The few studies dealing with leaf phenological responses to elevated nutrients in forest trees have given ambiguous results, i.e., while some reported delayed leaf-out and autumn leaf senescence, ...others reported advanced leaf phenology caused by increased nutrition. This study aimed to determine the effects of experimentally increased phosphorus (+P treatment) on the leaf phenologies of two juvenile provenances of common beech and sessile oak. Other objectives were to determine whether there were interspecific differences as well as intraspecific variations. Saplings were excavated in two mixed beech–oak stands and transplanted into four wooden boxes filled with a commercial soil substrate. Phosphorus fertilizer was added to two of the boxes, while the remaining boxes served as controls. Both species responded to +P treatment with advanced autumn leaf senescence in the first year of the experiment. Leaf senescence in common beech began significantly earlier, while in both species, the process was accelerated compared to that in the control. In the second year, the leaf senescence response to +P treatment was even more pronounced in both species. The +P effect on leafing phenology was absent in both common beech provenances and in an oak provenance. However, the other oak provenance showed advanced leafing, indicating the existence of intraspecific differences.
Croatian pedunculate oak (Quercus robur L.) populations represent southern range peripheral populations, often viewed as sources of valuable diversity and drought-resistant ecotypes. At the same ...time, they endure stronger selection pressures as a result of climate change. The leaves of 20 individuals per population (17) were sampled in a field trial and analyzed using 10 nuclear and 9 chloroplast SSRs to determine the level of intrapopulation genetic variability and genetic differentiation. Analysis with nSSRs revealed deviation from HWE in seven populations. AMOVA showed a high intra-population diversity (98.53%) and a small but statistically significant inter-population differentiation. Isolation by distance explained 19.6% of differentiation. Average FST between populations was low (0.013) compared with usual values for peripheral populations. Populations were rich in cpSSR haplotypes, confirming the hotspot of diversity caused by the encounter of recolonization routes. Unbiased haplotype diversity (HE) from 9 chloroplast SSRs and 325 individuals was (HE = 0.440). Sixty-six different haplotypes were grouped in three maternal lineages by both a median-joining network and a neighbor-joining algorithm. AMOVA for cpSSRs showed statistically significant diversity among populations (70.23%), suggesting genetic differentiation, but also a probable anthropogenic effect. AMOVA of nSSRs within and between lineages showed that original recolonization patterns of nuclear diversity were subsequently erased by gene flow.
Uslijed kronične nestašice žira domaćeg podrijetla, na tržištu je tijekom 2023. godine nabavljena velika količinašumskog reprodukcijskog materijala (ŠRM-a) iz inozemstva, a njegovo korištenje za ...obnovu sastojina hrastalužnjaka u Republici Hrvatskoj (RH) je u tijeku. U neslužbenim su se komunikacijama kao izvori unesenogŠRM-a spominjale provenijencije iz Mađarske, Rumunjske ili Francuske. U konačnici su, koliko nam je poznato,nabavljene sadnice i žir iz Mađarske. Međutim, stvarno podrijetlo uvezenog ŠRM-a nije niti važno jer jeovo priopćenje uglavnom načelnog karaktera i može poslužiti kao uputa za odlučivanje o njegovoj prikladnosti,neovisno o podrijetlu ili vrsti šumskog drveća.Potrebno je naglasiti da je postupak premještanja ŠRM-a (unutar EU) odnosno njegovog uvoza (iz trećih država),te korištenja u RH, reguliran Zakonom o šumskom reprodukcijskom materijalu (Narodne novine 75/09,61/11, 56/13, 14/14, 32/19, 98/19). Navedeni zakon zadovoljavajuće dobro određuje okvir za postupak odlučivanjao tome kakve provenijencije mogu biti prikladne kao izvor ŠRM-a i gdje ih koristiti, u slučaju potrebe.Nažalost, smatramo da postupak odlučivanja o nabavi i korištenju ŠRM-a, primijenjen ove godine, nije odgovaraonekim temeljnim stručnim postavkama. Primijenjena praksa predstavlja visoki rizik za očuvanje jedinstvenosti,bioraznolikosti i produktivnosti naših sastojina hrasta lužnjaka. Cilj je ovog priopćenja ukazati naneke propuste, pojasniti rizike takve prakse, pružiti savjetodavni doprinos iz perspektive naše specijalnosti –genetike šumskog drveća, i time pomoći da se u budućnosti za obnovu naših sastojina koristi prikladni ŠRM.
