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Acorn Morphometric Traits and Seedling Heights Variation of Pedunculate Oak (Quercus robur L.) from the Seed Stands in Croatia

Mladen Ivanković ; Hrvatski šumarski institut Jastrebarsko
Maja Popović ; Hrvatski šumarski institut Jastrebarsko
Saša Bogdan ; Šumarski fakultet Sveučilišta u Zagrebu

Sažetak

Seed zone delineation of pedunculate oak in Croatia was done according to ecological differences, stand productivity and administrative borders of Forest Range Offices (NN 107/08). Oak forests are divided into three seed zones and it is recommended to transfer reproductive material only within zones. Seed delineation was preformed due to Croatian Forest Reproductive Material Transfer Law (NN 75/09) that was aligned with EU Directive on forests reproductive material (1999/105/EC). Seed delineation should be done according to genetic differences between various zones i.e. provenance regions. Aiming at verification of current seed zones in Croatia, and on the basis of general knowledge on pedunculate oak genetic variation, research on genetic variation of the species in Croatia has been started. Due to that, seeds were collected within so called registrated seed stands which are normally used as a seed sources for regeneration of managed oak stands.
Results of the study of seed morphometric analyses are presented in this paper. Seed were collected during autumn 2006 below 25 trees within each of 17 seed stands that represented whole distribution range of the species in Croatia (Table 1). 30 acorn from each tree were sampled for morphometric analysis and measured the height of seedlings. Acorn length, widths and masses and seedlings height were measured and acorn volumes were calculated according to formula for cylinder volume (Figure 1, 2).
ANOVA was performed by MIXED procedure in SAS, in order to analyze significance of various effects. Results showed that current seed zones were not statistically significant effect (there were no significant differences between them), but there were significant differences between populations within zones, as well as between trees within populations (Table 2). Table 3 shows Type 3 significance F-test for fixed effect of populations within seed zones for studied acorn traits and for one-year seedling height.
Determined populations differences did not match current seed delineation i.e. there were no obvious geographic pattern in between population variability for studied acorn traits as well as analyzed seedlings traits. Tukey-Kramer’s test was performed to determine the form and the differentiation which populations are separated statistically significantly. Test did not give results from which we could observe regularity in the geographical separation of populations for analyzed seedlings traits (Table 5). Population HR 88 (Lacići-Gložđe, Koška) was significantly differed from the geographically closed population HR HR 58 (Darda), HR 577 (Poljadijske šume, Požega) and HR 627 (Repaš), while at the same time did not differ from the distant population (HR 387 – Karlovac, Rečićki lugovi and HR 609 – Buzet).
Statistically significant differences between populations for all analyzed traits clearly indicate the genetic differentiation of oak populations. However interpopulation differentiation did not correspond to the geographical pattern. Specific character of differentiation indicates ecotypic pattern of genetic differences between oak populations in Croatia, i.e. differentiation that are caused by adaptation to specific micro-enviromental conditions (e.g. humidity, temperature and edaphic features). To confirm the hypothesis of ecotype pattern of genetic diversity is necessary to conduct additional research in genetic tests (provenance and progeny tests). Differences between currently seed zones were not statistically significant for any of the analyzed traits, which has not confirmed valid justification of current seed delineation. Nevertheless, it should be noted that the analysis of seed morphometric traits are not adaptively valuable properties, while the results of the one-year seedling heights are not sufficiently reliable due to a very early age of plants. Therefore these results should be regarded only as a stimulus for further research of oak genetic diversity in Croatia.

Ključne riječi

seed delineation; provenance region; morphometric traits; acorn; seedling heights; seed zones

Hrčak ID:

72314

URI

https://hrcak.srce.hr/72314

Datum izdavanja:

14.10.2011.

Podaci na drugim jezicima: hrvatski

Posjeta: 1.690 *