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1.
Experiments were performed to determine conditions critical to the isolation and culture of protoplasts from leaf mesophyll cells of a Solanum Section Tuberarium diploid clone, a S. phureja × S. chacoense F1 hybrid. The optimum concentration of cellulase (Cellulysin) was 0.4%, while pectinase (Macerase) was inhibitory, even at a low concentration (0.075%). Maximum yields of protoplasts were achieved when the enzyme solution was not changed during incubation, and slow oscillation (60 rpm) on a shaker was used. When detached leaves were held under low light intensities or in the darkness for 3–5 days prior to protoplast production, results were more consistent than when the leaves were used directly from the greenhouse. Following dark or low light treatment the optimum osmolarity of the isolation and growth media was approximately 0.3–0.4 M. Of nine growth media tested only those of Nitsch and Ohyama and of Upadhya supported callus development, but the callus was often loose and did not differentiate roots or shoots. Callus from protoplasts cultured in the Upadhya medium modified by addition of glycine, vitamins, and casein hydrolysate, and subsequently transferred to the medium of Lam, formed roots and shoots when cultures were maintained in light. Mature plants were obtained following transfer to modified White's medium and later transplantation to soil.  相似文献   

2.
The pollination mechanisms and pollen vectors of Solarium rostratum have been examined by greenhouse experiments and field studies. Although the capacity for autogamy exists in this weedy annual, it rarely occurs because of two factors: (1) the morphology of the flower and (2) the foraging behavior of the various species of Bombus, the primary pollen vector in the regions studied. The percentages of geitonogamy and xenogamy are dependent on the flight pattern of the bees and the number of open flowers on a plant.  相似文献   

3.
Dnyansagab , Vishnu R., and Delmer C. Cooper . (U. Wisconsin, Madison.) Development of the seed of Solanum phureja. Amer. Jour. Bot. 47(3) : 176—186. Illus. 1960.—Ontogeny of the seed of Solanum phureja Juz. et Buk. is described. The megagametophyte, during the course of its development, ruptures the nucellus and at maturity lies in direct contact with the inner layer (endothelium) of the single massive integument. The mature megagametophyte, a 7-celled structure, consists of a 3-celled egg apparatus, an endosperm mother cell with fused polar nuclei and 3 persistent antipodals. Both 2- and 3-celled mature pollen grains are formed within anthers of the same flower; hence this character cannot be considered of any taxonomic value. Double fertilization occurs between 24 and 72 hr. after pollination. A cellular endosperm is formed, the peripheral layer acting as an absorbing tissue during the early ontogeny of the seed. Later this layer becomes organized as an aleurone layer and thereafter the source of nutrients is via the basal portion of the endosperm immediately adjacent to the apical end of the vascular tissue of the developing seed. Embryo development follows the Nicotiana variation of the Solanad type. The mature testa is composed of an outer layer of thick-walled epidermal cells, an inner layer of thin-walled cells and an intervening mass of disorganized tissue. In those instances where the ovule or young seed aborts, the endothelial cells of the integument become hyperactive and proliferate to such an extent that the space formerly occupied by the gametophyte or the developing endosperm and embryo becomes completely filled with endothelial tissue.  相似文献   

4.
In five of 66 anther-derived plants of Populus maximowiczii Henry (Salicaceae) unusual flowers were observed at ages six to eight months. Most flowers were male, occurring singly in a terminal position, and were characterized by cup-shaped, calyx-like floral discs bearing 14 to 18 stamens. The anthers failed to dehisce but did contain a few pollen grains when observed after squashing. One flower had, in addition to a set of stamens, two stigmas emerging from undeveloped ovaries. These flowers in haploid or dihaploid plants are in some ways similar to ancestral flowers that have been hypothesized for the Salicaceae, and may give an indication of the evolutionary pathway in the genus Populus.  相似文献   

5.
Mitotic chromosomes of 450 individuals, representing 59 accessions of 18 of the 22 species of Solanum sect. Basarthrum were studied. Statistical analyses of chromosome length, genome length, and centromere position yielded estimates of karyotype composition and asymmetry. A generalized karyotype of the section shows that most of the chromosomes are metacentric (44%) or submetacentric (53%). A general trend emerged: the greater the total genome length, the more asymmetric the karyotype. However, karyotype asymmetry does not seem to be based on major chromosomal rearrangements. There is variation in species groups in the karyotype formula, and chromosome length differences were useful in distinguishing series. Patterns of cytological variation reinforce the systematic arrangement of the taxa based on morphological, chemical, and molecular studies. Chromosomal differences characterize most of the species. Five species bear subtelocentric chromosomes, two have telocentrics, and two have satellites. The genomes of the staminate and pistillate plants of the dioecious S. appendiculatum are identical. Of the species proposed as progenitors of the domesticated cultigen S. muricatum, S. caripense is the most similar karyotypically.  相似文献   

