Područje delte rijeke Neretve sa svojim klimatsko-zemljopisnim uvjetima, predstavlja
jedinstveno područje obzirom na gotovo monokulturne nasade unšijske mandarine
(Citrus unshiu Marc.). Zbog ...nedovoljne istraženosti paše, kao i odlika meda od unšijske
mandarine cilj je istraživanja bio utvrditi skupljačku aktivnost pčelinje zajednice te sastav
nektara i meda. Istraživanje je bilo provedeno tijekom trogodišnjeg razdoblja od 2014. do
2016. godine na području Opuzena. Na četiri sorte (‘Kawano Wase‘, ‘Okitsu’, ‘Chahara’ i
‘Zorica’) bilo je praćeno izlučivanje nektara i koncentracija šećera na osnovu čega je
utvrđen i njihov medonosni potencijal. Analiza sadržaja mednog mjehura i peludnog tereta
bila je provedena prema metodi Soehngen i Jay (1974). Melisopalinološkom je analizom
bio utvrđen peludni spektar sadržaja mednog mjehura, peludnog tereta i meda. Od
fizikalno-kemijskih parametara su bili analizirani udio vode, električna provodnost, pH
vrijednost i aktivnost dijastaze. Mikroekstrakcijom vršnih para na krutoj fazi (HS-SPME) i
ultrazvučnom ekstrakcijom (USE) pomoću organskih otapala bili su utvrđeni isparljivi
spojevi u nektaru, sadržaju mednog mjehura i medu. Prosječno veću količinu nektara
izlučile su sorte ‘Okitsu’ (23,40 µL) i ‘Kawano Wase‘ (22,79 µL) u odnosu na sorte
‘Chahara’ (21,60 µL) i ‘Zorica’ (20,01 µL). Kod sorti ‘Kawano Wase‘ (20,66%), ‘Okitsu’
(20,35%) i ‘Chahara’ (20,17%) bila je utvrđena prosječno veća koncentracija šećera u
odnosu na sortu ‘Zorica’ (18,43%). Medonosni se potencijal kretao u rasponu od 301 do
361,5 kg/ha. Od obrađenih 10 470 skupljačica nektarni je teret utvrđen kod 1 079, peludni
kod 1 476, dok je nektarni i peludni utvrđen kod 40. Prosječno veći broj skupljačica s
punim mednim mjehurom (404) i peludnim teretom (622) je bio ustanovljen u 8:00 u
odnosu na one prikupljene u 13:00 i 18:00. U 8:00 je bila utvrđena prosječno najveća
masa peludnog tereta (8,47 mg), no ona se nije statistički značajno razlikovala od one u
13:00 (8,44 mg), dok je ustanovljena masa u 18:00 (7,67 mg) bila statistički značajno
manja u odnosu na prethodna dva praćenja. Analizirajući masu sadržaja mednog mjehura
utvrđeno je da se prosječna masa kretala od 20,22 mg u 8:00 do 21,88 mg u 13:00,
međutim, ustanovljeno je da nije bilo statistički značajne razlike. Prosječna se masa
ukupnog peludnog tereta prikupljenog skupljačem kretala od 5,18 g do 30,92 g, a prema
botaničkom podrijetlu utvrđene su 22 biljne vrste, među kojima su najzastupljenije bile
naranča (Citrus sinensis), dvogodišnji dimak (Crepis biennis) i česmina (Quercus ilex). U
peludnom je spektru sadržaja mednih mjehura pelud unšijske mandarine ustanovljena u
21% uzoraka. Osim mandarine utvrđeno je još 17 biljnih vrsta. U peludnom je spektru
meda osim peludi mandarine (C. unshiu), od nektarnih biljnih vrsta učestalije je bila
zastupljena pelud od pastirske torbice (Capsella bursa pastoris), biljaka iz porodice
glavočika (Asteraceae Taraxacum form), vazdazelene krkavine (Rhamnus. alaternus) i
naranče (C. sinensis), a od nenektarnih biljnih vrsta crni jasen (Fraxinus ornus), česmina
(Q. ilex), hrast (Quercus spp.), klupčasta oštrica (Dactylis glomerata) i maslina (Olea
europea). Prosječni se udio vode u uzorcima meda kretao od 17,1% do 18,1%, električna
provodnost od 0,20 mS/cm do 0,27 mS/cm, pH vrijednost od 3,82 do 4,06 te aktivnost
dijastaze od 7,78 do 12,02 DN. Analizom isparljivih spojeva je utvrđeno da su u nektaru
najzastupljeniji spojevi bili: 1H-indol, metil-antranilat, linalool, α-terpineol, fenilacetonitril,
1,3-dihidro-2H-indol-2-on i kafein. Linalool, α-terpineol, 1,8-cineol, 1H-indol, metilantranilat,
cis-jasmon, kafein, 1,3-dihidro-2H-indol-2-on i fenilacetonitril su bili
najzastupljeniji spojevi u sadržaju mednih mjehura, a fenilacetaldehid, fenilacetonitril,
linalool, 1H-indol, metil-antranilat, kafein i 1,3-dihidro-2H-indol-2-on u medu. Od utvrđenih
spojeva, 1H-indol, zatim 1,3-dihidro-2H-indol-2-on te fenilacetonitril do sada nisu bili
pronađeni u medu od agruma.
