USDA-ARS, Northern Crop Science Laboratory, Fargo, ND 58102-2765, USA.
Theor Appl Genet. 2011 Jul;123(2):351-8. doi: 10.1007/s00122-011-1588-6. Epub 2011 Apr 11.
Rust is a serious fungal disease in the sunflower growing areas worldwide with increasing importance in North America in recent years. Several genes conferring resistance to rust have been identified in sunflower, but few of them have been genetically mapped and linked to molecular markers. The rust resistance gene R ( 4 ) in the germplasm line HA-R3 was derived from an Argentinean open-pollinated variety and is still one of most effective genes. The objectives of this study were to determine the chromosome location of the R ( 4 ) gene and the allelic relationship of R ( 4 ) with the R ( adv ) rust resistance gene. A total of 63 DNA markers previously mapped to linkage group (LG) 13 were used to screen for polymorphisms between two parental lines HA 89 and HA-R3. A genetic map of LG 13 was constructed with 21 markers, resulting in a total map length of 93.8 cM and an average distance of 4.5 cM between markers. Two markers, ZVG61 and ORS581, flanked the R ( 4 ) gene at 2.1 and 0.8 cM, respectively, and were located on the lower end of LG 13 within a large NBS-LRR cluster identified previously. The PCR pattern generated by primer pair ZVG61 was unique in the HA-R3 line, compared to lines HA-R1, HA-R4, and HA-R5, which carry other R ( 4 ) alleles. A SCAR marker linked to the rust resistance gene R ( adv ) mapped to LG 13 at 13.9 cM from the R ( 4 ) locus, indicating that R ( adv ) is not an allele of the R ( 4 ) locus. The markers tightly linked to the R ( 4 ) gene will facilitate gene pyramiding for rust resistance breeding of sunflower.
锈病是一种严重的真菌病害，在全球向日葵种植区普遍存在，近年来在北美地区的重要性日益增加。向日葵中有几个抗锈病的基因已被鉴定出来，但其中很少有被遗传定位并与分子标记联系起来。种质系 HA-R3 中的锈病抗性基因 R（4）来自阿根廷的开放授粉品种，仍然是最有效的基因之一。本研究的目的是确定 R（4）基因在染色体上的位置，以及 R（4）与 R（adv）锈病抗性基因的等位关系。总共使用了 63 个先前映射到连锁群（LG）13 的 DNA 标记来筛选两个亲本系 HA 89 和 HA-R3 之间的多态性。构建了 LG 13 的遗传图谱，其中包含 21 个标记，总图谱长度为 93.8 cM，标记之间的平均距离为 4.5 cM。两个标记 ZVG61 和 ORS581 分别位于 R（4）基因的 2.1 和 0.8 cM 侧翼，位于先前鉴定的大 NBS-LRR 簇的 LG 13 的下端。与携带其他 R（4）等位基因的 HA-R1、HA-R4 和 HA-R5 系相比，引物对 ZVG61 产生的 PCR 模式在 HA-R3 系中是独特的。与锈病抗性基因 R（adv）连锁的 SCAR 标记位于 R（4）基因座 13.9 cM 处，位于 LG 13 上，表明 R（adv）不是 R（4）基因座的等位基因。与 R（4）基因紧密连锁的标记将有助于向日葵锈病抗性基因的聚合育种。
