Which biophysical and biochemical factors may contribute to higher resistance of cabbage (Brassica oleraceae L. var. capitata) to attack of the most important pests | Kateri biofizikalni in biokemični dejavniki lahko pripomorejo k večji odpornosti zelja (Brassica oleraceae L. var. capitata) na napad gospodarsko najpomembnejših škodljivcev

English. Research on the impact of certain biophysical (epicuticular wax content) and biochemical (colour, total polyphenols and antioxidative potential) factors on the resistance of cabbage (Brassica oleracea L. var. capitata) against damage caused by flea beetles (Phyllotreta spp.), cabbage stink bugs (Eurydema spp.) and onion thrips (Thrips tabaci) was carried out in 2010 at the Experimental field of the Biotechnical Faculty. In a field trial the following 20 cabbage genotypes were included: 9 early, 5 mid-early, 6 mid-late (regarding the longevity of growing period), 3 red, 17 white (regarding the colour), 14 hybrids and 6 varieties (regarding genetic origin). Statistical analysis showed that the biophysical and biochemical composition of cabbage leaves has the greatest impact on resistance of this vegetable to flea beetles attack. Flea beetles showed only weak preference to early and red cabbage, and to the hybrids, which have a high epicuticular wax content (r2 = –0.6137, r2 = –0.7603, and r2 = –0.6812). It has also been found a strong negative relationship between the antioxidative potential and extent of damage in the mid-late cabbage (r2 = –0.7185), red cabbage (r2 = –0.7811) and cabbage varieties (r2 = –0.7802).

Slovenian. Raziskava o vplivu nekaterih biofizikalnih (vsebnost epikutikularnega voska) in biokemičnih (obarvanost listov, skupni polifenoli in antioksidacijski potencial) dejavnikov na odpornost zelja (Brassica oleracea L. var. capitata) proti poškodbam, ki jih povzročajo kapusovi bolhači (Phyllotreta spp.), kapusove stenice (Eurydema spp.) in tobakov resar (Thrips tabaci), je potekala v letu 2010 na Laboratorijskem polju Biotehniške fakultete v Ljubljani. V poljski poskus je bilo vključenih 20 genotipov zelja in sicer 9 zgodnjih, 5 srednje zgodnjih in 6 srednje poznih genotipov (glede na dolžino rastne dobe), 3 rdeči in 17 belih genotipov (glede na barvo listov) ter 14 hibridov in 6 sort (glede na poreklo). Statistična analiza je pokazala, da biofizikalna in biokemična sestava listov zelja najbolj vpliva na odpornost te vrtnine na napad kapusovih bolhačev. Ti namreč kažejo šibko preferenco do zgodnjega in rdečega zelja ter do hibridov, ki imajo visoko vsebnost epikutikularnega voska (r2 = –0,6137, r2 = –0,7603 in r2 = –0,6812). Prav tako smo pri kapusovih bolhačih ugotovili močno negativno korelacijo med antioksidacijskim potencialom in obsegom poškodb pri srednje poznem zelju (r2 = –0,7185), pri rdečem zelju (r2 = –0,7811) in pri sortah zelja (r2 = –0,7802).