| Winter wheat cultivars Jubilejnall, Virgilio, and Kangyin655 were used to differentiate Chinese races of Puccinia strizformis and as the important resource for resistance breeding. It was reported that they contain unknown resistance genes. Those three cultivars crossed with other cultivars carrying known resistance genes, and susceptible cultivar Mingxianl 69, respectively. Crosses among those three cultivars were made too. Seedlings of the parents, F1, F2, and backcross progenies from some crosses were evaluated for resistance using five Chinese races and pathotypes. Data showed that there are at least four different genes in jubilej nail, namely, YrJul, YrJu2, YrJu3, and YrJu4. respectively. YrJul and YrJu2, two recessive genes, are effective against CY29 independly or repeatedly, but ineffective against CY23, Su-l and CY31. YrJu3 confers the resistance to CY23, Su-l and CY3I, but ineffective against CY29. YrJu4 is effective against CY23 and may be resistant to CY3 1. YrJu3 and YrJu4 complementarily confer the resistance to CY23. YrJu3 confers the resistance to Su-l, while YrJu3 and another gene (may be YrJu4) complementarily confer the resistance to CY3 1. YrJu3 is allelic or closely linked to a gene in Spaldings Prolific and, YrJu4 is as same as or closely linked to a gene in Kangyin655. Kangyin655 carries at least two resistance genes, YrKyI and YrKy2. YrKyl is effective against CY29, ineffective against Su-1 and CY3 1, and is differed from the known genes used in this test. YrKy2 is resistant to CY29, Su-l and CY31, and is allelic or closely linked to a gene in T Spelta album. YrKy] and YrKy2 complementarily confer the resistance to CY29. Based on the pedigree, we postulated that the genes in Kangyin655 could be from CkopoClleJlka ? B. Virgilio has at least two genes, Yrfrirl and YrVir2. The dominant gene YrVirI is effective against Su- 1, but not against CY 17 and CY23. The other gene Yr Vir2, which is effective against CY17 and CY23, but not against Su-l, is recessive and dominant depending on whether Virgilio is used as female or male parent. It was indicated that Virgilio maybe have a odifying factor?in its cytoplasm. YrVir2 was dominant when interacted with the odifying factor? and recessive when not. 48 F3 progenies from the cross of Mingxianl69 with Virgilio were used to identify the major genotype for resistance to CY1 7 and CY23, respectively. Based on mean and variance of each F3 progeny resistance index, those 48 progenies could be separated into 3 groups. The amount of plants in those 3 groups fitted the expected segregation ratio, 1:2:1. It was proved further that Virgilio has one major resistance gene locus to CY17 and CY23, respectively, and the separation of F, population was correct. To determine the chromosome location of the gene YrJu3 for resistance to Su- 1 and CY3 1, Jubilej nail was crossed with a set of susceptible T spelta aneuploids. F, seeds were obtained from self-pollinated monosomic F1 plants. Seedlings of F2 plants were inoculated with CY3 1 and Su- 1, respectively. The results showed that YrJu3 was located on chromosome 4B. Up to date, YrMor in Moro, Yr Yam in Yamhii, and YrCle in Clement were reported on chromosome 4B. Based on semi-diallele cross of Jubilejnall with Moro, YrJu3 was differed from YrMor. Yr Yam was reported from Alba which was one of the parents of Yamhii. Both Alba and Clement were ineffective to CY3 1. Thus, we confirmed that YrJu3 is a previously undescribed gene and is not as same as Yr Yam or YrCle. Jubilejnali... |
PDF Full Text Request