SSR引物及多态性位点数对陆地棉野生种系聚类结果的影响

利用SSR标记分析陆地棉野生种系的遗传多样性,对材料间相似系数的变异系数进行显著性测验和矩阵相关性测验,探讨引物和多态性位点数对研究结果准确性的影响。90对多态性引物在42份供试材料间共检测出530个等位位点,其中多态性位点440个,占83.01%。多态信息含量范围为0.046～0.888,平均为0.649;Shannon多样性指数在0.113～2.289之间变动,平均为1.248。显著性测验显示,当引物按PIC值降序排列时,利用25对引物或者150个多态性位点即可获得较准确的结果;升序排列时,至少需要50对引物或200个多态性位点才能获得较准确的结果。矩阵相关性测验显示,降序时20对、升序时50对引物或者达到150个多态性位点聚类即可达到90对引物时的精度。此外,在引物量较少时,扩增位点数较多的引物所提供的信息量更大,随着引物量的增加,这种差距趋于不明显;等位位点总数较少时,引物数量更重要,随着位点数的增加,引物信息含量的重要性已高于引物数起主导作用。综上,若要客观反映出42份陆地棉野生种系的遗传关系,有必要选用多态性引物30对,扩增多态性位点150个以上,增加引物到50对以上为佳。     

陆地棉新型核雄性不育系21A的初步研究

利用辐射诱变和回交育种成功培育出21A雄性不育系,经遗传分析和等位性测验发现,该不育性受1对隐性基因控制,它与国内发现的msc1、msc2、msc3、msc74个陆地棉隐性不育基因彼此是非等位基因;采用NCⅡ遗传交配设计,用21A不育系作母本,5个常规棉品种作父本,配制杂交组合,对10个组合的F1产量和品质性状的竞争优势和配合力进行分析,结果表明,该不育系杂种优势明显,一般配合力高,易于筛选优良的杂交组合,在生产优质杂交种方面具有很大的利用价值。     

一年生陆地棉细胞核雄性不育系洞A的宿生栽培效应

植物细胞核雄性不育系具有易于恢复但保持困难的特点。根据广西南部冬季无霜冻的气候特点,在广西南宁进行了一年生陆地棉细胞核雄性不育系洞A的三年露地栽培。结果表明:二、三年生洞A在5月上旬开花、6月下旬吐絮,这是一年生洞A在相同环境条件下难以达到的;与一年生洞A相比,二、三年生洞A的子指、单株铃数、产量显著增加,但单铃重、衣分显著下降,僵瓣率显著增加;纤维品质基本没有显著变化。说明利用陆地棉细胞核雄性不育系在南亚热带的宿生栽培进行良种繁育具有较好的前景。     

中国海南岛13种菊科植物的细胞学研究

对海南岛13种菊科植物进行了染色体研究,对其中9种植物进行了核型分析,结果为: 树菊Tithoni-a diversifolia A.Gray,2n=34=26m+8sm（2sat）;鳢肠Eclipta prostrata（L.）L.,2n=22=18m+4sm;金腰箭Synedrella nodiflora（L.）Gaertn.,2n=40=6m+30sm（2sat）+4st;三叶鬼针草黄花类型Bidens pilosa L.（yel-low flower）,2n=72=46m+26sm（2sat）;羽     

陆地棉×比克氏棉育成种质系的同工酶和RAPD分析

为了从分子水平上检验野生棉遗传特性向陆地棉转育的结果以及育成种质之间的遗传差异,通过等电聚焦电泳和RAPD技术,对来自科遗181陆地棉品系与野生比克氏棉杂交后代的6个遗传稳定的不同种质系及其亲本的过氧化物酶同工酶图谱和DNA指纹图谱进行了分析。结果如下（1）6个种质系的基本酶谱特征均倾向于陆地棉亲本,但在其中2个种质系的过氧化物酶图谱中,观察到各具有1条等电点值（PI）为4.85的野生亲本的特征带;（2）DNA指纹图谱的分析表明,不同种质系之间在基因组水平上具有高度的异质性。并且在OPO10和OPO112个引物的扩增图谱中观察到4个育成种质系具有野生比克氏棉亲本的特征带。     

陆地棉珠孔的结构及花粉管在其中的生长途径

在大多数被子植物中,花粉管经珠孔进入胚珠进而实现受精,但珠孔结构及花粉管在其中的生长途径是植物受精生物学研究中较薄弱的一个环节。迄今仅在向日葵中从超微结构水平上作了详细的研究［１］,因而需要扩大研究的对象。陆地棉花粉管生长所经雌蕊组织中,关于柱头、花柱［２,３］、珠心［４,５］和助细胞［６］的超微结构已有较详细的研究,但涉及珠孔这一环节,只有简单的描述［７］。本文报道我们在这方面的研究结果。材料和方法取陆地棉（ＧｏｓｓｙｐｉｕｍｈｉｒｓｕｔｕｍＬ．）授粉前和授粉后２２小时的胚珠,切除其合点端部分…     

陆地棉胚性愈伤组织的变异及高频胚胎发生

陆地棉（Ｇｏｓｓｙｐｉｕｍ ｈｉｒｓｕｔｕｍ Ｌ．）胚性愈伤组织在两年多的继代培养过程中,由淡绿或灰色疏松状转变成灰黄色致密团块状,胚胎发生能力经历了一个由低到高再到低的过程。培养两年半后,从中分离出３种不同的愈伤组织系。第一种可产生大量的胚状体;第二种可产生少量胚状体;而第三种失去了胚胎发生能力。第一种团块颗粒小,后两种团块颗粒大。通过选择培养第一种愈伤组织系,建立了３ 个陆地棉栽培品种的高频体细胞胚胎发生系。染色体观察显示：其变异频率随愈伤组织培养代数的增加而升高;３ 种不同的愈伤组织系中,二倍体细胞的频率大小依次为：第一种＞ 第二种＞ 第三种。此外,第一种含有较多的超二倍体细胞,而后两种含较多亚二倍体细胞     

