The first five loci have not been observed previously. It is suggested that a correlation may exist between the specific features of mouse Ag-NORs and the events involved in intra- and interchromosomal homogenization of rDNA.     

Ag-staining pattern, FISH and ISH with rDNA probes in the rice field eel (Monopterus albus Zuiew) chromosomes

The present paper reports the Results of rice field eel (Monopterus albus Zuiew) chromosomal analysis by Ag-staining techniques, FISH and ISH with 18S rDNA. Both the Ag-NORs and the hybridization signals were observed on the pericentromeric region of chromosome pairs 3 and 7. The Ag-NORs and the hybridization signals on homologous chromosomes 3 and 7 were corresponding to each other. And rDNA genes were mapped to bivalents 3q12-q24 and 7q14-q26. No heteromorphic sex chromosome pair was identified. The Results obtained were discussed with respect to the feature of Ag-NORs and the position of rDNA genes on chromosome pairs 3 and 7.     

Number and distribution of silver-stained nucleolar organizer regions and evolutionary relationships in domestic pigs

Variation in the numbers of silver-stained nucleolar organizer regions (Ag-NORS) were examined in 36 breeds of domestic pig of different geographic origins and five subspecies of wild boar. The relationship between Ag-NORs and evolution of domestic pigs was investigated. In all pigs observed, Ag-NORs were localized on the secondary constriction of chromosomes 10 and 8. The mean Ag-NOR numbers varied from 2.0–4.0, and decreased gradually with the different geographical distribution from south to north in China and from east to west in Europe. This regular change was caused mainly by the differences of frequency in chromosome 8 Ag-NOR type and was closely related to the evolution of domestic pig breeds.     

Frequency and non random distribution of silver-staining NORs on acrocentric chromosomes from neonate and adult human lymphocytes

The NORs frequency in a group of newborns and adults was determined by the gelatine silver staining technique. A higher number of Ag-NORs (χ² test, p<0.01) was found in adults than in newborns. The lack of correlation between cell proliferating rate index (PRI) and frequency of Ag-NORs let us suppose that the decrease of Ag-positive NORs in neonates could probably be due to factors different from cell kinetics. A non random distribution of Ag-NORs on the acrocentric chromosomes was also demonstrated: chromosome 21, in particular, showed the highest frequency, while chromosome 15, the lowest.