The physiological response of soybean cultivars to abiotic stress

Otpornost na stres je znaĉajan preduvjet za uspješnu proizvodnju soje u sve zahtjevnijim agroekološkim uvjetima, a meĊu razliĉitim vrstama abiotskog stresa istiĉu se sušni, temperaturni i solni stres. Cilj ove disertacije je bio istražiti neke od fizioloških mehanizama reakcije soje na navedene vrste stresa. Istraživanja su provedena sa šest kultivara soje u fazi klijanje-nicanje te dva kultivara u fazi cvatnje. U prvom pokusu je sjeme soje naklijavano u papirnim ruĉnicima natopljenim vodom ili otopinom koja je imala odreĊeni osmotski potencijal. Primijenjene su po dvije razine sušnog (otopina PEG 5% i 10%), solnog (otopina NaCl 50 i 100 mM) i temperaturnog stresa (10°C i 30°C, voda) te kontrola (20°C, voda) tijekom 7 dana. Osim % klijavosti, mase klijanca i hipokotila, analiziran je sadržaj vodikovog peroksida, prolina, fenola, intenzitet lipidne peroksidacije te ukupna i specifiĉna aktivnost enzima askorbat-peroksidaze, katalaze, gvajakol-peroksidaze i glutation-reduktaze u hipokotilu. Najjaĉi stresni uĉinak imali su viša razina sušnog stresa (PEG 10%) te niska temperatura (10°C). Visoka temperatura je djelovala povoljno na razvoj klijanaca, a blagi sušni stres (PEG 5%) je imao „priming“ efekt i povećao klijavost. Odabrana dva kultivara su u drugom eksperimentu uzgojena u posudama s tlom na otvorenom do faze cvatnje (R2), nakon ĉega su izložene razliĉitoj temperaturi (30°C, 10°C i 20°C kao kontrola) tijekom tri dana u klima komori. U najrazvijenijoj troliski su analizirani sadržaji fotosintetskih pigmenata i pokazatelji uĉinkovitosti fotosinteze, te svi prethodno navedeni pokazatelji reakcije biljke na stres. Vrlo znaĉajan utjecaj tretmana u obje razvojne faze soje, potvrĊuje da su primijenjeni tretmani izazvali oksidacijski stres i obrambene reakcije soje na molekularnoj razini. U cjelini, ukupne aktivnosti ispitivanih enzima su bile veće u klijanju na 10°C, a u cvatnji na 30°C, što sugerira razliĉitost stresnog efekta ambijentalne temperature ovisno o fazi razvoja soje.Stress resistance is an important pre-condition of successful soybean production in demanding agroecological conditions. Among different types of abiotic stress, drought, temperature and salt stress are the most prominent. This PhD dissertation aimed to investigate some of the physiological mechanisms of soybean response to the above mentioned stresses. The research was performed with 6 cultivars in the germination - emergence stage and two cultivars in the flowering stage. In the first experiment, soybean seed was germinated in paper towels soaked with water or the solution with given osmotic pressure. Two levels of drought (5% and 10% PEG solutions), salt (50 and 100 mM NaCl solutions) and temperature stress (10°C and 30°C), as well as control treatment (20°C, water) were applied through a 7 days germination period. Beside the evaluation of the seed germinability (%) at the end of the treatment, seedling and hypocotyl masses, the content of hydrogen peroxide, proline, phenols, the lipid peroxidation rate were determined, as well as total and specific activity of ascorbate peroxidase, catalase, guaiacol peroxidase and glutathione reductase in hypocotyl tissue were analysed. The highest stress effect in the germination stage had a higher level of drought stress (10% PEG) and low temperature (10°C). High temperature (30°C) was favourable for seedling development and mild drought stress (5% PEG) have had a “priming” effect and increased germination rate. In the second experiment, selected two cultivars were grown in the pots, filled with soil and kept in the open until the flowering stage (R2), and afterwards exposed to different temperature conditions (30°C, 10°C and 20°C as control treatment) during 3 days in a climate chamber. The contents of photosynthetic pigments, photosynthesis efficiency parameters and all the aforementioned physiological indicators of plant response to stress were determined in the most developed trifoliate leaf. Highly significant treatment influence on the analysed parameters in the both growth stages, confirms that the applied treatments invoked the oxidative stress and defence reactions in soybean at molecular level. In general, the total activities of tested enzymes were higher at 10°C in germination stage, and at 30°C in flowering stage, which suggests a diversity of stress effects of ambient temperature depending on the growth stage in soybean

