Molecular marker-assisted backcrossing of anthracnose resistance genes into common beans (Phaseolus vulgaris L.) varieties
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Date
2021-05-26
Journal Title
Journal ISSN
Volume Title
Publisher
Scientific Research Publishing Inc.
Abstract
Anthracnose, caused by Colletotrichum lindemuthianum, is a major disease
of common bean and results in high yield loss. Due to the high degree of
pathogenic variability of the fungus and the continual emergence of new
races, genetic resistance in the host is not durable. Gene pyramiding using
Marker Assisted Selection (MAS) is proposed as a viable approach to improve
the durability of major genes conditioning resistance to anthracnose. In this
study a common bean line Urugezi x AND 1062 susceptible to anthracnose
but already improved for Pythium root rot resistance was improved for an thracnose resistance through a backcross breeding program. Genotypic selec tion was done in Rubilizi laboratory in Kigali, Rwanada whereas phenotypic
selection was conducted in an anthracnose hotspot at Rwerere, a research
Centre of the Rwanda Agricultural and Animal Resources Development
Board (RAB). Analysis of variance for effect of bean varieties and anthracnose
isolates on disease expression showed significant differences (p < 0.001)
among varieties and isolates and for the interaction between isolates and va rieties. Developed BC2F1 plants were 41% of them resistant and 59% suscepti ble to anthracnose. However, the observed proportion of 26 resistants and 37
susceptible in BC2F1 plants didn’t fit the goodness of fit of the expected pro portion of 75 resistants to 25 susceptible. Only 41% of BC2F1 plants inherited
the resistance genes and were phenotypically resistant. Presence of
SCAR-markers, SAB3 and SBB14, in the developed resistant lines h suggested
successful resistance transfer of anthracnose resistance genes.
Description
Journal article
Keywords
Anthracnose, Common Bean, Resistance Genes, Pythium root rot
Citation
Uwera, A., Rusa-gara, J.N., Msolla, S.N., Musoni, A. and Assefa, T. (2021) Molecular Marker-As-sisted Backcrossing of Anthracnose Resis-tance Genes into Common Beans (Phaseo-lus vulgaris L.) Varieties. American Journal of Plant Sciences, 12, 771-781.