engleski

Intravarietal variability of the cultivar Plavac mali (Vitis vinifera L.)

The 'Plavac mali' is major autochthonous red winegrape cultivar in Croatia, mostly spread in the Central and South Dalmatia. Cultivar population is not expected to be genetically homogenous due to appearance of spontaneous mutations and their accumulation through vegetative propagation. However, types of expression, frequency and ratio of mutant individuals in the population are mostly unknown. Several ampegraphers reported on intravarietal variability describing so called „ types“ of 'Plavac mali' (Bulić, 1949 ; Jelaska, 1960 ; Maleš, 1981). So far, 'Plavac mali' was not undergoing organized clonal selection, so its population is expected to be genetically heterogeneous. In order to investigate the intravarietal variability we selected 160 phenotypically divergent 'Plavac mali' vines, across entire growing area on more than 50 different locations. All vines were monitored and analyzed (OIV descriptors and limited ampelometry) in situ for 2-3 consecutive years, and subsequently propagated to an ex situ collection planted in Split in year 2005. Besides classical analyses, accessions were also screened by AFLP in order to estimate intravarietal variability at the DNA level. As expected, the great variation within the population was recorded for different traits, and in some cases allowed us to define distinctive classes of supposed „ types“ such as „ early“ and „ late“ in term of ripening time ; „ small“ and „ large“ in term of bunch and berry size, confirming previous reports. However, genetic backround of these polymorphisms is still to be analyzed through the experiment in a single environment. As the only one evident and confirmed case of sport mutation is the accession with „ gray“ (instead of blue) berry skin color, which is confirmed on 15 SSR loci to be of the same genotype as 'Plavac mali'. Unexpectedly, AFLP analysis of the population sample has revealed significantly lower intravarietal variability in comparison to some other cultivars.

intravarietal variability; Plavac mali; AFLP

nije evidentirano