The Neretva river valley with its climatic and geographical conditions, is a unique area due
to the almost monoculture plantations of Satsuma mandarin (Citrus unshiu Marc.). Due to
insufficient pasture research and quality of honey from Satsuma mandarin, objective of
this study was to determine the foraging activity of honey bee colonies and the
composition of nectar and honey.
The three-year research was conducted from 2014 to 2016 in the Neretva valley in the
area of Opuzen. The amount of nectar and sugar concentration was monitored on four
varieties of mandarins, ‘Kawano Wase‘, ‘Okitsu’, ‘Chahara’ and ‘Zorica’ by sampling 10
open flowers for each variety in a single measurement. Six measurements per day were
performed at intervals of two hours (8:00, 10:00, 12:00, 14:00, 16:00 and 18:00). In the
final year of research, nectar secretion was monitored on flowers in the opening phase
and in the phase of a fully open flower. Nectar sampling was carried out using glass
capillaries with a capacity of 75 µL according to Corbet (2003). Based on the collected
data, the honey potential of investigated varieties was determined. Monitoring of
honeybee visits to mandarin was conducted in April 2016, according to Abrol (2007).
Flower visit is monitored by counting bees in the studied varieties. Two trees were
selected in each variety. On each of the trees, three branches were marked with the
uniform number of flowers. Visits are monitored by counting bees three times a day, at
10:00, 14:00 and 18:00 for 5 minutes per each branch. Floristic observations were
performed at selected locations and plant species listed that bloom at the same time as
the Satsuma mandarin. Foraging activity is determined using honey bee colonies of
Carniolan bees (Apis mellifera carnica, Pollmann, 1879). Returning bees were collected
on the hive entrance for the content of honey sac and pollen loads study. The analysis
was performed according to the method of Soengen and Jay (1974). Sampling of pollen
loads was conducted using outdoor pollen collector set on the hive entrance. From the
physico-chemical analysis of the collected samples of honey, the water content, electrical
conductivity, pH and activity of diastase, as well as qualitative melisopalynological
analysis were conducted. Analysis of volatile compounds was performed using
microextraction of headspace on a solid phase (HS-SPME) and ultrasonic extraction with
organic solvents (USE) on samples of nectar, honey sac contents and honey.
Mean values of the nectar quantity were larger and not significantly different in cultivars
‘Okitsu’ (23.40 mL) and ‘Kawano Wase‘ (22.79 mL), compared to the other two studied
varieties. Also, a statistically significant difference was found between the other two
varieties, where the average higher amount of nectar is found in variety ‘Chahara’ (21.60
mL) compared to ‘Zorica’ (20.01 mL). The range of the specified parameter in all the years
ranged from minimally 5 to maximally 75 µL. The lowest concentration of sugar (18.43%)
was found in variety ‘Zorica’ that was significantly different from the nectar of other studied
varieties. The mean values of the studied parameter in ‘Okitsu’ (20.35%), ‘Kawano Wase‘
(20.66%) and ‘Chahara’ (20.17%) were not significantly different. The mean values of the
quantity of secreted nectar in closed flowers of all varieties ranged from 18.96 to 21.03 µL
in open flowers, and are significantly different. Based on the mean values of the sugar
concentration, higher concentration was determined in open (21.62%) compared to the
closed flowers (19.04%), taking into account all the studied varieties. The honey potential
of investigated varieties ranged from 301 kg to 361.5 kg of honey per hectare. There is no
exact data on cultivated areas according to different varieties in the Neretva valley. The
estimation that different Satsuma mandarin varieties cover 1 700 hectares suggests that it
was possible to produce from 511.7 tons to 614.5 tons of mandarin honey in the study
period. The highest mean number of bees visits was determined on variety ‘Kawano
Wase‘ (12.89), followed by ‘Okitsu’ (11.56) and ‘Chahara’ (11.11), while the lowest (10.00)
visit was on the variety of ‘Zorica’.
Floristic research has identified a total of 78 taxa (species, subspecies, and varieties).
Based on the data on the flowering source, from the determined plants, nine of them were
the source of nectar only, 45 of nectar and pollen, while 24 were visited by bees
exclusively for pollen. Foraging activity of bee colonies was determined in the pasture
based on the analysis of foragers at the hive entrance. In total, 10,470 foraging bees were
processed, of which 2595 came with the load to the hive. Nectar was found in 1079,
pollen in 1476, however nectar and pollen loads together were found only in 40 bees.
7875 foraging bees returned to hive without load. The highest number of foraging bees
with nectar (404) and pollen load (622) was determined at 8:00, while the number of bees
at 13:00 and 18:00 was significantly lower. The average weight of the honey sac ranged
from 20.22 mg at 8:00 to 21.88 at 13:00, and the range was from 0.70 mg to 58.60 mg.
