Diversity Analysis Of Hexaploid Triticale And Identification Of Wheat-Rye Alien Chromosome Lines

Secale L. belonging to the wheat gene pool 3 has desirable traits, such as strong tillering ability, large spikelet number, multiple disease resistances and stress tolerance, which is the important gene donor of wheat genetic improvement. Hexaploid Triticale is a new species derived from chromosome doubling of tetraploid wheat and rye hybrid F1, which possesses the excellent characteristics of two parents and has an advantage on hybriding with wheat, so, it can be used as the intermediary material for transferring beneficial genes from rye to wheat. In this study, identifications of main agronomic traits and quality traits were conducted with 222 hexaploid Triticale germplasms introduced from CIMMYT; Chromosome composition analysis of hexaploid Triticale and wheat hybrid F1 and F2 was carried out with the methods of cytology and in situ hybridization; Screening, identification and chromosome composition analysis of wheat-rye alien chromosome lines were finished using the methods of morphology, cytology, in situ hybridization and molecular marker. The main results were as follows:(1) Investigations of 3 disease resistances, 6 agronomic traits and 8 quality traits belonging to 222 hexaploid Triticale germplasms showed that: 222 hexaploid Triticale germplasms had high resistances to wheat powdery mildew, stripe rust and leaf rust; besides, they grew prolifically with big spikes and strong stems; What's more, there were abundant diversities in main agronomic and quality traits, 222 hexaploid Triticale germplasms were clustered into six groups, and significant differences of agronomic and quality traits were observed among groups, so, the hexaploid Triticale germplasms were useful for wheat improvement.(2) Combining the methods of cytology and in situ hybridization, the chromosome composition and rye chromosome transfer in hexaploid Triticale and wheat hybrid F1 and F2 were figured out. 58 wheat-rye alien chromosome lines were screening out with stable cytology and traits, and the main agronomic traits and quality traits were identified.(3) 35 wheat-rye alien chromosome lines were selected out further, which were of great use with luxuriant growth, large kernel number per spike, high 1000 kernel weight, strong stems, high protein content, cold tolerance or disease resistance. Cytology, in situ hybridization and molecular marker analysis showed that there were 20 1BL/1RS alien translocation lines, 3 1R/1D alien substitution lines, 3 2R/2D alien substitution lines, 1 1R/1D-2R/2D alien substitution line, 1 2R alien addition line, 1 1BL/1RS-2R/2D alien substitution line, 1 1BL/1RS-2RL/2RL alien addition line, and 5 wheat-rye alien chromosome lines might be introgression lines. It was proved that 1A, 5A, 6A, 5B, 6B, 1D, 3D and 4D chromosomes of some lines had produced structural changes.