The negative impact of drought on plant growth may be modified by the different availability of mineral nutrients and by their adaptation to different local habitat conditions. In this study, we ...examine the impact of drought, fertilization with phosphorus and provenance, as well as their interactions, on the growth and allometric growth relationships between the belowground and aboveground organs of common beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Liebl.). The research was conducted on saplings originating from two mature mixed stands (dry and wet provenances) dominated by these species. In the common garden experiment, saplings were exposed to regular watering and drought in interaction with moderate and high phosphorus concentrations in the growing substrate (achieved by phosphorus fertilization). The obtained results indicate the negative impact of drought and phosphorus fertilization on the growth of both species. In common beech, a negative impact of phosphorus fertilization on the adaptive capacity to drought was demonstrated by unfavorable ratios between fine root mass and the mass of other organs. The sessile oak provenances under the impact of drought showed a different root collar diameter/stem height increment ratio, which indicates their different phenotypic plasticity as a consequence of adaptation to different frequencies of dry periods in their natural habitats.
Research highlights: The susceptibility of oaks to late spring and early autumn frosts is directly related to their leaf phenology. Drought may alter the leaf phenology and therefore frost tolerance ...of oaks. However, the effects of drought on oak leaf phenology and frost resistance have not been thoroughly studied. Background and objectives: One of the consequences of climate change is an increase in the frequency of dry episodes during the vegetation period. Pedunculate oak (Quercus robur L.) is an economically and ecologically important forest tree species that prefers humid habitats. Therefore, knowledge of the impact of drought on this species is of great importance for the adaptation of forestry strategies and practices to altered environmental conditions. The aim of this study was to determine the impact of drought on leaf phenology and spring frost susceptibility in nine provenances. Materials and methods: One-year-old saplings originating from nine European provenances were used in the trial. The saplings were exposed to experimental drought and then re-watered in two subsequent years. Spring and autumn leaf phenology were scored. The trial was impacted by a late spring frost in the third year, and the resulting leaf frost injury was scored. The effects of drought treatment on the phenology and frost susceptibility of plants from the provenances were analysed. Results: Leaf phenology of plants from most of the studied provenances was significantly influenced by the drought treatment (p < 0.001). Drought induced a carry-over effect on flushing phenology, which was observed as delayed bud burst (from 0.6 to 2.4 days) in the second year and as advanced bud burst (from 0.1 to 6.3 days) in the third year. Therefore, opposite shifts in flushing phenology may be induced as a result of differences in the time span when plants sense water deficits. In contrast to flushing, autumn leaf phenology was unambiguously delayed following the drought treatments for all studied provenances (from 2.1 to 25.8 days). Differences in late frost susceptibility were predominantly caused by among-provenance differences in flushing phenology. However, the drought treatment significantly increased frost susceptibility in the plants (the rate of frost-injured plants per provenance increased from 3% to 78%). This higher susceptibility to spring frost was most likely caused by the advanced flushing phenology that resulted from the drought treatment in the previous year.
