Adaptive significances of sexual system in andromonoecious Capparis spinosa (Capparaceae)

The sexual system of the perennial shrub Capparis spinosa L. (Capparaceae), which is distributed in arid deserts of northern Xinjiang, was investigated. The main results can be summarized as follows. (1) The species is andromonoecious, i.e. individuals possess both male and perfect flowers. Stamens of two floral morphs are normal and can be divided into long and short ones in each flower. The perfect flowers have well developed pistils, but male flowers have aborted pistils and only function as males. (2) There were very significant differ-ences among the populations in daily ratio of the two floral morphs, number of long and short stamens of perfect flowers and length of filaments and anthers of short stamens in male flowers (P<0.01), but no significant differ-ences occurred in biomass of floral organ (P>0.05). (3) Anthesis was nocturnal and lasted 15–16 h. Both male and perfect flowers opened about 18:00 at dusk. The number of two floral morphs produced on each individual was indeterminate every day during flowering, which would make the individual temporally androdioecious. However, the total number of male flowers was more than that of perfect flowers within the population every day. (4) The P/O ratios of perfect flowers in three populations were 1.57×104, 1.65×104 and 1.71×104. There was no significant difference in pollen numbers (P>0.05) within population between male and perfect flowers or between long and short stamens, and also no significant difference among the populations in pollen numbers of male and perfect flowers, and in ovule numbers and P/O ratios of perfect flowers (P>0.05). (5) Dynamic curves of pollen viability of long and short stamens in the two floral morphs were similar in three populations. Pollen longevity of both long and short stamens was about 18–20 h, and duration of stigmatic receptivity was about 16–18 h. (6) Floral visitors were hymenopterous and lepidopterous insects. There was a total of seven species of floral visitors in the three populations. The activities of them were greatly affected by the climate of the desert environment. (7) Perfect flowers were not apomictic and could produce fruits after self-pollination (autogamy and geitonogamy) and cross-pollination; thus they had a mixed mating system. These results suggest that the sexual system of andro-monoecy may reflect an environment-heredity interaction in C. spinosa. The male flowers increase the number of pollen grains, the P/O ratio and enhance male fitness of individuals. They also increase the floral display and consequently effect cross pollination by attracting more pollinators that bring cross-pollen to the stigmas of per-fect flowers, thus increase outcrossing rate and female fitness of individuals, which insure reproductive success of C. spinosa in the extreme desert environment.     

Archaeobotany of capers (Capparis) (Capparaceae)

The origins of capers, their use and cultivation are discussed. Capers seeds and charcoal are often recovered from archaeological sites of the Mediterranean and West Asia. These are referred to as C. Spinosa L. This is mostly a group of cultivars restricted to localities surrounding the Western Mediterranean and some places in the Eastern Mediterranean. Identification of the findings is discussed in terms of seed morphology, present distribution and ancient uses of C. aegyptia Lam., C. sicula Veill., C. cartilaginea Decne, C. orientalis Veill., C. decidua (Forssk.) Edgew. and other species. Citations of Capparis in early Rabbinic, Mesopotamian and Greco-Roman texts are presented. Received June 3, 2002 / Accepted October 8, 2002 Correspondence to: D. Rivera     

Phenological growth stages of caper plant (Capparis spinosa L.) according to the Biologische Bundesanstalt,Bundessortenamt and CHemical scale

Capparis spinosa is an evergreen perennial shrub known from ancient times. During the last years it has been intensively studied because of its multiple uses. The phenological growth stages of caper plant were described using the BBCH scale (Biologische Bundesanstalt, Bundessortenamt and CHemical industry). The decimal code established nine principal growth stages using a two‐digit numerical system, and every major stage was in turn subdivided into secondary growth stages.     

