Investigation of new sugar beet hybrids by tolerance indices in salt condition

In order to evaluate of new sugar beet hybrids for salt tolerance, 20 single cross hybrids produced by crosses between 5 diploid pollinators as male and 4 cytoplasmic male sterile as females ( caused by factorial design) along with parents were investigated in Rudasht salinity research station in 2012 and 2013. In each year, genotypes were studied in two experiments under saline (EC for water and soil about 12 and 8 dS/m respectively) and non-saline field conditions (EC for water and soil about 4 dS/m) using a randomized complete block design with two and three replications in first and second year, respectively. Four salt tolerance indices including salt tolerance index (STI), field emergency potential (FEP), beet tolerance index (BTI) and drought tolerance index (DTI) were calculated based on sugar yield in stress and non-stress condition. Regression analysis of sugar yield in two conditions with these indices showed that STI and BTI had significantly positive relationship coefficient with sugar yield under both stress and non-stress conditions suggesting that these indices are more efficient for determining salt tolerant genotypes. In based on the results of cluster analysis, hybrids 2×3, 3×1, 5×3 and 5×4 were recognized as salt tolerant hybrids with high yield and hybrids 1×1, 2×4, 4×3, 3×2 and 5×2 were introduced as susceptible hybrids with low yield for salinity condition.