Važno je znati kako će klimatske promjene utjecati na pojedine šumske vrste, a pritom je jednako važno istraživati i mjeriti značajke biljaka koje je relativno lako kvantificirati, a koje su snažno ...povezane s cjelokupnim funkcioniranjem biljke. Iz toga je razloga provedeno istraživanje funkcionalnih značajki lišća na petogodišnjim sadnicama obične bukve (Fagus sylvatica L.) i hrasta kitnjaka (Quercus petraea /Matt./ Liebl.) porijeklom iz dviju provenijencija čija se staništa odlikuju sličnim orografskim i edafskim, a različitim klimatskim značajkama, što je posebno izraženo u količini oborine. Prema tomu, jedna je provenijencija s područja Slavonskoga Broda koja raste na staništu s manjom količinom oborine (suha provenijencija), a druga s područja Karlovca koja uspijeva na staništu s većom količinom oborine (vlažna provenijencija). Na lišću biljaka iz tih provenijencija mjerena je površina lišća (LA), gustoća puči (SD), lisna masa izražena po površini (LMA) i sadržaj suhe tvari u lišću (LDMC). Provedeno istraživanje funkcionalnih značajki lišća potvrdilo je da je hrast kitnjak u odnosu na običnu bukvu bolje prilagođen na sušne stanišne uvjete pa se može pretpostaviti da će pod utjecajem globalnih klimatskih promjena biti kompetitivniji u odnosu na običnu bukvu. Međutim, obična je bukva pokazala veću fenotipsku plastičnost koja joj može omogućiti bolju prilagodbu na buduće suše stanišne uvjete. Nadalje, utvrđeni obrazac diferencijacije sušnije i vlažnije provenijencije, uzimajući u obzir obje vrste, pokazuje njihovu ekotipsku diferencijaciju. Pri razmatranju utjecaja klimatskih promjena na prirodne populacije tih dviju vrsta treba uzeti u obzir njihovu fenotipsku plastičnost, ali i uočenu funkcionalnu ekotipsku diferencijaciju.
It is important to know how certain species will be affected by climate change, and it is equally important to measure plant traits that are relatively easy to quantify and that are strongly related to the overall functioning of the plant. For this reason, we studied leaf functional traits on five-year-old common beech (Fagus sylvatica L.) and sessile oak (Quercus petraea /Matt./ Liebl.) saplings originating from two mature mixed beech-oak provenances with similar orographic and edaphic conditions, but different climate, especially precipitation. One provenance is the area of Slavonski Brod (dry provenance) and the other is the area of Karlovac (wet provenance). We measured leaf area (LA), stomatal density (SD), leaf mass per area (LMA) and leaf dry matter content (LDMC). The research confirmed that, compared to common beech, sessile oak is better adapted to the drier habitat conditions, so it can be assumed that it will be more competitive due to global climate changes. However, common beech showed greater phenotypic plasticity that may allow it to better adapt to future drier habitat conditions. Furthermore, the established pattern of differentiation of drier and wetter provenance of both species indicates their ecotypic differentiation. When considering the impact of climate change on natural populations of these two species, their phenotypic plasticity, but also the observed functional ecotypic differentiation, should be considered.
Background and Purpose: Natural stands of pedunculate oak in Croatia have been delineated in seed areas, zones and regions. The current bylaw recommends that the transfer of reproductive material ...remains limited within zones, but that it is permitted within areas. Clonal seed orchards (CSOs) of pedunculate oak were established to increase genetic quality of seed and to acquire a more regular seed yield than in natural stands. In total 150 plus trees were selected within three seed regions. The selection included a number of favourable traits of tree size and stem quality. Three CSOs were planted with grafted plus-trees. We aimed to establish whether these orchards encompass enough genetic diversity to potentially produce genetically improved and sufficiently diverse reproductive material. We also wanted to assess neutral genetic differentiation between these orchards and compare it with the genetic diversity obtained from chloroplast DNA markers, depicting conserved lineages from recolonization routes. We wanted to investigate spatial genetic structure in the area of our research and provide additional information on the transfer of forest reproductive material.
Materials and Methods: Leaves were collected from all clones in the CSOs. Total genomic DNA was extracted and clones were analysed with eight nuclear and ten chloroplast microsatellite markers. Spatial autocorrelation analysis was performed with nuclear microsatellite data and original plus trees’ coordinates, for each CSO separately, to determine whether shared favourable traits among the selected plus trees in smaller distances are the results of relatedness, which the sampling strategy tried to avoid.