However, comparing the resulting average values, there were no statistically significant
differences among investigated wights per times (hours). Average maximum weight of
pollen loads was found at 8:00 am (8.47 mg) and was not significantly different from the
values measured at 13:00 (8.44 mg). The mean weights of pollen loads collected at 18:00
(7.67 mg) were significantly lower in comparison to two previous samplings. The range of
pollen loads weight ranged from 0.50 mg to 45.90 mg. The mean total weight of pollen
collected in external pollen collectors during 2014 was 30.92 g in the morning and 8.78 g
in the afternoon measurements, and was significantly different. In 2015, the average
weight of collected pollen in the morning was 10.55 g and was not significantly different
from
Bosna i Hercegovina i Republika Hrvatska su poznate po postojanju brojnih endemskih vrsta i podvrsta riba, vezanih za dva velika riječna sliva, jadranski i dunavski. Rijeke jadranskog sliva znatno su ...kraće i izoliranije, u usporedbi s rijekama dunavskog sliva. Tako je u području donje Neretve koja pripada jadranskom slivu evidentiran određeni broj endemskih vrsta koje su nedovoljno opisane jer se njihovom ekologijom, biologijom, taksonomijom kao i njihovim međusobnim odnosom bavio mali broj istraživača. Tri vrste riba koje u tom smislu još nisu istražene su strugač (Squalius svallize), peškelj (Scardinius plotizza) i imotska masnica (Squalius microlepis). Ovim istraživanjem prvi put su opisane taksonomske i biološko-ekološke značajke navedenih riba područja donje Neretve. Cilj ovog rada bio je odrediti merističke i morfometrijske značajke, izraditi dužinsko-masenu i dobnu strukturu riba, von Bertanlanffyev rast, prikazati morfologiju probavnog trakta (odnos dužine probavila i totalnedužine tijela), izračunati Fultonov faktor kondicije (CF), odrediti kvalitativni i kvantitativni sastav ishrane, te molekularnom analizom definirati sistematski položaj ovih triju vrsta i njihove taksonomske karakteristike naspram drugih Ciprinidnih vrsta. Istraživanje je provedeno na Deranskom jezeru i rijekama Bregavi, Krupi i Matici. Analizirano je 60 jedinki strugača, 51 jedinku makala i 55 jedinki peškelja. Dobiveni morfometrijski i meristički parametri za tri istraživane vrste upućuju na nadopunu dosadašnjih ključeva za determinaciju vrsta. Maksimalne zabilježene vrijednosti masa i totalnih dužina predstavljaju najveće zabilježene vrijednosti u dosadašnjim istraživanjima za sve tri vrste.Također, stugač, makal i peškelj postižu visoke faktore kondicije. Kod sve tri istraživane vrste konstatiran je pozitivan alometrijski rast. Strugač i makal se hrane uglavnom makrozoobentosom, iako su u njihovim probavilima u zanemarivim količinama pronađene ribe i neidentificirani biljni materijal. U probavilima peškelja iz Deranskog jezera utvrđene su alge, detritus, neidentificirana biljna i anorganska tvar, te vodeni beskralježnjaci od kojih se Crustacea i Insecta pojavljuju kroz sve četiri sezone. Molekularno genetskim analizama i dobivenim filogenetskim stablom razvidna je međusobna srodnost vrsta roda Squalius, dok se vrste roda Scardinius odvajaju kao udaljenije od njih. Rezultatima ovog istraživanja došlo se do novih spoznaja o morfometriji i meristici triju vrsta, dužinsko-masenim odnosima, ishrani, dobi i rastu, te definiranju njihovoga sistematskog položaja.
Bosnia and Herzegovina and the Republic of Croatia are known for presence of numerous endemic species and subspecies of fish, associated with two major river basins, the Danube and the Adriatic. Rivers of the Adriatic basin are significantly short and isolated, compared with the rivers of the Danube basin. Thus, a certain number of insufficiently described endemic species exist in the Lower Neretva area, where a small number of researchers studied their ecology, biology, taxonomy and correlations between them. Three fish species that have not yet been studied in this respect are Neretva chub (Squalius svallize), Neretva rudd (Scardinius plotizza) and makal dace (Squalius microlepis). The objectives of the doctoral thesis are to define the systematic positions of these endemic species and their taxonomic relationships with other cyprinid species using molecular analysis, to complement the species identification keys established by morphometric and meristic parameters, to determine diet, growth according to von Bertalanffy and condition. Meristic and morphometric characteristics of the three studied fish species are identified in detail, and several differences in relation to previous studies, which can complement the current species identification keys, are established. The maximum recorded total length (TL) of the Neretva chub body was 28 cm, the maximum TL was 30.6 cm for makal dace, while the maximum TL of Neretva ruddwas 40.4 cm. The maximum body mass value of Neretva chub was 269.3 g, of makal dace313.80 g, and of Neretva rudd 1127.70 g, and these represent the highest values recorded in the studies so far. All this indicates