Grapevine Intravarietal Variability Research in Croatia and Clonal Selection

Sa？etak A high number of grapevine varieties have been traditionally grown in Croatia, most of them considered autochthonous. Because of the lack of systematic selection within them so far, it is supposed that a high level of intravarietal variability is present. The result of longterm growing of grapevine and vegetative propagation without systematic selection is high level of intravarietal variability. It is mostly caused by mutations, which can positively or negatively influence the growing characteristics of grapevine varieties. Clonal selection is a process of genotype (mutant) selection within variety populations, which are modified by some important variety characteristics. Clonal selection process is required in quality plant material production, with improved variety characteristics and guaranteed healthy conditions. Scientific researches of intravarietal variability and the improvement of clonal selection methods can highly contribute to the viticulture production development, and they are indirectly important for genetic resources preservation. This is essential for countries with high number of autochthonous varieties, in order to encourage their revitalisation process. In this paper, we give an overview of methods and recent research of intravarietal variability, as well as grape varieties improvement through clonal selection processes. Special attention is paid to Croatian grapevine research in the last ten years; the results point out a high level of intravarietal variability, and the necessity of clonal selection procedure for most of them