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Inheritance of White Mold Resistance in an Andean Common Bean A 195 and its Relationship with Andean G 122
Author(s) -
Viteri Diego M.,
Singh Shree P.
Publication year - 2015
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/cropsci2014.02.0145
Subject(s) - sclerotinia sclerotiorum , phaseolus , biology , inoculation , germplasm , white (mutation) , botany , horticulture , resistance (ecology) , plant disease resistance , gene pool , agronomy , gene , genetics , genetic diversity , population , demography , sociology
White mold caused by Sclerotinia sclerotiorum (Lib.) de Bary is a devastating disease of common bean ( Phaseolus vulgaris L.) in cool and wet production regions of the Americas and elsewhere. Partial resistance is found in common bean, wild bean, and Phaseolus species of the secondary gene pool such as P. coccineus L. The objectives were to determine (i) the inheritance of white mold resistance in a large‐seeded Andean common bean breeding line A 195 in response to contrasting S. sclerotiorum isolates and (ii) the genetic relationship between A 195 and an Andean germplasm accession G 122. White mold resistant (scores ≤ 4) A 195 was crossed with susceptible (scores > 7) pinto ‘Othello’ and resistant G 122. The F 1 and the three parents were inoculated with an aggressive S. sclerotiorum isolate ND710 in 2011. Parents and F 2 from resistant F 1 plants were inoculated with the less aggressive isolate ARS12D at the fifth internode on the main stem and reinoculated (primary branch) with ND710 and evaluated at 35 d in 2012. Two independent complementary dominant genes controlled resistance in the F 2 of A 195/Othello in response to either isolate. There was no segregation in A 195/G 122 F 2 in response to ARS12D. But a single dominant gene controlled the difference in resistance between A 195 and G 122 to ND710. The F 3 results corroborated the F 2 segregation ratios in both populations. This information should help introgress and pyramid higher levels of white mold resistance into common bean cultivars of different market classes.