Chávez-Medina J Alicia, Leyva-López Norma E, Pataky Jerald K
Departamento de Agropecuario, Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional-IPN, Unidad Sinaloa, Guasave, Sinaloa, Mexico.
Department of Crop Sciences, University of Illinois, Urbana 61801.
Plant Dis. 2007 Nov;91(11):1489-1495. doi: 10.1094/PDIS-91-11-1489.
A number of potential sources of general and specific resistance to southern corn rust were identified from 1,890 plant introduction accessions that were screened for reactions to Puccinia polysora race 9. Resistance appeared to differ among four accessions on which uredinia were not observed in initial screenings. Resistance to P. polysora in PI 186215 (Argentine inbred 2-687) was a chlorotic fleck, hypersensitive reaction that was conditioned by a single, dominant gene that was allelic with or very closely linked to the Rpp9 gene based on tests of allelism. All but 3 of 2,357 testcross progeny, (inbred 2-687 × Rpp9) × P were resistant. Resistance in Ames 19016 (Va59) was effective in F progeny and appeared to be dominant and simply inherited; however, this resistance appeared to be a slow-rusting or incomplete resistance that was effective in adult plants but not in young seedlings. Severity of southern rust was less than 10% on resistant progeny from crosses with Va59 compared with severity exceeding 70% on susceptible progeny. Resistance in plant introduction (PI) 186209 (Venezuelan flint) and NSL 75976 (IA DS61) were not effective in F hybrid combination and, thus, probably have limited value in commercial maize. Resistance in PI 186209 may be conditioned by a single recessive gene and resistance in NSL 75976 may be co-dominant.
从1890份植物引进种质资源中筛选了对多堆柄锈菌9号生理小种的反应，鉴定出了一些对南方玉米锈病具有一般和特殊抗性的潜在来源。在初步筛选中未观察到夏孢子堆的4份种质资源的抗性似乎有所不同。PI 186215（阿根廷自交系2 - 687）对多堆柄锈菌的抗性表现为褪绿斑点，即过敏反应，由一个显性单基因控制，根据等位性测试，该基因与Rpp9基因等位或紧密连锁。在2357个测交后代中，除3个外，（自交系2 - 687×Rpp9）×P均具有抗性。Ames 19016（Va59）的抗性在F代后代中有效，似乎是显性且简单遗传的；然而，这种抗性似乎是一种慢锈性或不完全抗性，在成株中有效，但在幼苗中无效。与Va59杂交的抗性后代上南方锈病的严重程度低于10%，而感病后代上的严重程度超过70%。植物引进种质（PI）186209（委内瑞拉硬粒玉米）和NSL 75976（IA DS61）的抗性在F1杂交组合中无效，因此，在商业玉米中可能价值有限。PI 186209的抗性可能由一个隐性单基因控制，NSL 75976的抗性可能是共显性的。
