大麦（Hordeum vulgareL.）花药培养再生植株染色体的遗传分析和酯酶同工酶

通过观察８２株大麦花药培养再生植株根实细胞有丝分裂和５６株花粉母细胞（ＰＭＣ）减数分裂过程中染色体的结构和分离情况，结果表明，单倍体和二倍体植株各为１７．１％和３５．４％，混倍体植株４７．５％，在混倍体植株中，有二倍体，三倍体，四倍体甚至六倍体细胞和一些非整倍体细胞，但仍以单倍体，二倍体和四倍体细胞为主，根尖细胞有线分裂过程中有染色体结构的变异，如染色体断片，环状染色体等，二倍体ＰＭＣ减数分裂过程     

利用药剂诱导玉米孤雌生殖Pa1代植株的倍性变异

为研究药物诱导玉米孤雌生殖植株的倍性变异，用2%DMSO 40mg/kgMH诱导掖单13号等材料获得结实。实验结果表明，孤雌生殖根尖体细胞以二倍体细胞最多，其次为非整倍体细胞，其它异倍体和单倍体细胞极少。Pa1植株可分为二倍体和混倍体两类，以二倍体占绝对多数的混倍体植株最多。讨论了体细胞染色体变异的来源问题。     

野生二倍体鸭茅染色体加倍及杂交利用研究

对滇中朗目山野生二倍体鸭茅用秋水仙素处理萌动种子，获得了混倍体鸭茅(同一植株根尖中二倍体细胞和四倍体细胞混存)，混倍体鸭茅的形态学特征及生长发育均与二倍体无明显差异；从混倍体鸭茅自然传粉后代中，获得了纯合同源四倍体鸭茅。同源四倍体鸭茅的气孔和种子均较二倍体大，但形态、发育与二倍体差异较小。以诱导所得混倍体为母本，与四倍体栽培种杂交，杂交F1代为四倍体，其形态学特征及物候发育均介于野生二倍体和四倍体栽培种之间，早期生长与四倍体栽培种相当，优于野生二倍体，繁殖性能与野生二倍体相当，强于四倍体栽培种，分蘖、再生性及干物质产量均强于二倍体，但明显不如四倍体栽培种。以鸭茅野生二倍体为母本，与四倍体栽培种进行杂交，获得的杂交三倍体高度不孕，但早期生长、分蘖、再生等明显优于母本二倍体，杂交三倍体开放传粉后代倍性复杂，混倍体、四倍体和五倍体都有。     

提高马铃薯双单倍体花药培养产生胚状体及再生植株频率的研究

用三种不同温度前处理和三种培养基相配合对７个从双单倍体马铃薯中随机抽取的品系进行了花药培养，选择出了较好的培养基和前处理的适宜温度及方法，从双单倍体花药中忸产生胚状体及再生植株频率有所提高达２７．５％和８．８％。倍性鉴定表明，从双单倍体诱导的胚状体分人的植株绝大多数为二倍体。而且多数为纯合体，说明这些胚状体来自己减数的配子，可能是由在胚状体发育过程中的体细胞染色体加倍形成的。     

糯玉米杂交种孤雌生殖后代的形态和细胞学研究

以不同浓度DMSO（二甲基亚砜）诱导得到的糯玉米杂交种孤雌生殖Pa1代和Pa2代为材料,研究糯玉米孤雌生殖后代的植株形态变化、细胞学行为变化和染色体数目的变异。研究结果表明,Pa1代的植株在表现型上基本整齐一致,但植株呈现退化。DMSO诱导玉米孤雌生殖除获得纯合二倍体植株外,还获得了部分的混倍体,细胞染色体有丝分裂细胞学行为也相对有较大的变异。Pa2代根尖体细胞染色体数目及有丝分裂细胞学行为变异均小于Pa1代。     

