Matroclinal inheritance of cuticular waxes in reciprocal hybrids of Rosa species, sect. Caninae (Rosaceae)

Chemical surface characters play a decisive role in the interaction between plants and their environment. Maternal or paternal inheritance of wax characters in Rosa, section Caninae may allow for ecological niche differentiation according to the parental evolutionary constraints. If so, the radiation of hybrid offspring may reflect the parentally determined framework of interaction and selection against pathogens and abiotic stresses. We tested the inheritance of cuticular chemical wax parameters of reciprocal hybrids within Rosa, section Caninae, the dogroses. We not only found an extremely rich spectrum of chemical compounds on abaxial and adaxial leaf surfaces of dogroses, but also a maternally skewed inheritance of some of these wax characters. The possible role of these findings for the evolution of the allopolyploid dogrose complex is discussed.     

Different levels of morphometric variation in three heterogamous dogrose species (Rosa sect.Caninae, Rosaceae)

Difficulties in delimiting well-defined entities in the dogroses (Rosa sect.Caninae) has resulted in very variable taxonomic treatments. The present study was undertaken to provide a background for taxonomy as well as plant breeding. Morphometric diversity was analysed on seedlings obtained from field collections in South Sweden of three species,Rosa dumalis, R. rubiginosa andR. villosa. A canonical variates analysis showed that the three species are relatively distinct whereas two subspecies ofR. dumalis were less well discriminated. Analyses of variance demonstrated that intraspecific variation is pronounced inR. dumalis and, to a lesser extent, inR. villosa.     

Inheritance of growth form and mechanical characters in reciprocal polyploid hybrids of Rosa section Caninae—implications for the ecological niche differentiation and radiation process of hybrid offspring

Within Rosa section Caninae (dogroses) two different growth types exist, arching (L-type) and erect (D-type). Due to the specific mode of chromosome allocation during meiosis, character inheritance in dogroses is maternally skewed. In this paper we try to assess the mode of inheritance of the ‘growth form’ in reciprocal hybrids of R. canina L. and R. rubiginosa L. to predict possible ecological niches and radiation processes of hybridogenic offspring. A quantitative analysis of mechanical properties indicates that neither an expected parentally skewed nor an intermediate habit was expressed by the hybrids, but a dominant L-type as in R. canina, regardless of the parental relationship (pollen-parent or seed-parent). Our results implicate two possible scenarios to be further tested: (a) R. canina acts as a species with a dominant allele for the growth form character. If so, this would be the first evidence of a Mendelian character inheritance in the dogroses. (b) ‘Growth form’ in the dogroses is not a Mendelian character, but a syndrom which realises as an emergent functional property with underlying phenotypic structural differences in stem and wood anatomy.The first two authors contributed equally to the study.     

Morphological and RAPD markers show a highly skewed distribution in a pair of reciprocal crosses between hemisexual dogrose species, Rosa sect. Caninae

 The dogroses, Rosa sect. Caninae, are polyploid and characterized by their unique meiosis with an unequal number of chromosomes in the male and female gametes. The pollen cells have 7 chromosomes and the egg cells 21, 28 or 35 depending on the ploidy level of the species. The resulting matroclinal inheritance was studied with both morphological and molecular markers in a pair of reciprocal crosses between R. dumalis and R. rubiginosa (2n=35). A canonical discriminant analysis based on seven morphological characters showed only a minor overlapping between the two progeny groups. In addition, the R. dumalis×R. rubiginosa offspring were more heterogeneous than the offspring from the reciprocal cross in each of the characters analysed. Eleven RAPD markers specific for the R. dumalis parent and 10 RAPD markers specific for the R. rubiginosa parent were scored in the offspring. Each of the offspring exhibited either all, or all-but-one, of the seed parent markers. The average number of pollen donor markers found in the offspring was 3.2 (R. dumalis×R. rubiginosa) and 2.7 (R. rubiginosa×R. dumalis). About half of the pollen donor markers were never transmitted to the progeny. This is, to our knowledge, the first time the highly skewed chromosome distribution in Rosa sect. Caninae has been demonstrated with statistically evaluated morphological data and with molecular markers. Received: 25 June 1998 / Accepted: 28 July 1998     

Geographically differentiating morphology of genetically similar dogroses: consequences of canina meiosis