a positive effect of the environmental conditions of the Lower Neretva on their growth. The number of scales in lateral line of Neretva chub is 47 to 49, in makal dace 67 to 75 with sporadic occurrences of numbers 66 and 76, while the numbers of scales in lateral line of Neretva rudd ranged from 38 to 42 with sporadic occurrences of numbers 37 and 43. The study of growth has shown that all three species have exceptionally fast growth in both length and mass, and reach much larger sizes than in rare past studies. They also achieve high condition factors, and thus confirm a very positive effect of environmental conditions on the growth of fish in the Lower Neretva area. The average value of condition factor of Neretva chub was CF = 0.98 0.14, of makal dace CF =0.97 0.03, and of Neretva rudd CF = 1.37 0.23. Positive allometric growth with a high b-value of b = 3.47 was found in Neretva chub and b = 3.25 in Neretva rudd, while the value registered in makal dace was b = 3.10, which also represents a positive allometric, i.e. nearly isometric growth. Stomach analysis provided evidence that the diet of Neretva chub consisted of diverse animal component with negligible plant component, where the class Insecta was the most frequent component in the diet of Neretva chub (Trichoptera, Diptera, Hymenoptera). The dominant diet component in stomachs of makal dace from the Matica River were the groups Ephemeroptera, Plecoptera, Trichoptera, Coleoptera and Diptera through all four seasons. Stomachs of Neretva rudd from Deransko Lake were found to contain algae, detritus, unidentified vegetable and inorganic matter, and aquatic invertebrates, of which Crustacea and Insecta occur through all four seasons. Molecular genetic analysis made it possible to clearly define their systematic position. In the DNA analysis, total of 15 samples from 3 different locations were sequenced. Based on the resulting phylogenetic tree, it is evident that the Squalius species are more related to each other, while Scardinius separates as more distant from them. In addition to primary objectives, secondary objectives were also achieved, providing a detailed insight into characteristics of the habitats of these fish species: physical and chemical characteristics of study area watercourses (the Rivers Bregava, Krupa and Matica, and Deransko Lake), and their climatic, hydrographic and hydrologic characteristics. Therefore, the intended scientific contribution in the scientific determination of kinship and systematic affiliation of the endemic cyprinids of Herzegovina and their detailed biological properties is also achieved, which is of exceptional importance in the European and global ichthyological research.
Invazivni ponto-kaspijski glavoči: riječni glavočić (Neogobius fluviatilis), glavočić okrugljak
(Neogobius melanostomus), keslerov glavočić (Ponticola kessleri) nedavno su uzrokovali
dramatične ...promjene struktura ribljih zajednica diljem europskih riječnih sustava. Iako je
njihova prisutnost u hrvatskom dijelu dunavskog slijeva primjećena i distribucija izučena,
njihova ishrana, utjecaj na autohtone populacije riba, kondicija, dob i rast, zastupljenost
haplotipova i porijeklo, do sada su bili nepoznati. Analiza sadržaja probavnog trakta
riječnog glavočića (Neogobius fluviatilis) ukazuje da mu je ishrana vrlo raznolika, ali
prevladavaju Trichoptera, Chironomidae, Bivalvia i Odonata. Ishrana mu se u znatnoj
mjeri preklapa s ishranom glavočića okrugljaka (Neogobius melanostomus), kojem u
ishrani prevladava Gastropoda. Mala riba i Gammarus sp. prevladavaju u ishrani
keslerova glavočića (Ponticola kessleri). Usporedba sadržaja probavnog trakta s plijenom
dostupnim u okolini ukazuje da riječni glavočić i glavočić okrugljak preferiraju Trichoptera,
Megaloptera i Coleoptera, a keslerov glavočić Trichoptera, Gammarus sp. i Pisces.
Analize ukazuju na potencijalno pozitivan utjecaj prisustva ponto-kaspijskih glavoča na
neke populacije riba: glavočića okrugljaka i keslerova glavočića na zlatnog vijuna
(Sabanejewia balcanica), riječnog glavočića na šarana (Cyprinus carpio), karasa
(Carassius carassius), manjića (Lota lota) i velikog vijuna (Cobitis elongata). Međutim,
postoje i naznake da keslerov glavočić negativno utječe na klena (Squalius cephalus), a
glavočić okrugljak na malog vretenca (Zingel streber). Pozitivan alometrijski rast utvrđen
je za sve tri analizirane vrste ponto-kaspijskih glavoča upućujući na vremenski duže
prisutne populacije. Kondicijski faktor najveći je za glavočića okrugljaka, a najmanji za
riječnog glavočića. Za riječnog glavočića je utvrđena dob I, II i III, a za glavočića
okrugljaka i keslerova glavočića I, II, III i IV, s tim da najveću brzinu rasta ima riječni
glavočić, a najmanju glavočić okrugljak. Za svaku od analiziranih vrsta ponto-kaspijskih
glavoča utvrđen je jedan crnomorski haplotip. Malen broj haplotipova upućuje na relativno
malobrojne populacije ponto-kaspijskih glavoča što potencijalno smanjuje visinu njihova
invazivnog potencijala u savskom slijevu.
