The assessment of promising fiber flax lines of breeding variety testing according to the main agronomic traits and adaptability

The purpose of the research is a comprehensive assessment of promising lines of fiber flax according to the main agronomic traits and adaptability based on the results of breeding variety testing in the conditions of the North-Western region of the Russian Federation. The research was carried out in the conditions of Pskov region in 2016-2019 on sod-weakly podzolic light loamy well-cultivated soil. The hydrothermal coefficient (HTC) for the growing season was in 2016 – 1.98, in 2017 – 1.60, in 2018 – 0.95 and in 2019 – 1.44. Abiotic conditions of the year had the greatest significant impact at 5 % significance level on the formation of plant height (79.2 %), the yield of flax seeds (83.6 %), flax straw (78,0 %) and flax fiber (68.5 %), the duration of the growing season (58.3 %). The share of the genotype prevailed in the formation of the fiber content in the stem (75.0 %). Variability was greatest in the yield of flax seeds (CV = 26.4...34.1 %); mainly average ‒ in the yield of flax straw and flax fiber (CV = 11.3…21.5 %) and weak ‒ in other characteristics (CV = 1.5...10.5 %). Based on the results of the research according to the complex of agronomic traits, three best lines of practical interest have been identified: P-4382-3-2 f-3, P-4453 c-6 and P-4629 sh-1. All of them belong to early ripening (the growing season is 77...79 days), are resistant to lodging (4.1...4.7 points) and fusarium wilting (86.5...93.3 %), tall (78...81 cm), have the yield of flax straw (50.2...51 c/ha) and flax seeds (5.9...6.9 c/ha) at the level of standard variety Voskhod. They are characterized by high fiber content (35.9...39.6 %) and flax fiber yield (18.4...19.9 c/ha), exceeded the standard by 2.5...5.9 % (abs.) and 7.6...17 %, respectively. Based on a comprehensive assessment of the breeding material according to productivity and adaptability parameters, using the ranking principle, the same genotypes are the most adapted to the soil and climatic conditions of the NorthWestern region, as having scored the lowest amounts of ranks. Their use in breeding programs will contribute to the development of new varieties that ensure high and stable yields of flax products of good quality.