High-resolution RFLP mapping of the fertility restoration (Rf3) gene against Triticum timopheevi cytoplasm located on chromosome 1BS of common wheat.

Abstract

Near-isogenic lines of alloplasmic wheat for the Rf3 gene controlling fertility restoration against the cytoplasm of Triticum timopheevi were developed by successive backcrossing of Chinese Spring to the F 1 plants between (timopheevi)-CS (male sterile) and T. spelta (carrying Rf3). The resultant three BC 3 F 1 plants were self-pollinated so as to obtain 125 BC 3 F 2 progenies. Using this population, we precisely mapped the Rf3 gene on the short arm of wheat chromosome 1B (1BS) of the RFLP linkage map. The Rf3 gene was localized at a position 1.2 cM and 2.6 cM distant from Xcdo388 and Xabc156, respectively. The genetic distances of Rf3 from Nor and Gli-B1 were calculated to be 22.3 cM and 18.6 cM, respectively, supporting previous data. Estimation of the physical distance of the region suggets that the Rf3 gene resides within 500 kbp from the adjacent RFLP markers. The marker order of the genetic map corresponded to that of the cytological map, except for the position of Xbcd98. Comparison between genetic and cytological maps clearly shows that RFLP markers are unevenly distributed throughout the chromosome arm, and recombinations took place unequally in the chromosome arm.

High-resolution RFLP map of the long arm of chromosome 5A in wheats and its synteny among cereals.

“…This kind of inversion of marker order between cytological and genetic maps was found also in the long arm of chromosome 1B of common wheat (Van Deynze et al, 1995;Gill et al, 1996b;Kojima and Ogihara, 1997).…”

Relative Response of Four Tomato Species to <i>Rotylenchulus reniformis</i> Infestation

“…In this study, our approach involved a combination of eggs and vermiform life stages extracted from roots of forty cotton accessions for resistance evaluation. Near isogenic lines (NIL) are vital genetic stocks for investigating the function and regulation of single genes [25], and aid in isolation of genes [26]. Tomato genotypes evaluated in this study were carefully selected to include parental lines, NILs, and S. lycopersicum cultivars with considerable common genetic background.…”

SSR markers associated with fertility restoration genes against Triticum timopheevii cytoplasm in Triticum aestivum

“…There is significant difference between fertility values of homozygotes for the allele from R18 or R9034 and heterozygotes in the two populations. Both R18 and R9034 were derived from Primepi, which carries a major fertility restoration gene, Rf3, on chromosome 1BS (Ma & Sorrels, 1995;Kojima et al, 1997;Ahmed et al, 2001). Based on the fact that the same SSR markers were significantly associated with fertility restoration in both populations, it is probable that both R18 and R9034 carry Rf3.…”

“…Kojima et al (1997) mapped the Rf3 gene with RFLP markers Xcdo388 and Xabc156 on chromosome 1BS using a BC 3 F 2 population of 125 plants. Ahmed et al (2001) identified an Rf gene linked to the RFLP marker XksuG9c on 1BS.…”

“…Ahmed et al (2001) identified an Rf gene linked to the RFLP marker XksuG9c on 1BS. This gene most likely corresponds to the Rf3 gene identified by Kojima et al (1997) since the same parental lines were used to produce the mapping populations. Ma & Sorrels (1995) located Rf3 in Primepi to 1BS, 23 cM from Nor and associated with RFLP markers Xcdo442-1B and Xbcd249-1B.…”