棉属茎,叶表皮毛的研究

棉属植物茎、叶表皮毛的多少及其形态是识别种或品种的主要特征之一,并且与种或品种的抗虫或抗逆性有密切联系。Ramey(1962)研究指出,多毛性状是受 H_1和H_2两个主效基因和一些修饰基因的控制,H_2具有多效性。较系统地研究棉属茎、叶表皮毛的性状报道较少。本文报道利用扫描电镜对棉属植物的茎、叶表皮毛性状观察的结果。     

IDENTIFICATION OF MONOSOMES FOR SIX CHROMOSOMES IN GOSSYPIUM HIRSUTUM

Six primary monosomes of the amphidiploid species Gossypium hirsutum have been identified as separate chromosomes of the complement. On the basis of cytogenetic tests involving translocations, a diploid species of the D genome group, and genetic markers, 4 of the 6 monosomes were designated chromosomes 1, 2, 4 and 6 of the A subgenome and 2 were designated chromosomes 17 and 18 of the D subgenome. Fourteen other monosomes were identified as duplicates of 3 of the above 6 primaries.     

FIBER INITIATION ON THE COTTON OVULE (GOSSYPIUM HIRSUTUM)

Cotton ovules at the stage of fiber initiation were studied with a scanning electron microscope. On the day before anthesis the anatropous ovule had many anomocytic stomata, especially on the chalazal end. At anthesis, fibers first appeared at the crest of the funiculus and then around the lateral circumference of the ovule. Fiber initials were delayed for a few hours at the chalazal cap and for 3 or 4 days at the extreme end of the micropylar region. The morphological differentiation of a fiber began when an epidermal cell rounded up and protruded. After a brief period of diametric expansion, the initial began elongation toward the micropylar end. Between 2 and 3 days of age the fibers segregated into small groups, developed tapered tips, and began spiral growth. Fiber density was about 3,300 fibers per mm², and the ratio of fiber initials to total epidermal cells was 1:3.7 at anthesis.     

THE ULTRASTRUCTURE OF COTYLEDONARY TISSUE FROM GOSSYPIUM HIRSUTUM L. SEEDS

Quiescent cottonseeds stored in a dry, anaerobic situation for over a year have been shown to contain cells whose contents are ultrastructurally similar to those of normal, fully hydrated plant cells. Plastids, mitochondria, and nuclei of the cells of cotyledon tissue in dry seeds possess normal-looking double membranes even under conditions of extreme desiccation. Previous reports have indicated on the basis of light microscopic work, that the cells of certain dry seeds do not possess nuclear membranes or mitochondria. The cells of the dry cottonseed do contain these structures, however. Dictyosomes have not been observed in the spongy parenchymal cells of the cotyledon tissue; it is suggested that they are concerned with translocation and/or utilization of material. The storage materials in the cells, protein and oil, are contained in vacuolar areas enclosed by a single membrane.     

GENETIC DIVERSITY IN GOSSYPIUM HIRSUTUM AND THE ORIGIN OF UPLAND COTTON

Gossypium hirsutum has a large indigenous range encompassing most of Mesoamerica and the Caribbean, where it exhibits a diverse array of morphological forms spanning the wild-to-domesticated continuum. Modem, highly improved varieties (“Upland cotton”), which currently account for about 90% of world cotton commerce, are day-length neutral annuals derived from subtropical, perennial antecedents. To assess levels and patterns of genetic variation in the species and to elucidate the origin of Upland cotton, 538 accessions representing the full spectrum of morphological and geographical diversity were analyzed forallozyme variation at 50 loci. Levels of variation are modest overall but are low in Upland cotton. Relationships among accessions reflect pre-Columbian influences of aboriginal peoples and later European colonists superimposed on the preagricultural pattern. In contrast to expectations, two centers of diversity are evident, one in southern Mexico-Guatemala and the other in the Caribbean. Introgression of G. barbadense genes into G. hirsutum has been common in a broad area of sympatry in the Caribbean. The germplasm of present cultivars traces to Mexican highland stocks, which, in turn, were derived from material originally from southern Mexico and Guatemala. Despite the widespread belief that germplasm from several other species has been incorporated into modem Upland stocks through intentional breeding efforts, the 50 Upland cultivars examined contain no unique alleles, suggesting that retention of genes from transspecific sources has been minimal. The most recent infraspecific treatment, which recognizes seven races, does not adequately represent genetic relationships.     

国产稗属植物的细胞学研究

对国产７种（含变种）稗属Ｅｃｈｉｎｏｃｈｌｏａ植物的细胞学进行了初步研究。９个供试材料的体细胞分别表现两种染色体数目２ｎ为３６或５４。除光头稗Ｅ．ｃｏｌｏｎｕｍＬ外,分析了其余种的核型,其结果为：稗Ｅ．ｃｒｕｓ．ｖａｒ．ｃｒｕｓｇａｌｌｉ２ｎ＝５４＝５８ｍ＋６ｓｍ;西来稗Ｅ．ｃｒｕｓ．ｖａｒ．ｚｅｌａｙｅｎｓｉｓ（Ｈ．Ｂ．Ｋ．）Ｈｉｔｃｈｃ ２ｎ＝５４＝４２ｍ（２ＳＡＴ）＋１２ｓｍ（４ＳＡＴ）;