Intra- and interspecific variation in genome size in Lathyrus (Leguminosae)

2C nuclear DNA amounts for 24 species of Lathyrus (section Lathyrus ) were determined using flow cytometry. A greater than two-fold variation was observed, ranging from 10.2 pg in L. basalticus to 24.2 pg in L. latifolius. In general, the perennial species had greater DNA amounts than the annuals. Significant intraspecific variation was observed in five species of Lathyrus (from 10.1% in L. annuus to 28% in L. tingitanus). A positive correlation was observed between DNA values obtained by flow cytometry and those previously determined by microdensitometry. Finally, the distribution of DNA amounts in species within section Lathyrus appears to be continuous.     

Molecular characterization of Lathyrus species using chloroplast DNA trnH-psbA

Lathyrus L. is an important genus contributing in human food, animal feed and fodder. The genetic variation is studied among and within six species sampled over a large geographical area: Lathyrus cicera, Lathyrus sativus, Lathyrus sylvestris, Lathyrus tuberosus, Lathyrus ochrus and Lathyrus aphaca. The phylogenetic relationship among these species was assessed using sequences of chloroplast DNA trnH-psbA (intergenic spacer). The highly polymorphic spacer' length was 330 bp. The phylogenetic analyses using Maximum Parsimony and Genetic Distances, agreed with the universal taxonomy of Kupicha. L. sativus and L. cicera could be considered as sister species, sharing a common ancestor.     

The use of seed proteins revealed by SDS PAGE in taxonomy and phylogeny of some Lathyrus species

Electrophoretic seed protein patterns of 18 samples belonging to 14 species and 4 sections of Lathyrus are treated by principle component analysis (PCA). The morphological ground and karyological structure data of these samples are also discussed in the light of sectional and groups delimitation. The species under study of section Cicercula are separated into 3 groups and L. hirsutus referred to the most primitive species within Lathyrus species. This agrees with their previous grouping delimination based on morphological characters and with chromosomal features such as karyotype structure. L. aphaca referred to the most advanced species in this genus, which agrees with the modification of this morphological characteristics and reduction in chromosome criteria. Section Nissolia hasan intermediate position between section Cicercula and section Aphaca. This revised version was published online in July 2006 with corrections to the Cover Date.     

Reproductive versus floral isolation among morphologically similar Serapias L. species (Orchidaceae)

Flowers of the Mediterranean orchid genus Serapias L. form small, dark tubes that vary among taxa in diameter and depth. Visiting insects use the floral tube as shelter and act as pollinators if they touch the sticky viscidium at the rear of the tube and remove the pollinarium. It has been assumed that floral tube size and shape limit access to the flowers and thus may act as a barrier to gene flow between different Serapias species. Here we investigated floral characters and nuclear microsatellite markers in populations belonging to three morphologically similar Serapias species to test whether these species show evidence for floral or reproductive isolation. We found strong overlap of floral traits between two species, suggesting that floral isolation is nonexistent between them. Microsatellite markers applied to the same populations were highly polymorphic and revealed clear genetic differentiation among all three species. These results suggest that reproductive isolation exists, despite the lack of floral isolation between two of the species. In contrast to morphological characters, diagnostic microsatellite alleles were found for all Serapias species. The microsatellite markers could thus provide a useful tool to identify Serapias species and further investigate evolutionary relationships in this fascinating orchid lineage.     

A Comparison of the Flowering and Branching Control Systems in Lathyrus odoratus L. and Pisum sativum L.

In the sweet pea (Lathyrus odoratus L.) the difference in floweringbehaviourbetween photoperiodic (long-day) and day-neutral cultivars appearsto be due to a difference in their ability to produce a graft-transmissiblefloral inhibitor. The flowering control systems in the sweetpea and the garden pea (Pisum sativum L.) appear to be verysimilar on the basis of inter-generic graft results. It is suggestedthat the major flowering genes Dn* in L. odoratus and Sn andDne in P. sativum control steps in a biochemical pathway commonto these two species (which are related at the tribal level)and that the product of this pathway inhibits flowering andpromotes outgrowth of basal laterals in both species.     