UTJECAJ SUMPOROVODIKA NA DEETIOLACIJU PŠENIČNE TRAVE (Triticum æstivum L.)

Hydrogen sulfide (H2S) is involved in many physiological processes and responses to the abiotic types of stress. The aim of the study was to determine the effect of sodium hydrogen sulfide (NaHS) and the time of application on the physiological properties of etiolated wheatgrass plants. Two genotypes of wheatgrass were grown under controlled conditions for five days without light and then with a 12-hour photoperiod, watered for three consecutive days with 100, 200, and 500 mM NaHS solutions. The plants were watered in three variants, 7-9, 10-12, and 13-15 days after sowing, respectively. The highest content of phenols, flavonoids, and hydrogen peroxide was found in wheatgrass plants watered with 100 mM of NaHS solution. The highest proline content and lipid peroxidation levels were found in the plants at 500 mM of NaHS solution. Also, the significant influence of the watering period on the examined physiological parameters was determined. The results show that H2S significantly affects the de-etiolation process and concentration of physiologically active compounds in wheatgrass plants.Sumporovodik (H2S) je uključen u velik broj fizioloških procesa i reakcija na abiotske tipove stresa. Cilj istraživanja bio je utvrditi utjecaj natrijevog hidrogensulfida (NaHS) i vremena primjene na fiziološka svojstva etioliranih biljaka pšenične trave. Dva su genotipa pšenične trave uzgajana u kontroliranim uvjetima pet dana bez svjetlosti te nakon toga uz dvanaestosatni fotoperiod, zalijevane tri dana zaredom otopinama NaHS koncentracija 100, 200 i 500 mM. Varijante tretmana zalijevanja uz osvjetljenje bile su sedmoga do devetoga, desetoga do dvanaestoga te trinaestoga do petnaestoga dana nakon sjetve. Najveći sadržaj fenola, flavonoida te vodikova peroksida utvrđen je kod biljaka pšenične trave zalijevanih otopinom 100 mM NaHS. Najviši sadržaj prolina i lipidna peroksidacija utvrđeni su kod biljaka pri 500 mM NaHS. Također, utvrđen je i značajan utjecaj perioda zalijevanja na ispitivane fiziološke parametre. Rezultati pokazuju da H2S značajno utječe na proces deetiolacije kod biljaka pšenične trave i sadržaj fiziološki aktivnih komponenata u pšeničnoj travi

