Micromorphological analysis in flowers and leaves of grapevine (Vitis vinifera ssp. sativa)

MICROMORPHOLOGICAL ANALYSIS IN FLOWERS AND LEAVES OF GRAPEVINE (Vitis vinifera ssp. sativa) SEM analysis represents an important tool to recognize some plant traits, morpho-physiological characters useful in studying reproductive fitness and plant-environmental relationships. Some cultivars of grapevine cultivated in Emilia, the Western part of Emilia-Romagna Region, have been studied to obtain a morpho-functional characterization of flowers. Malbo gentile, Trebbianina, Lambrusco di Sorbara, L. Montericco and L. Barghi showed hermaphrodite flowers with a normally developed gynoecium but back-reflexed stamens. Their flowers produced anomalous pollen, without furrows and pores-acolporated pollen-unable to let pollen tube growth. In Termarina and Lambrusco salamino, differently, hermaphrodite flowers had erect stamens at the anthesis and produced normal tricolporate pollen. These results have been related with those reported from OIV and IPGRI grapevine descriptors (1), relatively to the occurrence of morphologically hermaphrodite but functionally female flowers. Grapevine leaf traits are frequently related with susceptibility or tolerance to biotic and abiotic stress (2,3,4). Moreover, seventeen Vitis genotypes, from different Italian Regions, have been analysed at SEM to characterize leaves traits. Results showed that the genotypes differ for stomatal density and size: mean stomata density ranged between 100 and 200 stomata/mm2. Highest values of stomata density were recorded in the cultivar Nero d’Avola from Sicily and in V. Berlandieri, an American species from which several currently-used rootstocks have been obtained, while the lowest value was in wild grapevine (Vitis vinifera ssp. sylvestris). Evaluating density, position and types of trichomes, a wide variation - mainly with respect of density - resulted within the observed genotypes. These characters are usually taken in consideration as ampelographic descriptors (1) but they play also an important role in pathogen resistance and may be related with plant resistance to stress. References 1. IPGRI, UPOV, OIV. 1997. International Union for the Protection of New Varieties of Plants, Geneva, Switzerland/Office International de la Vigne et du Vin, Paris, France/International Plant Genetic Resources Institute, Rome, Italy. 2. Boso S., Alonso–Villaverde V., Santiago J.L., et al. (2010). Vitis, 49: 43-50. 3. Winkel T., Rambal S. (1993). Aust. J. Plant Physiol., 20: 143–157. 4. Boso S., Gago P., Alonso–Villaverde V., et al., (2011). Sci. Hort., 128: 228-238.