Characteristics improving bean resistance to drought identified

July 5, 2016, Universitat Autonoma de Barcelona
Experimental bean plantations in Palmira, Colombia. Credit: UAB / Center for Tropical Agriculture in Colombia

The common bean (Phaseolus vulgaris L.) is the most important food legume in the tropics. It is an inexpensive source of proteins and minerals for almost 400 million people, mainly from Africa and Latin America. It is generally cultivated by small farmers and subject to conditions limiting their productivity. Drought affects 60% of bean crops around the world and can cause from 10% in productivity losses to a total of 100% in some cases.

Researchers from the Universitat Autònoma de Barcelona and the Bean Programme at the International Center for Tropical Agriculture (CIAT) in Colombia have identified drought-resistant genotypes and the morpho-physiological characteristics related to this resistance. The experiments were conducted in Palmira, Colombia, from June to September in 2012 and 2013, and the results were recently published in Frontiers in Plant Science.

For researcher at the UAB Plant Physiology Laboratory and the International Centre for Tropical Agriculture José Arnulfo Polanía, "the experiments demonstrate that there is no dominant morph-physiological characteristic but rather a strategic combination of several characteristics which confers this resistance to drought onto specific varieties of beans". Polanía adds that "we determined which specific characteristics belonged to each area, depending on whether or not the land retained moisture and whether the droughts were intermittent or ongoing".

The study has revealed this strategic combination of characteristics, the key to succeeding in the genetic improvement of drought resistance. After evaluating 36 advanced bean lines, obtained by crossing different varieties, and taking into account the results of different parameters related to the use of , growth and production, the lines of drought-resistant beans were classified into two groups: water "savers" and "spenders".

The "water saver" genotypes were identified for having several morpho-physiological characteristics which allow them to save water: less opening of the stomas, small leaves, moderate growth, and efficiency in remobilising carbon from the leaves and stems to the formation of sheath and grain. These genotypes correspond to the bean lines SER 16, ALB 60, ALB 6, BFS 10, BFS 29 and G40001, suitable for cultivation in semi-arid regions where extreme droughts are common and the land does not retain much moisture, as can be found in areas of Central America, Africa and the south of Mexico.

In contrast, the "water spender" genotypes include a system of deep roots which maximise water extraction, allowing them to grow more, combined with an efficient remobilisation of their reserves through the stem and leaves to the formation of sheath and grains, thus producing more grain even under stressful conditions. These correspond to the lines NCB 280, NCB 226, SEN 56, SCR 2, SCR 16, SMC 141, RCB 593 and BFS 67, and are appropriate for areas with intermittent droughts, on soils which can retain moisture. These areas correspond to Central America, South America and Africa.

Explore further: The Mesoamerican bean decoded

More information: Jose A. Polania et al, Effective Use of Water and Increased Dry Matter Partitioned to Grain Contribute to Yield of Common Bean Improved for Drought Resistance, Frontiers in Plant Science (2016). DOI: 10.3389/fpls.2016.00660

Related Stories

The Mesoamerican bean decoded

February 24, 2016

An Ibero-American team of scientists decoded the Mesoamerican variety of the bean genome coinciding with the celebration of the International Year of Pulses, as designated by the United Nations. Sequencing such a common source ...

Image: Root-zone soil moisture map

May 13, 2016

ESA's SMOS mission was launched in 2009 to provide global observations of soil moisture and ocean salinity – two important variables in Earth's water cycle. While this novel Earth Explorer satellite continues to advance ...

Central America tests drought-resistant 'miracle' beans

December 1, 2015

"These beans are miraculous because they beat droughts," crowed Manuel Ceren, a farmer in El Salvador trying out a hybrid, climate change-defying crop produced by Salvadoran, Colombian and Honduran experts.

Kaolin effectively controls whitefly in beans

January 5, 2016

In Colombia, bean crops contribute significantly to the region's agriculture. Because these important crops are vulnerable to pests and diseases, growers often need to rely on chemicals to protect valuable crops. New research ...

Recommended for you

Why do Hydra end up with just a single head?

January 18, 2019

Often considered immortal, the freshwater Hydra can regenerate any part of its body, a trait discovered by the Geneva naturalist Abraham Trembley nearly 300 years ago. Any fragment of its body containing a few thousands cells ...

How our cellular antennas are formed

January 17, 2019

Most of our cells contain an immobile primary cilium, an antenna used to transfer information from the surrounding environment. Some cells also have many mobile cilia that are used to generate movement. The 'skeleton' of ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.