Comparative biological characteristic of white lupin (Lupinus albus L.) varieties

Abstract

The study was conducted in 2014-2016 on the experimental field of the Institute of Forage Crops, Pleven, Bulgaria. Aboveground and root biomass plant material of seven white lupin (Lupinus albus L.) varieties different originated was analyzed in two phenological stages. Plants were analyzed for height, fresh weight, number of leaves, nodule number and nodule weight in the beginning of flowering stage, and for number of pods, number of seeds and seed weight in the technical maturity stage. Degree of earliness of varieties was assessing as well. The group of ultra early varieties can be defined PI533704 and Zuter varieties with coefficient of earliness 1.00, to early - PI368911, PI457938 and KALI (coefficient of earliness 1.25), and to late Lucky801 and PI457923 (coefficient of earliness >1.66). A strong positive correlation was found between the seed productivity with number of seeds per plant (r=0.943) and plant height (r=0.765); close relationship of fresh aboveground mass weight with plant height (r=0.822), number of leaves (r=0.965) and fresh root mass weight (r=0.876). The varieties of interest for breeding were selected by different signs. It was concluded that the number and weight of nodules as well fresh root mass weight can be used as selection criteria for creating varieties with a higher symbiotic nitrogen fixation potential.