Efeito Da Temperatura E Do Substrato Sobre A Germinação De Sementes De Visgueiro Do Igapó

In Colombia, the cape gooseberry is grown in salt-affected areas.

The effect of increasing sodium chloride (0, 60 and 120 mM NaCl)

stress was investigated on the growth, proline content and total

antioxidant activity (TAA) in leaves of cape gooseberry plants kept

in 2 L pots and grown under greenhouse conditions. Plant leaves

were analyzed 45, 55, 65 and 75 days after transplanting (DAT). The

vegetative growth (measured as total plant and organ dry weight

[DW], leaf number and leaf area, as well as plant height) was significantly

lower at 120 mM NaCl, as compared to the control and

60 mM treated plants. At 60 mM NaCl, all determined leaf parameters

and total plant DW were markedly reduced, as compared to

non-salinized plants. The leaf proline content increased significantly

during the evaluation period and tended to be higher with increasing

NaCl concentrations, but without statistical differences. The

TAA, measured as μM Fremy’s salt per g-1 FW, increased constantly

during the evaluation period and, from day 55, was significantly

higher than in leaves of non-salinized plants. After 75 DAT of salt

stress, the TAA and proline content did not differ between the 60

and 120 mM NaCl treatments. For all sampling dates, the 120 mM

salt concentration significantly enhanced the free radical scavenging

activity, as compared to the control and the 60 mM NaCl treatment.

All treatments showed a nearly 12% increase in the radical scavenging

activity during the experiment’s duration. In conclusion, cape

gooseberry plants protect themselves from salinity (120 mM NaCl)

stress by increasing leaf antioxidant activity, as confirmed by the

higher radical scavenging activity, but not significantly with proline

synthesis.

Introduction

Salt stress poses a major environmental threat to agriculture