Breeding wheat for weed-competitive ability: I. Correlated traits

Authors: Kissing Kucek, Lisa; MALLORY, ELLEN - University Of Maine; DARBY, HEATHER - University Of Vermont; DAWSON, JULIE - University Of Wisconsin; SORRELLS, MARK - Cornell University

Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2021
Publication Date: 10/25/2021
Citation: Kucek, L.K., Mallory, E., Darby, H., Dawson, J., Sorrells, M. 2021. Breeding wheat for weed-competitive ability: I. Correlated traits. Euphytica. 217. Article e202. https://doi.org/10.1007/s10681-021-02930-9.
DOI: https://doi.org/10.1007/s10681-021-02930-9

Interpretive Summary: Weeds reduce productivity in agriculture. Plant breeding may help develop crop varieties that are more competitive with weeds. Identifying varieties with better weed competition, however, is difficult and expensive. We studied methods to select for weed competition indirectly, which can save costs when developing new varieties. Early growth and early height of a plant are easy to measure traits that are strongly related to the ability to compete with weeds. The best varieties for weed competition will change among regions. Plant breeding needs to take place in many locations to develop ideal competitive varieties for farmers.

Technical Abstract: Competition from weeds often reduces wheat yields, especially in organic management systems or when herbicide-resistant weeds are present. Breeding wheat for increased competitive ability is an important aspect of integrated weed control. Selecting directly for weed-competitive ability (WCA), however, is challenged by difficult field measurements, genotype by environment interactions, and low heritability. To improve selection efficiency, breeding programs can utilize secondary selection traits that are easier to measure, have higher heritability and are highly correlated with WCA. To identify potential secondary selection traits for WCA, we conducted metaanalysis of the published literature, and contributed new data from the northeast United States. Among studies worldwide, early vigor and early plant height were easy to measure and were consistently correlated with WCA. Significant genotype by environment effects suggested that some secondary selection traits are only useful in certain environments. WCA and its correlated traits were heavily influenced by genotype by environment interactions. As a result, decentralized breeding would maximize gain from selection for WCA and early vigor.