Effects of salt stress on eco-physiological characteristics in Robinia pseudoacacia based on salt-soil rhizosphere.
Robinia pseudoacacia is the main arbor species in the coastal saline-alkali area of the Yellow River Delta. Because most studies focus on the aboveground parts, detailed information regarding root functioning under salinity is scare. Root traits of seedlings of R. pseudoacacia including morphological, physiological and growth properties under four salinity levels (CK, 1‰, 3‰ and 5‰ NaCl) were studied by the pot experiments to better understand their functions and relationships with the shoots. The results showed that seedling biomass decreased by the reduction of root, stem and leaf biomass with the increase of salinity levels. With increasing salinity levels, total root length (TRL) and total root surface area (TRSA) decreased, whereas specific root length (SRL) and specific root area (SRA) increased. Salt stress decreased root activity (RA) and the maximum net photosynthetic rate (Amax) and increased the water saturation deficit (WSD) significantly in the body. Correlation analyses showed significantly correlations between root morphological and physiological parameters and seedling biomass and shoot physiological indexes. R. pseudoacacia seedlings could adapt to 1‰ salinity by regulating the root morphology and physiology, but failed in 5‰ salinity. How to adjust the water status in the body with decreasing water uptake by roots was an important way for R. pseudoacacia seedlings to adapt to the salt stress.
Key Laboratory of Agricultural Ecology and Environment, Shandong Agricultural University, Taian 271018, China.
Peili
P
Mao
Key Laboratory of Agricultural Ecology and Environment, Shandong Agricultural University, Taian 271018, China.
Yujuan
Y
Zhang
Key Laboratory of Agricultural Ecology and Environment, Shandong Agricultural University, Taian 271018, China. Electronic address: caobanghua@126.com.
Banghua
B
Cao
Key Laboratory of Agricultural Ecology and Environment, Shandong Agricultural University, Taian 271018, China.
Longmei
L
Guo
Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; Institute of Agro-biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014,China. Electronic address: shaohongbochu@126.com.
Hongbo
H
Shao
Key Laboratory of Agricultural Ecology and Environment, Shandong Agricultural University, Taian 271018, China.
Zhenyu
Z
Cao
Key Laboratory of Agricultural Ecology and Environment, Shandong Agricultural University, Taian 271018, China.
Qiankun
Q
Jiang
Key Laboratory of Agricultural Ecology and Environment, Shandong Agricultural University, Taian 271018, China.
Xuan
X
Wang
D001673:Biodegradation, Environmental; D002681:China; D018517:Plant Roots / Q000502:physiology; D058441:Rhizosphere; D031301:Robinia / Q000254:growth & development*; D055049:Salt Tolerance; D055051:Salt-Tolerant Plants / Q000254:growth & development*; D036226:Seedlings / Q000254:growth & development; D012987:Soil / Q000737:chemistry*
D012987:Soil
Biomass; Maximum net photosynthetic rate; Root morphology; Root physiology; Salt tolerance; Salt-soil