Variability of Avena fatua L. seed morphology and germination temperatures Acomparison between Slovenia, Italy, Hungary and Croatia

Considering the high morphological and ecological diversity of wild oat (Avena fatua L.), the objective of this study was to examine the variability of spikelets and seeds from Slovenia, Croatia, Hungary and Italy. Intraspecific variation in spikelet and seed morphology and germination temperature was assessed for eight populations, collected across these four countries in the summer of 2015. Eight morphological features were analyzed in 30 samples per each population. The variations of the selected morphological traits were assessed using Statistica 7.0 software. Variation in morphological parameters was detected between the two Slovenian populations. Additionally, significant differences were observed in morphological paramteres between the two Slovenian and other tested populations (Croatian CR1 and CR2, Hungarian H1 and H2, and Italian IT1 and IT2). Seed and awn mass were greatest in population SL2, whereas awn length, spikelet length, and spikelet width were greatest in population SL1. The tested Slovenian populations differed in color compared to other populations, while awn hairiness did not differ between the tested populations. When considering their germination behaviour, the Slovenian populations did not emerge at 5 °C and 10 °C, whereas the other tested populations emerged at 10 °C. A temperature of 35 °C affected germination energy but did not reduce it below 50%. The best germination percentage was observed in the Hungarian populations. Finally, despite the observed differences in morphology and germination behaviour, all the tested populations were grouped in the same cluster, based on the analyzed parameters.