Despite their genetic homogeneity, many taxonomic species are described as European dogroses (Rosa L. section Caninae (DC.) Ser.) with consistent morphological variability. Here we report a morphometric study of 27 hip and leaf characters of proximate dogrose populations that include Rosa agrestis, a member of the subsection Rubigineae, in Flanders. In principal components analysis one R. agrestis population in Kanne had intermediate morphology between R. canina and R. corymbifera, on the one hand, and three other R. agrestis populations, on the other, suggesting hybridogenic origin. Half-sib R. agrestis seedlings were grown under controlled conditions and their leaf characters were studied. A tendency toward deviating morphology in seedlings from the Kanne population, analogous to the mother plants in the field, and a correlation for specific leaf characters between mother plants and their corresponding seedlings reinforce a genetic basis for the observed divergence in the Kanne population. The assumed hybridogenic mother plants did not produce fewer seeds per hip than the others of the pure populations. In addition, for all sampled dogroses, which included six species, the diameter of the discus was correlated with the number of seeds per hip, whereas the diameter of the orifice was not correlated with this character. This implies that only the diameter of the orifice and not the diameter of the discus might be decisive for species identification among European dogroses.     

Evidence of apomixis in hemisexual dogroses, Rosa section Caninae

All members of Rosa section Caninae, dogroses are polyploid and characterized by their unbalanced meiosis, which in most cases leads to a pronounced morphological influence from the maternal parent. In a previous investigation on a pair of reciprocal crosses between two species in this section, Rosa dumalis and R. rubiginosa (2n=35), nine offspring plants (approximately 10%) did not receive any of the 21 RAPD markers present in the respective pollen parent. This was interpreted as a possible occurrence of apomixis. These nine plants have now been subjected to a further study with additional markers. Thirteen new RAPD markers showed the same result as in the previous investigation: none of the nine plants inherited any of the pollen donor markers. The reproducibility of the RAPD markers was checked by mixing DNA samples to obtain a series of artificial hybrids between the two parent plants. Twelve RAPD markers gave the expected result, whereas one marker appeared only 50% of the time. In addition, pollen viability, mean number of seeds per hip, mean seed weight, and mean weight of fruit flesh per hip have been studied on the four progeny groups: R. dumalis×R. rubiginosa plants which received pollen donor markers (PM plants), R. dumalis×R. rubiginosa plants which did not receive any pollen donor markers (NPM plants), R. rubiginosa×R. dumalis PM plants and R. rubiginosa×R. dumalis NPM plants. A canonical discriminant analysis based on these four reproductive characters separated the four progeny groups. There were significant differences between the two PM groups in all investigated characters, and also between the PM and the NPM groups in pollen viability. The result from the RAPD markers together with the differences in pollen viability between the PM and NPM progeny groups is taken as an indication that apomixis occurs within the Caninae section. Received: 13 October 1999 / Revision accepted: 28 January 2000     

Cryptic species in the fern <Emphasis Type="Italic">Ceratopteris thalictroides</Emphasis> (Parkeriaceae). III. Referential diagnostic characters of three cryptic species

Three cryptic species of Ceratopteris thalictroides, named the south type, the north type and the third type, were examined for their morphological characteristics, using sporophytes cultivated under common conditions. The discriminant analysis for leaf characters followed by one-way layout ANOVA or Kruskal–Wallis test for selected combinations of characters revealed that the following characters may be effective for identifying the three types: the relative lengths of stipe to blade and to pinna, the degree of dissection, the segment densities on rachis and pinna rachis, and the elongation degree of ultimate segments. The number of annulus cells on sporangia also proved to be a possible distinguishing character. As morphological data were obtained from a limited number of cultivated sporophytes, they are regarded as not definitive, but only referential diagnostic characters of the types and should be utilized not solely, but collectively, to avoid identification errors of the types. An identification trial using herbarium specimens proved these diagnostic characters to be useful to a considerable degree. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Karyotaxonomic study of some species ofPeucedanum (Umbelliferae)

A study of morphometric karyotype characters was carried out in 14 species ofPeucedanum s. lat. (Umbelliferae — Apioideae) and in one species of the related genusLomatium. The differences of the species in their karyotype characters are correlated only to a limited degree with their similarities of dissimilarities in morphological (i. a. carpological) characters, and thus with their taxonomic position. The evolution of these two sets of characters seems to have proceeded not synchronously or even in different directions in the group of platycarpousUmbelliferae united in the genusPeucedanum. Therefore, it is unlikely that morphometric chromosome characters revealed by monochrome staining can be used appropriately in the taxonomic revision of the polymorphous genusPeucedanum.     