ELECTRICAL CONDUCTIVITY OF SOYBEAN SEED AT DIFFERENT IMBIBITION TEMPERATURES

Krupna i srednja frakcija sjemena tri kultivara soje (Zora, Lucija i Korana) su testirani uobičajenim metodama analize kvalitete sjemena (masa 1000 zrna, sadržaj vlage, energija klijanja - EK, standardni test klijavosti - SK) te “cold” testom (CT). Zatim je proveden test konduktiviteta sjemena (EC) “bulk” metodom na tri konstantne temperature imbibicije (10, 20 i 30oC, 24 h), uz određivanje % usvojene vode sjemenom tijekom imbibicije. Ispitivani kultivari soje se nisu značajno razlikovali po EK, SK i CT. Srednja frakcija je imala vrlo značajno veću EK i SK u odnosu na krupnu frakciju. Prema postojećoj kategorizaciji EC sjemena za krupnozrne leguminoze i CT, obje frakcije sjemena pokazuju visok vigor. EC sjemena soje je varirao od 18,0 μScm-1g-1 do 29,5 μScm-1g-1, s vrlo značajno većim vrijednostima na 30oC. Najveći EC, uz najmanji CT, utvrđen je kod sjemena kultivara Korana. Frakcija sjemena nije značajno utjecala na EC. Značajna negativna korelacija između EC i CT kod sjemena srednje frakcije indicira da je EC na 20oC pogodan za brzu analizu vigora sjemena soje, ukoliko u uzorku prevladava srednja frakcija. Količina usvojene vode sjemenom nakon imbibicije u EC je iznosila od 114,5 do 130,4% u odnosu na početnu masu sjemena. Uz značajan utjecaj kultivara, frakcije i njihove interakcije, najveći intenzitet usvajanja vode utvrđen je pri najvišoj temperaturi imbibicije i kod srednje frakcije sjemena. Dobiveni rezultati upućuju na daljnja istraživanja procesa imbibicije sjemena u laboratorijskim i poljskim uvjetima, sa svrhom boljeg poznavanja genetskog potencijala soje za otpornost na imbibicijsko oštećenje i uspješno nicanje u nepovoljnim uvjetima.Large and medium-sized seed of three soybean cultivars (Zora, Lucija and Korana) were evaluated using commonly applied seed quality analytical methods (1000 grain mass, moisture content, rate of germination - EK, standard germination test - SK) as well as cold test (CT). Afterwards, seed electrical conductivity test (EC) - „bulk“ method - was performed at three constant temperatures (10, 20 and 30oC, 24 h), with subsequent determination of seed water uptake during imbibition, as the % of the initial seed sample weight. The tested soybean cultivars did not show significant differences regarding EK, SK and CT. Medium-sized seed showed very significantly higher EK and SK in comparison with large seed. According to the current EC evaluation scale for large-seeded legumes and CT values, both seed categories expressed high vigour. EC test varied between 18.0 – 29.5 μScm-1g-1, and significantly higher values were seen at 30oC during imbibition. The highest EC and the lowest CT values were obtained with the seed of cultivar Korana. Seed size had no effect on EC test value. The established significant negative correlation between EC and CT in medium-sized seed implies that EC test performed at 20oC could be suitable tool for fast soybean seed vigour analyses, if medium-sized seed dominated in seed sample. Seed water content after imbibition in EC test varied between 114.5 - 130.4% regarding seed initial weight. Considering significant influence of cultivar, seed size category and their interaction, the highest water uptake rate was observed at the highest imbibition temperature applied, as well as in medium-sized seed. These results suggest further investigation of seed imbibitional processes in both laboratory and field conditions, with aim of better comprehension of soybean genetic potential in imbibitional damage resistance and successful emergence in adverse conditions

ANTIOKSIDATIVNI ODGOVOR U LISTU JAGODA (Fragaria x ananassa Duch) NA TRETMANE BIOSTIMULATORIMA UZ REDUCIRANU GNOJIDBU DUŠIKOM I KALIJEM

Strawberry cultivar Elsanta was grown in peat based substrate in a green house. Full dose and 50% reduced nitrogen and potassium fertilization were applied during fruit bearing period in spring, along with biostimulators Viva®, Megafol® and their combination. The specific activities of guaiacol peroxidase (GPXs; EC 1.11.1.7), catalase (CATs; EC 1.11.1.6), ascorbate peroxidase (APXs; EC 1.11.1.11) and glutathione reductase (GRs; EC 1.6.4.2) in strawberry leaf were stimulated by biostimulators and reduced fertilization. The strongest link seen here was between the enzymes of ascorbate-glutathione cycle (APXs and GRs), which were positively related to trifoliate leaf fresh mass (TLFM). The highest TLFM was observed in Megafol® treated plants.Sorta jagoda Elsanta uzgajana je u tresetnom supstratu u plasteniku. Puna doza i 50% smanjena doza dušika i kalija primjenjene su tijekom proljetnoga plodonošenja, uz primjenu biostimulatora Viva®, Megafol® i njihove kombinacije. Specifične aktivnosti gvajakol peroksidaze (GPXs; EC 1.11.1.7), katalaze (CATs; EC 1.11.1.6), askorbat peroksidaze (APXs; EC 1.11.1.11) i glutation reduktaze (GRs; EC 1.6.4.2) u listu jagode bile su značajno više poslije tretiranja biostimulatorima i reduciranom gnojidbom. Najjača povezanost uočena u ovom istraživanju, bila je između enzima askorbat-glutation ciklusa (APXs i GRs), koji su bili u pozitivnoj korelaciji s masom svježega lista (TLFM). Najveća masa svježega lista (TLFM) uočena je na biljkama tretiranim Megafolom®