6.
试图根据成虫形态学证据探讨长足虻科各亚科之间的系统关系,同时检验各个亚科的单系性.在比较形态学研究基础上,同时参考前人有关长足虻科高阶元分类的研究结果,筛选出42个来自头部、胸部(包括足和翅)、腹部、雌性和雄性外生殖器在亚科水平的分类特征,为了考察亚科的单系性,也包括亚科的自有衍征;运用支序分类的方法,首次分析并讨论了世界长足虻科17个亚科之间的系统发育关系.结果表明,长足虻科是一个严格的单系群,其支持的共同衍征为体色金绿,亚前缘脉端部与第1径脉中部愈合,前缘脉接近肩横脉处有1个缺刻,第2基室与盘室愈合,臀室短小、终止于径脉分叉点之前,雄性外生殖器明显向下或向前弯折,生殖背板具生殖孔,下生殖板与第9背板愈合.金长足虻亚科Sciapodinae腋瓣发达,中脉分叉,为最基部的支系,是最原始的亚科;而长足虻科的其他亚科构成一单系群,其共同衍征为腋瓣不明显,中脉不分叉.斜脉长足虻亚科Plagioneurinae也比较原始,是靠基部的支系,支持其单系性的特征为腹部第7~8节膜质化,生殖孔基位.异长足虻亚科Diaphorinae和锥长足虻亚科Rhaphiinae以及斯长足虻亚科Stolidosomatinae和合长足虻亚科Sympycninae分别构成姊妹群关系,斯长足虻亚科Stolidosomatinae的两个属Pseudosympycnus和Stolidosoma系统地位还有待进一步研究.此外,巴长足虻亚科Babindellinae、聚脉长足虻亚科Medeterinae和寇长足虻亚科Kowmunginae构成单系群,其共同衍征为臀脉短或不明显,无后顶鬃.研究所用标本大部分保存在中国农业大学昆虫标本馆,包括与美国史密森研究院和澳大利亚博物馆交换而来的标本,部分标本保存在比利时皇家科学院.  相似文献   

7.
A study was made of the number of plastids and mitochondria present in generative cells of Solanum immediately after microspore mitosis, and the fate of these organelles during development of the pollen was determined. Changes were followed via electron microscopy of anthers of S. chacoense and S. tuberosum Group Phureja × S. chacoense. In earliest stages the generative cells were oval and had one surface along the intine and other surfaces in contact with the vegetative cell. As the pollen matured the generative cells elongated, became spindle-shaped, and were completely engulfed in the vegetative cells. At the earliest stages studied, both mitochondria and plastids were present in the generative cell. Plastids of the generative cell were, in contrast to those of the vegetative cells, fewer, smaller, and lacking in starch. Through the maturation stages the content of these organelles in the vegetative cells remained unchanged. While the generative cells retained mitochondria until anthesis, their plastids disappeared completely during maturation. This selective loss during generative cell maturation could lead to transmission of those characteristics encoded in plastid DNA through the pistillate parent only. The mechanism could explain earlier genetic evidence that plastid characters of Solanum were transmitted uniparentally.  相似文献   

8.
Four related species in the unicellular volvocalean genus Carteria [C. crucifera Pascher, C. eugametos Mitra, C. inversa (Korshikov) Bourrelly and C. cerasiformis Nozaki et al.] were delineated on the basis of recent comparative light and electron microscopy of a large number of culture strains. However, the species thus delineated may not represent natural or monophyletic entities. In the present study, 1128 base pairs of the chloroplast protein-coding gene (large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase gene) from 12 Carteria strains representing the four species as well as from related volvocalean species were analyzed to elucidate the phylogenetic status of the taxonomic or morphologic species of Carteria. The sequence data showed that the 12 Carteria strains exhibit four robust monophyletic groups which are strictly consistent with the four taxonomic species. These results are discussed in relation to contrasting results found in other microalgal genera. It is concluded that phylogenetic analysis, based on DMA sequence data and comparative morphologic characterization of species and using a large number of culture strains, is essential to a natural system of microalgal species taxonomy.  相似文献   