Beiträge zur Nomenklatur der Gattung Lathyrus L

In connection with a taxonomic study in a group of Eurasiatic species of the genus Lathyrus L. (Subgen. Orobus (L.) Baker) some problems of nomenclature and new combinations are reported. For instance, the correct name for the Lathyrus montanus Bernh. ist the new combination Lathyrus linifolius (Reichard) Bässler. Lathyrus friedrichsthalii (Griseb.) Maly is a subspecies of Lathyrus alpestris (Waldst. et Kit.) Kit.     

Covariance and decoupling of floral and vegetative traits in nine Neotropical plants: a re-evaluation of Berg's correlation-pleiades concept

Nearly forty years ago R. L. Berg proposed that plants with specialized pollination ecology evolve genetic and developmental systems that decouple floral morphology from phenotypic variation in vegetative traits. These species evolve separate floral and vegetative trait clusters, or as she termed them, "correlation pleiades." The predictions of this hypothesis have been generally supported, but only a small sample of temperate-zone herb and grass species has been tested. To further evaluate this hypothesis, especially its applicability to plants of other growth forms, we examined the patterns of phenotypic variation and covariation of floral and vegetative traits in nine species of Neotropical plants. We recognized seven specific predictions of Berg's hypothesis. Our results supported some predictions but not others. Species with specialized pollination systems usually had floral traits decoupled (weak correlation; Canna and Eichornia) or buffered (relationship with shallow proportional slope; Calathea and Canna) from variation in vegetative traits. However, the same trend was also observed in three species with unspecialized pollination systems (Echinodorus, Muntingia, and Wedelia). One species with unspecialized pollination (Croton) and one wind-pollinated species (Cyperus) showed no decoupling or buffering, as predicted. While species with specialized pollination usually showed lower coefficients of variation for floral traits than vegetative traits (as predicted), the same was also true of species with unspecialized or wind pollination (unlike our prediction). Species with specialized pollination showed less variation in floral traits than did species with unspecialized or wind pollination, as predicted. However, the same was true of the corresponding vegetative traits, which was unexpected. Also in contrast to our prediction, plants with specialized pollination systems did not exhibit tighter phenotypic integration of floral characters than did species with generalized pollination systems. We conclude that the patterns of morphological integration among floral traits and between floral and vegetative traits tend to be species specific, not easily predicted from pollination ecology, and generally more complicated than R. L. Berg envisaged.     

Parental effects in a partially self-incompatible herb Campanula rapunculoides L. (Campanulaceae): influence of variation in the strength of self-incompatibility on seed set and progeny performance

We employ a full reciprocal diallel design between 10 parental plants that differed in their strength of self-incompatibility (SI; strong, intermediate, and weak) to examine parental effects on seed set and 10 components of fitness of progeny performance in Campanula rapunculoides. We perform ANOVAs to separate the influence of the strength of SI and the identity of the maternal and paternal parent on family performance. We calculate the phenotypic and genetic correlations between traits to determine potentially evolutionary constraints. Finally, we employ maximum likelihood methods to estimate the components of quantitative genetic variance, as defined by Cockerham and Weir in their BioModel c. Our most significant finding is that weak SI plants have high outcrossed seed set as maternal parents. We argue that direct or pleiotropic effects of modifiers of SI probably cause this. Second, we find that extranuclear interactions, as defined by the BioModel, have strong effects on seed set and several vegetative and flowering traits. These findings indicate that some maternal plants selectively provision seeds sired by specific paternal donors and that some of this variation appears to be associated with modifiers of the strength of SI. We find other sources of significant quantitative genetic variation for all of the traits we examine and discuss the possible role these play in the evolution of the reproductive system. Taken together, our findings show that variation in the strength of SI may influence levels of quantitative genetic variation that, in turn, can influence the reproductive success of individuals in C. rapunculoides     

INFLORESCENCE DEVELOPMENT IN BRASSICA CAMPESTRIS L.

Vegetative seedlings of the Ceres strain Brassica campestris L., a quantitative, long-day plant, were induced to flower by exposure to a 16-hr, long-day cycle. Cytohistological and cytohistochemical changes associated with inflorescence development were examined. Developing shoot apices were classified in vegetative, transitional, and reproductive stages. The vegetative apex possessed a biseriate tunica, central zone, peripheral zone and pith-rib meristem. The transitional stage at 48 hr was marked by an increase in size and by a stratification of the upper cell layers of the shoot apex with a concurrent decrease of apical cytohistochemical zonation. The reproductive stage was initiated at 58 hr by periclinal cell divisions in the 3rd and 4th cell layers of the flank region. Cytohistochemical zonation in the vegetative apical meristem was restored in the floral apex. An “intermediate developmental” phase was not observed between the vegetative and reproductive stage.     

