Beans, beans, beans

Two bean projects

Project 1: Viviana Medina (a PhD student in my lab) and Jorge Berny ran many bean experiments (2015-2017) in collaboration with Matthew and Paul Gepts.
Project 2: A large team of UC Davis researchers continued this work on Jorge's MAGIC population in an (2020-2023) USDA funded grant A synoptic approach to physiological breeding for drought resilience in bean: https://portal.nifa.usda.gov/web/crisprojectpages/1022320-a-synoptic-approach-to-physiological-breeding-for-drought-resilience-in-bean.html

Project 1: 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 many publications.

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:

shared pots 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

Drought and the Bean Stalk

How two popular types of dry beans deal with drought stress.

planting field experiment — 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.

Project 2: A synoptic approach to physiological breeding for drought resilience in bean

Field trials

In 2021 and 2022 we ran field trials in Davis on hundreds of genotypes of common bean (Jorge's MAGIC population). We used neutron probes (installation left image) to measure soil moisture.

Troy Magney and Chris Wong (post-doc on the project) put up a hyperspectral sensing tower (right image) to measure each plot; see: Wong et al. (2023). https://doi.org/10.34133/plantphenomics.0021

We ran the experiments providing terminal drought and Chris measuring gas exchange (right image). A field day allowed us to show case the work (left image).

Root trial

To explain the field results we chose to do a 'bioassay'-type screening root trial. Are drought tolerant bean genotypes deep rooted?

Main result: Root depth didn't vary as much between genotypes as biomass allocation did.

The greenhouse trial was able to measure ~300 root tubes over a month, using the protocol of:

Berny Mier y Teran, JCTA. Konzen, ER. Medina, VPhD. Palkovic, A. Ariani, A. Tsai, SM. Gilbert, ME. Gepts, P. (2019) Root and shoot variation in relation to potential intermittent drought adaptation of Mesoamerican wild common bean (Phaseolus vulgaris L.), Annals of Botany, https://doi.org/10.1093/aob/mcy221

root tube attachement — When making caps for root tubes glue doesn't work on the tubes, but after many trials we found that physical plastic rivets work well.

root washing — Washing roots with water.

root weighing — Prototyping a weighing system to evaluate where in the soil profile water is being taken up. Here we weighed the pot/tube at the beginning and end of a week drought, BUT weighted it as if it was a see-saw. By weighing the tube at the base and just past the middle we can detect whether water extraction took place in deep or shallow layers.

Publications include:

Wong, CYS. et al (in press) PhenoSpec: A mobile tower-based remote sensing system for continuous high-throughput phenotyping of vegetation physiology. Plant Methods

Wong, CYS. Gilbert, ME. Pierce, MA. Parker, TA. Palkovic, A. Gepts, P. Magney, TS. Buckley, TN. (2023) Hyperspectral Remote Sensing for Phenotyping the Physiological Drought Response of Common and Tepary Bean. Plant Phenomics 5, 0021 https://doi.org/10.34133/plantphenomics.0021

Medina, V.PhD Berny-Mier Teran, JC.TA Gepts, P. & Gilbert, ME. (2017). Low stomatal sensitivity to vapor pressure deficit in irrigated common, lima and tepary beans. Field Crops Research 206: 128-137 https://www.sciencedirect.com/science/article/pii/S0378429016306499

Gilbert, ME., & Medina, V.PhD (2016). Drought Adaptation Mechanisms Should Guide Experimental Design. Trends in Plant Science, 21(8), 639-647.

Medina, V.PhD & Gilbert, ME. (2016). Physiological trade-offs of stomatal closure under high evaporative gradients in field grown soybean. Functional Plant Biology, 43(1), 40-51.