Simulating drought tolerance of peanut varieties by maintaining photosynthesis under water deficit

Authors: ZHEN, XIAOXING - Auburn University; ZHANG, QIONG - Auburn University; SANZ-SAEZ, ALVARO - Auburn University; CHEN, CHARLES - Auburn University; Dang, Phat; BATCHELOR, WILLIAM - Auburn University

Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2022
Publication Date: 8/26/2022
Citation: Zhen, X., Zhang, Q., Sanz-Saez, A., Chen, C., Dang, P.M., Batchelor, W. 2022. Simulating drought tolerance of peanut varieties by maintaining photosynthesis under water deficit. Field Crops Research. 287. Article 108650. https://doi.org/10.1016/j.fcr.2022.108650.
DOI: https://doi.org/10.1016/j.fcr.2022.108650

Interpretive Summary: Peanuts grown in the United States and around the world rely on rainfall for growth but are challenged with more severe and persistent drought events. Breeders are constantly in search for peanut plants with drought adaptive traits to maintain high yield under water-limited environments. Recently, several peanut varieties have been developed that exhibit drought tolerant characteristics. Crop models can be used to simulate the impact of these traits for different environments. The overall goal of this study was to develop an approach to simulate drought tolerant traits using the CROPGRO-Peanut model and assess the long-term yield response to these traits. Four peanut varieties and one advanced breeding line variety with varying degrees of drought tolerance response were grown under both field and environmentally controlled rainout shelter conditions in 2019 and 2020. The drought tolerant trait was the ability of peanut to maintain high photosynthesis under drought conditions observed in rainout shelter experiments and data was incorporated into the crop model as a new drought tolerance cultivar coefficient. The evaluation results with independent data showed that the modified model simulated peanut growth and yield under water-limited conditions reasonably well. The drought tolerant mechanism of maintaining photosynthesis under drought condition was shown to be an advantageous trait for peanut varieties, which produced higher simulated rainfed yield. Research results enhance knowledge of peanut drought characteristics and will facilitate the development of drought tolerant peanut varieties.

Technical Abstract: Over two-third of global peanuts are grown mainly in seasonally rainfed regions across arid and semi-arid zones where drought is a major yield limiting factor. Breeders are targeting drought adaptive traits by selecting high yielding genotypes under water-limited environments. Recently, several peanut varieties have been developed that exhibit drought tolerant characteristics. Crop models can be used to simulate the impact of these traits for different environments. The overall goal of this study was to develop an approach to simulate drought tolerant traits using the CROPGRO-Peanut model and assess the long-term yield response to these traits. Four peanut varieties and one advanced breeding line variety with varying degrees of drought tolerance response were grown under both field and rainout shelter conditions in 2019 and 2020. The trait of maintaining photosynthesis under water deficit was observed in the rainout shelter experiments and incorporated into the crop model as a new drought tolerance cultivar coefficient. The evaluation results with independent data showed that the modified model simulated peanut growth and yield under water-limited conditions reasonably well. The rainfed yield, seasonal evapotranspiration (ET), and grain water use efficiency (WUE) were simulated for both drought tolerant and baseline peanut varieties at two representative sites using weather data from 1998-2020. The drought tolerant mechanism of maintaining photosynthesis under water deficit was shown to be an advantageous trait for peanut varieties, which produced higher simulated rainfed yield with enhanced seasonal ET and grain WUE, especially for dry seasons. Using sensitivity analysis, the simulated photosynthesis and yield was sensitive to values of the drought tolerant factor over an expected range of values. Further research is needed on other potential drought tolerant mechanisms, such as maintaining nitrogen fixation, pod harvest index and leaf growth under drought.