Results: We found 28 chloroplast haplotypes belonging to four maternal lineages, and significant differentiation between CSOs, indicating origin from different refuges. Nuclear microsatellites’ diversity in the CSOs is quite high and comparable to diversity found within a recent study of Croatian natural populations. Nuclear microsatellites did not show genetic differentiation between CSOs, i.e. between the seed regions and seed zones they represent. No genetic differentiation was found with nuclear microsatellites among haplotypic lineages. We found no genetic structure within the analysed regions.
Conclusions: Lack of differentiation between CSOs found with nuclear microsatellites confirms the permission for transfer of reproductive material between zones within the seed area 1 - Lowland Forests. If original differentiation between chloroplast haplotypic lineages was present after recolonization, it was erased by subsequent gene flow. Lack of genetic structure, with nuclear microsatellites within regions indicates successful sampling strategy.
Sažetak
Divlja trešnja (
Prunus avium
L.) vrsta je diskontinuiranog areala koja raste u mješovitim šumama južne, središnje i zapadne Europe U šumarstvu dugoročni programi oplemenjivanja teže ...poboljšanju kvalitete i proizvodnje njenog drveta. U Hrvatskoj je na osnovi osam fenotipskih kriterija kvalitete drvne mase, na području tri sjemenske regije, provedena selekcija i odabrano 27 stabala divlje trešnje, te je 2002. godine osnovana klonska sjemenska plantaža na području šumarije Kutina. Za potrebe ovog istraživanja u plantaži je odabran uzorak od 24 klona, predstavljenih sa po tri ramete (Tablica 1). Na svakoj je rameti odabrana i obilježena po jedna primjerna grana. Izmjerena je puna dužina odabrane grane i svih njenih izbojaka koji su nosili cvjetove i plodove. Izmjeren je opseg rameta na 50 cm visine i preračunat u promjer. U proljeće 2013. godine na primjernim su granama, na svakoj rameti u ožujku prebrojani svi generativni pupovi (PUP) prije otvaranja. U travnju su prebrojani cvjetovi (CV), te na uzorku 20 cvatova, broj cvjetova u cvatu (BRC). U lipnju su na primjernim granama prebrojani svi plodovi. Broj pupova, cvjetova ili plodova je za sve izmjerene ramete sveden na 100 cm dužine grane. Varijabla Iskorištenje pupova (IPUP) izračunata je za svaku rametu kao omjer stvarnog broja cvjetova i potencijalnog broja cvjetova (formula u Materijal i metode). Zametanje plodova (ZPL) izračunato je kao omjer cvjetova i plodova. U periodu od 10. travnja do 06. lipnja 2013, na istim rametama na kojima su izvršene izmjere, provedena su fenološka opažanja cvjetanja divlje trešnje (Slika 1). Izvedene fenološke varijable su OP – početak otvaranja pupova – broj dana od 1. siječnja 2013. do dana kada je rameta ušla u fenofazu 1, PR – početak receptivnosti – broj dana do dana kada je rameta ušla u fenofazu 2, ZR – završetak receptivnosti – broj dana do dana kada je rameta ušla u fenofazu 6, TR – razlika ZR – PR, tj. broj dana koji je rameta provela u fenofazama 2 – 6, PVR – početak vrhunca receptivnosti – broj dana do dana kada je rameta ušla u fenofazu 3, ZVR – završetak vrhunca receptivnosti – broj dana do zadnjeg dana koji je rameta provela u fenofazi 5, TVR – trajanje vrhunca receptivnosti – razlika ZVR – PVR, tj. broj dana koji je rameta provela u fenofazama 3 – 5, KR – količina receptivnosti – zbroj koeficijenata ženske plodnosti za pojedine fenofaze u kojima je rameta zatečena na dane opažanja. Koeficijenti