The Mechanism of Action of Vernalization in Lathyrus odoratus L.

In the sweet pea (Lathyrus odoratus L.) genes Dn^l andDr^h controlthe production of a graft-transmissible substance which delaysflowering and promotes outgrowth of basal laterals. Seed vernalizationpromotes flowering and reduces lateral outgrowth in intact plantsand grafted scions of genotype DnⁱDn^l, suggesting that vernalizationreduces output of the Dnⁱ system, possibly by disrupting therelationship between chronological and plastochronic age. Whenlateral outgrowth and floral abortion are used as indicatorsof inhibitor levels, it can be shown that vernalized Dnⁱ plantspossess more inhibitor but initiate flower buds at a lower nodethan unvernalized dn plants. This supports the suggestion thatin regard to floral initiation vernalization also alters thesensitivity of the shoot apex to the flowering hormone(s). InLathyrus odoratus an hormonally based vernalization responseof considerable magnitude can be shown for day-neutral (dndn)lines, supporting the suggestion that vernalization also influencesthe level of a flower promotor. Lathyrus odoratus L., sweet pea, vernalization, flowering, branching, genotype, grafting     

Variation in morphology of <Emphasis Type="Italic">Teucrium polium</Emphasis> aggr. populations in Bulgaria

The aim of this study was to investigate natural serpentine and non-serpentine populations of Teucrium polium aggr. and to document the differences in their morphological traits, as well as estimate which characters are most likely contributing to differentiation of the populations. Nine populations distributed both on and off serpentine soils were investigated, and 12 different morphological features of 270 individuals were studied by univariate and multivariate statistical analyses. The results did not demonstrate clear delimitation of the serpentine from the non-serpentine populations. Using these ecotypes as classification factors in the discriminant analysis, it can be stated that stem height, leaf length in the fifth leaf pair, internode length between the fourth and the fifth leaf pairs, and corolla tube length are features with the greatest discriminant ability. The character variation was generally higher for the vegetative features, while reproductive features failed to demonstrate clear differences. The similarity groupings indicated by the cluster analysis were synchronous with groups distinguished by both the discriminant and PCA analyses. Significant differences were observed between sets of vegetative characters in all populations investigated.      

Variation in reproduction and growth in declining Scots pine populations

Disentangling how variation in reproduction and growth is linked in plants across different ecological scales, and how allocation rules change in response to stress are fundamental aspects of life history theory. Although it is known that reproductive allocation is an allometric process and that environmental conditions can influence demographic traits, patterns of variation in vegetative and reproductive functions across and within individuals of tree species suffering drought-induced decline have rarely been documented. In this study we use Scots pine (Pinus sylvestris L.) as a model species to explore patterns of variation in cone production and growth in two declining populations at the southern edge of its distribution. A Bayesian approach was used to assess how these demographic traits vary as a function of drought effects and competition and covary across different ecological scales. The allometric trajectories relating tree size with cone production and growth differed along gradients of drought impacts and biotic interactions. Although reproduction and growth increased with tree size, cone production reached a maximum at intermediate sized trees and stabilized or decreased at larger sizes. Drought stress effects (defoliation at the tree level and overall decline at the plot level) and competition for resources reduced cone production and growth. Our results also showed differential effects of defoliation on cone production depending on tree size, with stronger effects on larger individuals. After accounting for these effects, much of the variation of demographic traits and correlations among them occurred at small ecological scales across individuals (i.e. within plots) and within individuals across years. This resulted in covariations between demographic traits among nearby individuals and within individuals through time, suggesting a consistent advantage in resource acquisition of some individuals within plots, and trade-offs between growth and cone production within trees across years. In conclusion, this study reports that drought-induced forest decline is associated with lower growth and cone production in Scots pine, which could contribute to explain the long-term impacts of drought in southern populations of this species and, in particular, its low regeneration capacity after severe drought.     

