July 2022: Water Use Efficiency in Popcorn: Which Physiological Traits Would Be Useful in Breeding?

Dear PhotosynQ User,

Welcome to the PhotosynQ community newsletter!

We have the following study by Leite et al. (2021) as our featured project this month. This study conducted to identify the key physiological trait in popcorn plants to facilitate breeding for water use efficiency. We hope you enjoy reading our selected study and please stay safe and healthy!

Best,

PhotosynQ Team

Jhean Torres Leite, Antonio Teixeira do Amaral Junior, Samuel Henrique Kamphorst , Valter Jário de Lima, Divino Rosa dos Santos Junior, Kátia Fabiane Mereiros Schmitt, Yure Pequeno de Souza, Talles de Oliveira Santos, Rosimeire Barboza Bispo, Gabrielle Sousa Mafra, Eliemar Campostrini and Weverton Pereira Rodrigues

Water Use Efficiency in Popcorn (Zea mays L. var. everta): Which Physiological Traits Would Be Useful for Breeding?

https://doi.org/10.3390/plants10071450

Breeding for drought tolerance is one of the key priorities in corn research. The water shortage at reproductive stage can cause 20-30% yield losses in corn. Identification of key physiological traits to facilitate the selection is paramount for the success of the corn breeding programs.

Leite et al. (2021) characterized a set of popcorn inbred lines for the root phenotype in association with such physiological traits.

They used a MultispeQ to measure the maximum quantum efficiency of photosystem II.

Fig 1. genotypic correlations between shoot and root physiological and morphological characteristics under water stress. PH = plant height; LA = leaf area; SDW = stem dry weight; LDW = leaf dry weight; ShDW/RDW = shoot dry weight/root dry weight ratio; LW = leaf width; LL = length of the leaf midrib; SD = stem diameter; A = net photosynthetic rate; gs = stomatal conductance; E = transpiration rate; VPD leaf/air = vapor pressure deficit; TL = leaf temperature; Fv/Fm = chlorophyll fluorescence; SPAD index = relative chlorophyll content; AWUE = agronomic water use efficiency; WF = Water footprint; RL = root length; RDW = root dry weight; SRA = support root angle; NSR = number of support roots; SRD = support root density; CRA = crown root angle; NCR = number of crown roots; and CRD = crown root density. *P<0.05; ** P<0.001 (Pearson Correlation).

According to Figure 1 (above):

Fv/Fm is significantly correlated with plant height, leaf area, stem diameter, stem dry weight, shoot dry weight/root dry weight ratio, crown root density, water footprint and agronomic water use efficiency under drought stress conditions.

This study highlights the correlation of MultispeQ-derived chlorophyll fluorescence parameters as biomarkers for breeding drought tolerance in crops, as well as the usefulness of MultispeQ as a phenotyping tool in crop improvement programs.