Characterization and association of phenotypic and biochemical traits in onion under short day tropical conditions

The aim of the present study was to characterize 58 onion genotypes based on morphological and biochemical traits. Genotypes comprised of landraces, open-pollinated varieties, hybrids and breeding materials. Thirteen quantitative, nine qualitative and four biochemical traits were analyzed. Significant variability was observed in the evaluated morphological and biochemical traits. Pusa White Flat (PWF) was highest yielder and maximum TSS was recorded in 106BS2 (15.30 +/- 3.03 degrees B). Arka Kalyan had highest dry matter (15.70 +/- 0.57%), Red Creole3 had highest pyruvic acid (6.32 +/- 0.17 mu mol/ ml) and total phenolic content was recorded highest (36.96 +/- 2.00 mg/g FW) in Juni. Genotypes with waxy leaves and firm skin were also identified. Significant correlations between marketable yield and morphological traits were observed. Highly significant correlation between TSS and dry matter (r = 0.45), pyruvic acid and dry matter (r = 0.35) and significant and negative correlation between TSS and TPC (total phenolic content) (r = -0.32) was observed. The finding of this study were important to assess the genetic diversity of indigenous and exotic material and also to know about the correlation of desired traits which will be helpful in devising efficient strategies for trait introgression, breeding new germplasm resources and selecting diverse parents for heterosis breeding programme in short day tropical onion.