Breeding Evaluation of Alfalfa (Medicago sativa L.) Polycross Progenies by Multivariate Analysis Based on Agro-morphological Traits

The alfalfa varieties are mostly synthetic populations of wide genetic base and a number of breeding schemes have been proposed for their creation. The progeny testing plays an important role in new alfalfa variety development because it gives information about the genetic value of the parental components based on the values established in their progeny.From 2018 to 2021 nine polycross progenies (23-M, S11-17, S11-34, S12-1/8, 9K11, 8K7, AI17, 9P17 and 3P17) originated in a polycross nursery were tested at the experimental field of the Institute of Agriculture and Seed Science “Obraztsov chiflik” – Rousse. The field experiment was performed in a randomized block design in four replicates and harvesting plot size of 10 m2. The objective of the study was to evaluate the alfalfa polycross progenies based on main agro-morphological traits performance and to predict their genetic potential as a source of parental material for new alfalfa variety breeding. 9K11 and 8K7 progenies showed superior scores regarding green mass and dry matter yield, plant height, stem producing ability and regrowth rate, while S11-34 and 3P17 progenies distinguished with high phenotypic expression of crude protein content and leaf/stem ratio. These progenies are valuable germplasm source to be used in a further breeding programme for new alfalfa variety development.