Invazivni ponto-kaspijski glavoči: riječni glavočić (Neogobius fluviatilis), glavočić okrugljak
(Neogobius melanostomus), keslerov glavočić (Ponticola kessleri) nedavno su uzrokovali
dramatične promjene struktura ribljih zajednica diljem europskih riječnih sustava. Iako je
njihova prisutnost u hrvatskom dijelu dunavskog slijeva primjećena i distribucija izučena,
njihova ishrana, utjecaj na autohtone populacije riba, kondicija, dob i rast, zastupljenost
haplotipova i porijeklo, do sada su bili nepoznati. Analiza sadržaja probavnog trakta
riječnog glavočića (Neogobius fluviatilis) ukazuje da mu je ishrana vrlo raznolika, ali
prevladavaju Trichoptera, Chironomidae, Bivalvia i Odonata. Ishrana mu se u znatnoj
mjeri preklapa s ishranom glavočića okrugljaka (Neogobius melanostomus), kojem u
ishrani prevladava Gastropoda. Mala riba i Gammarus sp. prevladavaju u ishrani
keslerova glavočića (Ponticola kessleri). Usporedba sadržaja probavnog trakta s plijenom
dostupnim u okolini ukazuje da riječni glavočić i glavočić okrugljak preferiraju Trichoptera,
Megaloptera i Coleoptera, a keslerov glavočić Trichoptera, Gammarus sp. i Pisces.
Analize ukazuju na potencijalno pozitivan utjecaj prisustva ponto-kaspijskih glavoča na
neke populacije riba: glavočića okrugljaka i keslerova glavočića na zlatnog vijuna
(Sabanejewia balcanica), riječnog glavočića na šarana (Cyprinus carpio), karasa
(Carassius carassius), manjića (Lota lota) i velikog vijuna (Cobitis elongata). Međutim,
postoje i naznake da keslerov glavočić negativno utječe na klena (Squalius cephalus), a
glavočić okrugljak na malog vretenca (Zingel streber). Pozitivan alometrijski rast utvrđen
je za sve tri analizirane vrste ponto-kaspijskih glavoča upućujući na vremenski duže
prisutne populacije. Kondicijski faktor najveći je za glavočića okrugljaka, a najmanji za
riječnog glavočića. Za riječnog glavočića je utvrđena dob I, II i III, a za glavočića
okrugljaka i keslerova glavočića I, II, III i IV, s tim da najveću brzinu rasta ima riječni
glavočić, a najmanju glavočić okrugljak. Za svaku od analiziranih vrsta ponto-kaspijskih
glavoča utvrđen je jedan crnomorski haplotip. Malen broj haplotipova upućuje na relativno
malobrojne populacije ponto-kaspijskih glavoča što potencijalno smanjuje visinu njihova
invazivnog potencijala u savskom slijevu.
Invasive Ponto-Caspian gobies have recently caused dramatic changes in fish
assemblage structures throughout the Danube basin. While their presence in the Croatian
part of the basin has been noted and distribution studied, their dietary habits, impact on
native fish communities, condition, age and growth, presence of haplotypes and origin,
until now, have been unknown. In 2011, 17 locations in the Sava River Basin were
sampled for fish and 15 for benthic invertebrates. Fish population monitoring data,
available for nine seasons (2003-2006 and 2010-2014) and 12 locations, were used to
analyse the impacts of Ponto-Caspian gobies on benthic fish abundance. Gut content
analysis indicates that the monkey goby (Neogobius fluviatilis) diet is very diverse, but
dominated by Trichoptera, Chironomidae, Bivalvia and Odonata. The diet overlaps
considerably with the round goby (Neogobius melanostomus) diet, although Gastropoda
are dominant in the latter's diet. Small fish and Gammarus sp. dominate the bighead goby
(Ponticola kessleri) diet. Comparison of gut content with the prey available in the
environment indicates that monkey and round gobies exhibit preference for Trichoptera,
Megaloptera and Coleoptera, and bighead goby for Trichoptera, Gammarus sp. and
Pisces. Ponto-Caspian gobies in the Sava River are spreading upstream, towards the
reaches with lower fish diversity. Analyses indicate potentially positive impacts of PontoCaspian
gobies presence on some fish populations: round and bighead goby on Balkan
golden loach (Sabanejewia balcanica) and monkey goby on common carp (Cyprinus
carpio), crucian carp (Carassius carassius), burbot (Lota lota) and Balkan loach (Cobitis
elongata). However, there are also indications that bighead and round goby could
adversely impact the native chub (Squalius cephalus) and zingel (Zingel streber)
populations, respectively. Positive allometric growth has been determined for all three
analyzed Ponto-Caspian goby species, suggesting that they have been present for a
longer period of time. Condition factor, as a function of available energy resources, is the
largest for the round goby and the lowest for the monkey goby. Age I, II, III have been
determined for the monkey goby and age I, II, III, IV for the round and bighead goby, with
the highest growth rate determined for the monkey goby and the lowest for the round
goby. For each of the analyzed Ponto-Caspian goby species only one haplotype,
originated from native Black Sea populations, has been found. Determined monkey goby
haplotype has also been found in Ukraine and Slovakia and determined round goby
haplotype in Ukraine, Bulgaria, Slovakia, Serbia, Poland and Belgium. Determined
bighead goby haplotype has also been found only in Ukraine. A small number of
haplotypes indicates a relatively small number of Ponto-Caspian goby populations and
potentially reduces their invasive potential in the Sava River Basin. Although the PontoCaspian
goby caused significant disruptions in some areas of the Danube basin, density
of its population and impacts are relatively limited in the Sava River and its tributaries. As
Ponto-Caspian gobies are still in the expansionary period of invasion and the ecosystem
still adapting to new circumstances, continued monitoring of fish population dynamics in
the Sava basin is needed to determine the outcome and impacts of this invasion.
