Streszczenie:

The aim of this research was to study the effect of stecklings planting density on the seed stalk architecture, cluster yield and seed quality of 20 mono- and multigerm breeding lines and cultivars of red beet. The study included the new monogerm lines - AR79 A and AR79 B - breed in the Unit of Genetics Plant Breeding and Seed Science at the University of Agriculture in Kraków. The experiment was conducted in the years 2010 and 2011, in the open field conditions. Two planting densities of stecklings: 50 × 25 and 50 × 40 cm, were applied. Standard crop management practices, as recommended for red beet seed production under Polish conditions, were followed. The increase in plants interspacing from 50 × 25 to 50 × 40 cm led to the lower height, but twice higher number of shoots per plant, lower number of single, but higher number of bush and bush with main stem seed stalks, twice higher yield per plant as well higher thousand-seed weight and germination capacity. A large variation between genotypes in the features of seed-bearing plants, such as morphological structure, clusters yield and seed quality, were noted. Compared to other genotypes, the new monogerm breeding lines AR79 A and AR79 B formed very high, mostly bush or bush with main stem seed plants developing one of the largest numbers of unluckily, late-ripening shoots, yielded on the average level and producing the seeds of relatively low quality. The research has expanded the knowledge about the generative development of red beet. The results will facilitate Polish breeding programs aimed at the selection of monogerm red beet lines.