|
Effects of different concentrations of acid rain on biomass allocation and physiological characteristics in Morus alba seedlings under cadmium pollution
XU Chenyang, MAO Xiaoyu
2018, 30(12):
2112-2120.
DOI: 10.3969/j.issn.1004-1524.2018.12.17
To explore the effects of different concentrations of acid rain (AR5.6, AR3.0) on the biomass allocation and physiological character of Nongsang12 seedlings under heavy metal Cd and provide a theoretical basis for breeding of Morus alba in areas with severe heavy metal pollution and frequent acid rain, we measured biomass accumulation, photosynthetic capacity and chlorophyll fluorescence of Nongsang12 seedlings under Cd stress (100 mg·kg-1), and the physiological effect by faintly acid and severe acid rain solution of Nongsang12 seedlings under Cd stress. The results showed as follows: 1) When compared to the controls, decreases in dry matter accumulation (DMA), net photosynthetic rate (Pn), transpiration rate (E), intercellular CO2 concentration (Ci), stomatal conductance (Gs), the maximum photochemical efficiency of PSⅡ (Fv/Fm), potential activity of PSⅡ (Fv/F0), electron transport rate (ETR) to different degree and increase in non-photochemical quenching (qN) in Nongsang12 seedlings under Cd stress were found. 2) Further decreases in Pn, E, Ci were found in Nongsang12 seedlings under treatment of AR3.0 which were greater than those of AR5.6; Increases of Fv/Fm, Fv/F0, effective quantum yield of PSⅡ Y(Ⅱ), ETR under treatment of AR5.6 and decreases of Fv/Fm, Fv/F0 were found. 3) Compared to the treatment of Cd, increases of proportions in stem and leaf and decreases of Pn, E, Ci, Gs, Fv/Fm, Fv/F0, Y(Ⅱ), ETR in Nongsang12 seedlings were remitted by AR5.6 but intensified by AR3.0. Finally, we got the following conclusion: There was a negative effect exerted by Cd stress on DMA and it was behaved in the decrease of root weight (RW), besides, there was also negative effect of gas exchange rate and impairment of photosynthetic apparatus in Nongsang12 seedlings; Different concentrations of acid rain leaded to varying degrees damage of biomass allocation, gas exchange rate and impairment of photosynthetic apparatus in plants, and the negative influences under treatment of AR3.0 were greater than those of AR5.6; Under Cd stress, the combination with AR5.6 could result in a positive influence to the recovery of impairment of photosynthetic apparatus, but the combination with AR3.0 could intensify the degree of stress.
References |
Related Articles |
Metrics
|