EFFECT OF POLYETHYLENE GLYCOL AND ASCORBIC ACID ON EARLY GROWTH OF RED CLOVER

Unos vode u sjeme u ranoj fazi klijanja i reakcija genotipova na manjak vode tijekom imbibicije od velike su važnosti za rast, razvoj i realizaciju visoko kvalitetnih prinosa crvene djeteline. Cilj rada je bio istražiti utjecaj vodnog stresa izazvan primjenom polietilen glikola na rani rast 9 različitih genotipova crvene djeteline (eksperimentalne populacije-TPEXP1, TPEXP2, TPEXP3, TPEXP4; domaći kultivari-Croatia, Nada i uvozni kultivari-Viola, Rajah, Diana) te procijeniti može li egzogena primjena askorbinske kiseline pozitivno utjecati na svladavanje negativnog učinka vodnog stresa. Utjecaj vodnog stresa izazvan polietilen glikolom utvrđen je kod sjemena svih ispitivanih genotipova koji su reagirali smanjenjem postotka klijavosti kao i dužine korjenčića. Pozitivan utjecaj egzogene primjene askorbinske kiseline na svladavanje negativnog učinka vodnog stresa bio je u prosjeku najviši kada je sjeme naklijavano na podlozi s 15% PEG 6000 prvih 48 sati, a potom na podlozi s 15% PEG 6000 i 0,56 mM askorbinske kiseline.Seed water uptake in the early stage of germination and reaction of different cultivars to water deficit during imbibition are of great importance for growth, development and realisation of highly qualitative yields of red clover. The aim of this study was to investigate the reaction of different red clover genotypes (experimental populations-TPEXP1, TPEXP2, TPEXP3, TPEXP4; domestic cultivars-Croatia, Nada and foreign cultivars-Viola, Rajah, Diana) on water stress induced by polyethylene glycol and to evaluate if the exogenously applied ascorbic acid can alleviate the negative effects of water stress. Effect of water stress induced by polyethylene glycol was observed in seeds of all genotypes which responded by reducing the percentage of germination and radicle length. Alleviation of the negative water stress effects through exogenously applied ascorbic acid was highest when seeds germinated on media with 15% PEG 6000 for the first 48 hours and after that on media with 15% PEG 6000 and 0.56 mM ascorbic acid