Summary:

The objective of this research was to study the seed stalk morphology, cluster yield and quality of 20 mono- and multigerm breeding lines as well as cultivars of red beet. The seed plants derived from the roots of the two sizes, during 2012 and 2013 in field conditions, were evaluated. Large stecklings formed plants with a higher number of shoots and lower percentage of the single seed stalks, and produced higher yields, and thousand-cluster weight compared to small stecklings. The monogerm genotypes developed higher plants with higher number of shoots and a lower number of a single seed stalks than the multigerm ones. The open-pollination and hybrid cultivars, as well as the cytoplasmic male sterile (CMS) and their maintainer fertile lines, mostly presented comparable values of the studied traits. The cultivars yielded better and formed higher plants, and produced seeds with better quality than the CMS lines, which in turn formed more shoots and a higher number of bushes with the main stem plants compared to the cultivars. The characteristics of the generative plant development stage of different genotypes of red beet will be useful in breeding programs designed to create new, especially, monogerm hybrid cultivars.