A multisite managed environment facility for targeted trait and germplasm phenotyping

Abstract

Field evaluation of germplasm for performance under water and heat stress is challenging. Field environments are variable and unpredictable, and genotype × environment interactions are difficult to interpret if environments are not well characterised. Numerous traits, genes and quantitative trait loci have been proposed for improving performance but few have been used in variety development. This reflects the limited capacity of commercial breeding companies to screen for these traits and the absence of validation in field environments relevant to breeding companies, and because little is known about the economic benefit of selecting one particular trait over another. The value of the proposed traits or genes is commonly not demonstrated in genetic backgrounds of value to breeding companies. To overcome this disconnection between physiological trait breeding and uptake by breeding companies, three field sites representing the main environment types encountered across the Australian wheatbelt were selected to form a set of managed environment facilities (MEFs). Each MEF manages soil moisture stress through irrigation, and the effects of heat stress through variable sowing dates. Field trials are monitored continuously for weather variables and changes in soil water and canopy temperature in selected probe genotypes, which aids in decisions guiding irrigation scheduling and sampling times. Protocols have been standardised for an essential core set of measurements so that phenotyping yield and other traits are consistent across sites and seasons. MEFs enable assessment of a large number of traits across multiple genetic backgrounds in relevant environments, determine relative trait value, and facilitate delivery of promising germplasm and high value traits into commercial breeding programs.

Carbon isotope fractionation for cotton genotype selection

“…Certainly, the DNA code may carry information that influences alternate plant responses to each new environment, but the way information is integrated throughout the growing season is critically determinant for crop yield at the physiological level and across the community of plants (Rebetzke et al, 2013). In this sense, field physiological evaluations of the germplasm performance for abiotic stress, as well as water and heat constraints are challenging.…”

Predicting the future of plant breeding: complementing empirical evaluation with genetic prediction

“…Field-based, managed-environment methods have been advocated and utilised to enable genetic gain for important environmental components of the TPE that contribute to repeatable GÂE interactions (Fischer et al 1989;Cooper et al 1995Cooper et al , 1997Cooper et al , 2014Campos et al 2004Campos et al , 2006Kirigwi et al 2004;Trethowan et al 2005;Bänziger et al 2006;Weber et al 2012;Rebetzke et al 2013). Two maize breeding examples and the managed-environment solutions that have been implemented for the US corn-belt TPE to deal with important environmental components and the associated GÂE interactions are considered below: brittle snap resistance, and drought resistance.…”

Climate-smart agriculture global research agenda: scientific basis for action

“…Canopy temperature (CT) is an example of a widely used, high-throughput germplasm screening tool. CT is linked to stomatal conductance, an indirect indicator of water uptake by roots, especially under drought and heat stress [75,76]. In one study, researchers found that 60% of variation in yield from recombinant inbred lines grown under drought conditions was explained by CT [77].…”