Morphology and ultrastructure of Mammillaria gracillis (Cactaceae) in in vitro culture

Morphogenetic status of cactus Mammillaria gracillis Pfeiff. tissue culture was studied by light and electron microscopy. In vitro propagated shoots spontaneously developed callus. This callus regenerated normal and hyperhydric shoots without exogenous hormones. Tumour tissue induced by wild or rooty strains of Agrobacterium tumefaciens never expressed any morphogenetic potential. Light microscopy showed cellular characteristics of morphologically different tissues. Ultrastructural studies revealed changes in plastids: secondary dedifferentiation of mature chloroplasts, thylakoid swelling and disruption, phytoferritin accumulation, plastid elongation and increase in size. Changes in chlorophyll and carotenoid content were in accordance with degradation of the thylakoid system. Plastids were confirmed as very sensitive organelles to an artificial hyperhydric environment as well as to Agrobacteria-mediated cell transformation.     

Inter- and Intra-Varietal Genetic Variability in Malvasia Cultivars

The DNA molecular analyses together with ampelography, ampelometry, and biochemistry are essential for grapevine identification and investigation of genetic differences among the Vitis vinifera L. cultivars and clones. Ten Malvasia cultivars (i.e., Istrian Malvasia; M. delle Lipari; M. bianca di Candia; M. di Candia Aromatica; M. del Lazio; M. bianca lunga, also known as Malvasia del Chianti; M. nera di Brindisi/Lecce; M. di Casorzo; M. di Schierano, and M. nera di Bolzano) were analyzed using molecular approaches to study the genetic inter-varietal variability. Thirty Istrian Malvasia genotypes (i.e., 8 Italian clones, such as ISV 1, ISV F6, VCR 4, VCR 113, VCR 114, VCR 115, ERSA 120, ERSA 121, and 22 autochthonous grapevine accessions grown in Istrian Peninsula, Croatia) were investigated to evaluate the morphological and genetic intra-varietal variability. DNA analysis allowed discrimination of all Malvasia genotypes at molecular level using AFLP, SAMPL, and M-AFLP markers. Italian clones and autochthonous Croatian accessions of Istrian Malvasia were grouped according to their different geographic origins. These results showed the great genetic variability of Malvasia genotypes suggesting the need for the preservation of autochthonous grapevine biotypes found on different areas to approve the correct choice and selection of the grape multiplication materials.     

Morphological and proteomic analyses of sugar beet cultures and identifying putative markers for cell differentiation

Normal (N), habituated nonorganogenic (HNO), and tumour (T) sugar beet cell lines were analysed in order to establish specific patterns of extracellular proteins and identify protein markers that might explain the distinct phenotypical characteristics. Electron microscopy showed that the ultrastructure of N cells corresponds to that of parenchyma cells, and that these cells contain plastids with large starch grains. HNO and T cells had enlarged, lobed nuclei with an increased number of nucleoli; the number of nuclei in HNO cells was greater than in T cells. The T plastids were elongated, with reduced thylakoids and abundant phytoferritin deposits, while HNO plastids were small and vacuolated, with an irregular, underdeveloped thylakoid system. The extracellular proteome of the cells was separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis. Greater differences in protein expression were observed between the HNO and N lines than between the T and N lines. Sixteen of the most prominent bands differentially expressed among the cell lines were cut out from the gel and analyzed by mass spectrometry. Cell wall-modifying enzymes were identified, including a peroxidase whose expression was twofold higher in N and T tissue than in HNO tissue; pectinesterase, which was expressed at a level threefold lower in the T line than in the other cell lines; and xyloglucan endotransglucosylase, which was expressed at a level sixfold higher in HNO and T tissue. Three proteins belonged to the chitinase gene family and their expression was higher in HNO and T tissue than in N tissue. The differential expression of these proteins suggests that these play a role in cell line-specific cell wall composition and cell-to-cell adhesion.     

Essential Oil Composition of Three Globularia Species

The chemical composition of the essential oils obtained by hydrodistillation from the aerial parts of Globularia cordifolia L., G. meridionalis (Podp.) O.Schwarz , and G. punctata Lapeyr . was characterized by GC‐FID and GC/MS analyses. Among the 33 identified compounds, the most abundant present in all investigated samples were oct‐1‐en‐3‐ol (2.9–47.0%), 6‐(1,5‐dimethylhex‐4‐enyl)‐3‐methylcyclohex‐2‐enone (8.2–40.9%), and fukinanolid (7.4–31.6%). Multivariate statistical analyses (PCA and HCA) of the hitherto studied Globularia volatile compounds confirmed to some extent the assumed phylogenetic relationships of the Globularia species studied, including the close relationship between the morphologically similar species G. cordifolia and G. meridionalis, but also evidenced several discrepancies in the current classification of Globularia species.