Beans, beans, beans

A few of the 50 bean genotypes from tepary, common and lima bean species that Viviana Medina worked on in her PhD.

Phaseolus diversity in response to water stress

Viviana Medina has pioneered work on the physiological adaptations of three species of Phaseolus. This work was in close collaboration with Paul Gepts, Jorge Berny and Sarah Dohle and has led to development of a number of manuscipts…more coming soon.

Vivi, with her 800 children in the background.

The take home message is that there is little difference in response of beans to severe water deficits, as determined by Vivi’s innovative experiment:

We found that if soil water deficit was controlled by using shared pots, then there were remarkably little differences in ‘drought response’ between species and genotypes. That is, leaf area differences in conventional experiments lead to differences in soil drydown rates and thus stress.

News coverage of Vivi’s project

Crop Science Society of America poster of Vivi’s

Viviana and Rafael and our 1960’s tractor, planting Vivi’s field experiment in 2015. UC Davis supports it’s ag so well that when the brakes failed on the tractor it was replaced with a reconditioned pre-WWII tractor. It’s not as if our College is number 1 in the world in Agriculture.
The ‘BeanOCart’ a high-throughput cart for phenotyping: canopy temperature, plant height, PRI, NDVI and canopy cover (RGB camera) of two rows of beans. Vivi and I constructed this after visiting the USDA Arizona phenotyping course. Thanks to the UC Davis recycle-bicycle unit for the donation of the many MTB tires.

Phaseolus diversity in stomatal responses to the atmospheric environment

The Gilbert and Gepts labs focus on bean physiology has led to publication of a large dataset relating stomatal condcutance to the atmospheric evaporative demand:

  • Medina, V. Berny-Mier Teran, JC. Gepts, P. & Gilbert, ME. (2017). Low stomatal sensitivity to vapor pressure deficit in irrigated common, lima and tepary beans. Field Crops Research. TBD.
  • Medina, V. & Gilbert, ME. (2016). Physiological trade-offs of stomatal closure under high evaporative gradients in field grown soybean. Functional Plant Biology, 43(1), 40-51.