四倍体刺槐离体培养及其不定根发育和叶片解剖观察   总被引：9，自引：0，他引：9       下载免费PDF全文

李云  王树芝  田砚亭  罗晓芳 《中国水土保持科学》2003,1(1):91-94

 .通过茎段离体培养建立了四倍体刺槐无性系的微体繁殖体系。结果表明:基本培养基为MS或WPM培养基。BA、NAA影响芽的增殖生长,在一定的范围内,BA对芽的增殖影响比NAA大,而NAA对芽的高生长影响比BA大,二者的比例对芽的增殖生长也有影响,芽增殖生长的最适BA和NAA组合应为BA0.5mg·L-1+NAA0.1mg·L-1。四倍体刺槐无性系生根的最适生长调节物质配比为NAA0.25mg·L-1+IBA0.4mg·L-1。对试管苗不定根发育过程及分步炼苗叶片结构的变化进行了解剖观察,发现试管苗嫩梢无潜伏根原基,不定根由诱生根原基发育形成,诱生根原基源于髓射线细胞的分裂和分化,植株叶解剖观察,进一步证明了分步炼苗可提高移栽成活率。  相似文献   

Geographic variation in tetraploid wheat (Triticum turgidum spp. turgidum convar. durum) landraces from two provinces in Ethiopia     

Luciano Pecetti  Ardeshir B. Damania 《Genetic Resources and Crop Evolution》1996,43(5):395-407

There is considerable wealth of genetical and morphological variation in tetraploid wheat collected from Ethiopia by past expeditions. Several authors have speculated on the reasons for this concentration of diversity so far removed from the centre of origin of wheats in West Asia. The present study reports results of evaluation carried out on material collected in the early 1970's from Ethiopia. The landraces from the two provinces Shewa and Tigray were found to be distinctly different. This divergence was attributed to the differences in environmental conditions between them. Wide differentiation among landraces within each province was also present. The Ethiopian farmer's practice of growing composite cultivars in the field has resulted in bulk samples of Ethiopian landraces containing several agrotypes. The proportion of total variance due to differences among agrotypes within landraces was by far the greatest found in this study, followed in most cases by the variation among landrace populations within provinces which exceeded, in turn, the variation between province gene pools. The optimal strategy for further germplasm collections and implications for improvement and conservation in locally-based community gene banks are discussed.  相似文献   

Phylogenetic relationships among natural populations of perennial buckwheat, Fagopyrum cymosum Meisn., revealed by allozyme variation   总被引：2，自引：0，他引：2  

Kyoko Yamane  Ohmi Ohnishi 《Genetic Resources and Crop Evolution》2001,48(1):69-77

Twenty natural populations of F. cymosum, an insect-pollinated allogamous wild species of Fagopyrum, were investigated for their chromosome number and allozyme variation at 10 Ioci encoding 8 enzymes. Diploid populations were obtained in Sichuan, Yunnan and Tibet in China, whereas tetraploid populations were obtained in Tibet, the Himalayan hills, Thailand and southern China. Both diploid and tetraploid populations maintained a large amount of allozyme variation. The average heterozygosity, H_e, ranged from 0.045 to 0.389 (0.213 on average). Tetraploid populations showed higher H_e values than diploid populations. Natural populations of F. cymosum were locally well differentiated (G_ST = 0.322), probably due to reproductive isolation between the two ploidy levels and to distribution over wide areas from southern China to the Himalayan hills. The phylogenetic tree constructed by the neighbor-joining method based on allozyme variation clarified two distinct groups of diploid populations, the Sichuan and Yunnan groups. As for the tetraploid populations, polyploidization occurred twice independently, once in Yunnan and once in eastern Tibet. Tetraploid F. cymosum diffused to warmer areas such as southern Yunnan and Thailand as well as to cooler areas of Tibet and the high Himalayan hills and became the most widely distributed of the Fagopyrum species.  相似文献   

Significance of allelic diversity and 2n gametes for approaching maximum heterozygosity in 4 x ppotatoes     

Joanna E. Werner  Stanley J. Peloquin 《Euphytica》1991,58(1):21-29

Summary High level of heterozygosity is directly related to heterosis for yield in polysomic polyploids. Modern breeding schemes in potato (2n=4×=48) involve utilization of wild or cultivated 2 x relatives that provide a source of allelic diversity, and 2n gametes that transfer diversity to the 4 x level. Different levels of allelic diversity and different modes of 2 n egg formation were considered theoretically to determine their significance for the recovery of heterotic 4 x progeny from 2××4× crosses. The support from the experimental data is provided.Decline in parental allelic diversity in 2××4× crosses or 4××4× crosses resulted in significant yield reduction. The average level of homozygosity and loss of intra-locus interactions are equally adequate to predict the trend in yield changes in 4 x potatoes derived from parents of variable allelic diversity utilizing different modes of 2 n egg formation.The differences between the modes of 2 n gamete formation increase when the genetic diversity decreases. The more genetically diverse parents the less pronounced differences between 2 n gametes. Breeding of 4 x cultivars for polygenic traits where nonadditive effects are important should be oriented towards maximizing heterozygosity in terms of allelic diversity. Utilization of 2 n gametes to generate 4 x progeny following 2×–× or 2×–2× crosses upgrades the level of heterozygosity depending on diversity present in parents.  相似文献   

