Abstract:
Electrical parameters such as resistance in high frequency (
r), resistance in low frequency (
rl), specific extracellular resistance (
re), specific intracellular resistance (
ri), value of conductance (
G), susceptance (
B) and relative permeability of plasma (RPP) and content of proline (Pro) in the stems of desert plant
Reaumuria soongorica under drought stress from four provenances (Lanzhou, Zhangye, Jiuquan and Wuwei) were measured. The relationships between these electrical parameters and RPP and Pro were analyzed. Results showed that with increasing drought stress, stem RPP and Pro increased gradually or increased and then decreased. Significant differences existed among the four provenances (
P < 0.05) for RPP in the order Lanzhou > Zhangye > Jiuquan > Wuwei and for Pro in the order Wuwei > Jiuquan > Zhangye > Lanzhou. The
r of stem decreased gradually,
re,
ri and
G increased at first and then decreased, while
rl decreased at first and then increased. The variation of B was complex. The six electrical parameters differed significantly between provenance and drought stress treatments (
P < 0.05). Correlation analysis and path analysis showed a significant correlation among
ri,
re,
r, B and RPP, and a significant correlation among
ri,
re,
r, G and Pro. However, RPP and Pro showed significant effects on
ri, with path coefficients of 0.938
RPP and 0.897
Pro, respectively. These results indicated that
ri was the best parameter for evaluating the drought resistance of
R. soongorica stems and is an effective method for studying adversity stress in desert plants.