| The fertility restoration ability of restorer lines in wheat to Triticum timopheevi cytoplasm is controlled by both major genes and minor genes and by female parent genotypes. However, information about the number of genes involved in fertility restoration and their effect is often not available, which slows down the identification of desirable genotypes for breeding of the restorer lines. RFLP technology was employed to detect chromosome regions associated with known fertility restoring genes (Rf genes) in two restorer lines R113 and Primepi. Through mapping a testcross population created for each restorer line, RFLP markers were found that may be linked to some of the known Rf genes. Also, several new chromosome regions were discovered that affect the fertility restoration. Loci in male sterile lines that may be related to genes controlling ease of restoration were discovered and epistatic effects were examined.; Four translocation lines with Rf genes from Aegilops umbellulata 6U chromosomes were used to identify the transferred chromosomal segments and their map locations on wheat chromosomes. Parents of the four lines including an addition line of 6U were surveyed primarily with homoeologous group 6 RFLP markers. Extensive DNA homology was found between 6U and the short arm of homoeologous group 6 chromosomes. In three of the four lines, the transferred 6U segments were located on 6BS; in the fourth one, the translocation may be located on 6AS.; To provide RFLP markers for powdery mildew genes Pm1, Pm2, Pm3, Pm4, near isogenic lines (NIL) for each gene were screened with DNA clones of known chromosome or chromosomal group locations. By mapping polymorphic markers in F2 progenies from crosses of the NILs with the recurrent parent Chancellor, it was found that Pm1 co-segregated with Xcnlbcd347-7A, Pm2 was 3.5 cM from Xcnlbcd1871-5D, Pm3b was 1.3 cM from Xcnlbcd1434-1A, Pm4a co-segregated with Xcnlbcd1231-2A(2) and Xcnlcdo678-2A, and was closely flanked by Xcnlbcd1231-2A(1) and Xcnlbcd292-2A both at a distance of 1.5 cM.; RFLP markers linked to loci controlling Hessian fly-resistance from Triticum tauschii were also identified for two wheat germ plasm lines KS89WGRC3 (C3) and KS89WGRC6 (C6). H23 in C3 is linked to Xksuh4-6D (7.0 c M) and Xksug48-6D (13.7 cM). H24 in C6 is linked to Xcnlbcd451-3D (5.9 cM), Xcnlcdo482-3D (5.9 cM) and Xksug48-3D (12.9 cM). |
