Abstract:
Investigating differences in resistance to alkaline stress among three willow species can provide a theoretical basis for planting willow in saline soils. Therefore we tested three willow species (Salix matsudana, Salix gordejevii and Salix linearistipularis), already known for their high stress tolerance, to alkaline stress environment at different pH values under hydroponics. Root and leaf dry weight, root water content, leaf water content, chlorophyll content, photosynthesis and chlorophyll fluorescence of three willow cuttings were monitored six times over 15 days under alkaline stress. With the increase in alkaline stress, the water retention capacity of leaves of the three species of willow cuttings was as follows: S. matsudana > S. gordejevii > S. linearistipularis and the water retention capacity of the root system was as follows: S. gordejevii > S. linearistipularis > S. matsudana. The chlorophyll content was significantly reduced, damage symptoms were apparent. The net photosynthetic rate (Pn), rate of transpiration (E), and stomatal conductance (Gs) of the leaves showed a general trend of decreasing, and the intercellular CO2 concentration (Ci) of S. matsudana and S. gordejevii first declined and then tended to level off, while the intercellular CO2 concentration of S. linearistipularis first declined and then increased. The quantum yield and energy allocation ratio of the leaf photosystem II (PSII) reaction centre changed significantly (φPo, Ψo and φEo were obviously suppressed and φDo was promoted). The photosystem II (PSII) reaction centre quantum performance index and driving force showed a clear downwards trend. Based on the results it can be concluded that alkaline stress tolerance of three willow was as follows: S. matsudana > S. gordejevii > S. linearistipularis. However, since the experiment was done on young seedlings, further study at saplings stage is required to revalidate the results.
摘要:
研究3种柳树对碱性胁迫的抗性差异,可为在盐渍土壤上种植柳树提供理论依据。因此,我们测试了三种柳树(Salixmatsudana,Salixgordejevii和Salixlineistipularis),已经以其高应力耐受性而闻名,在水培法下不同pH值的碱性胁迫环境。根和叶干重,根系含水量,叶片含水量,叶绿素含量,在碱性胁迫下,在15天内对3种柳枝的光合作用和叶绿素荧光进行了6次监测。随着碱性应力的增加,三种柳枝插条叶片的保水能力如下:S.matsudana>S.gordejevii>S.linearistipularis,根系的保水能力如下:S.gordejevii>S.linearistipularis>S.matsudana。叶绿素含量显著降低,损伤症状明显。净光合速率(Pn),蒸腾速率(E),叶片的气孔导度(Gs)总体呈下降趋势,马祖达纳和戈尔德耶维的细胞间CO2浓度(Ci)首先下降,然后趋于稳定,而线性肺链球菌的细胞间CO2浓度先下降后升高。叶光系统II(PSII)反应中心的量子产率和能量分配比例发生了显着变化(φPo,Φo和ΦEo被明显抑制,ΦDo被提升)。光系统Ⅱ(PSII)反应中心量子性能指标和驱动力呈明显下降趋势。根据结果,可以得出结论,三种柳树的碱胁迫耐受性如下:马苏达纳柳树>gordejevii柳树>线性叶树。然而,由于实验是在幼苗上进行的,需要在树苗阶段进一步研究以重新验证结果。