Genetic diversity and population differentiation of Capparis spinosa (Capparaceae) in Northwestern China

To explore the influence of vicariance on differentiation patterns of taxa in arid regions, we systematically assessed the genetic diversity and variability of Capparis spinosa, a typical xerophyte that is widely distributed in the Tianshan Mountains and adjacent areas. In total, 300 individuals from 25 populations were sampled, and 14 haplotypes were identified using two cpDNA sequences (rpS12-rpL20 and ndhF). A high level of total genetic diversity (H_T = 0.859) was detected, and this was attributed to the extensive distribution range, which included numerous large populations. The SAMOVA results suggested that the 25 populations were clustered into 4 major geographical groups; a similar divergence trend was found by constructing a BEAST phylogenetic tree and a network diagram. The AMOVA results revealed that significant genetic differentiation occurred among groups. Our results indicated a considerable correlation between genetic divergence and geographical distribution. Isolation due to complex mountain and desert geography might limit gene exchange between disjunct populations, resulting in high differentiation between geographical groups.     

Isolation of Two Plasticizers,Bis(2-ethylhexyl) Terephthalate and Bis(2-ethylhexyl) Phthalate,from Capparis spinosa L. Leaves

Many plants have been known to be contaminated and accumulate plasticizers from the environment, including water sources, soil, and atmosphere. Plasticizers are used to confer elasticity and flexibility to various fiber and plastic products. Consumption of plasticizers can lead to many adverse effects on human health, including reproductive and developmental toxicity, endocrine disruption, and cancer. Herein, we report for the first time that two plasticizers, bis(2-ethylhexyl) terephthalate (DEHT) and bis(2-ethylhexyl) phthalate (DEHP), have been isolated from the leaves of Capparis spinosa L. (the caper bush), a plant that is widely used in food seasonings and traditional medicine. 297 mg/kg of DEHT and 48 mg/kg of DEHP were isolated from dried and grounded C. spinosa L. leaves using column chromatography and semi-preparative high-performance liquid chromatography. Our study adds to the increase in the detection of plasticizers in our food and medicinal plants and to the alarming concern about their potential adverse effects on human health.     

Chloroplast DNA diversity within and among populations of the allotetraploid Prunus spinosa L.

High chloroplast DNA (cpDNA) diversity was found within and among populations of Prunus spinosa sampled from seven European deciduous forests. A study of 12% of the total chloroplast genome detected 44 mutations, which were distributed over 24 haplotypes; four were common to two or more populations and the rest were unique haplotypes. The most-abundant and widely distributed haplotype was H2 (frequency = 41% approximately). Six of the seven populations were polymorphic. All of the six polymorphic populations had ”private” haplotypes (frequency < 5%) in addition to common haplotypes. The UPGMA dendrogram demonstrated a correlation between populations and their geographical locations. The total diversity was high (h_T= 0.824) and a major portion of it was within populations (h_s= 0.663). The level of population subdivision for unordered alleles was low (G_ST= 19.5%) and for ordered alleles was lower (N_ST= 13.6%). No phylogeographic structure could be demonstrated in the present geographical scale. High polymorphism in the cpDNA of P. spinosa has to be considered carefully when planning phylogenetic studies involving this species. Received: 20 September 1999 / Accepted: 10 November 1999     

Association between chloroplast DNA and mitochondrial DNA haplotypes in Prunus spinosa L. (Rosaceae) populations across Europe

Chloroplast DNA (cpDNA) and mitochondrial DNA (mtDNA) were studied in 24 populations of Prunus spinosa sampled across Europe. The cpDNA and mtDNA fragments were amplified using universal primers and subsequently digested with restriction enzymes to obtain the polymorphisms. Combinations of all the polymorphisms resulted in 33 cpDNA haplotypes and two mtDNA haplotypes. Strict association between the cpDNA haplotypes and the mtDNA haplotypes was detected in most cases, indicating conjoint inheritance of the two genomes. The most frequent and abundant cpDNA haplotype (C20; frequency, 51 %) is always associated with the more frequent and abundant mtDNA haplotype (M1; frequency, 84 %). All but two of the cpDNA haplotypes associated with the less frequent mtDNA haplotype (M2) are private haplotypes. These private haplotypes are phylogenetically related but geographically unrelated. They form a separate cluster on the minimum-length spanning tree.     