9.
Pollen-ovule ratio, pollen grains per flower, pollen grain volume, pollen biomass, ovules per ovary, seeds per fruit, seed volume, seed biomass, and corolla size were studied to reveal patterns of variation within a monophyletic group. Solanum sect. Basarthrum includes 22 neotropical species of two clades, one having small, few-seeded red fruits, and the other having larger, many-seeded green fruits. The former includes self-incompatible species and a dioecious species, while the latter includes self-incompatible species, self-compatible (and autogamous) species, and a domesticate (the “pepino”). Although the pollen quantity and ovule quantity of the self-incompatible species are significantly higher in the green-fruited subgroup than in the red-fruited subgroup, the pollen-ovule ratios of the self-incompatible species are not significantly different between the two subgroups, suggesting parallel evolution of the pollen-ovule ratio. Furthermore, the pollen-ovule ratio tracks the breeding system: self-incompatible species have significantly higher pollen-ovule ratios than self-compatible species, resulting both from fewer pollen grains and more ovules of the latter. The pollen-ovule ratio of the dioecious species is among the highest of all, resulting only from fewer ovules. The pepino is self-compatible but has a pollen-ovule ratio like its wild self-incompatible progenitors and shows wide variation in seed production and pollen quality, but not in pollen quantity. Among all species, pollen size and quantity are inversely proportional, as are seed size and quantity.  相似文献   

10.
Studies of andromonoecious species have shown that sex expression (proportions of hermaphrodite and staminate flowers) is quite variable. It is not known, however, whether this variation is due to variation among individuals for genetically fixed patterns of allocation to staminate and hermaphrodite flowers (population level variation) and/or to developmental plasticity of individuals in a heterogeneous environment (organismal level variation). Distinguishing between these two levels of variation is important for understanding the evolution of andromonoecy. This study investigates levels of variation in sex expression in the andromonoecious Solanum hirlum. Sex expression in this species is shown to be plastic among individuals of the same genotype (organismal level variation) and determined, in part, by the resource status of the individual. Among the genotypes examined there is also genetic variation for developmental plasticity. Thus, developmental plasticity can potentially respond to selection, and the evolution of this developmental system may have been instrumental in the establishment and maintenance of andromonoecy in S. hirtum.  相似文献   

11.
利用分支系统学(Cladistics)的原理和方法,选取光镜下的24个性状,对鲴亚科17种寄生六鞭毛虫进行了系统发育分析,初步阐明了这17种六鞭毛虫相互间的亲缘关系。结果还表明,鲴亚科寄生六鞭毛虫的分化较晚;一些明显特征:如杆状条纹,是进化适应的结果,具有系统学意义。还通过对寄生六鞭毛虫在鲴亚科鱼类中的区系分布特点分析,探讨了宿主相互间的亲缘关系。结果表明:寄生六鞭毛虫的区系分布能够反映宿主相互间  相似文献   

12.
Enzyme electrophoresis was employed to measure genetic variation within and divergence among 32 populations of three species in Solanum sect. Petota (S. brevidens, S. etuberosum, and S. fernandezianum). These species are self-compatible, diploid (2n = 2x = 24), and members of the monophyletic series Etuberosa. Solanum etuberosum is distributed in southern Chile, S. brevidens occurs in southern Chile and adjacent southern Argentina, and S. fernandezianum is endemic to Masatierra Island in the Juan Fernández Archipelago, 650 km west of continental Chile. Very low levels of observed heterozygosity (0.00–0.04) are found within populations of all three species. Interspecific mean genetic identities between S. brevidens and S. etuberosum (0.854) were similar to their intraspecific values (0.923, 0.865, respectively), with both species monomorphic for alleles at nine of the 12 loci examined. Solanum fernandezianum shows no heterozygosity and is more divergent to both S. brevidens (0.780) and S. etuberosum (0.698) than either is to each other. The divergence of S. fernandezianum to S. brevidens and S. etuberosum results from novel alleles at two of the 12 isozyme loci; in addition, it possesses only a subset of the variability found in S. brevidens and S. etuberosum at three other loci.  相似文献   

13.
A technique using micronized metal powders was developed for both general labeling of pollen and marking of individual pollen grains. After labeling, pollen flow is analyzed by the use of backscatter scanning electron microscopy and X-ray microanalysis. To test the efficiency and efficacy of the technique, we assessed differences in pollen distribution in Solanum rostratum, an enantiostylous species with dimorphic anthers which are putatively feeding and pollinating anthers. Pollen from each set of anthers was labeled using different micronized metal powders. We could not confirm the differentiation of functional anthers in S. rostratum. This technique provides an efficient and convenient method for tracking pollen movement within and between flowers, and anthers within a single blossom can be differentially marked.  相似文献   

14.
15.
几种转基因植物体细胞克隆变异的多样性研究   总被引:4,自引:0,他引:4  
郑易之  SalaF 《植物研究》2001,21(2):266-271
分析了杨树、水稻和甘蔗转基因植株体细胞克隆的表型变异和基因组DNA多态性。探讨了以下问题:转基因植株体细胞克隆的1)表型多样性, 2)基因组DNA多样性, 3)二者的相关性, 4)表型变异和DNA变异的可遗传特性, 5)产生的可能原因,以及6)在农业生产上的应用。  相似文献   