su izračunati na temelju tablice postotaka ženske plodnosti iz Diaz i Merlo (2008) (Tablica 2.). Rezultati deskriptivne statistike za varijable PUP, CV, IPUP, PL i ZPL prikazani su u Tablici 3 i na Slici 2, zajedno sa grafikonom prosječnih koeficijenta unutarklonske varijabilnosti. Na temelju meteoroloških podataka za Kutinu 2012. i 2013. godine izračunati su parametri zadovoljenja potreba biljaka za zimskim inaktivnim temperaturama (Winter chilling), kao i proljetnim temperaturama potrebnim za pokretanje sokova i početak vegetacijskog
perioda i (Forcing), po Luedeling i dr. 2013. (The Chilling Hours Model, The Utah Model za „Winter chilling“ i Growing Degree Hours Model za „Forcing“). Na temelju zemljopisnih koordinata utvrđene su nadmorske visine izvornih majčinskih stabala. Cilj istraživanja bio je utvrditi raznolikost nekih reproduktivnih svojstava na klonovima divlje trešnje iz klonske sjemenske plantaže Kutina, utvrditi međusoban odnos tih svojstava, odnos sa svojstvima vegetativnog rasta i fenološkim svojstvima. Pritom se nastojalo zapažene odnose staviti u kontekst podataka o okolišnim uvjetima u vrijeme cvatnje i plodonošenja. Od promatranih generativnih svojstava i početka otvaranja pupova (OP) klonovi su se statistički značajno razlikovali u svim svojstvima (CV, BRC, IPUP, ZPL, PL, OP) osim broja generativnih pupova (PUP) (ANOVA – Tablica 4). Te su razlike kod BRC i CV bile uzrokovane razlikama između klonova sa ekstremnim vrijednostima, dok se veći Oroslavje na ostalih klonova međusobno nije statistički značajno razlikovala (Tukey Kramer test), ali statistička značajnost međuklonskih razlika rasla je po varijablama od stadija pupa do konačnog plodonošenja. Statistički najznačajnije razlike među klonovima ustanovljene su za početak otvaranja pupova (OP) (Tablica 5), gdje je i unutarklonska raznolikost bila značajna. Meteorološke prilike u 2012. i 2013. godini bile su relativno povoljne i biljke su zadovoljile svoje potrebe (Winterchilling i Forcing). Vrijednosti zametanja plodova (ZPL) bile su u skladu s drugim istraživanjima ili čak više, što upućuje na zadovoljavajući rodni potencijal ovih klonova u slučaju povoljnih vremenskih uvjeta, prisustva polinatora i pravovremenog suzbijanja štetnika. U ovom smo istraživanju utvrdili pozitivnu korelaciju između početnog broja generativnih pupova, te naknadnog broja cvjetova i, konačno, plodova. Početni broj pupova bio je pozitivno koreliran i sa samim zametanjem plodova. Isto se tako pokazalo da su klonovi koji su ranije ušli u vrhunac receptivnosti (PVR) bili uspješniji u plodonošenju i zametanju plodova (Tablica 6). Međutim, iskorištenje pupova kao omjer stvarnog i potencijalnog broja cvjetova pokazalo je suprotan trend, što nije u skladu sa spomenutim istraživanjem, ali odgovara čestom opažanju o međusobnoj kompeticiji ne samo vegetativnih i generativnih organa biljke, nego i međusobnoj kompeticiji generativnih organa. Fenološke varijable bile su značajno korelirane sa nadmorskom visinom, ukazujući na to da kasniji klonovi dolaze izvorno sa viših nadmorskih visina. Kasniji klonovi statistički značajno imaju ramete manjih promjera. Fenološke varijable uglavnom nisu bile značajno korelirane sa reproduktivnim svojstvima, sa izuzetkom IPUP i ZPL. Kod svojstva IPUP, kasniji klonovi, kod kojih je kasnije i nastupio početak otvaranja pupova i receptivnosti cvjetova (PR – ulazak u fenofazu 2) imali su bolje iskorištenje pupova, međutim naknadno slabije zametanje plodova (ZPL).
