EN
Festuca pratensis Huds, occuring in nature as a diploid (2n=14) has been an object of many artificial polyplodization attemps.In present study an attempt has been made to select spontanous polyploids of F.pratensis from twin embryos of diploid meadow fescue varieties and to compare them with the colchitetraploid cv.Westa (2n=28).The studied material was found to have a low per cent (0.07) of seeds with twin embryos.It was found that 96.00% of twin plants were diploids.The most frequent among spontanous polyploids were triploids (3.46%), less frequent - tetraploids (0.47%) and pentaploids (0.08%).No haploids were found.The obtained spontaneous triploids and tetraploids, as compared to the colchitetraploid cv.Westa, were charcterized by a significant variation of their morphological traits.It was found that in natural tetraploids from twin-embryonic seeds of F.pratensis, polyploidization has no influence on the tillering ability decrease and plant organ enlargement observed in the colchitetraploid cv.Westa.