La Trobe
1386140_Zhu,J_2023.pdf (4.36 MB)

Genotype-by-environment interaction analysis of dry matter yield of perennial ryegrass cultivars across south-eastern Australia using factor analytic models

Download (4.36 MB)
journal contribution
posted on 2023-12-15, 03:50 authored by Jiashuai Zhu, Khageswor Giri, Noel CoganNoel Cogan, Kevin F Smith, Joe L Jacobs
Genotype-by-environment interaction (G×E) is commonly observed in perennial ryegrass species and significantly impacts dry matter yield (DMY) performance across environments. Variation in DMY of perennial ryegrass cultivars and their distinct responses to different environments directly influence the profitability of the Australian dairy industry. In this study, we implemented a separate two-way factor analytic strategy to fit multi-environment-multi-harvest data collected from 18 trials spanning 14 years to account for the G×E effects across complex pasture environments in south-eastern Australia to achieve accurate DMY predictions. Three mega-environments were identified, and the seasonal and environmental DMYs of 126 cultivars or breeding lines (defined by a combination of varieties and endophytes) were predicted. Statistical differences in DMY performance and crossover G×E effects in cultivar rankings were observed among the three mega-environments. Several high-yielding cultivars specific to each mega-environment were also identified. The analysis demonstrated the importance of accounting for G×E effects when predicting the DMY of perennial ryegrass and highlighted the potential for identifying high-yielding cultivars specific to mega-environments. The research rationalizes implementing an appropriate independent pasture trialling system to generate necessary data for the dairy industry and could further facilitate dairy farmers to select suitable cultivars based on their specific environments and perennial ryegrass breeders when accounting for the genetic relationship of cultivars.


This work was undertaken as part of the 'Forage Value Index' (FVI) project jointly funded by Agriculture Victoria, Dairy Australia, and the Gardiner Dairy Foundation.


Publication Date



Field Crops Research



Article Number








Rights Statement

© 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (