盐胁迫下水氮对小桐子幼树生理生态的影响

发布时间：2019-01-09 08:30

【摘要】：我国盐渍化土地面积较广,具有较高的开发利用的潜力。小桐子作为生物柴油的原料树种,因其具有较高的含油量和抗盐胁迫能力而受到广泛的关注。虽然小桐子具有较强的抗盐胁迫能力,但有利于小桐子生长的生理生态特性的水氮耦合效应不清。因此,为了进一步揭示盐胁迫条件下不同水氮处理对小桐子幼树生理生态的影响机制,通过盆栽和小区试验相结合的方法,设置三个灌水处理与四个施N处理完全组合试验,取得以下结论:(1)NaCl处理相同时,与每次灌水0.9L和1.8L相比,每次灌水2.4L处理下小桐子幼树的株高、茎粗、壮苗指数、干物质量、和水分利用效率均显著提高(P0.05)。当每次灌水量为2.4L时,与不施NaCl处理相比,每kg风干土施入NaCl分析纯质量0.25g的处理促进小桐子幼树的干物质质量及灌溉水利用效率均显著提高,而施NaCl 0.5g的处理使得各干物质质量和灌溉水利用效率下降甚微(P0.05)。(2)不施氮条件下,与每次灌水0.8L处理相比,1.6L和2.4L处理均促进小桐子的净光合速率、腾腾速率、气孔导度、气孔密度、叶水势、生物量、根冠比及灌溉水利用效率增大。灌水量相同时,与不施N相比,施氮处理促进小桐子的净光合速率、蒸腾速率、气孔导度均增加。灌水量的增加促进小桐子的株高、茎粗的增长,显著降低根区土壤中NO3-和Na+的含量和土壤导电率。(3)与高水高氮处理相比,高水中氮的小桐子净光合速率、蒸腾速率、气孔导度、叶水势分别显著提高5.15%、5.86%、8.81%、23.25%。可见,试验小区内每千克风干土含NaCl分析纯质量为0.5g时的盐胁迫下,种植小桐子的最优水氮调控模式为每株小桐子灌水9.6L,施N30g。
[Abstract]:The salinized land in China has a wide area and has a high potential for exploitation and utilization. As the raw material of biodiesel, Jatropha jatropha has been widely concerned because of its high oil content and salt stress resistance. Although Jatropha jatropha has strong salt stress resistance, the coupling effect of water and nitrogen is not clear, which is beneficial to the physiological and ecological characteristics of Jatropha jatropha. Therefore, in order to further reveal the effect mechanism of different water and nitrogen treatments on the physiological and ecological characteristics of young trees under salt stress, three irrigation treatments and four N application treatments were set up by combining pot and plot experiments. The following conclusions were obtained: (1) the plant height, stem diameter, seedling strength index and dry matter quality of young trees of Paulownia vulgaris under the same NaCl treatment were higher than those of 0.9 L and 1.8 L under each irrigation of 2.4 L, respectively. And water use efficiency increased significantly (P0.05). When the irrigation amount was 2.4 L, compared with the treatment without NaCl, the dry matter quality and the utilization efficiency of irrigation water of the young tree of Paulownia jatropha were significantly improved by the treatment of 0.25g per kg dry soil with NaCl analysis. However, the dry matter quality and irrigation water utilization efficiency of NaCl 0.5g treatment decreased very little (P0.05). (2), compared with each irrigation 0.8L treatment without nitrogen application. The net photosynthetic rate, transpiration rate, stomatal conductance, stomatal density, leaf water potential, biomass, root-shoot ratio and irrigation water use efficiency increased in the treatments of 1.6 L and 2.4 L, respectively. At the same irrigation rate, the net photosynthetic rate, transpiration rate and stomatal conductance of jatropha increased under nitrogen application compared with those without N application. The increase of irrigation increased the plant height and stem diameter, and significantly decreased the content of NO3- and Na and the conductivity of soil in root zone. (3) compared with the treatment of high water and high nitrogen, the net photosynthetic rate and transpiration rate of jatropha curcas in high water were increased. Stomatal conductance and leaf water potential were significantly increased by 5.15% and 8.81% and 23.25%, respectively. It can be seen that under salt stress of 0.5 g NaCl per kilogram of air-dried soil, the optimal water and nitrogen regulation model for planting Jatropha jatropha is 9.6L per plant and N 30g.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S794.9

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