| 0 | PI 638738 | Yecora Rojo Lr47 | Triticum aestivum L. subsp. aestivum | California, United States | NSGC |  | | 2005 | DEVELOPED | | | | | | Genetic material | Yecora Rojo isogenic line for Lr47. BC6F4 homozygous line for leaf rust resistance gene Lr47 (from PI 603918). The T.speltoides 7S chromosome segment carrying Lr47 is located 2-10 cM from the centromere and is 20-30 cM long. The chromosome segment was selected during the 6 backcrosses using molecular markers. Yecora Rojo isogenic lines with and without Lr47 were compared in field trials at Kings, California in 2003 and at Kings and Davis, California in 2004. The isogenic lines with and without the gene showed similar agronomic characteristics including height and heading time. Depending on the environment some of the plants carrying the Lr47 chromosome segment showed purple stems. No significant differences in yield were observed between the isogenic lines grown at Kings. However, at Davis under strong stripe rust infection pressure, the lines carrying Lr47 showed a 10% increase in stripe rust infections which resulted in a significant decrease in yield. These results suggest that the 7S chromosome segment has probably replaced a gene located in the 7A chromosomes of Yecora Rojo that has a small positive effect on resistance to stripe rust races present in these locations. Analysis of the isogenic lines for grain protein content showed a significant increase (average 0.6%) associated with the presence of the Lr47 chromosome segment in the tested locations. [See PI 638738-638742 for accessions from the same Crop Science registration.] | 1673392 | PI 638738 |
| 1 | PI 638739 | Kern Lr47 | Triticum aestivum L. subsp. aestivum | California, United States | NSGC |  | | 2005 | DEVELOPED | | | | | | Genetic material | Kern isogenic line for Lr47. BC6F3 homozygous line for leaf rust resistance gene Lr47 (from PI 603918). The T.speltoides 7S chromosome segment carrying Lr47 is located 2-10 cM from the centromere and is 20-30 cM long. The chromosome segment was selected during the 6 backcrosses using molecular markers. Kern isogenic lines with and without Lr47 were compared in field trials at Kings, California in 2003 and at Kings and Davis, California in 2004. The isogenic lines with and without the gene showed similar agronomic characteristics including height and heading time. Depending on the environment some of the plants carrying the Lr47 chromosome segment showed purple stems. No significant differences in yield were observed between the isogenic lines grown at Kings. However, at Davis under strong stripe rust infection pressure, the lines carrying Lr47 showed a 18% increase in stripe rust infections which resulted in a significant decrease in yield. These results suggest that the 7S chromosome segment has probably replaced a gene located in the 7A chromosomes of Kern that has a small positive effect on resistance to stripe rust races present in these locations. Analysis of the isogenic lines for grain protein content showed a significant increase (average 0.4%) associated with the presence of the Lr47 chromosome segment in the tested locations. [See PI 638738-638742 for accessions from the same Crop Science registratio.] | 1673393 | PI 638739 |
| 2 | PI 638740 | Yecora Rojo Yr36 Gpc-B1 | Triticum aestivum L. subsp. aestivum | California, United States | NSGC |  | | 2005 | DEVELOPED | | | | | | Genetic material | Yecora Rojo isogenic line for Yr36 and Gpc-B1. BC6F3 homozygous line for T.dicoccoides stripe rust resistance gene Yr36 and high-grain protein content gene Gpc-B1 into HRS recurrent parent Yecora Rojo. The high-grain protein content allele for the Gpc-B1 gene and the linked stripe rust resistance gene Yr36 were originally transferred from T.dicoccoides. These linked genes (less than 3 cM apart) were mapped in the short arm of chromosome 6BS and molecular markers were developed to facilitate their introgression. This isogenic line has been designated as the type T.aestivum germplasm line for the Yr36 gene. The two genes were transferred by 6 backcrosses followed by selection of homozygous BC6F2 plants using molecular markers. The isogenic lines of Yecora Rojo were compared in field trials in Madera and Davis, California in 2004 under severe stripe rust infections using a split plot design with 5 replications and large plots. Isogenic lines with and without the genes showed similar agronomic characteristics including height and heading time. The line with the Yr36-Gpc-B1 genes showed reduced stripe rust infections (average 36%), higher yields (average 970 kg/ha), and increased grain protein content (average 0.8%). [See PI 638738-638742 for accessions from the same Crop Science registration.] | 1673394 | PI 638740 |
| 3 | PI 638741 | UC1113 Yr36 Gpc-B1 | Triticum turgidum L. subsp. durum (Desf.) van Slageren | California, United States | NSGC |  | | 2005 | DEVELOPED | | | | | | Genetic material | UC1113 isogenic line for Yr36 and Gpc-B1. BC6F3 homozygous line for T.dicoccoides stripe rust resistance gene Yr36 and high-grain protein content gene Gpc-B1 into HRS recurrent parent UC1113. The high-grain proteint content allele for the Gpc-B1 gene and the linked stripe rust resistance gene Yr36 were originally transferred from T.dicoccoides. These two linked genes (less than 3 cM apart) were mapped in the short arm of chromosome 6BS. This isogenic line has been designated as the type germplasm for the Yr36 gene in T.durum. The two genes were transferred by 6 backcrosses followed by selection of homozygous BC6F2 plants using molecular markers. The isogenic lines of UC1113 were compared in field trials in Madera and Davis, California in 2004 under severe stripe rust infection pressure using a split plot design with 5 replications and large plots. Isogenic lines with and without the gene showed similar agronomic characteristics including height and heading time. The line with Yr36-Gpc-B1 genes showed reduced stripe rust infections (average 34% reduction in severity), slightly higher yields (average 240 kg/ha, but not significant), and increased grain protein content (average 1.1% increase). [See PI 638738-638742 for accessions from the same Crop Science registration.] | 1673395 | PI 638741 |
| 4 | PI 638742 | Anza Lr37 Yr17 Sr38 | Triticum aestivum L. subsp. aestivum | California, United States | NSGC |  | | 2005 | DEVELOPED | | | | | | Genetic material | Anza isogenic line for a 2NS/2AS translocation carrying rust resistance genes Lr37/Yr17/Sr38. BC6F4 homozygous line for the rust resistance genes transferred into HRS recurrent parent Anza. The Lr37 (leaf rust resistance), Yr17 (stripe rust resistance), and Sr38 (stem rust resistance) were initially introgressed in the winter bread wheat VPM1 from T.ventricosum. Rust races with virulence to Yr17 and Lr37 have been identified in some countries, but this gene cluster still provides resistance to a wide range of races and is useful in combination with other resistance genes. The 2NS/2AS translocation replaced approximately half of the short arm of chromosome 2A. Molecular markers for this segment were used to introgress these resistance genes into Anza using 6 backcrosses. Isogenic lines with and without the gene were tested in field trials at Davis and Kings, California in 2004 under severe stripe rust infection pressure. The isogenic lines were morphologically similar and showed no significant differences in flower time and height. The presence of Yr17 significantly reduced the severity of stripe rust infection (61% reduction in severity). The recurrent parent Anza has the slow rusting complex Lr34/Yr18 suggesting that the addition of Yr17 increases the resistance to stripe rust provided by Yr18. The improved resistance of the Yr17 isogenic lines resulted in significant increases in yield in both locations (average 663 kg/ha). The molecular and field data confirmed that the 2NS chromosome segment including the Lr37/Yr17/Sr38 resistance genes was successfully transferred to Anza. [See PI 638738-638742 for accessions from the same Crop Science registration.] | 1673396 | PI 638742 |