Inflorescence development of Whytockia (Epithemateae, Gesneriaceae) and phylogenetic implications within Gesneriaceae

 The inflorescence development in Whytockia has been studied in order to explore the developmental basis for inflorescence architecture. The developmental pattern of the pair-flowered cyme in Whytockia basically conforms to that of most members in Gesneriaceae. However, the additional flower beside the terminal one in Whytockia is not equivalent to the frontal flower as in other Gesneriaceae because the former is located in the front-lateral position while the latter is in the front-median position. Also, the zigzag monochasial branching system in Whytockia represents the consecutive front-lateral branches rather than the lateral branches as in other Gesneriaceae. The inflorescence in Whytockia is flowering in a basipetal sequence, and its seemingly acropetal flowering sequence is due to the vigorous development of the consecutive front-lateral branches. In addition, the inflorescence of Whytockia does not represent the basic unit of the inflorescence in Epithemateae, and it is derived as compared to that of Rhynchoglossum. The development relationships of the inflorescence between Whytockia and its allies in Epithemateae are discussed on the basis of developmental and comparative evidence. Received February 15, 2002; accepted September 17, 2002 Published online: December 11, 2002     

Molecular relationships in Genista L. Sect. Spartocarpus Spach (Fabaceae)

 A molecular investigation on the species of Genista belonging to sect. Spartocarpus was undertaken with the aim of inferring phylogenetic relationships within the section. The combined cladistic analysis of ITS 1 and 2 and of the chloroplast DNA trnL^(UAA) intron yielded a single most parsimonious cladogram with G. aetnensis as sister group to the rest of the section, which is in turn divided into two major clades, one of which includes G. nissana, G. aucheri, G. sessilifolia, G. spartioides and G. haenseleri, and the other the remaining species of the section. This latter group has G. holopetala and G. radiata forming a clade, which is a sister group to a not entirely resolved monophylum including the G. ephedroides species complex. The latter shows a basal collapse of G. cilentina, G. dorycnifolia and G. numidica, and then a clade including G. ephedroides and G. valsecchiae, as well as a collapsed monophylum with G. demarcoi, G. gasparrini and G. thyrrena. The clade including the G. ephedroides species group has the lowest within-group molecular variation and appears to be recent in origin, as compared to the rest of the section. The pattern of cladogeny in the section seems to be related to geographical isolation, and is broadly congruent with palynological and biogeographical evidence. Received March 3, 2001 Accepted October 8, 2001     

Variability of nectar production and composition in Linaria vulgaris (L.) Mill. (Scrophulariaceae)

 We studied nectar characteristics during the long flowering period (late June to end of November) in two populations of Linaria vulgaris (L.) Mill. spontaneously growing in the Botanical Gardens of Siena University (Tuscany, central Italy). The two populations were close to each other but they differed in blooming period. Plants of population 1 sprouted in May and flowered from the end of June to the end of September. Population 2 sprouted at the end of August and flowered from September to the end of November. Differences in nectar production and composition were found between and within populations. Flowers of population 1 produced a very small amount of nectar (not collectable) that remained on the nectary surface. The quantity of nectar increased in late September, when each flower produced 2–3 μl of nectar that flowed into the spur. Total sugar concentration was 175.8 mg/ml in young flowers. Flowers of population 2 produced 5–8 μl of nectar with a total sugar concentration of 200.9 mg/ml in the young stage. In bagged senescent flowers nectar volume decreased in both populations and nectar sugar concentration decreased down to 11.6 mg/ml in population 2 and increased up to 289.6 mg/ml in population 1. For both populations, the decrease in nectar volume in bagged flowers may have been due to water loss by evaporation. In population 2, the decrease in sugar concentration may have been due to nectar reabsorption that was never observed in population 1. Nectar variability is discussed in relation to insect visits and seed set. Received August 14, 2002; accepted December 17, 2002 Published online: June 2, 2003     

Allozyme variation in Mexican species and classification of Datura (Solanaceae)

