Comprehensive Evaluation of Agronomy and Quality Traits of Onion Germplasm Resources of Long-day Ecotype
LIU Du，MA Huili，ZHANG Xu，YU Zhengjiao，ZHANG Yadi，HU Yunjie，QIN Lei*，WANG Yong*
Key laboratory of Biology and Genetic Improvement of Horticultural Crops（Northeast Region），Ministry of agriculture and rural affairs，College of Horticulture and Landscape Architecture，Northeast Agricultural University，Harbin 150030，Heilongjiang，China
Abstract：The diversity of 29 agronomic traits and 5 quality traits were evaluated in 88 onion germplasm accessions from different regions，followed by the variation coefficient analysis，Shannon-wienter index analysis，correlation analysis，principal component analysis and cluster analysis．The results showed that onion resources had rich variation at 29 agronomic traits．The variation coefficient of flavonoid content was the largest（64.79%）．The bulb transverse diameter and scale bud number showed the largest diversity index（1.53）．The variation coefficient of the flesh scale color was the largest（140.69%）．The bulb membranous cortex performed the highest diversity index（1.18）．Nine phenotypic traits and 5 quality traits exhibited significant correlation．The principal component analysis showed that ten traits including the bulb diameter，pseudostem outer skin color，number of flower stems，flower stem height，anther color，leaf wax powder，soluble sugar content，and soluble protein content were the main factors that largely contributed to the phenotypic variation．Based on the principal component analysis and comprehensive score（F-value），the top 10 onion accessions were obtained．These onion germplasm resources were divided into two groups by systematic clustering analysis．The onion accessions in the first group showed low yield，nevertheless，the second group had a greater production potential with larger bulb vertical diameter，bulb transverse diameter，bulb transverse diameter，more fleshy scales，and higher VC，flavonoid，organic sulfide content．
