Chromosomal differentiation withinCrocus vernus agg. (Iridaceae) in the Carpathian Mts.

Western and eastern Carpathian populations ofCrocus heuffelianus s. lat. (incl.C. scepusiensis) have 2n = 18 but differ in karyotype. While western populations are chromosomally monomorphic, eastern populations exhibit geographical karyotypic differentiation.     

Seed coat structure ofCrocus vernus agg. (Iridaceae)

Cytotypes of theCrocus vernus aggregate differ slightly in their seed surface patterns.Crocus albiflorus may be grouped together withCrocus vernus subsp.vernus, both are relatively easily distinguishable by their seed surface patterns from theCrocus scepusiensis—Crocus heuffelianus group.     

Self-incompatibility inCrocus vernus subsp.vernus (Iridaceae)

Outcross, self- and mixed pollinations were performed inCrocus vernus subsp.vernus, a species with bicellular pollen, dry stigmas and hollow style. No differences were noted among the above pollinations concerning the germination of pollen and the growth of pollen tubes until the top of ovary. Within 45 min after pollinations 62% of pollen grains germinated. Pollen tubes penetrated the papilla cuticle extending along the papilla wall; on entry into stigmatic lobes they continued growth in the stylar secretion to ovarian locules. Here, however, self-pollen tubes failed to reach or to enter the ovule micropyle; while pollen tubes from either outcross- or mixed pollinations grew until fertilizing ovules. These observations gave evidence of a self-incompatibility system inCrocus, which appeared to be neutralized by mentor effect. The ovary as site of incompatibility response is discussed.     

A study on pollen grains ofCrocus cartwrightianus (Iridaceae)

Crocus cartwrightianus andC. cartwrightianus cv.albus pollen have been studied from structural and ultrastructural points of view and the germination assayed in vivo and in vitro.C. cartwrightianus pollen is regularly shaped and sized, has a low percentage of anomalous grains and has a high germination rate in vitro, whileC. cartwrightianus cv.albus is less regularly shaped with some variation in size and has a high percentage of anomalous grains and a low germination percentage in vitro. Ultrastructural observations have revealed, in the pollen of both the taxa, the presence of a thin elongated vegetative nucleus and a generative cell surrounded by a thin membrane. However,C. cartwrightianus pollen shows a thicker intine, andC. cartwrightianus cv.albus shows numerous pollen germination anomalies which are in common withC. sativus.     

Cytology ofCrocus sativus and its allies (Iridaceae)

Populations ofC. cartwrightianus, C. hadriaticus andC. thomasii from the Balkans have 2n = 16 as has the Middle EasternC. pallasii subsp.haussknechtii. C. dispathaceus andC. pallasii subsp.pallasii have 2n = 14 whileC. pallasii subsp.turcicus has 2n = 12.C. niveus has 2n = 28 andC. sativus is an autotriploid with 2n = 24. Karyotype variation was found between populations ofC. pallasii subsp.pallasii in Central Turkey and also inC. pallasii subsp.turcicus.     

Pregamic and postgamic self-incompatibility systems inCrocus (Iridaceae)

Ovule fertilization and seed set were investigated inCrocus thomasii andCrocus vernus subsp.vernus, after different matings. The results gave evidence for a strict ovarian barrier inC. thomasii, which prevents self-fertilization either in self- or mixed- and double-pollination. InC. vernus the ovarian barrier to selfing is not so effective, but a further incompatibility reaction is expressed after self-fertilization resulting in a complete failure of embryogenesis. The implications of the present observations in respect to the mechanisms of pregamic- and postgamic rejection, indicate that a gametophytic system of self-incompatibility controls the ovule fertilization, and a not yet defined system of self-incompatibility controls embryogenesis.     

Geographic variability of flower colour inCrocus scepusiensis (Iridaceae)

The distribution of four variants for flower colour ofCrocus scepusiensis in the northern part of the Western Carpathians is described. The frequency of white stigmata morphs declines from east to west. In the center of the area stigmata colour morphs show strikingly patchy distribution. White perianth morphs usually occur at low frequencies and their distribution with minor exceptions is restricted to the central part of the area, where patchy distribution of the morphs is a rule. These distribution patterns suggest that the founder effect has played a major role in determining the genetic composition of individual populations. The cline for stigmata colour may also be explained by the dynamics of population expansion. No influence of selection can be demonstrated, but the association between perianth and stigmata colour, and the excessively low frequency of white perianth morphs may imply that the polymorphisms are not selectively neutral.     

Labellum micromorphology in theOphrys bertolonii agg. and some related taxa (Orchidaceae)

Micromorphology and distribution of trichomes in six taxa of theOphrys bertolonii aggregate (O. bertolonii, O. bertoloniiformis, O. benacensis, O. aurelia, O. drumana, O. catalaunica) are described. A fairly good homogeneity between all the taxa, with a moderate degree of variability even within the same taxon, has been observed. Comparison of these characters with those ofO. promontorii andO. garganica corroborates the inclusion of the former species into theO. sphegodes aggregate. Trichome analysis of a hybrid is exemplified byO. ×chiesesica (O. drumana ×O. fuciflora).     