Influence of genotype and culture conditions on the production of embryos from anthers of tetraploid wheat (Triticum turgidum)     

M. Ghaemi  A. Sarrafi  G. Alibert 《Euphytica》1992,65(2):81-85

Summary Anther culture of 10 tetraploid wheat (Triticum turgidum) genotypes and two backcross lines representing a wide range of genetic variation was studied in a randomized block design with three replications. Each replication consisted of 2 pots with 3 plants. The day length was 16h and temperature 25° C/15°C for day/night in a controlled greenhouse where the anther donor plants were grown. Two different treatments were used for anther culture. The first one was potato 2 medium (Chuang et al., 1978) modified by adding 0.5 mg/l glutamine and solidified by gelrite (4g/l) (Henry & De Buyser, 1981). Cultures were incubated in light (15 E m^–2 S^–1) at 26°C at 16h day length. The second medium was described by Fadel & Wenzel (1990), differing from the first by the nature of the sugar (maltose) and consistency of the medium (semiliquid by ficoll). Anther cultures were incubated in the dark at 28°C. The study of about 1300 anthers per genotype and treatment showed that both genotype and treatment affected embryo formation of tetraploid wheat. The backcross lines exhibited significant differences for androgenic abilities when compared to their common parent. Most of the genotypes were medium dependent for androgenesis and revealed significant interactions with the two treatments. Five green plantlets were regenerated and fertile doubled haploid plants were obtained from three out of the 12 studied genotypes.  相似文献   

栽培措施对四倍体刺槐生物量的影响     

胡瑞阳  张国君  李云  袁存权  孙宇涵  徐兆翮  孙鹏 《经济林研究》2011,29(4):46-53

为了探索根龄、栽培密度和刈割方法对四倍体刺槐饲料林生物量及再生能力的影响,确定合理的饲料林栽培模式,对不同根龄、不同密度、不同刈割周期及留茬高度和不同刈割工具及刈割部位的当年生林分从总质量、叶质量等生物量指标方面进行了测量分析.结果表明:四倍体刺槐饲料林生物量随根龄的增长而增加;其合理的栽培密度为0.4 m×0.8 m...  相似文献   

四倍体刺槐大小孢子发育时期与花器形态的相关性   总被引：14，自引：1，他引：14  

郝晨  李云  姜金仲  刘洋 《核农学报》2006,20(4):292-295,F0003

本研究通过观察四倍体刺槐花器,得出相应的花蕾外部形态、大小、颜色和花序中不同序位花蕾发育时期与大小孢子细胞学发育时期密切相关。因此根据花器形态特征可判断大、小孢子发育细胞学的时期,从而为四倍体刺槐花器离体培养接种外植体的选择提供依据。  相似文献   

苹果试管染色体组工程育种   总被引：7，自引：0，他引：7  

石荫坪  王强生 《落叶果树》1993,25(4):1-6

用秋水仙０．４％和０．８％的浓度，诱变苹果７个二倍品种自然授粉的胚，通过试管培养，抑制胚芽成梢，促使染色体组突变的四倍体细胞分化不定芽，形成植株。经染色计数梢端切片，鉴定出一批同质的四倍体株系，部分植已栽植于果园。此项研究了简易可靠的诱变，有效地避免或减轻了浣诱变中嵌合体的干扰，为人工创造四倍种质，有计划地进行多倍体育种开辟了新途径。  相似文献   

葡萄二倍体和四倍体杂交胚挽救的影响因素     

郭印山  郭修武  张海娥  李轶晖  李成祥 《果树学报》2006,23(1):115-117

采用L25(55)的正交试验设计,对葡萄二倍体和四倍体杂交胚挽救过程中的影响因素如培养基种类、接种时间、植物生长物质浓度等进行了研究。结果表明:影响胚挽救成苗率最重要的是接种时间,然后依次是IBA浓度、GA3浓度、培养基种类和6-BA浓度。获得了一批胚挽救实生苗,最高出苗率达到73.08%。  相似文献   

黄花菜二倍体与四倍体植株的比较解剖学初步研究     

刘选明  何立珍  刘清波 《湖南农业大学学报(自然科学版)》1994,(3)

研究材料为黄花菜（ＨｅｍｅｒｏｃａｌｌｉｓｃｉｔｒｉｎａＢａｒ）二倍体“长嘴子花”和同源四倍体“ＨＡＣ－大花长嘴子花”．研究结果表明：黄花菜植株的形态结构既有一般单子叶植物的某些特征，又有与其生活环境相适应的自身特点．四倍体与二倍体相比较，其器官巨型化，组成各器官的组织细胞也普遍随之增大，且其根尖分生细胞的核仁数，茎、叶和花瓣中的维管束数目也均增多，四倍体花粉粒明显大于二倍体，并常有异常花粉粒的产生．本文还对四倍体黄花菜高产优质与形态结构的相关性进行了讨论．  相似文献