Study on relationships of morphological traits with growth indices in monogerm cultivars of sugar beet

In order to determine the correlation of morphological traits with growth indices of sugar beet monogerm cultivars, a study was carried out in Abdolrasool Motahari Research Station, Karaj, Iran in 2010. The studied cultivars included Zarghan, Shirin, Rasoul, Jolgeh, Gadouk, SBSI001 and SBSI002. The study was based on a Randomized Complete Block Design with four replications. All quantitative and qualitative morphological traits were recorded on 15 plants per plot. During growing season, the roots and shoots of the studied cultivars were sampled four times for estimating physiological growth indices. Results of analysis of variance showed significant differences between the cultivars with respect to all quantitative morphological traits except root position in soil at 1% probability level. Also, with respect to the physiological growth indices, the cultivars showed significant differences at 1% probability level except specific leaf area, net assimilation rate, relative growth rate and crop growth rate. Analysis of correlation of the traits revealed that as leaf area duration and biomass duration (dry matter production during growing season) increased, crop growth rate as well as root and shoot biomass and consequently, total biomass showed an ascending trend. Furthermore, specific leaf area increased with the increase in leaf length and leaf blade width. Therefore, in order to increase the yield in breeding programs, breeders should look for cultivars with longer leaf area duration and biomass duration and higher crop growth rate.