Affiliation:
1. Universidade Federal de Viçosa, Brasil
2. EPAMIG
3. Universidade Federal de Viçosa, Brasil; Universidade Federal de Viçosa
4. Universidade Federal de Viçosa, Brasil; Universidade Federal de Viçosa, Brasil
Abstract
The pathogenic variability of the fungus Colletotrichum lindemuthianum represents an obstacle for the creation of resistant common bean (Phaseolus vulgaris L.) varieties. Gene pyramiding is an alternative strategy for the development of varieties with durable resistance. RAPD markers have been proposed as a means to facilitate pyramiding of resistance genes without the need for multiple inoculations of the pathogens. The main aims of this work were to define the inheritance pattern of resistance present in common bean cultivar AB 136 in segregating populations derived from crosses with cultivar Rudá (susceptible to most C. lindemuthianum races) and to identify RAPD markers linked to anthracnose resistance. The two progenitors, populations F1 and F2, F2:3 families and backcross-derived plants were inoculated with race 89 of C. lindemuthianum under environmentally controlled greenhouse conditions. The results indicate that a single dominant gene, Co-6, controls common bean resistance to this race, giving a segregation ratio between resistant and susceptible plants of 3:1 in the F2, 1:0 in the backcrosses to AB 136 and 1:1 in the backcross to Rudá. The segregation ratio of F2:3 families derived from F2 resistant plants was 1:2 (homozygous to heterozygous resistant). Molecular marker analyses in the F2 population identified a DNA band of approximately 940 base pairs (OPAZ20(940)), linked in coupling phase at 7.1 cM of the Co-6 gene. This marker is being used in our backcross breeding program to develop Rudá-derived common bean cultivars resistant to anthracnose and adapted to central Brazil.
Subject
Genetics,Molecular Biology
Reference23 articles.
1. A single gene or complex locus of linked resistance genes confer resistance to four pathotypes of Colletotrichum lindemuthianum in common bean;Alzate-Marin A.L.;Phytopathology,1999
2. Backcross assisted by RAPD markers for the introgression of Co-4 and Co-6 anthracnose resistant genes in common bean cultivars;Alzate-Marin A.L.;Ann. Rpt. Bean Improv. Coop.,1999
3. Isolation of plant DNA from fresh tissue;Doyle J.J.;Focus,1990
4. Identification de RAPD markers linked to a major rust resistance gene block in common bean;Haley S.D.;Theor. Appl. Genet.,1993
5. Selection for monogenic resistance traits with coupling and repulsion-phase RAPD markers;Haley S.D.;Crop Sci.,1994
Cited by
16 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献