Abstract

GARZON, Luz Nayibe; BLAIR, Matthew W.  and  LIGARRETO, Gustavo A.. Use of molecular marker assisted selection for resistance to anthracnose in common beans. Agron. colomb. [online]. 2007, vol.25, n.2, pp.207-214. ISSN 0120-9965.

The anthracnose caused by Colletotrichum lindemuthianum is one of the most significant diseases in beans (Phaseolus vulgaris L.) and can produce yield losses up to 95%. In this study, a breeding program utilizing molecular marker assisted selection (MAS) was initiated. In order to obtain commercial Colombian climbing beans resistant to C. lindemuthianum, the program incorporated genes Co-5 and Co-4²taken from G2333, a resistant Mesoamerican cultivar. From the crosses between G2333 and seven cultivated Andean beans, were obtained progenies RC₁F₁. The cultivated Andean beans included Bola roja and Rojo moteado types gathered from Cundinamarca and Boyacá crops. The BC₁F₁ plants were selected using the SCARs molecular markers SAB3 and SAS13 linked to Co-5 and Co-4² genes, respectively. In a genotypic evaluation of 1.271 RC₁F₁ plants, 608 and 603 were amplified with SAB3 and SAS13, respectively. The segregation expected ratio (1:1) in X² tests was obtained for each molecular marker indicating X² = 2,38, P = 0,12 for SAB and X² = 33,32, P = 0,07 for SAS13. The amplification with both molecular markers was obtained in 299 plants BC1F1, according to the expected ratio (X² = 1,11, P = 0,78) adjusted to the independent segregation. These plants were selected to continue the breeding program. In this study, a molecular marker assisted selection was implemented and introduction of resistant genes into commercially important Colombian beans was accelerated.

Keywords : Colletotrichum lindemuthianum; breeding; genes Co-4² and Co-5; SAB3; SAS13.

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