KLIJAVOST I VIGOR SJEMENA KRES SALATE NAKON TRETMANA BILJNIM EKSTRAKTIMA

The usage of biologically active and environmentally friendly compounds has increasingly important role in the primary food production. This study was conducted in order to examine the impact of five commercial plant extracts on the seed vigour of garden cress (Lepidium sativum L.). The applied plant extracts significantly increased the germination. The highest fresh weight of seedlings, and also the lowest dry matter accumulation were observed in the treatment KE-plantasalva® without the sea salt addition. Equisetum extract inhibited the root elongation and resulted in the highest percentage of dry matter accumulated in seedlings, but also the lowest fresh weight.Korištenje biološki aktivnih i okolišno prihvatljivih pripravaka ima vrlo značajnu ulogu u primarnoj proizvodnji hrane. Ovo istraživanje provedeno je s ciljem ispitivanja utjecaja pet komercijalnih biljnih ekstrakata na vigor sjemena kres salate (Lepidium sativum L.). Korišteni biljni ekstrakti značajno su povećali klijavost. Najveća svježa masa klijanaca, a ujedno i najniža akumulacija suhe tvari, utvrđena je pri tretmanu KE-plantasalva® bez dodatka morske soli. Ekstrakt preslice inhibirao je izduživanje korijena i rezultirao najvišim postotkom akumulacije suhe tvari u klijancima, ali, također, i najnižom svježom masom

ANTIOKSIDATIVNI ODGOVOR U LISTU JAGODA (Fragaria x ananassa Duch) NA TRETMANE BIOSTIMULATORIMA UZ REDUCIRANU GNOJIDBU DUŠIKOM I KALIJEM

Strawberry cultivar Elsanta was grown in peat based substrate in a green house. Full dose and 50% reduced nitrogen and potassium fertilization were applied during fruit bearing period in spring, along with biostimulators Viva®, Megafol® and their combination. The specific activities of guaiacol peroxidase (GPXs; EC 1.11.1.7), catalase (CATs; EC 1.11.1.6), ascorbate peroxidase (APXs; EC 1.11.1.11) and glutathione reductase (GRs; EC 1.6.4.2) in strawberry leaf were stimulated by biostimulators and reduced fertilization. The strongest link seen here was between the enzymes of ascorbate-glutathione cycle (APXs and GRs), which were positively related to trifoliate leaf fresh mass (TLFM). The highest TLFM was observed in Megafol® treated plants.Sorta jagoda Elsanta uzgajana je u tresetnom supstratu u plasteniku. Puna doza i 50% smanjena doza dušika i kalija primjenjene su tijekom proljetnoga plodonošenja, uz primjenu biostimulatora Viva®, Megafol® i njihove kombinacije. Specifične aktivnosti gvajakol peroksidaze (GPXs; EC 1.11.1.7), katalaze (CATs; EC 1.11.1.6), askorbat peroksidaze (APXs; EC 1.11.1.11) i glutation reduktaze (GRs; EC 1.6.4.2) u listu jagode bile su značajno više poslije tretiranja biostimulatorima i reduciranom gnojidbom. Najjača povezanost uočena u ovom istraživanju, bila je između enzima askorbat-glutation ciklusa (APXs i GRs), koji su bili u pozitivnoj korelaciji s masom svježega lista (TLFM). Najveća masa svježega lista (TLFM) uočena je na biljkama tretiranim Megafolom®