瑞香属和荛花属的数量分类研究

瑞香属和荛花属为瑞香科瑞香亚科的落叶或常绿灌木,中国西南部是瑞香属和荛花属的重要分化中心。全世界共有瑞香属95种、荛花属70种,中国分布有瑞香属52种、荛花属49种。瑞香属和荛花属的分类学研究一直存在不同程度的分歧。花盘形状和果实类型在传统分类中一直是区分瑞香属和荛花属的典型特征,而花盘形态和果实类型在2个属中存在交叉和过渡,部分植物分类学家根据这些特征将两个属进行过不同程度的归并。该研究采用数量分类法对瑞香属77种(变种)和荛花属62种(变种)植物,选取32个形态学性状进行聚类分析和主成分分析。结果表明:聚类分析和主成分分析均显示两属均未形成单系类群。在主成分分析中,前3个主成分分析的贡献值为35.56%,传统分类中用来区分两属的花盘形状、叶序及果实类型等特征对前3个主成分贡献相对较小,因此,传统分类学中对这两个属进行区分的性状并没有典型的分类学意义。同时,聚类图和主成分分析得到的散点图均不能将这两个属区分开来。数量分类研究结果显示两属植物存在明显的交叉,支持瑞香属和荛花属不是两个独立自然类群的观点。     

中国17种蔷薇属植物45S和5S的rDNA分布研究

为了探寻蔷薇属植物亲缘关系及系统发育研究的分子细胞遗传学证据,该研究采用双色FISH(荧光原位杂交)技术,对原产中国7个组的17种蔷薇属植物的45S和5S rDNA进行了定位分析。结果表明:(1)多数蔷薇属植物1组染色体对应1个45S rDNA位点和1个或2个5S rDNA位点,偶尔出现1~2个rDNA位点的丢失,但复伞房蔷薇(Rosa brunonii)的1组染色体对应了2个45S rDNA位点。(2)二倍体的蔷薇属植物至少有1对5S rDNA位点与45S rDNA位点共定位,而四倍体材料的5S rDNA位点与45S rDNA位点没有共定位,但所有四倍体材料均至少有1种rDNA信号纯合,表明它们应为二倍体直接加倍产生的同源四倍体。(3)绝大多数材料45S rDNA位于染色体短臂、5S rDNA位于染色体长臂,但缫丝花(R. roxburghii f. roxburghii)有1个5S rDNA信号位于染色体的短臂上,表明它与蔷薇属其他种的亲缘关系较远。(4)阿克苏地区和伊犁地区的疏花蔷薇的核型不同,且45S和5S rDNA的数量和位置不同,分子细胞遗传学证据也支持阿克苏地区的疏花蔷薇应为疏花蔷薇的新变种。(5)该研究中共有8个二倍体和6个四倍体蔷薇属植物的双色FISH为首次报道。研究认为,无论二倍体还是四倍体蔷薇属植物中出现的异形同源染色体、rDNA信号位置在同源染色体上的差异以及rDNA信号的增加和丢失,可能都与染色体结构变异和染色体重组有关,在分子细胞遗传学水平上证明染色体结构变异和染色体重组在蔷薇属植物演化过程中具有重要的作用。     

The natural delimitation ofCentaurea (Asteraceae: Cardueae): ITS sequence analysis of theCentaurea jacea group

Taxonomic complexity has hindered partitioning the genusCentaurea into natural subdivisions, even though it has long been recognized as an unwieldy, artificial assemblage. Most of the remaining difficulties center in theCentaurea jacea group, whose taxa share a common advanced type of pollen. Because it comprises half the species of the genusCentaurea, as well as five other disputed genera previously segregated fromCentaurea (Chartolepis, Cheirolepis, Cnicus, Grossheimia andTomanthea), theCentaurea jacea group is a significant taxonomic challenge. Newer molecular approaches are useful for resolving complex relationships because they provide more precise inferences of evolutionary relationships than traditional morphological characters. Sequences of the Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA were analyzed for a comprehensive sample of this group. Results indicated that theCentaurea jacea group is monophyletic and includes the segregated genera, but not two other genera (Oligochaeta andZoegea), whose inclusion in theCentaurea jacea group was doubtful. In addition to pollen morphology, the ITS phylogeny is also supported by karyological evidence and by good correlation with biogeographic distribution of the species. The monophyly of theCentaurea jacea group suggests that a natural delimitation ofCentaurea that minimizes nomenclatural changes is possible, but only if a new type of the genus is designated.     

Anchusella, a new genus ofBoraginaceae from the Central-Eastern Mediterranean

The two closely related speciesLycopsis variegata andAnchusa cretica, formerly placed inAnchusa subg.Rivinia, were compared with the type species ofLycopsis andAnchusa, on the basis of a set of macro and microcharacters. The presence of only two fertile stamens as well as other peculiar characters in flower structure, androecium, gynoecium, pollen and fruit, supports the institution of the new genusAnchusella, consisting ofA. variegata andA. cretica. Karyological and eco-chorological aspects are consistent with morphological data in pointing to the autonomy of this genus, which appears characterized by autapomorphic, advanced traits.     

中国蔷薇属植物物种丰富度分布格局及其与环境因子的关系

物种丰富度的大尺度地理格局及其成因是宏观生态学及生物地理学的中心议题之一。蔷薇属(Rosa L.)植物具有很高的经济价值和生态价值,探讨中国蔷薇属植物的丰富度分布格局及其影响因素可为该属植物资源的保护和合理开发利用乃至其系统进化研究提供重要依据。基于蔷薇属植物在中国的15451条分布数据和11种地理、气候等环境因子进行了物种丰富度分析和相关性分析,研究结果显示:(1)蔷薇属植物在中国分布不均匀。在水平方向上,蔷薇属植物于26.19°—34.29°N带内有较高的物种丰富度,之后随着纬度的增加而降低,且随着经度的增加表现为先增加后减少,于99.10°—108.47°E间存在明显的峰值;在垂直方向上,蔷薇属植物的物种丰富度随海拔的增加表现为先增加后减少,956.46—3518.60m范围内的丰富度最高。西南横断山区为蔷薇属物种分布的中心地区,新疆北部及东北长白山周边地区为局部聚集区。(2)蔷薇属物种丰富度与各能量、水分和生境异质性因子均呈正相关关系,与气候稳定性因子呈负相关关系。表明中国蔷薇属植物在水分和热量条件好、气候季节性变化小且生境异质性程度高的地方,有着更高的物种丰富度。(3)蔷薇属...     

Variation in wild populations of annual beet (Beta,Chenopodiaceae)

Among the morphological variation in wild annual populations of sect.Beta only tepal characters show a geographic pattern, and hence can be used to distinguish different taxa. Two morphological types correspond with taxa already described:B. macrocarpa (incl.B. bourgaei) has a Macaronesian and W. to E. Mediterranean andB. adanensis an E. Mediterranean distribution area. A third type in the Aegean region is not well known yet and possibly has to be included inB. macrocarpa. Both diploid and tetraploid (x = 9) cytotypes are found withinB. macrocarpa, the latter exclusively on the Canary Islands.     

The phylogeny ofActaea (Ranunculaceae): A biogeographical approach

Phylogenetic analyses of the genusActaea were performed using morphological, ecological and biogeographical characters. Using solely morphological characters, the relationships of the three identified species-groups remain uncertain. Close biogeographical examination and comparison of the areas with ecological peculiarities as well as climate data gave important insight into the phylogeny ofActaea and the whole tribe. Consequently, the obtained biogeographical data were used for phylogenetic reconstructions. Both, from the point of view of morphological and biogeographical data,A. pachypoda andA. asiatica are the most ancestral species. They grow on the east sides of the continents, mainly in broad-leaved forests. In West Eurasia the apomorphicA. spicata andA. acuminata occur under similar climatic and ecological conditions, but these species are adapted to another climate rhythm. The most advanced species (A. erythrocarpa, A. rubra) are to be found in the boreal forests where they are widely distributed. This biogeographical approach revealed that the evolution of the species led to a gradual widening and shifting of their ecological constitutions.     

