Premium
Survival and recovery of perennial forage grasses under prolonged Mediterranean drought: I. Growth, death, water relations and solute content in herbage and stubble
Author(s) -
VOLAIRE FLORENCE,
THOMAS HENRY,
LELIÈVRE FRANÇOIS
Publication year - 1998
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1998.00288.x
Subject(s) - dactylis glomerata , lolium perenne , perennial plant , agronomy , tiller (botany) , biology , irrigation , drought tolerance , forage , poaceae , bromus , fructan , fructose , biochemistry
Swards of Dactylis glomerata cultivars (cvs) KM2 and Lutetia and of Lolium perenne cvs Aurora and Vigor were grown under full irrigation or prolonged summer drought (80 d) in a field experiment in the South of France. After irrigation was withheld, leaf extension rates of all cvs fell by 90% within 9–12 d, and rapid scorching of laminae followed. Tiller mortality at the end of the drought was very different in the cocksfoot cvs (4% for KM2 and 76% for Lutetia) and intermediate (41%) for both ryegrass cvs. Following re‐watering, rates of herbage regrowth were closely correlated with tiller survival. Measured minerals contributed c . 0·52 MPa to osmotic potential in all treatments, whereas water‐soluble carbohydrates (WSC) contributed 0·25 MPa under irrigation and 0·46 MPa during drought. There was no systematic difference between the two species for summer survival under severe drought, but large differences between the cocksfoot cvs. The traits most strongly associated with superior survival were: (a) a deep root system and greater water uptake at depth; (b) low water and osmotic potentials in surviving laminae, i.e. better tolerance to dehydration; (c) large pool‐size of WSC reserves (fructans having degree of polymerization >4) in entire tiller bases (stubble); (d) low accumulation of proline in stubble; (e) rapid nitrogen uptake after rewatering.