提高马铃薯双单倍体花药培养产生胚状体及再生植株频率的研究

用三种不同温度前处理和三种培养基相配合对７个从双单倍体马铃薯（Ｓ．ｔｕｂｅｒａｓｕｍＬ，２ｎ＝２ｘ＝２４）中随机抽取的品系进行了花药培养，选择出了较好的培养基和前处理的适宜温度及方法．从双单倍体花药中诱导产生胚状体及再生植株频率有所提高达２７．５％和８．８％．倍性鉴定表明，从双单倍体诱导的胚状体分化的植株绝大多数为二倍体，而且多数为纯合体，说明这些胚状体来自己减数的配子，可能是由在胚状体发育过程中的体细胞染色体加倍形成的．     

普通野生稻花粉植株性状的研究

对普通野生稻195株花粉植株的H1代和少数H2代进行的形态学、育性、倍性、遗传性、抗病性、耐冷性和外观品质等多种特性的观察研究结果表明：育性正常的二倍体花粉植株H1代占总数的85.6%；全不育的占14.4%，其部分植株根尖细胞染色体数为n=12的单倍体或12和18的异数体。有一部分花粉植株具有宝贵的可供利用的性状和特性。本研究还获得了4个抗白叶枯病的H2纯系。这批新质源对水稻育种、生物技术及稻作学基础理论的研究具有重要意义。     

白芦笋花药培养再生植株染色体倍性检测研究

采用茎尖压片染色体计数法对两个品种的白芦笋花药培养的再生植株进行了染色体的倍性检测。试验结果显示了芦笋花药培养再生植株中染色体构成的多样性,还观察到再生植株中极个别细胞出现染色体缺失现象。‘Thielim’品种中再生植株的染色体变异率为11．1％,单倍体占1-8％,双倍体占88．9％,三倍体占4．2％,四倍体占5．1％。‘硕丰’品种中再生植株的染色体变异率为9．1％,双倍体占90．9％,三倍体占5,9％,四倍体占3,2％,没有发现单倍体。     

花粉植株的诱导及其在育种中的意义综述

一、花粉植株的诱导概况 (一)花药培养花药培养是将花药离体后进行培养,使花粉发育成单倍体植株。单倍体植株染色体加倍后,成为具有同型遗传因子的纯合二倍体,不仅能正常开花结实,而且植株后代整齐一致,性状稳定,这在育种工作中和生物理论研究上都有重要意义。因此很早就有人提出单倍体育种的设想,企图通过某种方法从杂交后代产生大量单倍体,加倍后变成纯合的二倍体,直接用于选种实践,但未找到     

不同倍性水稻的花粉发育特征分析

以水稻品种红米2x和其对应的同源四倍体红米4x为试验材料,用激光扫描共聚焦显微镜观察了不同倍性水稻的花粉发育特征。结果表明,不同倍性水稻花粉粒形成过程基本相似,但与相应的二倍体水稻相比,同源四倍体水稻在减数分裂及后期发育过程中存在多种异常现象,如纤维素壁降解不完全、细胞不均等分裂及分裂不同步等现象;在成熟花粉中,二倍体水稻的正常花粉占89.92%,败育率为10.18%,四倍体水稻的正常花粉占69.96%,败育率高达30.04%;四倍体水稻的花粉直径显著大于二倍体水稻,且四倍体水稻的花粉粒萌发延迟。认为不同倍性水稻的花粉发育存在差异,染色体加倍对水稻花粉发育产生了不良影响。     

丹参三倍体育性的细胞学分析

由丹参四倍体和二倍体杂交获得丹参三倍体,三倍体植株高度不育。为探讨其育性的细胞学机制,我们采用细胞学和解剖学的方法,对其花粉母细胞发育过程中的染色体和细胞学表现进行了观测。结果表明,丹参三倍体植株生长正常,在花粉母细胞减数分裂过程中存在落后染色体、染色体不均等分向两极、染色体桥等异常现象,分裂结果产生三分体、微核等,而且花粉粒形态异常,产生畸变,萌发率极低。这些说明,丹参三倍体在生长发育过程中,由于减数分裂过程中染色体数目不平衡,在减数分裂过程中产生各种畸变、异常的染色体和细胞的行为表现,是造成其不育的主要原因。本研究为丹参三倍体育性研究提供理论依据,也为丹参育种生产实践提供指导。     