A new species of Lathyrus L. (section Cicercula; Fabaceae) from Turkey

A new species, Lathyrus egirdiricus H.Genc & A.Sahin (section Cicercula; Fabaceae), is described from Turkey, with illustrations and taxonomic comments. Characteristics of the species are compared with those of the related species Lathyrus hirsutus L., L. stenophyllus Boiss. & Heldr., L. sativus L., L. cassius Boiss. and L. gorgoni Parl., from which it differs mainly in the shape, length, width and venation of leaflets, length and width of the stipule, flower colour, legume and style length. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 301–305.     

Chloroplast DNA characters, phylogeny, and classification of Lathyrus (Fabaceae)

Mapped cpDNA restriction site characters were analyzed cladistically and the resulting phylogenetic hypotheses were used to test monophyly and relationships of the infrageneric classification of Lathyrus (Fabaceae) proposed by Kupicha (1983, Notes from the Royal Botanic Garden Edinburgh 41: 209-244). The validity of previously proposed classification systems and questions presented by these classification schemes were explored. Two cpDNA regions, rpoC (rpoC1, its intron, part of rpoC2, and their intergenic spacer) and IR- (psbA, trnH-GUG, part of ndhF, and their intergenic spacers), were analyzed for 42 Lathyrus and two Vicia species. PCR (polymerase chain reaction) amplified rpoC and IR- products digested with 31 and 27 restriction endonucleases, respectively, resulted in 109 potentially informative characters. The strict consensus tree suggests that several of Kupicha's sections may be combined in order to constitute clades. The widespread section Orobus and the South American section Notolathyrus should be combined. Section Lathyrus, characterized by a twisted style, should either include sections Orobon and Orobastrum or be redefined as three sections, one of which is characterized by a 100 base pair deletion in the IR- region. Finally, a weighted parsimony analysis positions sections Clymenum (excluding L. gloeospermus) and Nissolia, both with phyllodic leaves, as sister sections. The affiliation of Lathyrus gloeospermus (section Clymenum) remains problematic.     

Chromosome pairing and chiasma formation in autopolyploids of different Lathyrus species.

Chromosome pairing and chiasma formation were studied in natural and induced tetraploids (2n = 28) of Lathyrus odoratus (induced), Lathyrus pratensis (natural and induced), Lathyrus sativus (induced), and Lathyrus venosus (natural), as well as in triploids of L. pratensis and diploids of L. odoratus, L. pratensis, and L. sativus. All natural tetraploids appeared to be autotetraploids and their meiotic metaphase I behaviour was very similar to that of the induced autotetraploids, with average numbers of pairing partner switches exceeding 4 or even 5. Multivalent frequencies were high, but the numbers of chiasmata were not much higher than necessary to maintain the configurations. Interstitial chiasmata were common, but not predominant. Fertility was reduced, but sufficient for predominantly vegetatively reproducing species. The triploids of L. pratensis had an even higher multivalent frequency than the tetraploids, but still produced some viable progeny at or close to the tetraploid level, suggesting that in mixed populations of diploids and tetraploids, triploids can contribute to gene flow between the ploidy levels. There was no significant correlation between chiasma frequency and ring bivalent frequency in the diploids and multivalent frequency in the corresponding tetraploids. In the tetraploids, chiasma frequency and multivalent frequency were negatively correlated.     

Phylogenetic analysis of symbiotic genes of nodule bacteria in the plants of the genus Lathyrus (L.) (Fabaceae)

The comparative analysis of the symbiotic genes nifD, nifH, nodA of wild-growing Lathyrus L. species (Fabaceae) connected by genes sequences of 16S aRNA to Rhizobium leguminosarum bv. viceae, Rhizobium tropici, Agrobacterium sp., and Phyllobacterium sp. was carried out. It was demonstrated that all tested genes of strains taken for analysis had high degree of homology with analogous genes of Rhizobium leguminosarum bv. viceae. It was suggested that symbiotic genes were introduced into Rhizobium tropici, Agrobacterium sp., and Phyllobacterium sp. strains by means of horizontal gene transfer over from Rhizobium leguminosarum bv. viceae strain. The recombinant strains were formed, capable to nodulate Lathyrus L. species that earlier was not considered characteristic for these plants.     

