COMPARATIVE ANATOMY OF SOME PARENTS AND HYBRIDS OF THE HAWAIIAN MADIINAE (ASTERACEAE)

Comparative leaf morphology and anatomy was examined in five species and four hybrids involving three genera of Hawaiian Madiinae (Asteraceae). The comparisons included Argyroxiphium grayanum, Dubautia ciliolata subsp. ciliolata, D. knudsenii subsp. knudsenii, D. scabra subsp. leiophylla, D. scabra subsp. scabra, and Wilkesia gymnoxiphium, and the hybrids A. grayanum × D. scabra subsp. leiophylla, D. ciliolata subsp. ciliolata × D. scabra subsp. scabra, D. knudsenii subsp. knudsenii × D. scabra subsp. leiophylla, and W. gymnoxiphium × D. scabra subsp. leiophylla. Foliar morphology, leaf tissue organization, and various characters of stomata and trichomes were compared, using epidermal peels, cross and paradermal sections, and clearings of leaves. Pronounced anatomical differences among these closely related taxa were characterized, and effects of hybridization on the expression of anatomical features were documented. Most comparisons of parents and hybrids revealed statistically significant differences in leaf size, distribution of adaxial and abaxial stomata, and marginal and surface trichomes. In most instances hybrids demonstrated intermediate status in their foliar characters, indicating that these features are inherited from both parents. However, differences in foliar characters were usually of sufficient magnitude to allow recognition of hybrids as well as parents.     

三种胡子鲶及其杂种F1的乳酸脱氢酶同功酶的比较研究

垂直板聚丙烯酰胺凝胶电泳图谱揭示所有实验鱼的LDH-A_4均表现相同的迁移率,革胡子鲶的LDH-B_4比另两种的迁移较缓慢。胡子鲶和斑点胡子鲶具有五条由A、B座位编码的LDH谱带,且其迁移位置对应相同;革胡子鲶则只有三条LDH酶带。全部实验鱼的肝组织、斑点胡子鲶和革胡子鲶的脑组织存在靠近阴极的酶带,杂种斑点胡子鲶×胡子鲶的LDH与双亲的相问,而杂种胡子鲶×革胡子鲶、斑点胡子鲶×革胡子鲶则显示一些由来自双亲的基因编码的杂合带。利用LDH的表型差异对三种鱼的进化关系、遗传特性和杂交育种问题进行讨论。     

几种鲤科鱼类及杂种的乳酸脱氢酶同工酶的比较

用聚丙烯酰胺凝胶电泳法,分析了14种鲤科鱼类和4个杂交种的肌肉、心脏、晶状体、脑和肾脏的乳酸脱氢酶(LDH)同工酶。根据LDH酶谱的异同可将雅罗鱼亚科的5种鱼分成两组:草鱼、鳡和鳤;青鱼和赤眼鳟。鳊亚科中青梢红鲌的LDH谱形与长春鳊、团头鲂和红鳍鲌相似,而与(歺又鱼)条有明显的区别。鲢亚科中的鳙与鲢的谱形相似。密鲴亚科中的细鳞斜颌鲴与黄尾密鲴的谱形也非常相似。将谱形相似的鱼类进行杂交,如细鳞斜颌鲴♀×黄尾密鲴♂、鳙♀×鲢♂,不仅杂种的成活率高而且可繁殖后代。谱形相差很大的鱼类进行杂交,如草鱼♀×团头鲂♂及草鱼♀×鳙♂,杂种的成活率都很低。这些结果和酶谱所显示的关系是一致的。       

曲霉和青霉属内杂种和亲株的蛋白质电泳图谱比较

曲霉属内黑曲霉(Aspergitlus niger)与米曲霉(A.oryzae)具有特征明显不同的可溶性蛋白质电泳图谱,其种间杂种具有双亲的部分或全部电泳带并与黑曲霉相近。来自杂种Ⅰ的多数分离子电泳带与黑曲霉相近,只有一个分离子产生米曲霉的电泳带并具有米曲霉的遗传特性。青霉属内产黄青霉(Penicillium chrysogenum)与展青霉(P.patulum)种间及种内不同菌株间的电泳图谱基本相同,种内或种间杂种具有双亲的电泳带。结果讨论了蛋白质图谱分析的意义。     

