[Construction and analysis of near-isogenic line derived from wheat cultivar sumai 3]

Wheat scab can cause significant yield lost and quality decrease as well as toxicoses in animals and humans. Sumai 3, a resistant cultivatr to scab, is widely used in the wheat breeding of scab resistance. To study the inheritance of resistance to scab in Sumai 3, the highly susceptible cultivar Chuan 980 was crossed with Sumai 3 and backcrossed with Sumai 3 as a recurrent parent for seven times, thus a near-isogenic line S016 susceptible to scab was developed. S016 was evaluated in five regions and a period of two years for resistance to spread of scab in spike. Results showed that S016 was as highly susceptible to wheat scab as one of the parent Chuan 980. Molecular markers (RFLP, RAPD) were screened to identify chromosome regions of negative element of resistance gene (s) in S016. The DNA polymorphism between the near-isogenic lines was showed using six restrict enzymes (EcoRI, EcoRV, HindIII, Dra I, BamH I, Xba I) and 85 probes located in wheat chromosome 2D. Among the amplified bands of 450 10-mer random primers, OPH191400 and OPH191200 were perhaps linked to negative regulator element. Some reported probes linking to scab resistance gene(s) did not show any polymorphism between this near-isogenic line and their generation.