A Switch Therapy Protocol with Intravenous Azithromycin and Ciprofloxacin Combination for Severe, Relapsing Chronic Bacterial Prostatitis: a Prospective Non-comparative Pilot Study

Chronic bacterial prostatitis (CBP) is characterized by intense clinical symptoms, frequent relapse episodes and poor quality of life. Aggressive antibacterial therapy is warranted to eradicate causative pathogens and to achieve a permanent cure. We administered a “switch-therapy” protocol to 30 patients showing severe CBP symptoms and two or more relapse episodes in the previous 12 months. Patients received intravenous azithromycin (500 mg/day) and ciprofloxacin (800 mg/day) for three days, followed by oral ciprofloxacin (1 g/day) for 25 days. Twenty-seven (90%) patients showed pathogen eradication at test-of-cure (TOC) visit. Five cases of infection relapse were detected at follow-up. At the TOC visit, 25 patients (83%) showed mild/absent symptoms, measured with the NIH-chronic prostatitis symptom index. These results indicate the efficacy of a “switch-therapy” protocol, based on combined azithromycin and ciprofloxacin. Comparative studies on larger CBP patient populations are warranted to confirm these encouraging results

INDUKCIJA LATERALNIH IZBOJA TREŠNJE NA PODLOZI GISELA 6

Number of lateral branches and overall development of seedlings is a crucial parameter for achieving the required quality standards dedicated to modern intensive production systems. Branched seedlings have formed the structure of the canopy, which is defined and cultivation model for future plantations. In addition to the uniformity of the plantation better and earlier productivity is achieved. The research, in order to standardize the techniques for induction of lateral branching, was conducted in 2013 in the nursery (Koprivna, Eastern Croatia) on 3 cherry cultivars grafted on Gisela 6 rootstock. The treatments included the application of different combinations of Bioregulators 6-Benzyladenine and gibberellic acid 4 and 7 (BA+GA4+7) as well as cyclanilide on cultivars ´Carmen´, ´Grace Star´ and ´Black Star´. All applied treatments resulted in a significant increase in the number of new branches compared to the control. Cultivar Black Star induced the development of the highest number of branches. Treatment BA + GA4 + 7 increased the number of lateral shoots compared to the control in all the investigated cultivars. The most significant induction in the number of branches has been achieved with Cyclanilide treatment which improved more correct distribution and resulted in a more uniform length of induced shoots. Combination of the treatment cyclanilide and BA + GA4 + 7 has not resulted in synergistic increase in the number of branches in response to treatment with cyclanilide. The applied treatments also significantly influenced the length of the branches and the branching angle. Results of this study indicate the need for further testing of cyclanilide as a potential regulator of growth in nursery production.Broj lateralnih grana, odnosno ukupna razvijenost sadnica, danas predstavlja ključni parametar za postizanje potrebnih standarda kvalitete namijenjenim suvremenim intenzivnim sustavima uzgoja. Razgranate sadnice imaju formiranu strukturu krošnje, čime je definiran i uzgojni model budućega nasada. Pored uniformiranosti nasada, postiže se bolja i ranija produktivnost. Istraživanje u cilju standardiziranja tehnike indukcije lateralnoga grananja provedeno je 2013. godine u rasadniku voćnih sadnica (Koprivna, Istočna Hrvatska) na 3 sorte trešnje cijepljenih na podlozi Gisela 6. Tretmani su uključivali aplikaciju različitih kombinacija bioregulatora 6-benzyladenina i giberelina (BA + GA4+7) te ciklanilida na sortama Carmen, Grace Star i Black Star. Svi su primijenjeni tretmani rezultirali značajnim povećanjem broja novih grana u odnosu na kontrolu. Sorta Black Star inducirala je razvoj najvećega broja grana. Tretman BA + GA4+7 povećao je broj lateralnih izboja u odnosu na kontrolu kod svih ispitivanih sorti Najznačajnija indukcija broja grana postignuta je pri tretmanu s ciklanilidom, koji je poboljšao pravilniju distribuciju i rezultirao uniformnijom dužinom induciranih izbojaka. Kombinacija tretmana ciklanilid i BA + GA4+7 nije rezultirala sinergičnim povećanjem broja grana u odnosu na tretman s ciklanilidom. Primijenjeni su tretmani, također, značajno utjecali na dužinu grana i kut grananja. Rezultati ovog istraživanja ukazuju na potrebu daljnjih ispitivanja ciklanilida, kao potencijalnoga regulatora rasta u rasadničarskoj proizvodnji. Tretman BA + GA4+7 rezultirao je povećanjem broja lateralnih izboja u odnosu na kontrolu kod svih ispitivanih sorti

