Drought Tolerance in Wild Plant Populations: The Case of Common Beans (Phaseolus vulgaris L.)

Abstract

Reliable estimations of drought tolerance in wild plant populations have proved to be challenging and more accessible alternatives are desirable. With that in mind, an ecological diversity study was conducted based on the geographical origin of 104 wild common bean accessions to estimate drought tolerance in their natural habitats. Our wild population sample covered a range of mesic to very dry habitats from Mexico to Argentina. Two potential evapotranspiration models that considered the effects of temperature and radiation were coupled with the precipitation regimes of the last fifty years for each collection site based on geographical information system analysis. We found that wild accessions were distributed among different precipitation regimes following a latitudinal gradient and that habitat ecological diversity of the collection sites was associated with natural sub-populations. We also detected a broader geographic distribution of wild beans across ecologies compared to cultivated common beans in a reference collection of 297 cultivars. Habitat drought stress index based on the Thornthwaite potential evapotranspiration model was equivalent to the Hamon estimator. Both ecological drought stress indexes would be useful together with population structure for the genealogical analysis of gene families in common bean, for genome-wide genetic-environmental associations, and for postulating the evolutionary history and diversification processes that have occurred for the species. Finally, we propose that wild common bean should be taken into account to exploit variation for drought tolerance in cultivated common bean which is generally considered susceptible as a crop to drought stress.

Climatic adaptation and ecological descriptors of wild beans from Mexico

“…The most widely used strategy consists of the identification of wild and landrace germplasm resistant to drought stress (Cortés, Monserrate, Ramírez‐Villegas, Madriñán, & Blair, 2013; Porch et al., 2013). Some traits in wild P. vulgaris accessions have been associated with resistance to water stress.…”

“…The use of environmental information in breeding programs has been promoted by the use of methodologies that can predict the presence of specific traits in germplasm growing at specific locations with consequent savings of time and cost (Cortés et al., 2013; Parra‐Quijano et al., 2012; Rodriguez et al., 2015; Song et al., 2015; Thormann et al., 2015; von Wettberg, Marques, & Murren, 2016). However, conservation programs are not considered important by the government and have therefore not received economic support, resulting in the low representation of wild crop relatives in germplasm banks (Castañeda‐Álvarez et al., 2016; Maxted et al., 2016).…”

Legume Crops Phylogeny and Genetic Diversity for Science and Breeding

“…Perhaps because of their evolution outside the wetter regions where bacterial and fungal pathogens occur, tepary beans also provide high levels of resistance to specific Xanthomonas and rust infections, respectively. Recently, Cortés et al (2012aCortés et al ( , 2012bCortés et al ( and 2013 analyzed the drought tolerance of wild common beans based on climatic data for each accession's collection site and found a correlation with allelic diversity in candidate genes for drought tolerance, such as the ASR and DREB transcription factors.…”

Genome-wide identification and characterization of aquaporin gene family in common bean (Phaseolus vulgaris L.)

“…Wild common bean is organized into two genetically different gene pools (Mesoamerican and Andean) (Koenig and Gepts 1989;Kwak and Gepts 2009;Mamidi et al 2013), with a broad environmental distribution in Mexico and Central to South America (Cortés et al 2013). These two gene pools were independently domesticated in what is now Mexico and South America (Gepts et al 1986;Bitocchi et al 2013) about 8,000 years ago.…”