TY - JOUR
T1 - Resistance to Puccinia polysora in maize accessions
AU - Chávez-Medina, J. Alicia
AU - Leyva-López, Norma E.
AU - Pataky, Jerald K.
PY - 2007/11
Y1 - 2007/11
N2 - 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 Pl 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 x Rpp9) x PS were resistant. Resistance in Ames 19016 (Va59) was effective in F1 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 F1 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.
AB - 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 Pl 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 x Rpp9) x PS were resistant. Resistance in Ames 19016 (Va59) was effective in F1 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 F1 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.
KW - Rpp genes
UR - http://www.scopus.com/inward/record.url?scp=35348931032&partnerID=8YFLogxK
U2 - 10.1094/PDIS-91-11-1489
DO - 10.1094/PDIS-91-11-1489
M3 - Artículo
SN - 0191-2917
VL - 91
SP - 1489
EP - 1495
JO - Plant Disease
JF - Plant Disease
IS - 11
ER -