小麦单细胞再生植株后代染色体与DNA变异的初步研究

为了使体细胞无性系变异更好地应用于作物品种改良,以小麦单细胞培养再生植株后代为材料,研究了其染色体和DNA的变异.结果表明,再生植株后代与未经培养的亲本相比,花粉母细胞减数分裂染色体行为发生异常,终变期染色体数目和体细胞染色体数目发生变化,而且早期世代变异幅度大.但随着繁殖世代的增加,花粉母细胞减数分裂染色体行为和体细胞染色体数目的变化渐趋稳定,至第五代基本稳定.对农艺性状已稳定的再生植株第九代不同株系总DNA进行RAPD-PCR扩增,结果表明,不同株系与未经培养的亲本相比在DNA水平上存在变异,出现亲本特异性谱带缺失,该类株系表现为矮秆、早熟.     

Insert copy number,chromosome number,pollen stainability,and crossability ofAgrobacterium-transformed diploid potato

Two 2n-pollen producing cultivated diploid, 2n = 24, potato genotypes DM56.4 and US-W5337.3 were inoculated with binaryAgrobacterium vectors. The T-DNA contained a neomycin phosphotransferase II coding region fused to a nopaline synthase promoter providing gene expression in plants and resistance to kanamycin. A total of 28 clones regenerated as adventitious shoots from callus tissue, growing on medium with kanamycin, was analyzed for chromosome number, pollen stainability, and crossability. Several clones were tested and found to retain crossability with diploid and tetraploid clones. Nine out of 10 of the regenerants from DM56.4 had been doubled; seven of these were tetraploids with 2n = 48, one clone had 2n = 49, and another 2n = 46. Five of 14 regenerants of US-W5337.3 had been doubled, and three of these had fewer than 2n = 48. Pollen stainability revealed that the tetraploid regenerants from DM56.4 were male sterile, whereas tetraploids from US-W5337.3 had stainable pollen. All of the diploid regénérants produced 2n pollen. Crossability of several diploid and tetraploid regenerants was high. The number of T-DNA inserts revealed by Southern blot analysis was also determined. Six, 10, and 9 regenerants had 1, 2, and 3 inserts of T-DNA, respectively. There were single regenerants each with 5, 6, or 7 inserts. Selection for higher insert number among regenerants should be feasible based on the range of insert number found. Identical restriction patterns within three groups of clones indicated that the 28 clones analyzed emerged from only 21 cells derived from independent transformation events. The variability in chromosome number and pollen stainability suggests that variation in other traits would be obtainable.     

甘蓝型油菜-埃塞俄比亚芥种间杂交非整倍体后代的遗传

非整倍体Nj04-089为甘蓝型油菜(Brassica napus L.)与埃塞俄比亚芥(B. carinata A. Br.)种间杂交后代中获得的附加系。为分析Nj04-089的遗传特性,利用显微镜对Nj04-089自交后代的根尖细胞染色体进行计数、对花粉母细胞染色体分裂行为进行观察,并采用PCR、GISH和Southern杂交等技术对Nj04-089的2个连续自交后代的附加染色体进行了遗传分析。结果显示：这两个连续自交世代根尖细胞染色体数2n=37～51条;花粉母细胞减数分裂的中期染色体构型分别为(0-4)Ⅰ+ (16-23)Ⅱ+ (0-2)Ⅲ 和 (0-8)Ⅰ+ (14-24)Ⅱ+ (0-4)Ⅲ + (0-1)Ⅳ,且观察到染色体桥、染色体落后、分裂周期不同步等异常行为。PCR、GISH和Southern杂交结果表明在该非整倍体后代中未检测到芸薹属B组染色体或大的片段,推测非整倍体附加的染色体并非整条或大片段B组染色体。       

CROSS–FERTILIZATION BETWEEN DIPLOID AND TETRAPLOID RYEGRASSES

Preliminary studies have been undertaken to determine the degree to which diploid and tetraploid ryegrass varieties intercross under field conditions. The results obtained through the use of diploid and tetraploid non-red-base tester plants indicate that pollen from tetraploid ryegrasses constitutes little or no danger to the genetic purity of diploid seed crops, even if grown in close proximity. A small proportion of viable triploid hybrids can arise in the progenies of tetraploid plants heavily exposed to diploid pollen, but here again their frequency and incidence are not of practical consequence.     

