Registration of Two Mid‐Altitude Climbing Bean Germplasm Lines with Yellow Grain Color, MAC56 and MAC57

Journal of Plant Registrations, Vol. 1, No. 2, September 2007 143 Two common bean (Phaseolus vulgaris L.) germplasm lines with climbing growth habit and yellow seed type, MAC56 (Reg. No. GP-271, PI 644088) and MAC57 (Reg. No. GP-272, PI 644089) were released by the International Center for Tropical Agriculture (CIAT) for tropical mid-altitude growing conditions (1200 to 1800 masl). These novel mid-altitude climbing beans (MAC series) with type IVa growth habit are tolerant of higher temperatures (up to 24°C seasonal average) compared to traditional, type IVb growth habit, climbing beans from the Andean gene pool which are generally found at cooler temperatures (16–20°C seasonal average) (Evans, 1973; Woolley et al., 1991). The new germplasms have fast growth rates, maturing much earlier than traditional climbing beans. They also have good climbing ability but without the aggressive growth of the IVb types (Checa et al., 2004). Both MAC56 and MAC57 belong to the “Canario” commercial seed class that is native to Peru, Mexico, and some other countries of Latin America and Africa (Voysest et al., 1994; Voysest, 2000; Pallottini et al., 2004). MAC56 and MAC57 are advanced generation F8-derived breeding lines from the cross Doré de Kirundo/LAS399 where Doré de Kirundo (G21715 from the CIAT germplasm bank) is a large seeded, type III growth habit landrace from Burundi that produces yellow grain; and LAS399 is an improved breeding line from Colombia produced by joint research between ICA (Instituto Colombiano de Agricultura) and CIAT at the “La Selva” Agricultural Research Station in Rionegro, Antioquia. LAS399 has type IVb growth habit, fl owers and matures at 67 and 140 d, respectively, is resistant to anthracnose [caused by the pathogen Colletotrichum lindemuthianum (Sacc. & Magnus) Lams.-Scrib.], and produces large red grain of the Radical commercial seed class (up to 60 g per 100 seed weight). LAS399 was developed from the cross Registration of Two Mid-Altitude Climbing Bean Germplasm Lines with Yellow Grain Color, MAC56 and MAC57