EVALUATION OF GERMINATION, EMERGENCE AND PHYSIOLOGICAL PROPERTIES OF SUGAR BEET CULTIVARS UNDER SALINITY

Abstract

This study aimed to determine a useful selection criterion for salt tolerance during the early development stage of sugar beet. Four sugar beet cultivars (Orthega, Valentina, FD Shoot, and Mohican) were exposed to NaCl stresses (Control, 5, 10, and 15 dS m(-1)), and morphological and physiological characteristics were investigated. Germination percentage, mean germination time (MGT), seedling length, and seedling fresh weight (SFW) in germination test; emergence percentage, mean emergence time (MET), root length, shoot length, plant fresh weight, relative chlorophyll content (Chl), relative water content (RWC) and electrolyte leakage of the plants grown in pod experiment were measured. The results showed that the maximum germination at control was recorded in FD Shoot, but it gave the lowest germination at 15 dS m(-1). In the pod experiment, the highest emergence rate was detected in Orthega and Mohican at all levels of NaCl. Increased salinity delayed MET and led to reduction in shoot length, root length, and RWC of sugar beet cultivars. Relative Chl content and electrolyte leakage enhanced from 32.7 SPAD and 21.6% in control to 38.5 SPAD and 35.6% in 10 dS m(-1), respectively. In general, there were significant differences among sugar beet cultivars, and they could keep the salinity up to 5 dS m(-1) in terms of the investigated traits. It was concluded that relative Chl content and electrolyte leakage should be used a promising clue for selection of tolerant or sensitive sugar beet cultivars for salinity.