Agronomic performance of common bean germplasm under high temperatures conditions in southern Honduras

Abstract

Common bean (Phaseolus vulgaris L.) production in Central America is threatened by increases in temperature caused by climate change and by expansion of common bean production into lowland, higher temperature areas like the Peten region in Guatemala, north coast of Honduras and Eastern Nicaragua. Most traditional bean cultivars are affected by high temperatures. Improved cultivars released during the past decades are better adapted to warmer temperature conditions in tropical lowlands, but over time could be affected due to continued increases in temperature. The objective was to identify bean accessions tolerant to high temperatures with desirable agronomic performance and commercial seed types for their release as cultivars or their use as parents in breeding programs. Three hundred twelve common bean germplasm accessions and improved lines were evaluated in trials conducted in different planting seasons during 2015-16 in Nacaome, a location in southern Honduras where high day (>36 °C) and night (>24 °C) temperatures are predominant year around. Heat tolerant bean lines were identified including the Andean landrace ‘Indeterminant Jamaica Red’, the Mesoamerican lines USMR20, SJC 730-79, MER 2212-28, ‘Beníquez’, SB-DT1, PR 9920-171 and FBN 1211-66, and the interspecific line INB 841. The greatest adaptation to high temperatures was observed in tepary bean (Phaseolus acutifolius A. Gray) lines used as tolerant checks. Among the common bean heat tolerant lines with good agronomic adaptation and seed yield, some lines have been released as cultivars or used as parents in breeding programs.