DIGITALNA ARHIVA ŠUMARSKOG LISTA
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|ŠUMARSKI LIST 1-2/2023 str. 21 <-- 21 --> PDF
number of days from January 1, 2013 until the day when the ramet entered phenophase 1, PR - beginning of receptivity - number of days until the day when the ramet entered phenophase 2, ZR - end of receptivity - number days until the day when the ramet entered phenophase 6, TR – the difference ZR – PR, i.e. the number of days the ramet spent in phenophases 2 – 6, PVR – the beginning of the peak of receptivity - the number of days until the day when the ramet entered phenophase 3, ZVR - the end of the peak of receptivity - the number of days until the last day that the ramet spent in phenophase 5, TVR - the duration of the peak of receptivity - the difference ZVR - PVR, i.e. the number of days that the ramet spent in phenophases 3 - 5, KR - the amount of receptivity - sum coefficients of female fertility for individual phenophases in which the ramet was found on given observations. The coefficients were calculated based on the table of female fertility percentages from Diaz and Merlo (2008) (Table 2). The results of descriptive statistics for the variables PUP, CV, IPUP, PL and ZPL are shown in Table 3 and Figure 2, together with a graph of the average intraclonal variability coefficients. On the basis of meteorological data for Kutina in 2012 and 2013, the parameters for meeting the needs of plants for winter inactive temperatures (Winter chilling), as well as spring temperatures, necessary for the initiation of juices and the beginning of the vegetation period (Forcing), according to Luedeling et al. 2013, were calculated. (The Chilling Hours Model, The Utah Model for “Winter chilling” and the Growing Degree Hours Model for “Forcing”). Based on geographical coordinates, the altitudes of the original mother trees were determined. The goal of the research was to determine the diversity of some reproductive traits on wild cherry clones from the clonal seed orchard Kutina, to determine the relationship between these traits, the relationship with vegetative growth traits and phenological traits. In doing so, an effort was made to place the observed relationships in the context of data on environmental conditions at the time of flowering and fruiting. From the observed generative variables and bud burst (OP), the clones differed statistically significantly in all variables (CV, BRC, IPUP, ZPL, PL, OP) except for the number of generative buds (PUP) (ANOVA - Table 4). These differences in BRC and CV were caused by differences between clones with extreme values, while most of the other clones did not differ statistically significant from each other (Tukey Kramer test), but the statistical significance of interclonal differences increased by variables from bud stage to final fruiting. The most statistically significant differences between clones were found for the bud burst (OP) (Table 5), where intraclonal diversity was also significant. The weather conditions in 2012 and 2013 were relatively favorable and the plants met their needs (Winterchilling and Forcing). Fruit setting values (ZPL) were in line with other researches or even higher, which indicates a satisfactory reproductive potential of these clones in case of favorable weather conditions, presence of pollinators and timely control of pests. In this research, we found a positive correlation between the initial number of generative buds, and the subsequent number of flowers and, finally, fruits. The initial number of buds was positively correlated with fruit set itself. It was also shown that clones that entered the peak of receptivity earlier (PVR) were more successful in fruiting and fruit setting (Table 6). However, the realisation of buds (IPUP) as a ratio of the actual and potential number of flowers showed the opposite trend, which is not in accordance with the mentioned research, but corresponds to the frequent observation about the mutual competition of not only the vegetative and generative organs of the plant, but also the mutual competition of the generative organs. Phenological variables were significantly correlated with altitude, indicating that the later clones came originally from higher altitudes. Later clones have statistically significantly smaller diameter ramets. Phenological variables were mostly not significantly correlated with reproductive traits, with the exception of IPUP and ZPL. With the IPUP trait, later clones, which had a later onset of bud burst (OP) and flower receptivity (PR – entry into phenophase 2), had better bud realisation, but subsequently weaker fruit set (ZPL).
Key words: Prunus avium, flowering, fruiting, phenology, correlations, fruit set, interclonal variability