COMPARATIVE LEAF ANATOMY OF SOLIDAGO AND RELATED ASTERACEAE

Leaf anatomy of 63 taxa is investigated to elucidate generic relationships among Brachychaeta, Brintonia, Chrysoma, Euthamia, Gundlachia, Oligoneuron, Oreochrysum, Petradoria, and Solidago. All these genera have been included at one time or another within Solidago. Aster ptarmicoides is also studied because it hybridizes with some species of Solidago (sens. str.). Qualitative and quantitative differences in mesophyll, storage parenchyma, secretory apparatus, bundle sheath extensions, and midvein structure allow rather precise grouping of the taxa. Brachychaeta, Brintonia, Oligoneuron, Oreochrysum, and Aster ptarmicoides should be considered as constituents of Solidago. They all have bundle sheath extensions and little or no water storage parenchyma. In Solidago secretory cavities, when present, are shaped and positioned differently from those in Euthamia. The absence of bundle sheath extensions and various combinations of other anatomical features suggest that Chrysoma, Euthamia, Gundlachia, and Petradoria are generically distinct from one another and from Solidago.     

INHERITANCE OF NUCLEAR 2C DNA CONTENT VARIATION IN INTRASPECIFIC AND INTERSPECIFIC HYBRIDS OF MICROSERIS (ASTERACEAE)

Nuclear DNA content varies over 20% within the diploid (2n = 18) species M. douglasii and M. bigelovii. Two different intraspecific crosses were made between M. douglasii biotypes which differed by about 10% in 2C nuclear DNA content. The F₂ progeny of one intraspecific cross showed no striking evidence of segregation for DNA content. The mean DNA contents of F₂ progeny from two sister hybrids from the second intraspecific cross were significantly different at the 1% level. An interspecific cross was made between biotypes of M. douglasii and M. bigelovii that differed by approximately 10% in DNA amount. The 12 F₁ progeny did not cluster around the parental midpoint, but instead encompassed nearly the entire range between the parental means. The five families of F₂ progeny studied each had a mean DNA content corresponding to that of the particular F₁ from which they were derived, indicating that the F₁ plants were not of identical DNA content. The results of this study suggest that DNA sequences which account for the DNA content differences among the plants are unstable and can undergo deletion or amplification in a hybrid. The altered DNA content may be heritably stable and show little or no segregation in the F₂ progeny.     

CYTOLOGICAL ANALYSIS OF ANTHURIUM ANDRAEANUM (ARACEAE), ITS RELATED TAXA AND THEIR HYBRIDS

Karyotypes and meiotic configurations of Anthurium andraeanum and closely related taxa were analyzed. The karyotypes of A. andraeanum, A. caperatum, A. formosum, A. kamemotoanum, A. lindenianum, A. roseospadix, A. cf. sanctifidense, A. subsignatum, A. garagaranum, and an unidentified Anthurium sp. commonly consisted of four large metacentric or submetacentric chromosomes, two fairly large acrocentric chromosomes, two satellite chromosomes, and 22 smaller chromosomes. Variation in the karyotypes of A. nymphaeifolium and A. ochranthum suggested chromosomal rearrangement in the genus. All taxa showed 15 pairs of chromosomes at prometaphase I of meiosis in pollen mother cells. Four large chromosomes appeared as ring bivalents, and the rest of the chromosomes appeared as either ring or rod bivalents. Regular bivalent formation at prometaphase I of meiosis in pollen mother cells of species hybrids suggested close genomic relationships among parental taxa. On the other hand, reduction of pollen fertility estimated by pollen stainability in those hybrids suggested genetic divergence of species.     

