Production and First Assessment of Iranian Secondary Tritipyrum Genotypes by GISH and AFLP Markers

BACKGROUND: Non-Iranian Primary Tritipyrum (2n=6x=42, AABBE(b)E(b)) set seed after Triticale (2n=6x=42, AABBRR) and Tritordeum (2n=6x=42, AABBH(c)H(c)) but, due to a few undesirable agronomic traits, it cannot fulfil the commercial expectations of farming. OBJECTIVES: To remove these deficiencies, six hexaploid Tritipyrum lines were crossed with four Iranian bread wheat cultivars which led to the production of 107 (F(1)), 479 (F(2)), 768 (F(3)), and 1539 (F(4)) Iranian Secondary Tritipyrum Genotypes (ISTG) seeds. This study was carried out for selecting the plants potentially carry the 5E(b) chromosome/s and are good candidates for salt tolerant by GISH and RFLP markers. MATERIALS AND METHODS: The procedure involved extracting the total DNA content of 209 plants, including non-Iranian primary Tritipyrum lines, Iranian wheat cultivars, Chinese Spring addition, and substitution lines for 5E(b) and Iranian secondary Tritipyrum genotypes (ISTG: F(1), F(2), F(3), F(4)). Genomic in situ Hybridization (GISH) on mitotic spreads of fertile new Iranian secondary Tritipyrum genotypes (ISTG) was carried out to demonstrate the feasibility of single E(b) chromosomes. There were three trials of 18 Fragment Length Polymorphism (AFLP) EcoRI/MseI primers to identify the presence of the 5E(b) chromosome in 105 ISTG plants, along with four wheat addition lines and substitution lines for the 5E(b) chromosome. RESULTS: GISH on mitotic spreads demonstrated the feasibility of producing 75 plants out of 105 fertile new Iranian secondary Tritipyrum genotypes (ISTG) with 0-14 single E(b) chromosomes. Among the mentioned markers, only the E(36)/M(59) marker showed 43, 50, 30 and 47 identical bands, respectively, in contrast to 53 expected bands in all plants with the 5E(b) chromosome which indicated 21, 33, 9 and 6 out of 75 ISTG plants, respectively, with the 5E(b) chromosome. CONCLUSION: This study indicated that 69 ISTG Tritipyrum plants were potentially carry the 5E(b) chromosome/s and are good candidates for salt tolerant tests in comparison with Iranian modern bread wheat cultivars.