Giovanni Cristofolini

SEROLOGICAL SYSTEMATICS OF THE TRIBE GENISTEAE (FABACEAE)

In order to assess the systematic relations within the tribe Genisteae, the water-soluble seed proteins of 45 species have been studied serologically. The reaction was tested by immunodiffusion and the results have been processed by cluster analysis and by principal component analysis. Based on these data, the genus Cytisus s.l. (incl. Chamaecytisus, Sarothamnus and Corothamnus) represents a single homogeneous unit, except for C. sessilifolius, which appears to be more closely related to Laburnum and to Genista than to the other species of Cytisus. Also, C. emeriflorus is very similar to Lembotropis nigricans; its inclusion in the genus Lembotropis is sustained. Genista is much more complex; its section Asterospartum should be segregated as the genus Cytisanthus Lang, being internally homogeneous, distinct from all other sections and fairly close to Lygos. A new combination, Cytisanthus aetnensis (Biv.) comb. nova, is published. Genista pilosa and G. anglica seem very much isolated, but the authors do not intend to propose here a new taxonomic rank, due to the scarcity of data. Teline is very similar to Genista. Even more similar to Genista is Chamaespartium sagittale, which biochemically and morphologically fits very well in the subgenus Genista, in spite of its winged stem. In a general arrangement of the tribe, two groups of genera represent the extreme points of diversification: (i) Cytisus-Lembotropis-Calycotome and (2) Genista-Teline-PetteriaSpartium and (with decreasing similarity) Cytisanthus and Lygos. Between these two groups there are a series of intermediate genera, that may be placed in one group or the other depending on the method of analysis: Adenocarpus, Argyrolobium (both of them should be included in the tribe), Cytisus sessilifolius and Laburnum. Ulex and Lupinus are

A serological contribution to the systematics of the genusLupinus (Fabaceae)

The immunological comparison of the seed reserve proteins suggests thatLupinus is a natural genus, the American and the Euro-African species belonging to the same stock. Among the Lupines of the Old World, the smooth-seeded and the rough-seeded species from two natural segregates. The genusLupinus is serologically related to the rest of theGenisteae and to the AsiaticSophoreae rather than to AmericanSophoreae andThermopsideae. The data suggest thatLupinus may have originated with the remainder of theGenisteae from primitiveSophoreae of temperate-subtropical Asia. America and the Mediterranean-African region are regarded as secondary centres of speciation.

Genetic diversity in Cytisus aeolicus Guss. (Leguminosae), a rare endemite of the Italian flora

ABSTRACT Cytisus aeolicus Guss, is an endemic plant restricted to the isles of Vulcano, Stromboli and Alicudi in the Aeolian archipelago. All known populations were assayed for genetic variability using enzyme polymorphism. Allozyme variation at 16 loci coding for 10 enzyme systems was examined. The great majority of loci turned out to be monomorphic or fixed heterozygous. The observed genetic depauperation is indicative of historical factors, such as the bottleneck effect associated with migration, and the founder effect in population re-establishment. The low genetic diversity is largely partitioned within rather than among populations, indicating that extant populations have not been established long enough for divergence to have occurred. The genetic uniformity, combined with the scattered distribution of small populations, and the negative shift of population size point to a critically endangered species. Strategies for conservation are considered.

A morphometric study of the Quercus crenata species complex (Fagaceae)

Abstract.Cristofolini G. and Crema S. 2005. A morphometric study of the Quercus crenata species complex (Fagaceae). Bot. Helv. 115: 155–167.Plants ascribed to the complex Quercus crenata – Q. pseudosuber, supposed to be hybrids Q. cerris × Q. suber, grow sympatric with both parental species in peninsular Italy and Sicily, but they also occur in the Alpes Maritimes, in northern Italy, in Slovenia and Istra, where Q. suber is absent. To test whether northern and southern plants of this complex should be regarded as different taxa, a morphometric survey was done on 91 specimens. Based on 36 morphological characters of the leaf and fruit, the northern and southern specimens did not form distinct aggregates in a principal components analysis (PCA), but they could be segregated in a discriminant analysis. PCA ordination plots further indicated that the southern specimens are morphologically more variable. Indeed, when tested individually, the means of six characters differed significantly between the two parts of the distribution range, and 12 characters were significantly more variable in southern plants. Based on our results, we propose that the two sets of plants are taxonomically distinct. The “southern” plants are hybrids inter parentes, for which we propose to maintain the name Quercus × pseudosuber Santi. The “northern” plants with reduced variability are possibly relicts of ancient hybridization and to them properly applies the name Quercus crenata Lam.

Systematics of the Complex Pulmonaria saccharata-P.vallarsae and Related Species (Boraginaceae)

Summary The complex Pulmonaria saccharata-P. vallarsae has been studied by means of morphological, biometric and biosystematic analysis of dried and living specimens, in natural environments and under cultivation. Hydroponic cultures have been used to distinguish the effects of environmental conditions and of phenological phases in determining phenotypic plasticity. An electrophoretic study of the seed proteins has been done. Inter- and infra-specific crossability has been experimentally tested. Chromosome counts on populations of all italian species have been made. The following species have been recognised: P. saccharata Miller, confined to Belgium and perhaps the Netherlands, to be excluded from Italy; P. affinis Jordan, which is strictly related to P. saccharata, and is distributed throughout France and in Eastern Spain; P. picta Rouy (= P. saccharata Auct. Fl. Ital.), distributed from SE France to Central Apennines, mainly on the Tyrrenic side of the Italian peninsula; P. vallarsae Kerner, endemic to...