林生山黧豆幼苗2,4—二氨基丁酸的合成及其与胁迫条件的关系

林生山黧豆幼苗用［3H］－天门冬氨酸标记后,高丝氨酸在6h内迅速增加。高丝氨酸合成速率降低后,2,4－二氨基丁酸的合成量上升,于18h达到高峰。赖氨酸和苏氨酸与二氨基丁酸的合成表现有协同反馈机制。结果支持了天门冬半醛转氨生成二氨基丁酸的假说。盐胁迫、渗透胁迫和热激增加了二氨基丁酸的合成,可能是因为不同胁迫条件都造成了细胞脱水,从而促进了二氨基丁酸的合成。     

Pleiotropic quantitative trait loci contribute to population divergence in traits associated with life-history variation in Mimulus guttatus

Evolutionary biologists seek to understand the genetic basis for multivariate phenotypic divergence. We constructed an F2 mapping population (N = 539) between two distinct populations of Mimulus guttatus. We measured 20 floral, vegetative, and life-history characters on parents and F1 and F2 hybrids in a common garden experiment. We employed multitrait composite interval mapping to determine the number, effect, and degree of pleiotropy in quantitative trait loci (QTL) affecting divergence in floral, vegetative, and life-history characters. We detected 16 QTL affecting floral traits; 7 affecting vegetative traits; and 5 affecting selected floral, vegetative, and life-history traits. Floral and vegetative traits are clearly polygenic. We detected a few major QTL, with all remaining QTL of small effect. Most detected QTL are pleiotropic, implying that the evolutionary shift between these annual and perennial populations is constrained. We also compared the genetic architecture controlling floral trait divergence both within (our intraspecific study) and between species, on the basis of a previously published analysis of M. guttatus and M. nasutus. Eleven of our 16 floral QTL map to approximately the same location in the interspecific map based on shared, collinear markers, implying that there may be a shared genetic basis for floral divergence within and among species of Mimulus.     

A phenetic study of Cassia sensu lato (Leguminosae-Caesalpinioideae: Cassieae: Cassiinae) in Thailand

Cassia L. sensu lato, a large heterogeneous genus of flowering plants, occurs naturally in the tropics around the world. Recent works based on floral morphology have supported a division of this genus into three genera, namely Cassia L. s. str., Chamaecrista Moench and Senna Mill. In order to investigate this new classification, 508 specimens of 18 taxa of the genus Cassia s.l. grown in Thailand were analyzed using cluster analysis and canonical discriminant analysis. The total 32 vegetative and reproductive morphological characters were employed in these analyses. In cluster analysis, Cassia s.l. can be separated into four groups, respectively viz. Chamaecrista, Senna alata, Senna and Cassia s /str. The four-cluster grouping is discussed. From a canonical discriminant analysis using the four-cluster grouping as a priori groups, it can be concluded that Cassia s. str., Senna, and Chamaecrista are indeed distinct taxa. The three most important characters that separate the three genera are filament length, fruit length, and ovary stalk length. These quantitative characters, together with some qualitative characters, were useful in constructing an identification key to these genera. Among the three genera, it was also found that Senna is rather a heterogeneous taxon. The difference between the studied species was discussed.     

Inheritance of UV-B tolerance in seven ecotypes of Arabidopsis thaliana L. Heynh. and their F1 hybrids

We used a partial diallel mating design to examine morphologic response to supplementary ultraviolet-B (UV-B) radiation of seven ecotypes of Arabidopsis thaliana L. Heynh. from several geographic locations in Europe. We were particularly interested in the inheritance of UV-B tolerance by the F1 generation. Morphologic traits included plant height, rosette diameter, number of shoots (lateral branches from the rosette) and branches (lateral branches above the rosette), and reproductive and vegetative dry mass. To effect a large difference in UV treatments, plants under treatment received 11 kJ/m2/day of biologically effective UV-B radiation while control plants received no UV-B radiation. Genotype effects were observed for all traits (P < .0001), but a significant treatment effect and genotype x treatment interactions were detected only for plant height (P = .0001), rosette diameter (P = .0229), and vegetative (P = .0260) and reproductive dry mass (P = .0900). General combining ability was significant for plant height (P < .0001) and vegetative mass (P = .0563), whereas specific combining ability was significant for rosette diameter (P = .0220) and vegetative mass (P = .0506). These results suggest that both pure lines and hybrids of Arabidopsis can be developed for greater tolerance of UV-B radiation. Similar findings for crop species might lead to the development of UV tolerant varieties.