Variance components and correlations of agronomic traits among cabbage (Brassica oleracea var. capitata L.) maturity groups

Abstract

In this paper we studied the variability and correlation of cabbage traits in different maturity groups. The study included early spring cabbages (planted in early spring, harvested in early summer) and autumn cabbages (planted in mid-summer, harvested in late autumn). Using coefficients of variation and correlation coefficients, we analyzed 17 cabbage traits in 35 commercially grown cultivars, F1 hybrids, and experimental F1 hybrids. The traits were analyzed separately for each maturity group. In the early cabbages, the coefficients of variation ranged from 4.8 to 44.2%. The calculated correlation coefficients differed between the two maturity groups. The early cabbages had 26 significant positive correlations. The positive correlations calculated among different traits of early cabbages defined this group fully and made it distinct from the late-maturing genotypes. Plant height and rosette diameter in the early genotypes were highly positively correlated with rosette weight, whole plant weight, head weight, usable portion of head, head height, and head diameter. Plant height and rosette diameter participate in the formation of active photosynthetic area in early cabbages. Rosette width in these genotypes provides a greater influx of light and heat, which results in greater head weight. Also, in early cabbages that have greater plant height, the leaf rosette will not lie on the cold surface of the ground in the spring. The activity of the cabbage plant is thus more focused towards the formation of larger head weight. Head volume in the late genotypes was highly positively correlated with rosette diameter, whole plant weight, head weight, usable portion of head, inner stem length, and head height. In late cabbages plant activity is directed towards the formation of head volume due to the longer duration of the growth period, larger leaves, and differences in climatic conditions.

U radu smo istraživali varijabilnost i korelacije svojstava kupusa iz različitih grupa zrenja. Ubuhvaćeni su rani-prolećni kupusi (posejani rano u proleće, posečeni u rano leto), i jesenji kupusi (posejani sredinom leta, posečeni kasno u jesen). Koeficijentima varijacije i korelacionim koeficijentima analizarano je 17 kupusnih svojtava, između 35 komercijalno gajenih sorata, F1-hibrida i eksperimentalnih hibrida kupusa. Svojstva sorata i F1-hibrida kupusa smo analizirali posebno kod svake grupe zrenja. Koeficijent varijacije analiziranih svojstava se kretao od minimalnih 4,8% do maksimalnih 44,2%. Navedeni koeficijenti varijacije su pripadali kupusima iz rane grupe zrenja. Međutim korelacioni koeficijenti su bili različiti između analiziranih grupa zrenja kupusa. Kupusi iz rane grupe zrenja imali su 32 signifikantno pozitivne korelacije, a kasno jesenji kupusi su imali 26 signifikantno pozitivnih korelacija. Visina biljke i prečnik rozete kod ranih genotipova je u visokoj pozitivnoj korelaciji sa masom rozete, masom cele biljke, masom glavice, korisnim delom glavice, visinom glavice i prečnikom glavice. Kod ranih kupusa sa većom visinom glavice, lisna rozeta tokom proleća neće ležati na hladnoj površini zemljišta. Ovako je aktivnost biljke više usmerena na formiranje veće mase glavice. Zapremina glavice kod kasnih genotipova je u visoko pozitivnoj korelaciji sa prečnikom rozete, masom cele biljke, masom glavice, korisni delom glavice, dužinom unutrašnjeg kočana i visinom glavice. Aktivnost biljaka kod kasnih kupusa na formiranju veće zapremine glavice je u funkciji dužeg vegetacionog perioda, većih listova rozete i drugačijih klimatskih uslova.