Šumarski list, Vol. 147 No. 1-2, 2023.
Izvorni znanstveni članak
https://doi.org/10.31298/sl.147.1-2.1
Genetic diversity of reproductive and phenological traits and their interrelationships in a clonal seed orchard of Wild Cherry (Prunus avium L.)
Ida Katičić Bogdan
; Sveučilište u Zagrebu, Fakultet šumarstva i drvne tehnologije
Višnja Jurkić
; Hrvatske šume d.o.o., Zagreb
Ivana Brlek
; Sveučilište u Zagrebu, Fakultet šumarstva i drvne tehnologije
Marko Bačurin
orcid.org/0009-0002-7034-5824
; Sveučilište u Zagrebu, Fakultet šumarstva i drvne tehnologije
Saša Bogdan
orcid.org/0000-0002-1672-2038
; Sveučilište u Zagrebu, Fakultet šumarstva i drvne tehnologije
Sažetak
Summary
Wild cherry (Prunus avium L.) is a species of discontinuous range that grows in the mixed forests of southern, central and western Europe. In forestry, long-term breeding programs aim to improve the quality and production of its wood. In Croatia, on the basis of eight phenotypic criteria of wood mass quality, a selection was carried out in the area of three seed regions and 27 wild cherry trees were selected. A clonal seed orchard was established in the area of the Kutina Forestry office in the year 2002. For the purpose of this research, a sample of 24 clones, represented by three ramets each, was selected in the orchard (Table 1). One exemplary branch was selected and marked on each ramet. The full length of the selected branch and all its shoots bearing flowers and fruits was measured. The circumference of the ramet was measured at a height of 50 cm and converted into a diameter. In March of 2013, all generative buds (PUP) were counted on exemplary branches, on each ramet, before opening. In April, flowers (CV) were counted, and on a sample of 20 inflorescences, the number of flowers in inflorescence (BRC). In June, all the fruits on the exemplary branches were counted. The number of buds, flowers or fruits was reduced to 100 cm of branch length for all measured ramets. The variable Bud realisation (IPUP) was calculated for each ramet as the ratio of the actual number of flowers to the potential number of flowers (formula in Material and Methods). Fruit set (ZPL) was calculated as the ratio of flowers to fruits. In the period from April 10 to June 6, 2013, on the same ramets on which the measurements were made, phenological observations of the flowering of wild cherry were carried out (Figure 1). Derived phenological variables are OP - beginning of bud opening (bud burst) –
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).
Ključne riječi
<i>Prunus avium</i>; flowering; fruiting; phenology; correlations; fruit set; interclonal variability
Hrčak ID:
294884
URI
Datum izdavanja:
28.2.2023.
Posjeta: 469 *