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), th
U ovom radu željeli smo ispitati različite parametre koji nam daju informaciju o učinkovitosti plantaža u proizvodnji genetski raznolikog potomstva. Koristili smo raspoložive inventurne podatke ...tvrtke “Hrvatske šume” d.o.o. o brojnom stanju i starosti rameta, te zabilježenim urodima u dvije klonske sjemenske plantaže hrasta lužnjaka; KSP “Plešćice” i KSP “Petkovac”.
U slučaju KSP „Plešćice” korišteni su inventurni podaci, te podaci o urodu za 2003.,2006.,2007.,2008.,2009. i 2010. godinu. Nakon 2010. godine zbog organizacijskih se razloga prestalo pratiti urod po klonovima i prešlo se na evidentiranje ukupnog uroda na plantaži, pa je za period 2010.-2017. godine nemoguće procjeniti genetsku raznolikost uroda.
U slučaju KSP „Petkovac” korišteni su inventurni podaci, te podaci o urodu za 2003.,2004.,2005.,2006.,2008.,2009. i 2010. godinu. U slučaju KSP „Petkovac” također se nakon 2010. godine napustilo evidentiranje uroda po klonovima.
Količine i varijabilnost uroda žira po godinama, kao i projekcije uroda za 2018. i 2019. godinu na temelju polinomijalnih regresijskih krivulja izračunali smo za sve godine evidentiranog uroda za cijelo razdoblje 2003. – 2017. godina. Rezultati su prikazani u tablici 1 i na slikama 1 i 2. Sve druge analize bile su moguće samo za godine kada se sakupljanje žira u plantažama provodilo odvojeno po klonovima. Korelacijama po metodama Pearsona i Spearmana usporedili smo raspodjelu uroda žira između parova istraživanih godina po klonovima, odnosno poredak udjela klonova u urodima žira između istraživanih godina. Obje korelacije bile su većinom statististički značajne između parova godina, sa ponekim iznimkama (tablica 2).
Ravnoteža uroda klonova po godinama, opisana kumulativnim krivuljama proizvodnje žira po godinama, po postocima rodnih klonova, prikazana je na slikama 3 i 4. Krivulje ravnoteže uroda klonova za obje plantaže prikazuju izrazito neravnomjernu raspodjelu uroda po klonova, što znači da je manjina klonova u istraživanim godinama
doprinosila većinskom količinom uroda. U uvjetima jednake plodnosti i sinkroniziranosti klonova doprinos u urodu bio bi razmjeran zastupljenosti klonova (clone size) tj. klonovi s većim brojem rameta značajnije bi doprinosili urodu. Iz tablice 3. može se primjetiti da je u slučaju KSP “Plešćice” ova korelacija bila slabija nego kod KSP “Petkovac”. Dapače, u tri od šest promatranih godina ona uopće nije bila značajna. U slučaju KSP “Petkovac” korelacija je bila značajna u svim promatranim godinama
Procjena efektivnih veličina populacije i genetske raznolikosti potomstva po godinama prikazani su u tablici 4. isključivo za žensku plodnost klonova. Prilikom izračuna doprinosa oba roditelja muška plodnost procijenjena je pomoću tri scenarija koja obuhvaćaju raznolik raspon potencijalnog muškog doprinosa u efektivnoj veličini populacije. Rezultati su prikazani u tablici 5. Usporedbom tri scenarija muškog doprinosa ukupnom efektivnom tj. statusnom broju (
Np
) vidljivo je da su vrijednosti za prvi ,gdje je muški doprinos razmjeran udjelu rameta datog klona u ukupnom broju rameta, intermedijarne u odnosu na druga dva scenarija. Najniži efektivni brojevi roditelja (
Np
), a time i najniži relativni efektivni brojevi (
Nr
), te najviše vrijednosti koeficijenta grupnog srodstva (Θ) dobivene su za drugi scenarij u kojem je muški doprinos jednak ženskome. Te su vrijednosti identične vrijednostima za samo žensku plodnost.
Najviši su efektivni brojevi i analogno druge vrijednosti dobivene za treći scenarij u kojem se pretpostavlja jednak muški doprinos svih klonova.
