Study of carotenoid content in durum wheat

The purpose of the study is to determine the variability and stability of traits related to the amount of yellow pigments in the grain, semolina and the finished pasta product. In addition the polymorphism in one of the phytoene synthase gene on chromosome 7A related to carotenoids synthesis was detected. In the investigation were included 10 durum wheat genotypes - cultivars and breeding lines of different origin - Bulgaria - Field Crops Institute - Chirpan and Dobroudja Agricultural Institute - General Toshevo, Europe, CYMIT-Mexico. All genotypes were grown in field conditions in competitive variety trials in three replications in harvesting years 2014/2016. The results obtained were processed statistically via basic statistics (TIBCO statistica 13.3.0 software package). Great variability was found between genotypes on the study traits. The breeding lines: M-431 (10.71 ppm in grain, 10.42 ppm in semolina and 8.96 ppm in pasta) and TD-97 (9.83 ppm in grain, 9.58 ppm in semolina and 8.52 ppm in pasta) and the Bulgarian standard cultivar Predel (9.25 ppm in grain, 8.87 ppm in semolina and 7.27 ppm in pasta) are characterized by the highest yellow pigment content in grain, semolina and pasta. Both lines are also distinguished by the lowest total pigment losses (2.6%) in milling grain to semolina and in processing to pasta product (11 - 11.4 %), while line TD-97 has the lowest total pigment losses (13.6%). Furthermore the genotypes characterized by the highest yellow pigment content (M-431 and TD-97) have an acceptable stability and can be used in the hybridization program to improve the color potential of Bulgarian durum wheat varieties. The Psy-A1 codominant marker, based on a 37 bp insertion at the 5' end of intron 2 of the PsyA1 gene amplifies two fragments. The Psy-A1a allele with a 194 bp fragment in length was observed in all 7 studied cultivars and lines of durum wheat. The 231-bp Psy-A1b allele is found in 3 genotypes. The obtained results could not be associated with phenotypic differences in the yellow pigment content in the durum wheat genotypes studied.