Bioraznolikost medonosnih biljnih vrsta iz različitih klimatsko-zemljopisnih područja
Hrvatske pruža veliki potencijal za proizvodnju specifičnih vrsta meda. Međutim, peludni
spektar, kao i kemijske ...značajke većine hrvatskih vrsta meda nedovoljno su poznati. U
jednu od vrsta meda, koja nije sustavno istraživana, ubraja se i med od metvice (Mentha
spp.). Stoga je cilj istraživanja bio utvrditi botaničko podrijetlo i profil isparljivih spojeva iz
sadržaja mednog mjehura u odnosu na med od metvice te skupljačku aktivnost pčelinje
zajednice na paši metvice. Istraživanje je bilo provedeno na pokusnoj lokaciji Mahovo
(područje Parka prirode Lonjsko polje) na pet pokusnih pčelinjih zajednica sive pčele (Apis
mellifera carnica Pollmann, 1879), gdje je praćena skupljačka aktivnost pčelinje zajednice
i posjećenosti pčela na paši metvice. Analiza sadržaja mednog mjehura i peludnog tereta
provedena je prema metodi Soehngen i Jay (1974). Na prikupljenim je uzorcima meda,
zatim, sadržaju mednog mjehura i peludnom teretu provedena kvalitativna
melisopalinološka analiza. Od fizikalno-kemijskih analiza bilo je provedeno utvrđivanje
udjela vode, električne provodnosti i pH vrijednosti. Analiza isparljivih spojeva provedena
je pomoću mikroekstrakcije vršnih para na krutoj fazi (HS-SPME) i ultrazvučne ekstrakcije
organskim otapalima (USE) na uzorcima meda i sadržaju mednih mjehura. Od
analiziranih skupljačica najveći je udio bio onih koje su skupljale nektar (1 774), zatim one
koje su skupljale pelud (1 190), a najmanje onih kod kojih je utvrđen puni medni mjehur i
peludni teret. U ranim popodnevnim satima (14:00) je utvrđen statistički značajno veći broj
skupljačica s punim mednim mjehurom, kao i s peludnim teretom u usporedbi sa
skupljačicama prikupljenim u 9:00 i 18:00. Prosječna se masa sadržaja mednog mjehura
kretala od 9,58 do 12,22 mg s rasponom od 0,20 do 50,60 mg. U uzorcima pčela
skupljenih u 9:00 sati bila je utvrđena statistički značajno niža prosječna masa sadržaja
mednog mjehura (9,02 mg) u odnosu na uzorke prikupljene u 18:00 (11,06 mg) i one
prikupljene u 14:00 (12,04 mg). Prosječna se masa peludnog tereta kretale od 4,77 mg do
9,60 mg, a raspon se kretao od 0,10 mg do 31,70 mg. U uzorcima pčela skupljenih u 9:00
sati utvrđena je statistički značajno niža masa peludnog tereta (7,73 mg) u odnosu na
uzorke prikupljene u 14:00 (8,63 mg), dok između skupljačica prikupljenih u 9:00 i 18:00 te
14:00 i 18:00 nije bila utvrđena statistički značajna razlika. Obzirom na posjećenost pčela
paši metvice utvrđeno je da je statistički značajno manji broj pčela bio utvrđen u 18:00 sati
(20,08) u odnosu na broj pčela u 10:00 (30,22) i 13:00 sati (36,50). Prema utvrđenom
peludnom spektru u analiziranim uzorcima meda, uz mirisnu metvicu (M. pulegium), kao
prateće biljne vrste bile su utvrđene zlatošipka (S. gigantea), amorfa (A. fruticosa), pitomi
kesten (C. sativa) i smiljkita (L corniculatus). Iz analiziranih uzoraka skupljačica utvrđeno
je da je u njihovim peludnim teretima utvrđen udio od 37,82% metvice, od kojih je veći
udio bio podrijetlom od mirisne metvice (20,42%) u odnosu na samo 1,93% peludi od
vodene metvice (M. aquatica). U uzorcima meda, prosječni je udio vode iznosio 17,3 % s
rasponom od 14,5 do 18,8%, zatim je električna provodnost iznosila 0,62 mS/cm s
rasponom od 0,37 do 0,75 mS/cm te se je pH vrijednost kretala u rasponu od 3,52 do 4,15
s prosjekom od 3,80. Na osnovu analize isparljivih spojeva u uzorcima meda su po
intenzitetu izdvojeni metil-siringat i vomifoliol, dok je u ekstraktu mednih mjehura, uz
navedene spojeve, utvrđen još i 3,7-Dimetilokta-1,5-dien-3,7-diol (terpendiol I). Također,
analizom vršnih para, kao najzastupljeniji spojevi, utvrđeni su hotrienol, 2-metoksi-4metilfenol,
cis- i trans-linalol oksidi, linalol i nerol oksid.
