Evaluation of flax (Linum usitatissimum L.) genotypes on environmental adaptability and stability in the North-Eastern Belarus

Flax is the only industrial crop cultivated in Belarus for fiber on the area over 50 thousand ha. An environmental adaptation is of special interest for innovative flax varieties. We focused on selection of genetic sources of adaptability and stability and the search for environmentally adapted genotypes among the extensive flax hybrids. For this, we have studied a response of the parent forms and 36 hybrid populations of fiber flax to abiotic factors and estimated the influence of environment on economically important traits. The field trials (Orshanskii Region, Belarus, 2012 to 2014) were carried out under weather conditions which varied in precipitations (16.7-27.1 mm) and daily air temperature (12.4-16.4 °С). Plant height, stem technical length, weight, and fiber content were studied in 10 parental varieties different in geographic origin (i.e. derived from Belarus, Russia, France, Ukraine, Lithuania), and also in their combinations. Morphological and biological screening identified 11 early ripening combinations, 15 forms with tall stem, 10 forms with a significant technical stem length, 4 ones with high stem weight, and 3 ones with high fibre content. A statistically significant impact (at 95 and 99 % level) of genotypes (Fo > Fe), environment factor and their interactions (genotype × environment) have been found. The estimation of stability and responsiveness to environmental conditions of each of the studied flax genotypes by Eberhart and Russell method revealed that high responsiveness to the improved growing conditions was characteristic of Alizee (bi = 1.12), Upite 2 (bi = 1.22), Lvovskiy 7 (bi = 1.02), Lvovskiy 7 × Yarok (bi = 1.79), Lvovskiy 7 × Voskhod (bi = 3.07) for plant height, K-65 (bi = 1.33), Velich (bi = 1.12), Upite 2 (bi = 1.22) Lvovskiy 7 (bi = 1.32), Yarok × K-65 (bi = 1.87), K-65 × Laska (bi = 1.37), Yarok × Velich (bi = 2.09) for technical stem length; Voskhod (bi = 2.38), Laska (bi = 1.85), K-65 (bi = 1.76), Voskhod (bi = 2.32), Yarok × Laska (bi = 1.87), Laska × Voskhod (bi = 2.16), Voskhod × Alizee (bi = 1.17), K-65 × Laska (bi = 1.31) for stem weight; Laska (bi = 1.14), Voskhod (bi = 1.27), Drakkar (bi = 1.59), K-65 (bi = 1.32), Vasilek (bi = 1.39), Yarok × Laska (bi = 2.54), Yarok × Voskhod (bi = 1.78), Velich × Voskhod (bi = 3.11), Yarok × Lvovskiy (bi = 1.31) for fiber content. Low levels of variance stability was found in Velich (S2di = 2.33), Lvovskiy 7 (S2di = 4.62), Drakkar (S2di = 6.18) for plant height; in Velich (S2di = 5.37), Lvovskiy 7 (S2di = 4.62), Drakkar (S2di = 6.20) for technical stem length; in Upite 2 (S2di = 1438.68), Yarok (S2di = 3465.94), Lvovskiy 7 (S2di = 2268.62) for stem weight; in Vasilek (S2di = 1.47), Upite 2 (S2di = 0.85), Drakkar (S2di = 3.98), Voshod (S2di = 3.65), Yarok (S2di = 2.29) for the fiber content. High adaptable, stable and productive genotypes were few thereby necessitating further researches to create new breeding material.