JOURNAL OF NANJING FORESTRY UNIVERSITY ›› 2017, Vol. 60 ›› Issue (02): 63-72.doi: 10.3969/j.issn.1000-2006.2017.02.010

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Improvement on growth and photosynthetic physiological performance of three willow clones or cultivar under Cd treatments and supplying Fe

DAI Qianli1, LI Jinhua1*, HU Jianjun1, LU Mengzhu1, GIUSEPPE Nervo2   

  1. 1. State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China;
    2. Unità di ricerca per le produzioni legnose fuori foresta, CRA-PLF, Casale Monferrato 15033, Italy
  • Online:2017-04-18 Published:2017-04-18

Abstract: 【Objective】 This paper investigated the effect of Cd concentrations with/without extra Fe on growth and photosynthetic physiology of different willow clones/cultivar is to explore the role of extra Fe on reducing Cd stress and improving Cd tolerance of willow and to shed more light on the regulation of extra Fe under Cd stress as its results for important practical significance. 【Method】 In greenhouse, cuttings of three willow clones/cultivar, Salix matsudana ‘Levante’, S. viminalis cl. 79026 and S. viminalis cl. 790260, were used for hydroponic culture in half of Hoagland nutrient solution(25 μmol/L EDTA-Na2Fe)with Cd concentrations(0, 10, 50, 100 μmol/L). In another hydroponic group, extra Fe(25μmol/L EDTA-Na2Fe)were supplied in solution with different Cd concentrations mentioned above. Growth(height and diameter), biomass(root, stem and leaf), photosynthesis indicators(chlorophyll a and b content, ration of chlorophyll a to b, net photosynthesis, stomatal conductance and intercellular CO2 concentration), Cd and Fe content of root, stem, leaf were measured for plants of each clone/cultivar after 42 d culture. 【Result】 ① With the increasing of Cd concentrations in solution, growth, biomass, chlorophyll a and b content, net photosynthetic rate, stomatal conductance and Fe content of stem and leaf decreased, however, ratio of chlorophyll a to b, intercellular CO2 concentration, Cd content of root, stem, leaf increased. Meanwhile, Fe content of root in three clones/cultivar decreased under low and middle Cd concentration(10, 50 μmol/L)and decreased under high Cd concentration(100 μmol/L). Under the same Cd concentration, Cd and Fe content of three clones/cultivar were root> leaf> stem. Cd content of root in S. matsudana was more than that of S. viminalis, while Cd content of leaf in S. viminalis were more than that of S. matsudana. ② In comparison with that under the low Cd concentration with extra Fe, chlorophyll a and b content of three clones/cultivar, growth and biomass of S. matsudana‘Levante‘ and S. viminalis cl. 79026 except that stem biomass of S. matsudana ‘Levante’, ratio of chlorophyll a to b, net photosynthetic rate of S. matsudana ‘Levante’ were significantly decreased, while Cd and Fe content of three clones/cultivar were increased and decreased under the middle and high Cd concentration with extra Fe. Under the high Cd concentrations with extra Fe, Cd content of leaf in S. matsudana ‘Levante’ and S. viminalis cl. 790260 were less than that under low and middle Cd concentration with extra Fe. And Cd content of root, stem, leaf and Fe content of leaf in S. matsudana were less than these of S. viminalis. ③ Compared with that in the culture without extra Fe, extra Fe in the culture improved growth, biomass, chlorophyll a and b content, stomatal conductance and intercellular CO2 concentration of willow under Cd stress, especially decreased Cd content of root and leaf and increased Cd content of stem under the high Cd concentrations with extra Fe. In addition, Cd content of root, stem and leaf in S. matsudana’ were less than these in S. viminalis. 【Conclusion】Cd stress inhibited growth, dry biomass accumulation, chlorophyll synthesis and photosynthesis of willow. At middle and high Cd concentrations, inhibition on growth and dry biomass accumulation of S. matsudana was greater than that of S. viminalis. Cd and Fe accumulation capacity of root was greater than that of stem and leaf in willow, while Cd accumulation capacity of S. viminalis was greater than that of S. matsudana. Extra Fe with Cd stress increased growth, biomass, chlorophyll content, Cd and Fe content of willow. As the result, extra Fe alleviated Cd stress on chlorophyll synthesis, photosynthesis, etc. of willow while effect on S. matsudana was greater than that on S. viminalis. The results showed that extra Fe supplying could improve growth and physiological adaptation of willows under Cd stress.

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