Morphological and photobiological characteristics of red fescue varieties and selection samples

The aim of the study is to investigate the associated morphological and photobiological features of red fescue (Festuca rubra L.) accessions in a collection nursery and to identify the sources of breeding traits for creating new varieties. The studies were conducted in 2023–2024 at the V.R. Williams Federal Scientific Center for Forage Production and Agroecology. The soil was sodpodzolic, humus – 2,1–2,3 %; рН KCl – 5,3; Р2О5 and К2О (according to Kirsanov) – 152.0 and 93.0 mg/kg, respectively. The nursery was established without replicates with the placement of standards – Iskrinka and VIK 16 varieties – every 5 breeding numbers. A total of 37 variety accessions of different ecological and geographical origin were studied. The standards were Iskrinka (lawn) and VIK 16 (forage) varieties. The dependence of gas exchange parameters on the concentration of carbon dioxide (СО2) and photosynthetically active radiation (PAR) was studied using a portable gas analyzer LI COR 6800 at PAR intensity from 0 to 1500 μМ/(м2·s). As a result of clustering by the main morphobiological characteristics, the variety accessions were divided into 2 clusters: cluster I (26 variety accessions) – with narrow and short leaves, lowgrowing, with a green mass yield of 1.19 kg/m2, seed yield of 57.5 g/m2; photosynthesis intensity of 5.71 μM СО2/( м2·s), transpiretion – 7.77 mM Н2О/(м2·s); the best numbers (3/6, 3/36, 3/37), along with the Iskrinka, Gostenka and Vezelka varieties, can be used as sources of selection traits in the creation of lawn varieties; cluster II (11 variety accessions) – tall, with large wide leaves; high phytomass yield – 1.99 kg/m2, seeds – 71.7 g/m2; photosynthetic intensity of 13.18 μM СО2/(м2·s), transpiration – 14.14 mM СО2/(м2·s); variety accessions 3/4, 3/13, 3/29 and variety VIK 16 can be used as sources of selection traits in the creation of forage varieties. The “variety accession genotype” factor reliably influences the manifestation of the main resulting traits with a strength of 7.5–35.8 %, the illumination factor – 22.4–52.6 %.