Za obje plantaže korelacija poretka ženskih efektivnih brojeva klonova za pojedine godine uroda, sa poretkom za količine uroda tih godina (po metodi Spearmana) je statistički značajna na razini p < 0,05.
Za primjenu mjera procjene genetske raznolikosti proizvedena u klonskim sjemenskim plantažama potrebna su sukcesivna višegodišnja praćenja cvjetanja/uroda, kao i saznanja o genetskoj dobiti dobivena testiranjem potomstva i uzgojne vrijednosti klonova u nedavno postavljenim testovima potomstva iz plantaža. Zbog svega toga je apsolutno preporučljivo da se daljnje sakupljanje uroda u ovim klonskim sjemenskim plantaža obavlja odvojeno po klonovima, jer se jedino na taj način, bez skupih molekularnih analiza, može doći do relevantnih informacija o doprinosu pojedinih klonova genetskoj raznolikosti potomstva.
In this study we wanted to investigate different parameters providing informations about the efficassy of orchards in producing genetically diverse progeny. We used available inventory data from the company „Croatian Forest” ltd. about the numbers and the age of ramets, as well as evidented crops in two clonal seed orchards (CSOs) of pedunculate oak : CSO „Plešćice” and CSO „Petkovac”.
For CSO „Plešćice” we used inventory data on ramets and crops for the years 2003, 2006, 2007, 2008, 2009 and 2010. and for CSO „Petkovac” for the years 2003, 2004, 2005, 2006, 2008, 2009 and 2010. After 2010 the collection of crops per clone was abandoned in both orchards and we only have data for overall crops in the orchards, until the year 2017.
We calculated the amounts and variability of acorn crops in different years, as well as projections of crops for years 2018 and 2019 based on polynomial regression curves, for all years of evidented crops between years 2003 and 2017. Results are shown in Table 1 and Figures 1 and 2. All other analysis were possible only for years in which crops were collected separately by clones.
We used Pearson’s product-moment and Spearman’s rank correlations to compare distributions of crops per clones between pairs of investigated years, ie. rank of clones in crops production between investigated years. Both correlations were mostly statistically significant with some exceptions (Table 2)
Clone fructification balance described by cummulative curves of acorn production in different years, per percentage of fructifying clones is shown in Figures 3 and 4. Clone balance curves in both orchards show irregular distribution of crops per clones, meaning that in investigated years minority of clones contributed to majority of crops. In conditions of equal clone fertility and maximal sinchronicity of clones, clone’s contribution to crops would be in concordance with the number of its ramets (clone size). Table 3 shows that in CSO Plešćice this correlation was weaker then in CSO Petkovac and, unlike in CSO Petkovac, not significant in all years.
Estimations of effective population sizes and genetic diversity of crops in different years is shown for female clone fertility in Table 4. For calculations of biparental contribution of clones, we used three scenarios encompassing various versions of potential male contribution in effective population sizes. Results are shown in Table 5. The values of effective (status) number of parents (
Np
) for the first scenario, where male contribution is proportionate to the percentage of clone’s ramets in the overall number of ramets of all clones, is intermediate between the other two scenarios. Lowest effective (status) number of parents (
Np
) and highest values of group ancestry coefficients (Θ) result from the second scenario where male contribution is equal to female. The highest effective numbers are gained for third scenario where equal male contribution of all clones is presumed.
In both CSOs, Spearman rank correlation between female effective numbers (
Nf
) and overall crops in different investigated years is statistically significant at p < 0,05 level.
These two CSOs are still filled with new ramets and are still relatively young. With increasing age and ramets’ tree sizes better results in crops and its genetic diversity are expected. For implementation of measures of crops genetic diversity estimations, it is necessary to monitor successively flowering and fructification in the CSOs through the years. The monitoring can then be combined with knowledge on genetic gain and clones’ breeding values obtained through recently established CSOs progeny trials. Therefore, we recommend collection of CSOs’ crops separately by clones, because without expensive molecular analysis it is the only way to get relevant information of individual clones contribution to genetic diversity of crops produced in the CSOs.
PDF