16.
鳃虱科(甲壳动物亚门,等足目)属间系统发育关系支序分析   总被引:1,自引:0,他引:1  
选择鳃虱科Bopyridae的47个形态学性状,利用PAUP软件,以支序分析方法对中国海域鳃虱科24属进行属间系统发育关系研究.支序分析结果较好地反映了鳃虱科内姐妹群的关系.根据分析结果,假鳃虱亚科中的巨鳃虱属Gigantione是鳃虱科中较早分出的一支,而背腹虱亚科中的仿腹虱属Parathelges和腹虱属Athelges则为较晚分化出来的;褐虾鳃虱亚科的褐虾鳃虱属Argeia盖腹虾鳃虱属Stegoalpheon和真虾鳃虱亚科的深海鳃虱属Bathygyge聚为一支,成为一对姐妹群;蟹鳃虱亚科的单系性得到分析结果的支持,假鳃虱亚科的单系性则不被支持.  相似文献   

17.
韩英兰  杨昌友 《植物研究》1996,16(4):459-462
首次报道中国稠李属花粉形态研究,结果表明:花粉粒形态、大小和外壁纹饰可作为划分种的依据。由此可区分为:花粉粒32.0×25.5μm、条纹细弯、穿孔明显的是亚洲稠李(P.asiatica Kom.);花粉粒37.5×17.7μm、体积大、穿孔多的是光叶亚洲稠李(var.subglabra Y.L.Hanet C.Y.Yang var.nov.);花粉粒32.0×24.4μm、条纹细直、穿孔少量的是欧洲稠李(P.aviummill.);花粉粒21.0×22.1μm、条纹宽、直、穿孔不明显,即北京稠李(P.beijingensis Y.L.Hanet C.Y.Yang sp.nov.),(新种已另文发表)。  相似文献   

18.
Male and hermaphrodite flowers from the andromonoecious perennial Solanum carolinense were compared. Hermaphrodite flowers were 11–16% heavier than males, and this difference was consistent for two clones studied. Hermaphrodite flowers contained a greater amount of nitrogen than did male flowers, but males had higher percent nitrogen. Male and hermaphrodite flowers had equal investment in male structures: stamen mass, number of pollen grains, mass of pollen grains ejected by vibration, and pollen size were all similar for the two flower types. In contrast, male flowers had reduced masses of disfunctional female structures: ovaries of males were ⅓ as massive, and styles 1/7; as massive, as those of hermaphrodites. These results are consistent with the hypothesis that male flowers (which occur where fruit set is unlikely) increase male fitness through pollen donation, while saving resources that would otherwise be invested in hermaphrodite flowers that abscise.  相似文献   

19.
Levels of outcrossing, using a Pgm polymorphism, were estimated for individuals from ruderal and agrestal populations of the predominantly monomorphic weed Solanum ptycanthum, at the northern edge of its range, and compared to agrestal populations sampled from the southern portion of its distribution. Individuals were grown in agricultural habitats in Ontario. Outcrossing estimates of the northern agrestals were very low (< 3%) and did not differ from ruderal estimates. Southern agrestals exhibited much higher outcrossing rates (10%–17%). Of the floral traits measured, degree of stigma exsertion and style position showed interpopulation variation and correlated with outcrossing rate. Outcrossing in northern individuals was largely precluded by the complete overlap in female and male functions and stigmatic surfaces that were in direct contact with anther sacs as the flower opened. The observed flexibility in mating system may have played an important role in colonization success of 5. ptycanthum.  相似文献   

20.
为研究中华稻蝗形态特征与地理特征的关系,选取中华稻蝗体长(LB)、头长(LH)、前胸背板长(LP)、前胸背板宽(WP)、前胸背板侧片长(LLP)、前胸背板侧片高(HLP)、前翅长(LEL)、后足股节长(LF)、后足股节宽(WF)和后足胫节长(LT)等10个性状,采用电子游标卡尺测量其长度进行比较,使用SPSS11.5统计软件进行体长方差分析、各个性状在不同种群间的多重方差分析以及各性状间与海拔高度间的相关性分析。结果显示:9个中华稻蝗种群分为南方组、北方组及一个过渡种群,雌雄虫中北方种群的体长均明显小于南方种群;各性状测量值呈现出随纬度增加而减少的趋势;10个性状中除前胸背板长、前翅长、后足股节长和后足胫节长与海拔高度之间的相关性不显著之外,其余性状均与海拔高度呈现显著的正相关。结果表明,秦岭的分隔是造成南北方种群形态特征产生差异的主要原因;体型较大、后腿股节较宽的中华稻蝗更有利于在高海拔环境生存。  相似文献   

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