ELECTROPHORETIC AND CYTOGENETIC EVIDENCE FOR ALLOPOLYPLOID ORIGIN OF MARSHALLIA MOHRII (ASTERACEAE)

Marshallia mohrii is a tetraploid species, 2n = 4x = 36, with approximately 17% of its pollen mother cells exhibiting a single quadrivalent at diakinesis of Meiosis I. The species is morphologically most similar to M. grandiflora, a member of the Grandiflora complex along with M. mohrii and M. trinervia. These data led to the preliminary hypothesis that M. mohrii originated by autopolyploidy. However, we rejected the autopolyploid hypothesis because the number of quadrivalents observed in 93 cells is significantly less than predicted by the Jackson-Casey-Hauber model for autotetraploids that have zero to two chiasma per pachytene bivalent. Enzyme electrophoresis was used to test the alternative hypothesis of allotetraploidy and to determine possible diploid progenitor(s). Eleven enzymes encoded by 25 loci were resolved for the three species in this complex. Marshallia mohrii exhibits fixed heterozygosity for the polymorphic loci. The diploid species possess three duplicated loci, one for isocitrate dehydrogenase and two for phosphoglucose isomerase. Of sixteen alleles among the polymorphic loci in M. mohrii, one allele (for Tpi-1) is also found in M. trinervia, and three alleles (one each for Tpi-1, Tpi-2, and Lap) are found in M. grandiflora. Marshallia mohrii also possesses one allele each at Idh-1, Idh-2, Pgi-4, and two each at Me and Mnr that are not shared with either of the two diploid species analyzed in this study. The cytogenetic and electrophoretic evidence suggest an allotetraploid origin of M. mohrii, possibly involving M. grandiflora, M. trinervia, and a third species. Inferences about ancestry are difficult because of the paucity of qualitative allozyme divergence among the diploids and because of the number of high frequency alleles in M. mohrii, not found in either M. grandiflora or M. trinervia.     

CHROMOSOME PAIRING AND POLLEN FERTILITY IN INTERSPECIFIC HYBRIDS OF SPECIES OF PARTHENIUM (ASTERACEAE)

Meiotic analyses and pollen viability tests were performed on F, hybrids between diploid guayule (Parthenium argentatum Gray 2n = 36), P. rollinsianum Rzedowski (2n = 36), P. alpinum var. tetraneuris Barneby (2n = 36), and P. alpinum var. alpinum Nutt. (2n = 36). Parthenium chromosomes are small and karyomorphologically similar, and meiotic analysis is difficult because of chromosome clumping. However, cytogenetic studies at metaphase I indicated univalents can be seen in a lateral view of the metaphase plate. Chromosome pairing and the number of univalents varied within and between the interspecific hybrids, with an average univalent number of 1.54 for the P. rollinsianum hybrids, 2.36 for the P. alpinum var. tetraneuris hybrids, and 2.46 for the P. alpinum var. alpinum hybrids. Pollen viability tests for the parental species and the hybrids were conducted by germination of pollen grains on stigmas. The percent of viable pollen recorded for the diploid guayule hybrids with P. rollinsianum, P. alpinum var. tetraneuris, and P. alpinum var. alpinum are 21.94, 13.47, and 11.17, respectively. The degree of chromosome pairing and pollen viability is striking because there are many morphological differences between the parents. The chromosome homology of these species based on their pairing behavior allows for the design of a backcross breeding program that would permit the transfer of the desirable characteristics from these species into diploid guayule.     

分布于日本和中国的鹅观草及其杂种的形态学和细胞学研究

本文对分布于日本的Agropyron tsukushiense (Honda) Ohwi var. transiense (Hack.) Ohwi (2n=6x=42)和分布于中国的Roegneria kamoji Ohwi (2n=6x=42)及其杂种F_1(2n=6x=42)进行了形态学及细胞学的研究,并同时探讨了亲本种的亲缘关系。总体来看,亲本材料之间在形态上虽有差异但并不十分显著。杂种F_1的形态特征介于其父、母本之间。在减数分裂过程中,亲本种和杂种F_1的染色体配对行为均十分正常。但在检查了大量的成熟花粉和穗状花序之后,发现杂种F_1有部份不育现象。上述研究结果表明A. tsukushiense var. transiens的三个染色体组与R. kamoji的三个染色体组同源。结合形态学和育性等方面的研究资料,作者认为上述两个材料仍应属于同一分类等级。但必须指出,由于长期的地理隔离,他们之间产生了一定的形态变异和生殖障碍。按照国际植物命名法规(ICBN)上述两个材料应组合为:Roegneria tsukushiensis (Honda) B. R. Lu, Yen et J. L. Yang及其变种var. transiens (Hack.) B. R. Lu, Yen et J. L. Yang comb. nov.     