The genus Dactylis L. in Italy. 1. The tetraploid entities

Summary Dactylis L. is present in Italy with some diploid (2n = 14) entities and a broad complex of tetraploids (2n = 28). The latter are the large majority of Italian populations. A biometrical and biochemical analysis on herbarium material and on specimens sampled from natural populations, showed that the characters concerning size and shape of the inflorescence form a continuous series, are strongly correlated among themselves, but do not correlate with other characters. The presence and dimensions of lobes on the lemma is variable on the same specimens and is more frequent on the western side of the Apennines than on the eastern side. The presence of papillae and of a smooth margin on the leaves have a weak mutual correlation, are more frequent in western populations, and are exclusive of coastal stands. Other characters vary irregularly, and do not correlate with the characters above. Protein characters also present some differences among the samples studies, but do not correlate with morphological c...

Reproductive ecology in the endemic Primula apennina Widmer (Primulaceae)

Abstract Disassortative mating in distylous self-incompatible species should result in the equilibrium of morph types in natural populations. Deviation from isoplethy may affect pollen transfer, and in isolated populations it could lead to Allee effect and genetic drift. Pollen limitation has been found to occur in several distylous species, for which mating opportunities are actually reduced to half population. In this study, we investigated the reproductive features and pollination ecology of the narrow endemic Primula apennina. We recorded equilibrium of morph frequencies in the studied population, reflecting the comparable fecundity found in the two morphs. Long-styled flowers produce more pollen grains of smaller size than short-styled ones: we hypothesize that in thrum flowers, pollen is more easily removed by the insect pollinator Macroglossum stellatarum, resulting in equal pollen amounts carried to both short styles and long styles. This lower pollen transfer efficiency from long-styled to short-styled flowers is also reflected in legitimate pollen–ovule ratio values. Despite results show no evidence of imminent threats to population persistence at study site, the strict dependence on one or very few pollinator species, and ecological traits, may increase extinction risks in the long-term period.

Detection of ephemeral genetic sub-structure in the narrow endemic Abies nebrodensis (Lojac.) Mattei (Pinaceae) using RAPD markers

A. nebrodensis (Nebrodi fir, Sicilian fir) is restricted to a small area of the Madonie Natural Park in Sicily. According to recent estimates, its only population consists of 30 adult individuals and a fluctuating number of juveniles derived from natural regeneration; besides, some hundreds of cultivated plants are preserved as ex situ collection. We used RAPD data from six 10-mer primers to examine the consequences of extensive historical clearance and human pressures on the extant population. Data from multiple life stages and different habitat conditions were considered, affording an opportunity to ascertain for the first time the structure of genetic variation in the extant uneven-aged population on both spatial and temporal scale. Consistent with previous works, we found that the history of disturbance and past land use did not affect drastically the biological diversity of the present-day population. Considerable levels of genetic variation were detected both in adult and juvenile sets. The non-significant correlation between genetic and physical distances (Mantel test; r = − 0.075) revealed a random distribution of genotypes in the natural stand. When the juvenile set was divided in 17 subsets, based on maternal provenance and growing conditions, Shannons index (54%) and AMOVA analysis (84%) indicated that most of genetic variation resides within subsets. Neighbour-joining cluster analysis supported the hypothesis of high cross-fertilization rates expected for a woody perennial species; nevertheless some grouping of related individuals suggested partial inbreeding and a weak pattern of genetic structure. Changes in structure can occur as the progeny ages and offspring thinning is responsible for moulding patterns of genetic diversity and population structure in time.

A reassessment of the sections of the genus Cytisus Desf. (Cytiseae, Leguminosae)

Recent morphological and molecular research on Cytisus and allied genera has produced a great deal of new data relevant to systematics, which have not yet been incorporated into a consistent classification system of the genus. We have compared and evaluated recently published cladograms and phenograms based on morphological and molecular (nuclear and plastid DNA) characters. The genus Cytisus sensu lato, including Calicotome, Chamaecytisus, Chronanthus, and Lembotropis, appears to be monophyletic. A subdivision of the genus Cytisus in 13 sections is presented; one species, C. tribracteolatus, remains incertae sedis. A new section (C. sect. Dendrocytisus) and two new combinations for taxa in C. sect. Calicotome are proposed.

Isolation and biodiversity in Cytisus villosus Pourret (Fabaceae, Genisteae): enzyme polymorphism in disjunct populations

ABSTRACT The genetic diversity of isolated populations of Cytisus villosus has been studied by means of enzyme polymorphism analysis. Two types of isolated populations were studied: “terrestrial islands” in Sicily, and “true islands” in the Aeolian archipelago. In the populations of “true islands” the number of alleles and the heterozygosity are lower than in “terrestrial islands”. Isolation amongst Sicilian populations seems to be more recent than isolation of the Aeolian populations, and may be attributed to climatic changes which occurred during the Holocene and/or to human activities. The disjunction of the Aeolian populations seems much more recent than the origin of the isles themselves; the colonization of the archipelago is attributed to a single, recent dispersal event not followed by local evolution. In view of the biological structure of the Aeolian populations, C. villosus must be regarded as a locally endangered species.