Nectariferous plants biodiversity from different climatic and geographical areas of Croatia
(Pannonian, Mountain and Adriatic) offers a great potential for the production of specific
types of honey. The diversity that we have in climazonal and biocenological schedule
represents a unique national treasure that is in Europe rarely found. However, due to nonsystematic
research, pollen spectrum and chemical properties of most Croatian honeys
are poorly understood. One of the honey types which is not systematically researched is
mint (Mentha spp.). According to available literature on European unifloral honeys, mint
honey belongs to rare types. Therefore the aim of this study was to characterize the mint
honey through determination of botanical origin (pollen spectrum) and content of the
honey sac and certain physical and chemical parameters (water content, electrical
conductivity and pH value). The second goal was to determine the profile of volatile
compounds in the honey sac content, as well as the end product, honey. At the same
time, one of the study goals was to investigate the behaviour of bees on mint nectar flow
through the foraging activity of bee colonies.
The research was conducted at the experimental site Mahovo, which is located in the
Lonjsko Polje Nature Park. Five experimental colonies of Carniolan (Apis mellifera carnica
Pollmann, 1879) bees in standard Langstroth-Root (LR) colonies were located at the
selected location. Gathering activity of honey bee colonies was conducted by sampling
from each colony three times a day (9:00, 14:00 and 18:00) for six days. Monitoring of the
foraging on the mint field was conducted on the five separate plots of 1 m2 by counting
bees for 1 min on the either side of the plot three times a day (10:00, 13:00, and 18:00) for
30 minutes during six days. Analysis of the honey-sac content and pollen loads was
carried out according to the method of Soehngen and Jay (1974). Qualitative
melisopalinological analysis of collected samples of honey, honey-sac content and the
pollen loads was conducted according to the methodology of von der Ohe et al. (2004).
From the physicochemical analyses, water content, electrical conductivity and pH were
performed. Analysis of volatile compounds was performed using solvent-free headspace
solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) in the
honey samples and the honey sac content.
From the totally analysed 8 721 workers, 2 992 have brought nectar, pollen, or both, while
5 471 returned to the hive without load. From analysed foragers that delivered load, the
main portion was of those who have gathered nectar (1 774), then those who have
gathered pollen (1 190), but the least those with honey and pollen load, which implies that
most foragers are specialized in collecting either nectar or pollen. Statistically higher
number of foragers with nectar or pollen load were determined in the early afternoon
(14:00) compared with foragers collected in 9:00 and 18:00.
The average weight of honey-sac content ranged from 9.58 to 12.22 mg with a range of
0.20 to 50.60 mg. Significantly lower average weight of honey-sac content (9.02 mg) was
determined in collected samples of bees at 9:00 o’clock compared to samples collected at
18:00 (11.06 mg) and 14:00, when average weight of 12.04 mg was determined. In the
largest group of foragers weight load was ≤ 10 mg, followed with group with load from 11
to 20 mg, and at the least number of bees collected ≥ 31 mg load.
Average weight of pollen load was from 4.77 to 9.60 mg, with range of 0.10 to 31.70 mg.
In the group of foragers collected at 9:00 o’clock statistically lower pollen load weight (7.73
mg) was determined in comparison to samples collected at 14:00 (8.63 mg). Contrary,
between groups collected at 9:00 and 18:00 as well as at 14:00 and 18:00 o’clock
difference was not significant.
Regarding attendance of bees to mint flowers, statistically lowest number of bees was
determined at 18:00 o’clock (20.08) in comparison to count at 10:00 (30.22) and 13:00
knowledge of the behaviour of bees foraging on mint. In addition to the scientific value of
the results, this study provides a contribution in practical terms, because they indicate
preliminary actions to be undertaken for the timely preparation of colonies for the main
pasture. At the same time, the original data on the profile of mint honey volatile
compounds can be used as potential biomarkers to determine its botanical origin.
Keywords: honeybee colony foraging activity, honey sac, pollen load, mint (Mentha spp.)
honey, pollen spectrum, volatile compounds
(36.50) o’clock.
According to pollen spectrum, accompanying plants to Mentha pulegium were Solidago
gigantea, Amorfa fruticosa, Castanea sativa and Lotus corniculatus.
From pollen loads of collected foragers it was determined that 37.82% samples contain
mint pollen, from which most part (20.42%) is from pennyroyal (M. pulegium) in
comparison to 1.93% of water mint (M. aquatica). Apart from mint pollen, additional 13
plant species were determined in the pollen loads, and the most frequent were Daucus
carota, Salvia spp, Ranunculus spp., Inula britanica, Plantago lanceolata, Solidago
gigantea, Amorfa fruticosa and Centaurea spp.
The average water content was 17.3% with a range from 14.5 to 18.8%. Electrical
conductivity was 0.62 mS/cm and the range from 0.37 to 0.75 mS/cm. pH value was in
range from 3.52 to 4.15 with the average of 3.80.
Based on the volatile compounds analysis of the honey-sac content, the most intensive
were 3 compounds: 3.7-dimethylocta-1.5-dien-3.7-diol (terpendiol I), followed by methyl
syringate and vomifoliol. In the extract of analysed honey samples were also 3.7dimethylocta-1.5-dien-3.7-diol
(terpendiol I). Also, by the analysis of major honey
headspace compounds hotrienol, cis- and trans-linalool oxides, linalool and neroloxide
were determined.