COMPARATIVE STUDIES ON THE CELL WALLS OF SEXUAL AND ASEXUAL BANGIA ATROPURPUREA (RHODOPHYTA). II ELECTROPHORETIC PATTERNS OF POLYSACCHARIDES1

Cellulose acetate electrophoresis of the hot water soluble polysaccharide extracts from whole filaments, as well as base, mid and tip segments, of marine asexual and sexual Bangia atropurpurea (Roth) C. Ag. Yielded distinctive patterns which demonstrated that changes occur in the outer cell walls during sexual reproduction. Heterogeneity of the sulfated polysaccharide components isolated from outer cell walls was shown to be specifically related to sexual reproduction. Two components (Band I and II) were detected in extracts from tips of sexual filaments, whole only one (Band I) was present in the vegetative segments of all filaments and in asexual reproductive regions. The faster running component (Band II) was detected during the later stages of sexual development, prior to maturation.     

栽培与野生射干的质量比较研究

本文对栽培与野生射干的药材性状、根茎及根的粉末特征、组织特征、薄层扫描、薄层层析及总黄酮的含量测定等方面进行了比较研究。结果表明,二者的质量基本一致,为推广应用人工栽培射干提供了依据。     

HYBRIDS AND PHYLOGENETIC SYSTEMATICS I. PATTERNS OF CHARACTER EXPRESSION IN HYBRIDS AND THEIR IMPLICATIONS FOR CLADISTIC ANALYSIS

Interspecific hybridization is considered common among plants, but the methods of cladistic systematics produce only divergently branching phylogenetic hypotheses and thus cannot give the correct phylogeny if an analysis includes hybrids. Empirical studies of the impact of known hybrids on phylogenetic analysis are lacking, and are necessary to begin to understand the problems that we face if hybrids are often included in cladistic analysis. Examination of the implications of hybrids for cladistics must begin with patterns of character expression in hybrids. This study includes 17 hybrids and their nine parental taxa that are Central American species of Aphelandra (Acanthaceae), analyzed using a set of 50 morphological characters. The hybrids are overwhelmingly intermediate as quantitatively scored for phylogenetic analysis. They express maternal and paternal, and primitive and derived characters in equal frequencies, showing no evidence of predominant inheritance of derived character states as has been assumed by most cladists who have considered hybrids theoretically. Because of their known genetic constitution, hybrids were useful in homology assessment and ordering character states. The parental character set was generally robust, but some changes were made to reflect the special evidence offered by the hybrids. These hybrids suggest that the inclusion of hybrids in phylogenetic analysis will not lead to unresolved cladograms with rampant homoplasy, as has been predicted by other authors. Instead, the patterns of character inheritance in these hybrids lead to the prediction that a hybrid will be placed by phylogenetic analysis as a basal lineage to the clade that includes its most derived parent, with relatively little effect on homoplasy. These predictions will be evaluated by incorporation of the hybrids in phylogenetic analyses, to be reported in a subsequent paper.     

THE NUCLEAR CYTOLOGY OF BIVALENT AND RING-FORMING RHOEOS AND THEIR HYBRIDS

The structural hybridity of the chromosomes of Rhoeo spathacea (R. discolor) that produces a ring of 12 chromosomes at meiosis is probably maintained by a balanced lethal system active in the zygotic or embryonic stage. Bivalent-forming plants have been identified that belong to the taxon R. spathacea var. concolor. In the clone studied the arm arrangement in R. s. var. concolor is very nearly the same as the arm arrangement in one of the balanced translocation complexes of R. spathacea.