與 “Thatcher”類似的 “RL6077” 基因型小麥被公認為攜帶有Lr34/Yr18基因,,該基因賦予小麥抗葉銹病和條銹病的成株植物抗性 (APR),。然而,在RL6077全基因序列中使用分子標記卻無法尋找到該基因,。
國際玉米和小麥改良中心(CIMMYT)的Sybil A. Herrera-Foessel和其他科學家把RL6077與敏感型小麥“Avocet”雜交,,從光敏感植株中分離獲得葉銹病和條銹病抗性植株。此品種已在各個地點種植并接受抗性評估,。結(jié)果表明,,其確實與銹病響應相關,該基因或緊密連鎖的基因能夠抵抗上述兩種銹病,。通過分子定位,,在4DL染色體上確定了五個分子標記。
與此同時,加拿大的研究者把Thatcher和RL6077雜交后,,在相同的染色體區(qū)域發(fā)現(xiàn)同一個基因(Lr67),,將其命名為Yr46,他們認為Lr67/Yr46可與其他抗銹病基因共同使用,,起到小麥抗葉銹病和條銹病的補償作用,。(生物谷Bioon.com)
生物谷推薦英文摘要:
TAG Theoretical and Applied Genetics DOI: 10.1007/s00122-010-1439-x
New slow-rusting leaf rust and stripe rust resistance genes Lr67 and Yr46 in wheat are pleiotropic or closely linked
Sybil A. Herrera-Foessel, Evans S. Lagudah, Julio Huerta-Espino, Matthew J. Hayden, Harbans S. Bariana, Davinder Singh and Ravi P. Singh
The common wheat genotype ‘RL6077’ was believed to carry the gene Lr34/Yr18 that confers slow-rusting adult plant resistance (APR) to leaf rust and stripe rust but located to a different chromosome through inter-chromosomal reciprocal translocation. However, haplotyping using the cloned Lr34/Yr18 diagnostic marker and the complete sequencing of the gene indicated Lr34/Yr18 is absent in RL6077. We crossed RL6077 with the susceptible parent ‘Avocet’ and developed F3, F4 and F6 populations from photoperiod-insensitive F3 lines that were segregating for resistance to leaf rust and stripe rust. The populations were characterized for leaf rust resistance at two Mexican sites, Cd. Obregon during the 2008–2009 and 2009–2010 crop seasons, and El Batan during 2009, and for stripe rust resistance at Toluca, a third Mexican site, during 2009. The F3 population was also evaluated for stripe rust resistance at Cobbitty, Australia, during 2009. Most lines had correlated responses to leaf rust and stripe rust, indicating that either the same gene, or closely linked genes, confers resistance to both diseases. Molecular mapping using microsatellites led to the identification of five markers (Xgwm165, Xgwm192, Xcfd71, Xbarc98 and Xcfd23) on chromosome 4DL that are associated with this gene(s), with the closest markers being located at 0.4 cM. In a parallel study in Canada using a Thatcher × RL6077 F3 population, the same leaf rust resistance gene was designated as Lr67 and mapped to the same chromosomal region. The pleiotropic, or closely linked, gene derived from RL6077 that conferred stripe rust resistance in this study was designated as Yr46. The slow-rusting gene(s) Lr67/Yr46 can be utilized in combination with other slow-rusting genes to develop high levels of durable APR to leaf rust and stripe rust in wheat.