Abstract:
Five species of herbs, including
Asparagus cochinchinensis,
Wedelia chinensis,
Sesuvium portulacastrum,
Ipomoea pescaprae,
Gaillardia pulchella were studied. The growth and physiological characteristics of 5 tested plants were studied by means of 2 salt stress methods of roots and leaves, and their salt tolerance was comprehensively evaluated by principal component analysis and membership function analysis. The results showed that the growth of 5 plants was inhibited by salt stress to different degrees. Under root salt stress, the RWC of
S. portulacastrum in 0.1%(G
1) salt concentration group was significantly higher than that of CK, the RWC of
W. chinensis in 0.2%(G
2) and 0.3%(G
3) salt concentration groups was significantly higher than that of CK except day 28. The POD activity of
G. pulchella was higher than CK in all treatment groups. The CAT activity of
W. chinensis,
S. portulacastrum and
G. pulchella was higher than CK. Under leaf salt stress, the RWC of
S. portulacastrum in 0.2%(Y
1) salt treatment group was higher than CK, POD activities of
W. chinensi and I. pescapra were higher than CK, and the RWC of
G. pulchella in 0.3%(Y
2) salt treatment group was significantly higher than CK at the 14
th and 28
th days, POD activities of
W. chinensis were higher than CK. The CAT activities of
W. chinensis,
S. portulacastrum and
I. pescapra were higher than those of CK in all treatment groups. Under the 2 salt stress modes, SPAD value of 5 tested plants in each treatment group was significantly lower than CK after 14 days of salt treatment, and MDA content was higher than CK during the whole salt stress stage. The salt tolerance of 5 tested plants was evaluated comprehensively. The salt tolerance of the 5 tested plants under root salt stress was ranked as
S. portulacastru >
A. cochinchinensis =
G. pulchella >
W. chinensis >
I. pescaprae. The order of salt tolerance of 5 plants under salt stress was
W. chinensi >
S. portulacastrum >
A. cochinchinensis >
G. pulchella >
I. pescapra. The comprehensive analysis showed that
S. portulacastru,
A. cochinchinensis and
W. chinensi showed stronger salt tolerance after root salt stress, while only
S. portulacastru and
W. chinensi showed stronger salt tolerance after leaf salt stress, and
S. portulacastrum showed stronger salt tolerance after root and leaf salt stress.