Evaluation of morphological and anatomical characters for discrimination and verification of some Medicago sativa (L.) Cultivars

<italic>Medicago sativa</italic> L. (alfalfa) is one of the most important legume forages in the world. The objective of this study was to characterize and discriminate among 15 alfalfa cultivars with a different geographical origin. Macro-morphological and anatomical characters as well as seed coat sculpture were investigated. Twenty five morphological characters were extracted directly from the fresh specimens. Transverse section in the main stem were carried out; stained and seventeen anatomical characters were examined by light microscope. Seed coat surface was investigated using Scanning Electron Microscope (SEM). Data obtained were coded and analysed using NTsys-Pc software (Version 2.02) and the resulted dendrogram is discussed. The results showed morphological and anatomical variation between the studied taxa. Vascular bundles ranged from 16 to 23. The Egyptian cultivar Nubaria has the lowest number of vessels (16) while the American Super supreme has the larger number (23). The seed coat ornamentation revealed five main surface patterns and suggests the presence of variations in anticlinal boundaries and periclinal walls that provide stable diagnostic characters for morphologically closely related taxa. The dendrogram showed that the Egyptian cultivar Nubaria was the most distant and clustered separately from all the other alfalfa cultivars which were grouped into two main clusters. Seed coat morphology and combination of other plant morphological and anatomical characters permitted identification and discrimination between the examined cultivars. Results obtained in this work could be considered for further breeding strategies and studies.

Dispersal potential of Scaevola crassifolia (Goodeniaceae) is influenced by intraspecific variation in fruit morphology along a latitudinal environmental gradient

Dispersal of plant propagules by ocean currents can result in long-distance dispersal and is important for the persistence of coastal species. However, the ability of such species to disperse via the ocean is often unknown because there is relatively little evidence that demonstrates that seeds or fruits can float and survive for extended periods in seawater. Furthermore, the seed or fruit traits, and intraspecific variation in these traits, that facilitate buoyancy remain largely unidentified. The genus Scaevola (L.) contains several widespread coastal species that may be capable of oceanic dispersal, such as S. crassifolia (Labill). We collected fruits of S. crassifolia along 700 km of a latitudinal environmental gradient. These fruits were used to determine the influence of fruit morphology and anatomy on fruit buoyancy. Morphological and anatomical variation in S. crassifolia was associated with dispersal potential. Our empirical data demonstrated that fruits with larger aeriferous mesocarp layers have greater buoyancy and, therefore, enhanced capacity for long range oceanic dispersal. Of three characters hypothesised to affect buoyancy (aeriferous mesocarp, air pockets in empty locules, and number of vascular cavities), only the properties of the mesocarp were significant. Intraspecific variation can significantly affect dispersal potential, and should not be overlooked in dispersal ecology.

Variability of Anthoxanthum species in Poland in relation to geographical-historical and environmental conditions: morphological and anatomical variation

Three Anthoxanthum species are found in Poland: the native A. odoratum L. s. str. and A. alpinum Á. Löve & D. Löve, and the alien A. aristatum Boiss. Major problems within this genus concern: (1) population variation of the native A. odoratum, representing various phases of ecological expansion to anthropogenic habitats; (2) population variation of A. odoratum and A. alpinum along the altitudinal transect; and (3) variation between populations of A. aristatum colonizing new areas and habitats outside its natural range of distribution (chorological expansion). In this study, morphological and anatomical variation of the three Polish Anthoxanthum species was analysed in detail. The variation of A. odoratum and A. aristatum was analysed in respect of environmental differences: habitat types and soil parameters. In the Babia Góra massif, variability distribution along the altitudinal transect was analysed for two vicariants: A. odoratum and A. alpinum. A odoratum in this massif does not cross the upper forest limit (i.e. forest line), and lower montane populations are morphologically very similar to lowland populations. Morphological and anatomical differences were detected between populations of A. alpinum along the altitudinal transect in the Babia Góra massif, with distinct upper montane populations. Moreover, clear morphological differences were found between the two altitudinal vicariants. Lowland populations of A. odoratum are characterized by great morphological variation, only weakly correlated with the type of occupied habitat and the phase of ecological expansion. The detected morphological variation reflects only to a limited extent the environmental variation of occupied habitats, and is not significantly correlated with the phase of chorological expansion. Some soil parameters are significantly correlated with some morphological characters studied in all the Anthoxanthum species. The analysed anatomical features of stems and leaves show continuous variation in the three species.

Range-wide morphological and anatomical variation in Larix laricina

To investigate the nature of infraspecific variation in Larix laricina (Du Roi) K. Koch, 60 naturally established stands constituting 44 provenances were sampled from throughout the species' range. Cones were scored for nine traits and short-shoot needle transverse sections were scored for seven traits and 20 radial distances. Variation in all traits was minimal, with the greatest components expressed between trees within stands and within trees. Canonical variates analysis of needle traits demonstrated that provenances were differentiated according to location, whereas canonical variates analysis of cone traits showed a much weaker geographic trend. These results are consistent with the hypothesis that Alaska and northern Yukon provenances resulted from geographically separate migratory waves originating from different locations in the south following glacial recession. While Alaska provenances were distinguished from other provenances based on canonical variates analysis of needle data, but not of cone data, this distinction is insufficient to recognize Alaska tamaracks separately at either the species or varietal level.