MEFLUIDIDE-INDUCED DROUGHT RESISTANCE IN SEEDLINGS OF 3 CONIFER SPECIES

Citation
Sn. Silim et al., MEFLUIDIDE-INDUCED DROUGHT RESISTANCE IN SEEDLINGS OF 3 CONIFER SPECIES, Canadian journal of botany, 71(8), 1993, pp. 1087-1092
Citations number
27
Categorie Soggetti
Plant Sciences
Journal title
ISSN journal
00084026
Volume
71
Issue
8
Year of publication
1993
Pages
1087 - 1092
Database
ISI
SICI code
0008-4026(1993)71:8<1087:MDRISO>2.0.ZU;2-C
Abstract
Short-term effects of the plant growth retardant mefluidide on drought resistance were investigated in seedlings of western red cedar (Thuja plicata Donn), yellow cedar (Chamaecyparis nootkatensis D. Don), and white spruce (Picea glauca (Moench) Voss). Mefluidide was applied as a root drench at concentrations of 0, 0. 1, and 0.4 mg - L-1. Following this, seedlings were stressed by withholding water for a period of up to 7 days and then watering regularly thereafter. Stomatal conductanc e of the mefluidide-treated seedlings decreased significantly and rema ined lower than the control seedlings throughout the stress period. As a result of the decreased conductance, shoot water potentials in mefl uidide-treated seedlings remained higher throughout the stress period. There was a decrease in net photosynthesis that was partially caused by stomatal limitations, the severity of which depended upon the conce ntration of mefluidide applied. Mefluidide treatment also resulted in an accumulation of abscisic acid in all three species, and this may ha ve been responsible for the effects on stomatal conductance and water relations. In contrast, the mefluidide-treated seedlings had the highe st rates of photosynthesis after rewatering, resulting primarily from a promotion of stomatal opening.