The physiological response of soybean cultivars to abiotic stress

Otpornost na stres je znaĉajan preduvjet za uspješnu proizvodnju soje u sve zahtjevnijim agroekološkim uvjetima, a meĊu razliĉitim vrstama abiotskog stresa istiĉu se sušni, temperaturni i solni stres. Cilj ove disertacije je bio istražiti neke od fizioloških mehanizama reakcije soje na navedene vrste stresa. Istraživanja su provedena sa šest kultivara soje u fazi klijanje-nicanje te dva kultivara u fazi cvatnje. U prvom pokusu je sjeme soje naklijavano u papirnim ruĉnicima natopljenim vodom ili otopinom koja je imala odreĊeni osmotski potencijal. Primijenjene su po dvije razine sušnog (otopina PEG 5% i 10%), solnog (otopina NaCl 50 i 100 mM) i temperaturnog stresa (10°C i 30°C, voda) te kontrola (20°C, voda) tijekom 7 dana. Osim % klijavosti, mase klijanca i hipokotila, analiziran je sadržaj vodikovog peroksida, prolina, fenola, intenzitet lipidne peroksidacije te ukupna i specifiĉna aktivnost enzima askorbat-peroksidaze, katalaze, gvajakol-peroksidaze i glutation-reduktaze u hipokotilu. Najjaĉi stresni uĉinak imali su viša razina sušnog stresa (PEG 10%) te niska temperatura (10°C). Visoka temperatura je djelovala povoljno na razvoj klijanaca, a blagi sušni stres (PEG 5%) je imao „priming“ efekt i povećao klijavost. Odabrana dva kultivara su u drugom eksperimentu uzgojena u posudama s tlom na otvorenom do faze cvatnje (R2), nakon ĉega su izložene razliĉitoj temperaturi (30°C, 10°C i 20°C kao kontrola) tijekom tri dana u klima komori. U najrazvijenijoj troliski su analizirani sadržaji fotosintetskih pigmenata i pokazatelji uĉinkovitosti fotosinteze, te svi prethodno navedeni pokazatelji reakcije biljke na stres. Vrlo znaĉajan utjecaj tretmana u obje razvojne faze soje, potvrĊuje da su primijenjeni tretmani izazvali oksidacijski stres i obrambene reakcije soje na molekularnoj razini. U cjelini, ukupne aktivnosti ispitivanih enzima su bile veće u klijanju na 10°C, a u cvatnji na 30°C, što sugerira razliĉitost stresnog efekta ambijentalne temperature ovisno o fazi razvoja soje.Stress resistance is an important pre-condition of successful soybean production in demanding agroecological conditions. Among different types of abiotic stress, drought, temperature and salt stress are the most prominent. This PhD dissertation aimed to investigate some of the physiological mechanisms of soybean response to the above mentioned stresses. The research was performed with 6 cultivars in the germination - emergence stage and two cultivars in the flowering stage. In the first experiment, soybean seed was germinated in paper towels soaked with water or the solution with given osmotic pressure. Two levels of drought (5% and 10% PEG solutions), salt (50 and 100 mM NaCl solutions) and temperature stress (10°C and 30°C), as well as control treatment (20°C, water) were applied through a 7 days germination period. Beside the evaluation of the seed germinability (%) at the end of the treatment, seedling and hypocotyl masses, the content of hydrogen peroxide, proline, phenols, the lipid peroxidation rate were determined, as well as total and specific activity of ascorbate peroxidase, catalase, guaiacol peroxidase and glutathione reductase in hypocotyl tissue were analysed. The highest stress effect in the germination stage had a higher level of drought stress (10% PEG) and low temperature (10°C). High temperature (30°C) was favourable for seedling development and mild drought stress (5% PEG) have had a “priming” effect and increased germination rate. In the second experiment, selected two cultivars were grown in the pots, filled with soil and kept in the open until the flowering stage (R2), and afterwards exposed to different temperature conditions (30°C, 10°C and 20°C as control treatment) during 3 days in a climate chamber. The contents of photosynthetic pigments, photosynthesis efficiency parameters and all the aforementioned physiological indicators of plant response to stress were determined in the most developed trifoliate leaf. Highly significant treatment influence on the analysed parameters in the both growth stages, confirms that the applied treatments invoked the oxidative stress and defence reactions in soybean at molecular level. In general, the total activities of tested enzymes were higher at 10°C in germination stage, and at 30°C in flowering stage, which suggests a diversity of stress effects of ambient temperature depending on the growth stage in soybean