Valuable scientific contribution of the dissertation results from the first time connection of
the honey-sac content and the end product of honey, from monitoring of pollen spectrum
changes and the knowledge of volatile compounds fate. Analysis of mint honey was
performed
Doprinos pčela i okoliša košnice isparljivim spojevima meda određen je pripravom saharozne probe (pčele u zatvorenoj košnici hranjene su saharoznom otopinom). Identificirani spojevi su srodni sastavu ...epitelnih voskova i voskova u košnici, a manje feromonima pčela. Toplinski tretman probe na 80 oC i uskladištenje 365 dana omogućilo je praćenje nastanka artefakata koji se mogu pojaviti u medu. Rezultati istraživanja uzoraka meda (kadulja, lavanda, vrba i amorfa) su izrazito ovisni o primijenjenoj metodi ekstrakcije sa značajnim kvalitativnim i kvantitativnim razlikama između ekstrakata vršnih para (bez otapala, HS-SPME) i ultrazvučnih ekstrakata s organskim otapalima (USE). Vršne pare su sadržavale više isparljive spojeve manjih molekulskih masa. USE tehnika omogućuje ekstrakciju poluisparljivih i vodotopljivih spojeva, posebice benzojeve, vanilinske i feniloctene kiseline. Upotreba ultrazvučne vodene kupelji (metoda neizravne sonifikacije) sa smjesom otapala (pentan : dietil-eter 1 : 2 v/v) pokazala se najprikladnijom za ekstrakciju svih uzoraka meda. S druge strane, ekstrakcija nepolarnih spojeva s pentanom, a potom ekstrakcija s polarnijim dietil-eterom omogućila je detaljniju analizu. Upotrebljene tehnike su komplementarne, a upotreba samo jedne od navedenih tehnika ne daje potpuni uvid u sastav spojeva meda te bi se mogli donijeti pogrešni zaključci, osobito kod identifikacije markera botaničkog porijekla meda.
Contribution of the honeybees and hives environment to volatile honey compounds is determined by preparing saccharose probe (the bees in closed hive were feeded with saccharose solution). Identified compounds were similar to cuticular and comb waxes and less to bee pheromones. Thermal treatment of the probe at 80 oC and 365 days storage enabled investigation of artefacts formation that may occur in honey. The results of honey (sage, lavender, willow and amorpha) investigation are highly dependent on the applied extraction method with significant qualitative and quantitative differences among headspace extracts (HS-SPME) and ultrasonic solvent extracts (USE). The headspace contained high volatile compounds with lower molecular masses. USE enabled the extraction of semi-volatile and water-soluble compounds, particularly benzoic acid, vanillic acid and phenyllactic acid. The application of ultrasonic water bath (indirect sonification) with the solvent pentane : diethyl ether 1 : 2 v/v was suitable for all the samples. On the other hand, the extraction of nonpolar compounds with pentane and thereafter extraction with more polar diethyl ether enabled more detailed analysis. Applied techniques are complementary and application of only one of them does not provide complete insight in the honey composition and wrong conclusions can be drawn, particularly regarding identification of the honey botanical origin markers.
Svrha rada bila je karakterizirati odabrane vrste meda (kesten, kadulja, bagrem i medljikovac) s obzirom na antioksidativni kapacitet te ispitati mogućnost korištenja antioksidativnog kapaciteta u ...identifikaciji botaničkog podrijetla meda. U cilju razumijevanja antioksidativne sposobnosti meda ispitana je povezanost antioksidativnog kapaciteta s fizikalno-kemijskim parametrima kakvoće meda. Osim toga, ispitan je utjecaj procesiranja i skladištenja na antioksidativni kapacitet i s njim povezane parametre kakvoće.
Rezultati su pokazali da je antioksidativni kapacitet meda prikladan za identifikaciju botaničkog podrijetla te da ukupnom antioksidativnom kapacitetu najviše doprinose fenolne komponente. Utvrđen je sinergistički utjecaj procesiranja i skladištenja na smanjenje kakvoće meda koji je više izražen kod svjetlijih vrsta meda (bagrem i kadulja). Antioksidativni kapacitet nektarnih vrsta meda tijekom procesiranja i skladištenja se povećao, što s nutritivnog stajališta predstavlja povoljnu promjenu, no istovremeno smanjenje drugih parametara kakvoće umanjuje pozitivan utjecaj procesiranja i skladištenja. Promjena antioksidativnog kapaciteta medljikovca bila je najmanja od promatranih vrsta.
The aim of this work was to characterise selected honey types (chestnut, sage, black locust and honeydew) with aspect of antioxidant capacity and to evaluate possible application of antioxidant capacity as a criterion for botanical origin differentiation. Towards better understanding honey antioxidant capacity, correlation between antioxidant capacity and physicochemical parameters was studied as well as impact of processing and storage on honey antioxidant capacity and correlated parameters.
Results showed that antioxidant capacity is suitable parameter for botanical origin differentiation and that phenolic compounds contribute significantly to the honey antioxidant capacity. Combined effect of processing and storage on honey quality degradation was observed which was more pronounced in lighter honey types (black locust and sage). During processing and storage honey antioxidant capacity increased, that is form nutritional point a positive effect, but at the same time quality degradation was determined with respect to other parameters, which impairs positive effect of processing and storage. Antioxidant capacity change of honeydew honeys was lowest from selected honey types.