不同染色体倍性水稻植株光合特性的研究

 以花培获得的粳稻02428单倍体、二倍体和四倍体植株为材料,测定了与光合作用有关的若干性状。气孔大小、比叶重随染色体倍性的增加而递增;而单位面积的气孔数则呈递减的趋势;叶绿素含量与染色体倍性无明显的相关性。剑叶净光合作用速率的两年测定结果相符,单倍体是9.39和10.16 mg CO^₂/dm²·h,二倍体是17.57和15.80 mg CO^₂/dm²·h,四倍体是22.64和22.52 mg CO^₂/dm²·h。讨论了性状表达与DNA剂量的关系。     

转基因大麦的gfp基因表达及染色体定位

为了深入探讨转基因的整合位置对基因表达的影响，对转绿色荧光蛋白基因（gfp）大麦的荧光表达和gfp基因的染色体位置进行了研究。结果表明，绿色荧光蛋白（gfp）在大麦的根尖和花粉中均有表达，四倍体的荧光表达强度大于二倍体，表现出基因的剂量效应。gfp基因插入到第6染色体（6H）短臂和另一染色体的短臂近末端。     

Oryzalin Treatment of Potato Diploids Yields Tetraploid and Chimeric Plants from which Euploids could be Derived by Callus Induction

Shoot apices from six diploid potato genotypes for polyploidisation were treated with oryzalin and colchicine solutions at different concentrations and incubation times. In addition to chimeric plants, diploids, one octoploid and completely ploidy doubled plants (4x) were regenerated in these experiments. Tetraploid plants were obtained for three of the six genotypes treated with oryzalin, and no tetraploid plants were obtained after colchicine treatments of any of the genotypes. The best result of 43% tetraploid plants was achieved using 28.8 μM oryzalin and 24 h of incubation with the L37 genotype. Moreover, we determined that doubled plants should not be selected on the basis of a single measurement and require additional ploidy checks in successive clonal generations. Some L37 plants that were initially identified as tetraploids by flow cytometry produced diploid or mixoploid plants in the next clonal generation. Morphological characters of doubled L37 plants were compared with the original genotype. The PVY resistance present in a parental clone was maintained in all regenerants and significant differences among ploidy variants were found for some quantitative characters. Molecular AFLP analyses did not show any differences among genotypes. Since polyploidizing substances may produce a large proportion of chimeric plants, we applied a method to increase the number of tetraploid plants. Callus culture of chimeric leaf explants was performed on regeneration medium and tetraploid shoots were obtained in four of the six genotypes tested. The best result of 40% tetraploid plants was achieved with explants from the L37 genotype. This method was successful in producing additional tetraploid genotypes from mixoploid plants obtained after oryzalin treatments.     

多倍体茶树的细胞学研究(一)

对从二倍体茶树品种凤凰水仙中获得的1株高度不孕的三倍体茶树的形态特征特性、核型和减数分裂的染色体行为进行观察表明:其核型组成为2n=3x=45=36M+9SM。可区分出3个基本相同的染色体组,同源染色体组3个成员的形态极为相似。终变期观察到1—9价体、多价体环或链等构型,所有细胞可见1—12个三价体,三价体在每个细胞中平均出现次数较高,为6.13次。后期Ⅰ∶86％的细胞具有1—6条落后染色体;到达每极区染色体数变化于12—29之间,82％的细胞具有18—24条染色体。后期Ⅱ∶93％的纺锤体中具有1—4条落     

药剂诱导玉米孤雌生殖技术选育自交系

2003～2006年用药剂诱导玉米孤雌生殖共获得254粒孤雌生殖一代(Pa1)种子。选取部分Pa1种子对根尖细胞和花粉母细胞进行细胞学观察。结果表明,Pa1植株的根尖细胞主要为二倍体,非整倍体也占很大比例,为24.0%。在花粉母细胞中正常二倍体频率比根尖体细胞明显提高,并且根尖细胞染色体数目变异不能延续到花粉母细胞。细胞学分析结合田间鉴定、方差分析获得孤雌生殖纯系13个,经测配获得杂交组合5个,均表现出较强的杂种优势。