A low-cost method to rapidly and accurately screen for transpiration efficiency in wheat

Abstract

BackgroundWheat (Triticum aestivum L.) productivity is commonly limited by the availability of water. Increasing transpiration efficiency (biomass produced per unit of water used, TE) can potentially lead to increased grain yield in water-limited environments (‘more crop per drop’). Currently, the ability to screen large populations for TE is limited by slow, low-throughput and/or expensive screening procedures. Here, we propose a low-cost, low-technology, rapid, and scalable method to screen for TE. The method uses a Pot-in-Bucket system that allows continuous watering of the pots and frequent monitoring of water use. To investigate the robustness of the method across environments, and to determine the shortest trial duration required to get accurate and repeatable TE estimates in wheat, plants from 11 genotypes varying in phenology were sown at three dates and grown for different durations in a polyhouse with partial environmental control.ResultsThe method revealed significant genotypic variations in TE among the 11 studied wheat genotypes. Genotype rankings for TE were consistent when plants were harvested the same day, at the flag-leaf stage or later. For these harvests, genotype rankings were consistent across experiments despite changes in environmental conditions, such as evaporative demand.ConclusionsThese results indicate that (1) the Pot-In-Bucket system is suitable to screen TE for breeding purposes in populations with varying phenology, (2) multiple short trials can be carried out within a season to allow increased throughput of genotypes for TE screening, and (3) root biomass measurement is not required to screen for TE, as whole-plant TE and shoot-only TE are highly correlated, at least in wheat. The method is particularly relevant in developing countries where low-cost and relatively high labour input may be most applicable.Electronic supplementary materialThe online version of this article (10.1186/s13007-018-0339-y) contains supplementary material, which is available to authorized users.

Development and application of a relative soil water content – transpiration efficiency curve for screening high water use efficiency wheat cultivars

“…That is, TE FC can be observed under soil moisture at field capacity or even saturated soil or water culture conditions. The situation is in accordance with Fletcher et al (2018), who measured the TE of wheat cultivated with sufficient water. Additionally, parameter b is significantly related to TE FC (Figure 9), b = 0.1806 × TE FC -1.2444 (R 2 = 0.7375, n = 12, p ≤ 0.01).…”

“…As is already known, variation in soil types (Ritchie, 1972;Tfwala et al, 2021), agronomic strategies such as fertilization (Hernandez et al, 2021) and organic amendments (Wang et al, 2021), growth regulators (Li et al, 2017(Li et al, , 2020, and environmental factors such as temperature (Vadez and Ratnakumar, 2016), atmospheric CO 2 concentration (Tausz-Posch et al, 2012;Christy et al, 2018) and VPD [atmospheric vapor pressure deficit, (Vadez et al, 2014)] might change the TE of a given cultivar. Previous studies have also reported alterations in the ranking of TE among varieties resulting from some of these factors (Zhao et al, 2008;Fletcher et al, 2018). Setting out to study the effects of such factors on the TE-RSWC curve and the underlying mechanisms will help us to understand changes in TE due to exposure to various surroundings.…”

“…Breeding for varieties with high transpiration efficiency (TE, biomass production per unit of transpiration) may help to achieve high WUE cultivars. However, the ability to screen cultivars with high TE from large populations is limited by slow, lowthroughput, and/or expensive screening procedures (Fletcher et al, 2018).…”

“…However, only 90% of soil evaporation is prevented with a 2 cm polyethylene bead layer. Fletcher et al (2018) provided a small pot-in-bucket method to rapidly and accurately screen for high TE wheat cultivars. However, the shortcoming of the pot-in-bucket method is that only one soil moisture can be formed due to the method of water supplementation.…”

Winter wheat crop water consumption and its effect on yields in southern Romania, in the very dry 2019-2020 agricultural year

“…Evaporation (E) refers to the loss of water from the soil where the crop is placed. Specific literature has been used and methods for determining transpiration (T) (Fletcher et al, 2018) or evapotranspiration (Lu et al, 2018;Kenjabaev et al, 2020) in wheat have been assimilated. Using the CROPWAT model (Smith et al, 2002) and the Mark Marsalis model (ACES, 2018), we were able to simulate the required daily plant consumption over the entire vegetation period.…”