【作者】 崔强；

【导师】 王庆成；

【作者基本信息】 东北林业大学 ， 森林培育， 2010， 博士

【摘要】 本文对桃叶卫矛(Euonymus bungeanus)、金银忍冬(Lonicera maackii)、红皮云杉(Picea koraiensis)和樟子松(Pinus sylvestris var. Mongolica)等4种木本植物在NaHCO3胁迫下的生理反应进行了研究,对参试树种耐盐碱能力进行评估,确定各树种对盐碱胁迫的耐受范围。主要研究结论如下：(1)4个树种苗木抗盐碱能力依次为忍冬>卫矛>樟子松>云杉。随胁迫强度的增加,4个树种苗木根、茎、叶及整株相对增长量均呈下降趋势,但下降幅度存在差异,依次为忍冬>卫矛>樟子松>云杉。(2)盐碱胁迫下,4个树种苗木的光合作用受到明显抑制,表现为叶绿索含量降低,净光和速率(Pn)下降。NaHCO3胁迫对云杉和樟子松P。的影响明显大于卫矛和忍冬。轻度胁迫导致云杉和樟子松P。显著下降(P<0.01),分别下降21.7%和22.5%,对卫矛和忍冬P。没有显著影响(P>0.05);中、重度胁迫下云杉和樟子松Pn下降幅度大于卫矛和忍冬的下降幅度。樟子松光合速率降低的主导因素为气孔限制因素；非气孔因素是造成云杉光合作用降低的主导因素；在轻度胁迫下卫矛叶片光合下降的原因是气孔限制,而在中、重度胁迫时,其光合下降的主要原因是非气孔限制；忍冬与卫矛相反。(3)随胁迫时间的延长,4个树种苗木叶片中游离脯氨酸含量总体上呈现出先上升后下降的趋势,在各个胁迫时期,随胁迫强度的增加,4个树种游离脯氨酸含量总体呈逐渐上升趋势。随胁迫时间的延长和胁迫强度的增加,4个树种苗木叶片可溶性糖和可溶性蛋白含量总体呈上升趋势。随胁迫强度的增加,4个树种苗木地上部分和根中Na+含量均逐渐增加,K+含量则逐渐下降。相同胁迫强度下,忍冬和卫矛地上部分Na+含量低于根系,云杉和樟子松地上部分Na+含量高于根系。相同胁迫强度下,4个树种苗木根系K+含量均低于地上部分。各胁迫强度下忍冬和卫矛根系Na+/K+均高于地上部分,云杉和樟子松根系Na+/K+均低于地上部分。(4) NaHCO3胁迫下,4个树种苗木叶片均受到一定程度的氧化损伤,表现为MDA和H202大量积累,电解质渗透率明显增大,卫矛和忍冬受害程度低于云杉和樟子松。各种抗氧化酶和抗氧化剂协同作用,共同抵御活性氧的伤害。与云杉和樟子松相比,卫矛和忍冬具有较高的SOD、CAT和APX活性。随胁迫强度的增加,卫矛和忍冬CAT和GR活性逐渐升高,云杉和樟子松CAT和GR活性逐渐降低。同时,卫矛和忍冬POD活性逐渐降低,云杉和樟子松活性逐渐升高。以上研究结果表明这4个树种在抗氧化防御效率方面存在明显的差异。更多还原

【Abstract】 In this paper, the responses of seedlings of Euonymus bungeanus, Lonicera maackii, Picea koraiensis and Pinus sylvestris var. mongolica under NaHCO3 stress were studied. Through this program, the tolerance scopes of woody plants refered in this research against saline and alkaline stress were tested. The main results were as follows:(1) The saline and alkaline stress tolerance of the five woody species followed L. maackii> E. bungeanus> P. koraiensis>P. sylvestris var. mongolica.With the increasing stress intensity, the relative growth increments of roots, shoots and leaves of seedlings of the five woody species expressed decresing trends as well as total biomass increments, but different species had different decresing scales. The order in decreasing scale of biomass increment of the five species followed P. koraiensis>P. sylvestris var. mongolica>E. bungeanus> L. maackii.(2) The photosynthesis was suppressed significantly in the above plants under saline and alkaline stress. It was expressed as the decrease of chlorophyll contents and net photosynthetic rate. The effects of NaHC03 stress on P. koraiensis and P. sylvestris var. mongolica were obviously larger than E. bungeanus and L. maackii. Mild stress led to a significant decrease in Pn of P. koraiensis and P. sylvestris var. mongolica,21.7% and 22.5% respectively, while it did not have significant effects on E. bungeanus and L. maackii. The decreasing scale of Pn of P. koraiensis and P. sylvestris var. mongolica larger than E. bungeanus and L. maackii under moderate and severe stress.According to the changes of photosynthesis parameters of the four seedlings, it was concluded that under lower stress intensity, The main factor leading to decreasing in photosynthesis rate of P. sylvestris var. mongolica was stomatal limitation. Non-stomatal limitation was the main factor leading to decreasing in photosynthesis rate of P. koraiensis. The main factor leading to decreasing in photosynthesis rate of E. bungeanus under mild strss was stomatal limitation, while non-stomatal limitation under higher stress intensity. L. maackii is contrary to E. bungeanus.(3) With the increasing stress time, the proline content contents in leaves of the four trees rose firstly, and then decreased. At any stage, with the increasing stress intensity, the proline contents in leaves of the four trees gradually increased. With the increasing stress time and intensity, the soluble sugar and protein contents in leaves of the four trees rose as a whole.With the increasing stress intensity, the shoot and root Na+ contents gradually increased, and K+ contents gradually decreased. Under the same stress intensity, the shoot Na+ contents and Na+/K+ ratio of E. bungeanus and L. maackii were lower than that of root, while the shoot Na+ contents and Na+/K+ ratio of P. koraiensis and P. sylvestris var. mongolica were higher than that of root. At the same time, the shoot K+ contents of the four seedlings were lower than that of root.(4) Under NaHCO3 stress, the leaves of the four trees suffered some from oxidative damage,it was testified as the increase in the MDA and H2O2 contents and electrolyte leakage rate. Compared with E. bungeanus and L. maackii,P. koraiensis and P. sylvestris var. mongolica suffed more damage.Different antioxidative enzyme and antioxidant cooperated with each other against reactive oxygen damage. E. bungeanus and L. maackii had higher SOD, CAT and APX activities than P. koraiensis and P. sylvestris var. mongolica. With the increasing stress intensity, the CAT and GR activities of E. bungeanus and L. maackii gradually increased while P. koraiensis and P. sylvestris var. mongolica gradually decreased. At the same time, the change of POD of the four trees were contrary to CAT and GR. The above results showed that the four trees had obviously different antioxidative ability.更多还原