 Fifty natural Datura populations, belonging to eleven species (D. ceratocaula, D. discolor, D. inoxia, D. kymatocarpa, D. lanosa, D. metel, D. pruinosa, D. quercifolia, D. reburra, D. stramonium, D. wrightii) from Mexico and adjacent USA, were investigated using starch gel electrophoresis. A total of 64 alleles were scored at 17 loci (DIA1, DIA2, GOT1, GOT2, G6PDH, IDH, MDH1, MDH2, MDH3, ME, PGD1, PGD2, PGM1, PGM2, PHI, SAD, SOD). The heterozygosity among the species ranged from 0.166 (D. ceratocaula) to 0.276 (D. wrightii). Most genetic diversity was found within populations (average H_s=0.242), while values between populations are relatively low (average Dst=0.066, Gst=0.171). The analysis of the genetic distance suggested new taxonomic relationships among the species. Rather than supporting the conventional infrageneric classification with three sections, the results revealed that the herbaceous members of the genus Datura form four groups. One group included four of the eight species of the section Dutra and was more similar to the section Ceratocaulis than it was to the other group that contained the remaining taxa of Dutra. Received February 13, 2001 Accepted December 25, 2001     

Structural and functional divergence of Campanula spatulata subspecies on Mt Olympos (Greece)

 Campanula spatulata is represented on Mt Olympos (2917 m) by two subspecies: the lowland spruneriana, from 400 to 1100 m, and the upland spatulata, from 1700 m to 2500 m. Spatulata populations significantly differed from those of spruneriana in the following features: (i) they consisted of shorter individuals with smaller flowers and lower flower production, (ii) they allocated more energy and resources below ground, (iii) they flowered much later in the year, had longer duration of flowering, and longer flower life span, (iv) they produced smaller fruits with fewer but heavier seeds, (v) they received lower numbers of insect visits for fewer hours per day, and (iv) they were pollinated by smaller insects. Between and within subspecies comparisons showed that in most cases the patterns of character change were neither gradual nor monotonous all along the elevation gradient. The differences in phenological characters are in agreement with patterns associated so far with elevation change. The taxonomic and biometric differences of the insect pollinators as well as the temporal separation of the flowering periods provide substantial evidence of reproductive isolation of the two C. spatulata subspecies on Mt Olympos. Received July 25, 2001 Accepted December 6, 2001     

The correlation between development of atypical bisexual flowers and phylogeny in the Aroideae (Araceae)

 In the intermediate zone of the inflorescence of genera of Aroideae one can find flowers with male and female characteristics. Until now, two types of developmental sequences of atypical bisexual flowers (ABFs) have been recognized: the Philodendron type and the Cercestis type. In the Philodendron type, bisexual flowers generally consist of functional carpels and staminodes inserted on the same whorl. In the Cercestis type, the gynoecium and stamens are inserted on two different whorls. These different ontogenetic patterns represent two different pathways in the evolution of unisexual flowers in this subfamily. A molecular phylogenetic analysis of 33 genera of Araceae, based on the chloroplast trnL intron and trnL–F intergenic spacer sequences was carried out. We use this phylogenetic analysis and those published by French et al. (1995) and Mayo et al. (1997) to examine the distribution of the two types of ABFs in selected genera. Our results suggest that the two developmental patterns of ABFs in Aroideae sensu Mayo et al. (1997) do not correspond to two separate evolutionary lineages but rather are more or less consistent within clades. Although this new molecular phylogeny does not include all aroid genera, it corroborates in general, at the subfamily level, the molecular analysis of French et al. (1995) based on chloroplast DNA restriction site data and the analysis of Mayo et al. (1997) based on morphological and anatomical data. Received March 15, 2001 Accepted October 11, 2001     

Infraspecific genetic variation in Biscutella laevigata (Brassicaceae): new focus on Irene Manton's hypothesis

