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Inheritance of Improved Leaf Rust Resistance in Somaclones of Wheat
Author(s) -
Oberthur Laura E.,
Harrison Stephen A.,
Croughan Timothy P.,
Long David L.
Publication year - 1993
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1993.0011183x003300030006x
Subject(s) - biology , coker unit , rust (programming language) , somaclonal variation , botany , seedling , plant disease resistance , horticulture , poaceae , gene , genetics , tissue culture , metallurgy , in vitro , programming language , coke , materials science , computer science
Leaf rust of wheat ( Triticum aestivum L.) caused by Puccinia recondita Roberge ex Desmaz. f. sp. tritici ( Prt ) has been controlled through incorporation of genetic resistance into host genotypes. Somaclonal variation may provide additional sources of resistance genes. This study was conducted to determine the gene source and inheritance of improved resistance to leaf rust found in somaclones of ‘Coker 916’. Two wheat somaclones, regenerated from immature embryo‐derived calli of Coker 916, had increased field resistance to leaf rust and were screened with 36 Prt isolates to identify Lr genes. Screening results indicate Coker 916 contains Lr 3, 10, and possibly Lr l4a, 15, 20, and either 27 or 31. The pedigree of Coker 916 includes known sources of Lr l, 3, 10, 11, 14a, and 27 seedling‐resistance genes. The two somaclones, LTC 122 and LTC 140, contain Lr 3, Lr 10, and additional resistance genes not found in Coker 916, possibly Lr genes 1, 3ka, 9, 14a, 15, 18, 20, 23, 27, 30, 31, 32, and/or 33. Four R l ‐derived R 2 LTC 122 lines reacted identically to leaf rust isolates; thus the altered resistance may have been monogenic in the R 0 plant. Crosses were made between Coker 916 and the somaclones. The F 2 progeny of LTC 122 × Coker 916 contained both Lr 3 and LR10 and segregated for two additional independent, dominant resistance genes in a 15 (low disease reaction): 1 (high disease reaction) ratio. Somaclonal variants should be useful sources of additional resistance to foliar pathogens.