Tropical Traits for Temperate Beans

Dry common beans—favorites like pinto, kidney, navy, red, black and snap—are grown mostly in the north-central and western regions of the United States. But thousands of miles away, Agricultural Research Service (ARS) geneticist Timothy Porch is working to make good beans even better.

Porch conducts research at the Tropical Agriculture Research Station in Mayagüez, Puerto Rico. He is looking for ways to reduce heat stress in common beans (Phaseolus vulgaris) grown in the continental United States by breeding heat-tolerant varieties.

Most common beans are adapted to relatively cool climates. But in the United States, common beans are cultivated at average temperatures that can exceed 86 degrees Fahrenheit during the day. These hot summers can hinder the reproductive development of bean crops, which in turn results in smaller potential yields.

However, tropical varieties of Phaseolus contain a much greater range of genetic diversity than the types commercially cultivated in the United States, and may carry traits that protect against heat stress. Porch is trying to bolster U.S. beans with high-temperature adaptations and other producer-friendly traits, such as drought tolerance and disease resistance.

In his search to find novel genetic traits, Porch has worked with two major germplasm centers: the International Center for Tropical Agriculture, in Cali, Colombia; and the ARS Western Regional Plant Introduction Station at Pullman, Wash.

Porch's research will support plant breeders' efforts to develop new bean varieties to meet market demands, increase yields and lower consumer costs. Producers will also be better positioned to respond to possible challenges in the future from emerging diseases and climate change.

Read more about the research in the November/December 2007 issue of Agricultural Research magazine.

ARS is the U.S. Department of Agriculture's chief scientific research agency.