 Genetic variation in 42 populations throughout the range of Biscutella laevigata L. (Brassicaceae), a morphologically variable central European species, has been investigated by enzyme electrophoresis with three loci (Amy1, Amy2, and Gpi2). Genetic identities and the Fitch-Margoliash tree suggest differentiation into four regional groups: 1) a northwestern diploid group (northern France and northern Germany), 2) a northeastern diploid group (southern Germany, Upper Austria, northern Lower Austria, Poland, and Romania), 3) a central diploid group in southern Lower Austria corresponding to subspecies austriaca, and 4) a southern tetraploid group in Alpine areas of France, Germany, Switzerland, Austria, Italy, and Slovenia corresponding to subspecies laevigata. Geographically isolated diploid relic populations that are genetically depauperate are found in the NW and NE diploid groups. On the other hand, the diploid relic subspecies austriaca from the NE Prealps and Alps is highly variable. Subspecies laevigata appears to be a genetical autotetraploid with multiple origins involving several diploid progenitors (the NW diploids, subspecies austriaca and B. prealpina). Received April 6, 2001; accepted March 6, 2002 Published online: October 14, 2002 Addresses of the authors: Karin Tremetsberger (e-mail: k.tremetsberger@gmx.net), Christiane K?nig, Rosabelle Samuel, Tod F. Stuessy, Department of Higher Plant Systematics and Evolution, Institute of Botany, University of Vienna, Rennweg 14, A-1030 Vienna, Austria. Wilhelm Pinsker, Institute of Medical Biology, University of Vienna, Waehringerstra?e 10, A-1090 Vienna, Austria.     

Geographic isolation and evolution of Mediterranean endemic Cyclamen: insights from chloroplast trnL (UAA) intron sequence variation

 In this study we construct a phylogenetic hypothesis for the relatedness among disjunct subspecies of Cyclamen repandum and its two allopatric congeners, C. creticum and C. balearicum in order to examine the evolutionary divergence of currently isolated populations across the western Mediterranean. The most parsimonious phylogenetic tree obtained from sequencing the cpDNA trnL (UAA) intron suggests a major phylogeographic divide in southern Greece between two clades. The first clade comprises samples of C. repandum subsp. peloponnesiacum (from the Peloponnese) and C. creticum (from Crete). The second comprises samples of C. repandum subsp. repandum (from Croatia, Italy, southern France, Corsica, Sardinia and Sicily), C. repandum subsp. rhodense (from Rhodes and Kos) and C. balearicum (from the Balearic Islands and southern France). These data suggest that C. creticum has evolved in allopatry from C. repandum subsp. peloponnesiacum and that C. balearicum and C. repandum ssp. rhodense have diverged from C. repandum subsp. repandum at its western and eastern distribution limits. At one small site on Corsica, a population of C. repandum may have introgressed with relictual populations of C. balearicum. These divergence patterns illustrate how a phylogenetic perspective can be used to better understand the evolution of endemism in the Mediterranean flora. Received February 19, 2001 Accepted August 22, 2001     

Reproductive biology of Colletia spinosissima (Rhamnaceae) in Argentina

 We studied the reproductive behavior of Colletia spinosissima Gmel. at six sites in two regions of Argentina during the 1998–2000 flowering seasons. Flowering takes place in winter. The flowers are homogamous, fragrant, and entomophilous. There was evidence of self-incompatibility and cross-incompatibility between nearby partners. Fruit set of open-pollinated flowers (13.3%) seemed pollen-limited, since low fecundity was consistently associated with small stigmatic pollen loads and with low numbers of successful pollen tubes, and fecundity increased with abundance of efficient pollinators. Reproductive success (percent ovules becoming viable seeds) was 3.6. It is hypothesized that homogamy was established in Colletia because in an impoverished pollination environment – such as the one likely prevailing when this lineage evolved – achieving pollen export and receipt in a single pollinator visit has selective advantages. A large stigma and an extragynoecial compitum would compensate for the homogamy-driven, increased pollen-stigma interference. Received March 8, 2001 Accepted July 19, 2001     

Molecular phylogenetics of Hippophae L. (Elaeagnaceae) based on the internal transcribed spacer (ITS) sequences of nrDNA

