Identification Of Hexaploid Triticale D Genome Introgression Lines

With the increasing of the global population,the quality of people’s life is constantly improved.Urbanization,returning farmland to forests and grasslands,and environmental pollution lead to a reduction in the area of cultivated area,which would bring huge pressure to China’s grain production.So the improvement of the yield and quality of food plays an irreplaceable role in the country’s food security,maintaining social stability,and promoting sustainable economic development.Triticale is a man-made cereal crop that was developed to combine the grain quality and productivity typical of Triticum species with the growth vigor,abiotic stress tolerance,and high lysine content of rye in one plant.It also has other outstanding characteristics such as high yield,high protein content,and large biomass,which plays an important role in the shortage of global food resources.However,with the rapid evolution of various disease physiological races,the resistance genes of triticale were gradually lost.Furthermore,it’s difficult to improve the yield and quality of triticale because of the narrow genetic diversity.Introducing the D genome chromosomes to develop various types of alien addition and substitution lines of triticale is a convenient approach in triticale breeding.In this study,the F₇ lines derived from wheat-rye-Psathyrostachys huashanica trigeneric hybrids were identified using GISH,FISH and molecular markers.The results were as follows:1.Specific molecular markers on 1D-7D chromosome were utilized to screen354 F₇derivatives.We detected the D genome specific markers in 63 lines.Among them,the number of lines with 1D,2D,3D,4D,5D,and 6D chromosome specific markers were 12,8,7,17,1,and 4,respectively.Six lines were simultaneously detected with 7D and 4D chromosome markers.In addition,6 lines contained 1D and3D chromosome markers.One line had 3D and 5D chromosome markers and one line contained 3D and 6D chromosome markers.2.GISH and FISH techniques were used to identify the chromosome composition of these triticale derivatives.The chromosome number of K16-1550-6-8,K16-4173-3,K16-1565-6-3,K16-1549-10-3 were 42,and they were 1D（1R）,2D（2R）,3D（3B）,4D（4B）substitution lines,respectively.K16-1565-6-4（2n=42）lacked a pair of 3B and one 5R chromosomes,but added a pair of 5D and one 3D chromosomes.The chromosome number of K16-601-1-4 were 43,added a pair of 5D chromosomes,but lacked one 5B chromosome.K16-4121-3（2n=44）was a 6D chromosome addition line.In addition,K16-1566-4-1（2n=44）lacked a pair of 4R chromosomes,but added a pair of 4D and 7D chromosomes.3.The eight lines were identified with molecular markers using wheat SSR markers of the 1D-7D,3B,4B chromosomes and rye specific markers of the 1R,2R and 4R chromosomes.The results showed that all lines could amplify the specific band of the D genome chromosome,respectively.Moreover,K16-1550-6-8 could not amplify the specific band of 1R,K16-4173-3 could not amplify the specific band of2R,K16-1565-6-3 and K16-1565-6-4 could not amplify the specific band of 3B,K16-1549-10-3 could not amplify the specific band of 4B,K16-1566-4-1 could not amplify the specific bands of 4R chromosome.These results were consistent with the above GISH and FISH results.