Chemotaxonomy of theSymphytum officinale agg. (Boraginaceae)

In a chemotaxonomic study of the genusSymphytum pyrrolizidine alkaloids and triterpenes were used as chemotaxonomical markers. A micro-extraction methods was developed for screening compounds of very small pieces of herbarium material. The occurrence of the pyrrolizidine alkaloids symphytine and (acetyl-)lycopsamine is very general forSymphytum taxa. Echimidine is present in someS. officinale L. plants and inS. tanaicense Steven. The triterpene isobauerenol is present inS. officinale, S. bohemicum Schmidt,S. tanaicense and inS. officinale var.lanceolatum Weinm. The chemotaxonomic hypothesis, proposed byGadella and collaborators, based on the presence of the triterpene isobauerenol inS. officinale and its absence inS. asperum Lepech. and the presence of the pyrrolizidine alkaloid echimidine inS. asperum and its absence inS. officinale, can no longer be applied absolutely to theS. officinale species complex. The pyrrolizidine alkaloid and triterpene pattern ofS. officinale (2n = 24) andS. bohemicum (2n = 24) is identical.S. bohemicum is morphologically, cytologically and phytochemically very similar toS. officinale. Furthermore, it readily crosses with the white flowered W. European diploids ofS. officinale. Therefore it seems likely that these two taxa are conspecific.S. tanaicense shows a pyrrolizidine alkaloid and triterpene pattern similar toS. officinale (2n = 40). Also on morphological and cytological grounds they are very similar. It seems highly probable thatS. tanaicense is conspecific withS. officinale (2n = 40) and represents an intraspecific variant only.S. officinale var.lanceolatum contained no pyrrolizidine alkaloids but did contain isobauerenol. This feature points to an origin fromS. officinale.     

Cytogenetic studies of cultivatedCrocus sativus (Iridaceae)

Meiosis and mitosis are described in cultivatedCrocus sativus of Iran. This indicates that this species is an autotriploid and sterile. Karyotype analysis, rare inversions, laggard chromosomes and distribution of chromosomes in the first anaphase are described, and the reasons for its sterility are given.     

Rapid cytofluorimetric determination of leaf nuclear DNA content in the polyploid seriesRanunculus marsicus (R. auricomus agg.,Ranunculaceae)

A cytofluorimetric method for DNA amount determination on nuclei released from fixed leaves has been successfully tested on samples belonging to the polyploid series ofRanunculus marsicus Guss & Ten. (sect.Auricomus). The procedure was devised to screen rapidly for different ploidy levels within topodemes and progenies.     

Biometrische Untersuchungen an Populationen vonOphrys cornuta,O. holosericea und ihren Hybriden (Orchidaceae)

Population variability ofOphrys holosericea (Burm. f.)Greut. subsp.holosericea (=O. fuciflora Crantz subsp.fuciflora) from near Vienna (Austria), and of subsp.maxima (Fleischm.)Greut. andO. cornuta Steven with intermediates from the Dalmatian island Hvar (Yugoslavia) was analysed and illustrated by scatter diagrams. A hybrid origin of these intermediates is suggested. Aspects of hybridization betweenO. holosericea agg. andO. scolopax agg. are discussed.

     

Notes on the pollination mechanisms ofMoraea inclinata andM. brevistyla (Iridaceae)

Individual flowers ofMoraea inclinata are nectariferous and last about six hours. They appear to be pollinated largely by bees in the familyHalictidae (Lasioglossum spp.,Nomia spp.,Zonalictus) and to a lesser extent by bees in the familyAnthophoridae (Amegilla). The mechanism of bee-pollination inM. inclinata is the Iris type; i.e., each flower consists of three pollination units (an outer tepal, a partly exserted anther, and the opposed style branch which terminates in a pair of petal-like crests). Bees rarely visit more than one pollination unit per flower. Transferral of pollen to the bee is passive and nototribic although all bees collected on the flowers were female and 55% of the bees carried pollen loads with 2–5 pollen taxa in their scopae.Moraea brevistyla flowers are nectariferous but lack scent and last two days. They are visited infrequently by bees and only one femaleLasioglossum spec. carried the pollen ofM. brevistyla. Unlike flowers ofM. inclinata those ofM. brevistyla deposit pollen only on the head and thorax. Bee-mediated autogamy in both species is avoided due to the erratic foraging patterns of the bees and the flexibility of each stigma lobe as the bee backs out of the flower. Approximately 2–4 flowers in the inflorescences of both species (6–8 flowers/infloresence) develop into capsules.     

