【作者】 李云；

【导师】 徐坤；

【作者基本信息】 山东农业大学 ， 蔬菜学， 2011， 硕士

【摘要】 铅是土壤主要污染物之一,不仅导致作物生长受抑,产量降低,且极易在植物体内积累,尤以地下器官积累量较大;而硅则对多种重金属有固定作用,降低植物对铅的吸收富集量,并可增强植株抗逆性,对多种作物具有显著的增产效应。生姜（Zingiber officinale Rosc.）是我国主要出口蔬菜,以地下根茎为产品,根系吸收的环境污染物质易在根茎富集,影响产品安全性。有鉴如此,本文采用水培和盆栽试验相结合的方法,研究了铅对生姜生长、产量及产品安全性的影响,以及生姜对铅的吸收富集规律,探讨了硅对生姜铅毒害缓解的生理机制。主要研究结果如下:1.土壤铅含量低于250 mg·kg^-1时,对生姜生长无显著影响,但随铅含量的增加,生姜植株生长量显著降低,土壤铅含量分别达500和1000 mg·kg^-1时,其单株产量分别比对照降低了18.06%和33.25%。但水培条件下,较低的铅浓度就表现出显著的抑制效应,100、250、500 mg·kg^-1铅处理生姜根茎的鲜重分别比对照降低了18.90%,25.07%和40.04%。2.生姜各器官铅含量随土壤铅含量的升高及生长的进行而显著增加,且以根的铅含量较高,根茎次之,茎、叶较少。土壤铅含量达250 mg·kg^-1时,生姜根茎铅含量为0.261 mg·kg^-1,未超过国家最高允许限量,而土壤铅含量分别达500和1000 mg·kg^-1时,根茎铅含量则分别超标175.67%和495.33%。3.水培试验表明,铅处理导致生姜根系及叶片MDA含量显著增加,短时间铅胁迫处理生姜根系及叶片SOD、POD、CAT和APX活性增加,但随着胁迫时间的延长,除SOD外,其它酶活性均显著降低,且以根系相关酶活性降幅较大。250 mg·L^-1铅胁迫处理30 d时,根系POD、CAT和APX分别比对照降低了18.65%、42.14%、56.70%。4.土壤施硅肥可缓解铅对生姜的胁迫,明显促进生姜的生长,提高产量,降低铅在生姜根茎中的积累,提高产品安全性。在土壤铅含量达500 mg·kg^-1条件下,施硅肥分别为1、2 g/kg^-1,株高比比不施硅处理提高11.99%和16.67%,单株产量分别提高33.23%和43.60%,根茎的铅含量分别0.225和0.071 mg·kg^-1分别降低72.79%和91.41%。5.生姜在铅浓度250 mg·L^-1条件下培养30 d,植株根、茎、叶及根茎鲜质量分别比对照降低了19.85%、21.42%、22.89%和18.96%,而添加Si 1.5 mmol·L-1后,则仅比对照分别降低了4.90%、12.35%、18.17%和11.53%;施硅处理水培生姜根、茎、叶和根茎的铅含量分别比不施硅处理降低了58.92%、55.74%、69.82%和58.27%。6.生姜在250 mg·L^-1铅胁迫条件下,增施1.5 mmol·L^-1Si表现出极强的缓解效应。如处理10 d时,施硅处理生姜根系、叶片MDA含量分别降低32.87%和30.43%,根系、叶片CAT和APX活性分别增加153.44%、40.79%和57.29%、60.96%,根系活力提高54.74%,叶片总叶绿素含量增加7.51%,光合速率提高207.50%。更多还原

【Abstract】 Lead is one of the major pollutants in the soil, not only cause crop growth inhibition, lower production, but also accumulate easily in plants. Particularly the lead accumulation of underground organ are more. Silicon has a fixed effect on a variety of heavy metals, reduce plant the amount of lead absorption enrichment in plant, and strengthen the plant resistance and increase crops yield remarkably. Ginger （Zingiber officinale Rosc.） is one of the main export vegetables to the rhizome in China, roots easily absorb environmental pollutants, which accumulate in the roots and affect product safety. In this view, hydroponic culture and pot experiments were used to study the lead on ginger growth, yield and the impact of product safety, as well as the absorption and accumulation of lead in ginger and discussed the physiological mechanisms for studying the silicon alleviation of lead poisoning of ginger. The main results were as follows:1. Soil lead levels less than 250 mg·kg^-1 had no significant effect on ginger growth. But with the lead content increased, the ginger plant growth was significantly reduced. When they were 500 and 1000 mg·kg^-1, the single plant yield decreased by 18.06% and 33.25% compared with control, respectively. However, under the conditions of hydroponic culture, the lower lead concentration showed significant inhibitory effect. When they were100, 250 and 500 mg·L-1, fresh weight of ginger rhizome reduced by 18.90%, 25.07% and 40.04%, respectively.2. The Pb content of different organs of ginger were both significantly increased with the growing and higher soil Pb contents and the Pb content of roots was higher, followed by rhizomes, that of stems, leaves was less. When the soil Pb content was 250 mg·kg^-1, the Pb content of ginger rhizome was 0.261 mg·kg^-1, which did not exceed the state maximum allowable limit, while the soil Pb contents were 500 and 1000 mg·kg^-1, respectively, the rhizome Pb contents were 175.67% and 495.33% more than national standard, respectively.3. Hydroponic experiments showed that MDA content of the ginger root and leaf were significantly increased, short lead stress SOD, POD, CAT and APX activities of ginger root and leaf increased, but with the stress time, in addition to SOD, others were significantly decreased and of enzyme activities of the roots drop considerably. With 250 mg·L^-1Pb stress for 30 d, POD, CAT and APX activities of the roots, were reduced by 18.65%, 42.14%, 56.70% compared with control, respectively,.4. Silicon fertilizer in soil could alleviate the stress of lead on the ginger, significantly promoted the growth of ginger, increased production, reduced lead accumulation in the ginger rhizome, improved product safety. Under 500 mg·kg^-1Pb stress, silicon fertilizer for the amount were 1,2 g·kg^-1, plant height increased 16.67% and 11.99%, yield increased by 33.23% and 43.60% compared with non-silicon treatment. The lead content of rhizome were 0.225 and 0.071 mg·kg^-1 decreased by 72.79% and 91.41% than non-silicon treatment.5. Ginger in lead concentration 250 mg·L^-1cultured 30 d, whose root, stem, leaf and rhizome fresh weight were reduced by 19.85%, 21.42%, 22.89% and 18.96% compared with control, while adding 1.5 mmol·L-1Si, only 4.90%, 12.35%, 18.17% and 11.53% lower than the control. When treated by adding silicon and hydroponic, ginger root, stem, leaves and rhizome of the lead content were 58.92%, 55.74%, 69.82% and 58.27% than non-silicon treatment, respectively.6. Under hydroponic ginger 250 mg·L^-1lead stress conditions, adding 1.5 mmol·L^-1Si significantly showed alleviation effect. Such as treated by silicon for the 10 d, MDA content of ginger root, leaf decreased by 32.87% and 30.43%, CAT and APX activities of root, leaf increased by 153.44%, 40.79% and 57.29%, 60.96%, root activity increased by 54.74%, total chlorophyll content of leaves and photosynthetic rate increased 7.51% and 207.50%, respectively.更多还原