磁化微咸水灌溉促进欧美杨I-107生长及其光合特性分析

Analysis of magnetic salinity water irrigation promoting growth and photosynthetic characterisitcs of Populus×euramericanna ‘Neva'

为探讨磁化作用下盐分胁迫对盐敏感树种欧美杨I-107光合机构及植株生长的影响,该文采用盆栽试验,研究磁化和非磁化处理0、4.0 g/L Na Cl溶液灌溉对1 a生欧美杨I-107生长、生物量累积及光合特性的影响。结果表明:与对照相比,盐分胁迫植株净光合速率（Pn）、气孔导度（Gs）、细胞间CO2浓度（Ci）及蒸腾速率（Tr）、水分利用效率（WUE）均降低,下降幅度为1.5%51.1%,气孔限制（Ls）值增大,为12.2%和26.7%;随胁迫时间的延长,原初光能转换效率（Fv/Fm）、光合性能指数（PIABS）及量子产额（ΦEo）均表现为先升后降的变化趋势,变化幅度为0.23%29.5%,其中PIABS降低最为显著,为13.6%29.5%;抑制植株生长,除茎生物量外,根、叶生物量及其生物量配比均显著降低,降低幅度为10.7%55.8%,同时对根系各形态参数均有不同程度的抑制作用,降低比例为14.1%%51.5%;较非磁化处理相比,磁化处理植株Pn、Gs、Ci及WUE提高,幅度为5.3%29.3%,Tr、Ls则显著降低,幅度为0.7%45.4%;Fv/Fm、ΦEo与PIABS较高且稳定,增加幅度为0.12%1.2%,对PIABS增幅最显著,为3.0%18.2%;提高了生物量累积为4.0%64%,根系特征值增大,幅度为4.1%51.2%。因此,磁化处理中植株光合机构受盐害程度较小,这有利于维持光合器官的功能完整性,有利于光合作用的进行,从而促进植株生长、发育。

The salt stress could injury the photosynthetic mechanism and affect the photosynthetic function of plants. To explore the action of salt stress on plants growth under magnetic treatments (M4,M0 Ms), and to understand the magnetized effect on reducing salt injury, parameters such as different morphological parameters, photosynthesis and the chlorophyll fluorescence parameters, were measured. Some experimental materials, from one-year cutting seedlings of salt-sensitive Populus × euramericanna‘Neva’, were irrigated with magnetized 0, 4.0 g/L NaCl solution, others were irrigated with the same solution but non-magnetized (NM0,NM4 NMs). The results showed that: 1) Pn, Gs, Ci, Tr, WUE decreased 1.5%-51.1% in NM4, and M4, Ls increased 12.2%and 26.7%respectively. There were extremely significant differences for them compared to NM0 and M0; the NM0 and M0 maintained higher but Ls lower than that of NMs. They respectively characterized by significant difference among the treatments (P<0.01). 2) ΦEo, Fv/Fm, and PIABS, first increased and then decreased with prolonging of stress time, showed same trend. Compared with NM0 and M0, the treatments in different group showed extremely significant difference (P<0.01); the Ms kept a relatively higher level compared to NMs, and the increasing proportion was within 0.12%-18.2%. 3) Compared with the control treatments (NM0, M0), the salt-stressed treatments decreased in the height, branch diameter, single leaf area, biomass parameters, root, and leaf biomass allocation proportions, with the increasing extent of 10.7%-55.8% for these parameters. The stem biomass, increasing from 15.8% to 20.9%, had extremely significant differences among the four groups (P<0.01). The Ms also kept a relatively higher level among those 6 biomass indexes compared to NMs. 4) The morphological parameters of root system declined, by 12.8%-51.5% in salinity treatments, but Ms kept higher than NMs, and there were extremely significant difference for the overall level of performances (P<0.01). Salt in soil could reduce the root/shoot ratio, root diameter, length, area and volume, which maintained higher levels of root morphological parameters in Ms respectively. There were extremely significant differences except the root volume compared with NM0 and M0 (P<0.01). In conclusions, the salt injury to photosynthetic mechanism of plants in Ms was less than in NMs which was beneficial to maintaining the integrity of the photosynthetic organ function, and thus-increasing physiological and biochemical activities in plants and promoting its growth.