Allozyme diversity in relation to geographic distribution and population size inLathyrus vernus (L.) Bernh. (Fabaceae)

Lathyrus vernus (L.) Bernh. is a diploid, long-lived perennial and insect-pollinated herb with no special adaptation to long-distance dispersal. It occurs on neutral soil in deciduous forests throughout western Eurasia. Due to specific habitat preferences,L. vernus has a fragmented distribution with isolated populations. We investigated allozyme variation at eleven loci in 20 populations ofL. vernus from one geographically central region (the Czech Republic and the Slovak Republic) and two geographically marginal regions (southern and central Sweden) in the species present-day distribution. There was a clear differentiation between the three regions and the genetic distance between the populations was highly correlated with geographic distance. The total genetic diversity (H_T) was 0.354. The proportion of genetic diversity due to differentiation between regions, and to differentiation between populations within regions, accounted for 10% each. There was no difference in level of genetic diversity between the three regions. No significant difference in level of genetic diversity was found between small and large populations. The genetic diversity inL. vernus may either be a result of the long generation-time of the species or peculiarities in the post-glacial migration species, e.g. survival only in refugia far east of the sampled populations and/or migration as a continuous process not involving founder-events.     

Biosystematic studies in European species ofGladiolus (Iridaceae)

Representative specimens of the EuropeanGladiolus species (excl.G. palustris) were used to study variability and relationships. 25 characters were measured for cluster, principal component and Wells hybrid analyses (Figs. 1–3). Three (with PCA) respective five (cluster analysis) main groups are revealed. Bulb characteristics appear to be very useful for indentification. The subspecific status ofG. communis subsp.byzantinus is confirmed. Hybrids of four different parental combinations were detected in our collection. Most species include polyploid series. Partly 3x, 4x, 6x, 8x, 12x and aneuploid cytotypes but no diploids were found. Polyploids as pioneers and hybridization of sympatric species are apparently linked to migrations during the glacial periods.     

First record of Ribes uva-crispa L. (Grossulariaceae) from the Madonie Mts., a new species of the Sicilian flora

Abstract

In this study, a first record of Ribes uva-crispa L. (Grossulariaceae) – a new species of the Sicilian flora – from the Madonie Mts. is reported. The autochthonous and relict new population of Ribes uva-crispa L. (Grossulariaceae) is found on Mount Carbonara (Madonie Mts., North-Central Sicily), which is several hundred kilometers away from the Central Apenninic and the South Mediterranean locations of its distribution range. R. uva-crispa shows a distribution similar to other taxa extending from the Euro-Asiatic area to the mountains of North Africa with disjunct populations on the main Sicilian reliefs (Madonie and Nebrodi Mts.), testifying ancient phytogeographical connections. This noteworthy record adds a new species – as well as a new genus and new family – to the vascular flora of Sicily. Based on the morphological characters, the population found is to be referred to Ribes uva-crispa L. subsp. austro-europaeum (Bornm.) Bech var. glanduligerum (Lindberg) Maire.     

Molecular (RAPD) analysis on Italian taxa of theOphrys bertolonii aggregate (Orchidaceae)

The RAPD technique has been used for analyzing the genetic material of seven Italian populations of theOphrys bertolonii aggregate (Orchidaceae). For comparison the related speciesO. sphegodes andO. fuciflora have also been analyzed. A high genetic variability has been observed within the same populations, and on the whole onlyO. bertolonii can be safely differentiated from the other taxa of the aggregate, which are undistinguishable with this method.     

Reversible inhibition of the pollen germination and the stigma penetration in Crocus vernus ssp. vernus (Iridaceae) following fumigations with NO2, CO, and O3 Gases

We assessed the pollen hydration, the pollen germination, and the stigma papilla penetration of CROCUS VERNUS subsp. VERNUS (Iridaceae) after 2 h fumigations with O (3), NO (2), and CO gases within humidified (90 - 100 % RH) box experiments. When the pollen and the pistil were separately fumigated, the pollen retained the capacity to emit a tube which penetrated papilla, and the stigma papillae retained the receptivity; when the pistils were first pollinated and then fumigated, the capacity of pollen to hydrate was not affected, but the germination was significantly reduced. The vulnerability to gases became evident at 0.3 ppm O (3), 0.2 ppm NO (2), and 0.5 ppm CO. The inhibition curves as a function of the gas concentrations were of an exponential type, and they saturated at 2 ppm NO (2), 25 ppm CO, and 0.5 ppm O (3), with germination percentages of 17 %, 27 %, and 60 %, respectively. Both the pollen germination and the papilla penetration were fully restored by prolonging for 60 - 90 min the incubation at 90 - 100 % RH, after the cessation of fumigations. The vulnerability of the pollen-papilla system is discussed.     

A new species ofThottea (Aristolochiaceae) from India

Thottea ponmudiana sp. nova from Kerala (India) can readily be distinguished from its closest allyTh. siliquosa and all the other known species of the genus by its yellow flowers with purple eyes, deeply lobed perianth with strongly reflexed margins, uniseriate stamens united in three bundles and strongly 4-angled, green, glabrescent fruits.