Are the effects of salinity on growth and leaf gas exchange related?

Title:

Are the effects of salinity on growth and leaf gas exchange related?

Creator:

Dunn, G. M. and Neales, T. F.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:84ea2fb8-4d1a-446d-a3e9-9a9ea2007a5b
uuid:84ea2fb8-4d1a-446d-a3e9-9a9ea2007a5b
urnnbn:urn:nbn:cz:aba007-000ffy

Type:

model:internalpart and TEXT

Format:

print

Description:

The responses of growth and leaf gas exchange to increasing salinity were measured in two halophytes [Atriplex nummularia (C4), Atriplex hastata (C3)] and one glycophyte [Hordeum vulgare (C3)]. The growth (dry mass) of both the halophytes was significantly increased, by 54 and 17 %, respectively, as salinity was increased in the range 0-200 mol m-^ NaCl. However, net CO2 assimilation rate (Pn)- the intercellular CO2 concentration (Cj) and leaf conductance (^1) were unaffected. At higher levels of salinity (in the range 400 - 600 mol m"^ NaCl) the growth of the two halophytes was severely reduced (by 44 and 51 %, respectively). At these levels of salinity q were significantly depressed. 25 mol m*^ NaCl significantly reduced the growth of H. vulgare by 44 %, but had no effect on Py^, g| and Cj. However, at 100 mol m'^ NaCl, where growth was decreased by 62 %, and g| were significantly reduced while q was unaltered. There was thus, no association between the effects of salinity on growth and leaf gas exchange at low salinities (25- 200 mol m'3 NaCl). At higher salinities, leaf gas exchange and growth were both severely inhibited but it is unlikely that a direct causal relationship existed. At these salinities sodium concentration in the leaves (tissue water basis) was above 400 mol m'3 in the halophytes and above 100 mol m'^ in H. vulgare which possibly affected both growth and leaf gas exchange independently. Also, the effects of salinity on total leaf chlorophyll concentration and net CO2 assimilation rate expressed on a chlorophyll (chl) basis (Pchi) were no better related to growth than was Pn

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

33-42 and 35-44

Source:

Photosynthetica | 1993 Volume:29 | Number:1

Harvested from:

CDK

Metadata only:

false