Exploring the link between more negative osmotic potential and ryegrass summer performance


  • L Vishna Y Weerarathne Massey University
  • Wencheng Dong Ningxia University
  • Minghe Nie Ningxia University
  • Yan Wang Ningxia University
  • Ignacio F Lopez Massey University
  • Cory Matthew Massey University http://orcid.org/0000-0002-6151-4828




This paper outlines recent research studying within-population variation in selected New Zealand perennial ryegrass cultivars, for traits related to tolerance of summer moisture deficit. Two clonal replicates of 220 genotypes from ‘Grasslands Nui’ (Nui, n=50), ‘Grasslands Samson’ (Samson, n=80), and ‘Trojan’ (n=90) were exposed to 1 month of moisture deficit challenge, with plant water relations measurements performed to evaluate putative drought-response mechanisms. Water use of individual genotypes ranged from <100 to >1000 g water/g DM indicating large within-population variation for this trait. Mean water use efficiency (WUE) was for Nui, Samson, and Trojan, respectively, 424±16, 412±10, and 319±9 g water/g DW (P<0.001), suggesting that commercial plant breeding may have indirectly reduced water use in modern cultivars without specific focus on water relations. Principal component analysis indicated more negative osmotic potential may contribute to reduced water use while maintaining yield under water deficit, giving a potential focus for future breeding selection targeting summer water deficit tolerance.


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How to Cite

Weerarathne, L. V. Y., Dong, W., Nie, M., Wang, Y., Lopez, I. F., & Matthew, C. (2018). Exploring the link between more negative osmotic potential and ryegrass summer performance. Journal of New Zealand Grasslands, 80, 155–160. https://doi.org/10.33584/jnzg.2018.80.332



Vol 80 (2018)