 The genus Hippophae comprises 7 species and 8 subspecies according to the latest classification, and has shown enormous ecological, nutrient and medicinal values. Here we analyzed the phylogenetic relationships among 15 taxa of the genus by comparing sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA). ITS sequences in Hippophae varied in length from 651 bp to 666 bp. The aligned sequences were 690 bp in length and 269 (39.0%) were variable sites with 150 being parsimony-informative. The amount of polymorphism observed within a taxon was extremely low in most taxa except for two putative hybrid species. The aligned sequences were analyzed by maximum parsimony (MP) and neighbor-joining (NJ) methods. In the strict consensus trees of parsimony analysis, the monophyly of Hippophae was supported by 100% bootstrap value. H. tibetana was at the basal position of the genus, and the remaining taxa formed two clades with high bootstrap support. The first clade included subspecies of H.␣rhamnoides and the other one consisted of remaining species. Parsimony analysis also suggested that the species H. tibetana, H. neurocarpa and H.␣salicifolia were all distinct. Although the sequence divergence among subspecies of H. rhamnoides was also remarkably high, the molecular data supported the monophyly of H. rhamnoides when H. rhamnoides subsp. gyantsensis Rousi was excxluded. The NJ trees showed essentially the same topology. The taxonomical arrangement that divided the genus into two sections was not supported based on the ITS sequences. However, the hybrid origin of H. goniocarpa and H. litangensis proposed previously was supported by the present ITS data. Received January 7, 2002; accepted May 10, 2002 Published online: November 22, 2002 Addresses of the authors: Kun Sun, Xuelin Chen, Ruijun Ma, Qin Wang, Institute of Botany, Northwest Normal University, Lanzhou 730070, China. Changbao Li, Song Ge (e-mail: gesong@ns.ibcas.ac.cn or song_ge@hotmail.com), Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.     

Karyology and cytotaxonomy of the genus Passiflora L. (Passifloraceae)

 The chromosomes of 31 species of Passiflora, distributed throughout the subgenera Astrophea, Calopathanthus, Distephana, Dysosmia, Passiflora, Plectostemma and Tacsonia were analysed. Three different karyotypes were observed: 2n = 12, 24, 36; 2n = 18, 72 and 2n = 20. The karyotype of these species was almost always constituted of metacentric and submetacentric chromosomes with variable karyotype symmetry. In the group with x = 6, represented by the subgenus Plectostemma, six diploid species with 2n = 12, one tetraploid with 2n = 24 (P. suberosa) and an intraspecific polyploid with 2n = 12, 36 (P. misera) were analysed. P. pentagona (subgenus Astrophea) may also be included in this karyological group since it presents 2n = 24 and may be of polyploid origin, with x = 6. The interphase nuclei in this group were areticulate, except those of P. morifolia and P. pentagona with semi-reticulate characteristics. Two small terminal heterochromatic blocks, positive for chromomycin A₃, were identified in the largest chromosome pair of P. capsularis and P. rubra, species very closely related, while P. tricuspis displayed four chromosomes with proximal blocks. In the group with x = 9, represented mainly by subgenus Passiflora, 20 species with 2n = 18 and one with 2n = 72 were studied. They presented chromosomes larger than those species with x = 6 and interphase nuclei of semi-reticulate type, except for P. mixta with areticulate nuclei. Four terminal CMA⁺ blocks were observed in P. edulis, six blocks in P. caerulea and P. racemosa, while five blocks were observed in the single P. amethystina plant analysed. P. foetida (subgenus Dysosmia), the only species with 2n = 20, exhibited six chromosomes with CMA⁺ blocks and interphase nuclei of the areticulate type. The meiotic analysis of representatives of the three groups (P. foetida, P. suberosa, P. cincinnata and P. racemosa) always presented regular pairing and regular chromosome segregation, except in P. jilekii where a tetravalent was observed. The analysis of the chromosome variation within the genus and the family suggests that the base number of Passiflora may be x₁ = 6 or x₁ = 12, whereas x₂ = 9 is only an important secondary base number. Received April 11, 2000 Accepted October 5, 2000