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Perennial ryegrass regrowth after defoliation - physiological and molecular changes
Citation
Lee, JM and Donaghy, DJ and Sathish, P and Roche, J, Perennial ryegrass regrowth after defoliation - physiological and molecular changes, Proceedings of the New Zealand Grassland Association, November, Lincoln, New Zealand, pp. 59-65. (2010) [Refereed Conference Paper]
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Copyright Statement
Copyright 2010 NZ Grassland Association, Authors & the University of Tasmania.
Official URL: http://www.grassland.org.nz/viewpublication.php?pu...
Abstract
Many aspects of plant growth and physiology following
defoliation have been investigated in perennial
ryegrass (Lolium perenne). The changes, however,
have rarely been characterised at a molecular (gene)
level. Perennial ryegrass plots were defoliated at the
3-leaf stage to 1 600 kg DM/ha (recommended grazing
practice) and throughout the subsequent regrowth
cycle, pasture mass, water-soluble carbohydrate (WSC)
content and expression of carbon metabolism genes
were determined. Plots accumulated 1 900 kg DM/
ha, 45% of this between the 2- and 3-leaf stages of
regrowth. Following defoliation, stubble WSC content
declined (P<0.001) until the first new leaf had emerged,
with replenishment occurring during emergence of the
second new leaf. In stubble tissue, expression of the
fructan degradation gene was greatest immediately after
defoliation (P<0.001), while expression of a fructan
synthesis gene was greatest following emergence of the
first leaf (P<0.05). Throughout regrowth, expression
of photosynthesis genes increased (P<0.05) in leaf
tissue, peaking at the 2-leaf stage of regrowth. These
data indicate how perennial ryegrass plants alter
their physiological processes following defoliation to
survive and grow, and support recommendations for
rotation lengths that are longer than the time taken to
reach the 2-leaf stage of regrowth. Understanding how
defoliation affects gene expression in perennial ryegrass
could influence future plant breeding outcomes.
Keywords: rotation length, leaf stage, water-soluble
carbohydrate, fructan, photosynthesis, gene expression
Item Details
| Item Type: | Refereed Conference Paper |
|---|---|
| Research Division: | Agricultural, Veterinary and Food Sciences |
| Research Group: | Crop and pasture production |
| Research Field: | Crop and pasture production not elsewhere classified |
| Objective Division: | Plant Production and Plant Primary Products |
| Objective Group: | Other plant production and plant primary products |
| Objective Field: | Other plant production and plant primary products not elsewhere classified |
| UTAS Author: | Lee, JM (Mr Jenn Ming Lee) |
| UTAS Author: | Donaghy, DJ (Associate Professor Danny Donaghy) |
| ID Code: | 69941 |
| Year Published: | 2010 |
| Deposited By: | Agricultural Science |
| Deposited On: | 2011-05-25 |
| Last Modified: | 2014-10-28 |
| Downloads: | 0 |
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