Exploring reasons for switching mobile operators in Croatia

Telekomunikacijska industrija jedna je od najbrže rastućih i najprofitabilnijih industrija na svijetu. U uvjetima rastuće konkurencije i sve sličnijim ponudama primarni cilj mobilnih operatora je zadržati svoje postojeće korisnike i izgraditi bazu lojalnih korisnika. U sklopu ovog istraživanja dobio se odgovor na pitanje kako pružatelji telekomunikacijskih usluga mogu svoje korisnike učiniti zadovoljnima i zadržati ih. Po uzoru na istraživanje autora Malhotra i Kubowicz Malhotra (2013) te Lunn i Lyons (2018) za američko i irsko telekomunikacijsko tržište provedeno je predmetno istraživanje za hrvatsko tržište na uzorku od 116 ispitanika kojim su se željeli identificirati glavni razlozi promjene mobilnog operatora kao i razlozi zadovoljstva. Identificirani su glavni razlozi promjene mobilnog operatora odnosno faktori zadovoljstva te su stavljeni u kontekst s demografskim obilježjima ispitanika. Rezultati istraživanja ukazuju na to da su glavni uzroci promjene mobilnog operatora mjesečna naknada koju ispitanici plaćaju za tarife, sadržaj tarifa i nemogućnost ostvarivanja dodatnih popusta i pogodnosti ako su dugogodišnju korisnici. Faktori koji u tolikoj mjeri ne utječu na odluku o promjeni su inovativnost, imidž i ljubaznost zaposlenika.The telecommunications industry is one of the fastest growing and most profitable industries in the world. In the conditions of growing competition and increasingly similar offers, the primary goal of mobile operators is to retain their existing customers and build a base of loyal customers. This research seeks to answer the question of how telecommunications service providers can make their customers satisfied and retain them. Following the research of Malhotra and Kubowicz Malhotra (2013) and Lunn and Lyons (2018) conducted in the US and Irish telecommunications markets, a survey of the Croatian market was conducted on a sample of 116 respondents to identify the main reasons for changing the mobile operator and reasons for satisfaction. The main reasons for the change of mobile operators, ie satisfaction factors, were identified and placed in context with the demographic characteristics of the respondents. The results of the research indicate that the main reasons for the change of mobile operator are the monthly fee paid by respondents for tariffs, the content of tariffs, and the inability to receive additional discounts and benefits if they are long – term users. Factors that do not influence the decision to change to such an extent are the innovation, image and kindness of the employees