Efekti 6-benzu aminopurina i tetciklacisa na proces tuberizacije kod krompira (solarium tuberosum l. Cv. Désirée) u uslovima in vitro

Abstract

The hormonal control of tuberisation in potato is complex. It also depends on environmental conditions, especially light conditions. The present work deals with effects of various combinations of 6-benzylaminopurine (BAP) and the growth retardant, tetcyclacis (Tc), on in vitro tuberisation in potato with the emphasis on process of stolon initiation. Potato shoots cv. Désirée were grown in in vitro cultures, on the MS media with various combinations of 0.01 - 10 mM BAP and 3 mM Tc, under long day conditions (16 h light/8 h darkness) or in continuous darkness. The effects on stolon and tuber initiation as well as on tuber diameter were determined in 30-day-old shoots. The obtained results showed that a decrease in endogenous gibbereliin level is a prerequisite for tuberisation under tuber non-inducing conditions in vitro. The increase in the cytokinin/gibberellin relationship stimulated stolon initiation under tuber non-inducing conditions in vitro, but only up to the level achieved by individually applied 3 mM Tc. The BAP interaction with Tc was not observed in the process of tuber initiation. In the process of the tuber enlargement, interaction between BAP and Tc, i.e. the increase in tuber diameter in comparison to values obtained by the individual application of these plant growth regulators, was observed only under tuber non-inducing conditions, when combination of 10 mM BAP and 3 mM Tc was applied.

Tuberizacija kod krompira predstavlja jedan od najpogodnijih model-sistema za proučavanje interakcija fitohormona i korelacija rastenja i razvića kod biljaka. Hormonalna regulacija ovog procesa, kome se posvećuje velika pažnja zbog značaja krompira za poljoprivredu, je složena i zavisi od uslova spoljašnje sredine, a pre svega uslova osvetljenja. U ovom radu su proučavani efekti kombinovanja 6-benzil aminopurina (BAP) i retardanta rastenja, tetciklacisa (Tc), na proces tuberizacije kod krompira u uslovima in vitro, sa naročitim osvrtom na proces inicijacije stolona. Ustanovljeno je da sniženje nivoa endogenih giberelina predstavlja neophodan uslov za tuberizaciju in vitro u neinduktivnim uslovima (dug dan). Povišavanje odnosa citokinini/giberelini stimuliše inicijaciju stolona u neinduktivnim uslovima za tuberizaciju in vitro, ali samo do nivoa koji se postiže pojedinačnom primenom 3 mM Tc. Nije uočena interakcija BAP i Tc u procesu inicijacije krtola. U procesu uvećavanja krtola uočava se interakcija samo u neinduktivnim uslovima, kada se primene 10 mM BAP i 3 mM Tc.