RAPD analysis of genetic variation between a group of rose cultivars and selected wild rose species

The genetic variability based on random-amplified polymorphic DNA markers was analysed among 10 cultivated rose varieties and 9 wild species from three different series of the genus Rosa. Using 13 different RAPD primers, 104 polymorphic DNA fragments with a high potential to differentiate rose genotypes could be produced. A dendrogram displaying the relative genetic similarities among the genotypes shows the existence of large genetic diversity among the cultivated roses as compared to the wild species. Furthermore, the main clusters found here are in agreement with known pedigrees and the classical taxonomy. However, the relationships between cultivated roses as inferred by RAPD markers do not correlate with the classical rose classification system. From the present data it is concluded that cultivated roses display a high level of genetic variability despite the fact that single morphological and physiological characters may be less polymorphic within rose groups. This contrasts with the widely accepted opinion of a lack of genetic variability in roses. This is also in accordance with the reported history of rose breeding which makes it highly probable that rose genomes comprise mosaics of different species genomes. As a consequence, it may be possible to utilize the high genetic variability of all genetic traits not under actual selection by breeders for future breeding programmes.     

A phenetic study of the taxonomic delimitation of Quercus acutifolia and Q. conspersa (Fagaceae)

A phenetic study ofQuercus acutifolia andQ. conspersa (Fagaceae) is carried out. The study was based on morphological characters, and included cluster analysis and principal component analysis. The results revealed that the characters employed so far to separateQuercus acutifolia andQ. conspersa seem to be quite unreliable. Nevertheless, both species can still be recognized as taxonomically different entities, although mostly based on characters of leaf margins. We propose that the individuals that have leaves with dentate-aristate margins correspond toQ. acutifolia, whereas those that have leaves with entire and not dentate-aristate margins belong toQ. conspersa.     

Natural and experimental hybridization inArmeria (Plumbaginaceae):A. villosa subsp.carratracensis

An experimental crossing program was carried out in order to test the hypothesis thatArmeria villosa subsp.carratracensis, a serpentine endemic from Southern Spain, is of hybrid origin. Fruit-set and mainly pollen stainability data in artificial hybrids demonstrate that internal interspecific barriers are weak. Two generations of backcrossing with the two putative parents —A. colorata andA. villosa subsp.longiaristata— can restore pollen stainability to an average of 83.2 and 68.7, respectively. A morphometric analysis of 148 specimens belonging to parental species, different artificial hybrid generations and wild putative hybrid race shows that (1) morphological characters have a strong genetic basis and thus are good markers in identifying hybrids and introgression inArmeria; (2) artificial backcrossing produces in morphometrical characters a variation which conforms in both trend and magnitude to what is commonly attributed in the wild to introgression; (3) the position of the putative hybrid race is intermediate between the two parental species used in the program. These results are in accordance with the hypothesis of hybrid origin ofA. villosa subsp.carratracensis. Natural and experimental hybridization inArmeria, I     

Nestling characteristics and identification of the lesser spotted eagle Aquila pomarina, greater spotted eagle A. clanga, and their hybrids

The lesser spotted eagle Aquila pomarina and the greater spotted eagle A. clanga are closely related endangered raptors whose taxonomic status, field identification, and ultimately conservation, have been complicated due to morphological similarity. However, the partial overlap in morphological features may also involve hybrids, which are known to exist, but which have so far been poorly described. This study investigated spotted eagle nestlings in Estonia, pre-identifying them according to mitochondrial DNA, nape patch and the appearance of their parents. Relative size of bill and toes (corrected for nestling growth) enabled us to separate the smaller A. pomarina, but hybrids were as large as A. clanga. All three groups had distinct plumages with hybrids being intermediate; the separation was clearest using both size and plumage indices. In all, 164 of 168 birds were correctly identified using a three-step procedure, separating: (1) A. clanga, having no nape patch; (2) 9 of 13 hybrids according to plumage index; and (3) the remaining hybrids by their large size (at least two features over the mean+2 SD values of A. pomarina). Knowing the sex helped to interpret size, but not plumage, characteristics, and its overall value for assisting identification was not high. The results support the view that spotted eagles with intermediate characters are usually hybrids which can be recognised by their appearance.Communicated by F. Bairlein