黄条金刚竹、阔叶箬竹和菲白竹在干旱、冻害和重金属Pb胁迫下光合生理响应研究

Photosynthetic and Physiological Responses to Drought,Cold and Pb Stresses in Pleioblastus kongosanensi,Indocalamus latifolius and Sasa fortunei

对黄条金刚竹Pleioblastus kongosanensi、阔叶箬竹Indocalamus latifolius、菲白竹Sasa fortunei抗寒、抗旱、重金属Pb胁迫3个方面综合评价,为这些竹种在城市绿地尤其是北方城市大面积推广应用奠定基础。研究测定在持续干旱胁迫、自然越冬期冻害胁迫和土壤重金属Pb含量在100 mg·kg-1、500mg·kg-1、1000 mg·kg-1、2000 mg·kg-15个梯度胁迫下3个竹种光合参数、叶绿素荧光参数和生理生化指标的变化,采用模糊隶属函数法方法对这些竹种的抗逆性进行综合评价。结果显示:(1)黄条金刚竹、阔叶箬竹、菲白竹适宜生长在土壤相对含水率≥12%、16%和21%的土壤中生长,且干旱胁迫持续时间分别是17 d、21 d、21 d,抗旱性菲白竹>阔叶箬竹>黄条金刚竹,但耐旱指数差异不显著;(2)冻害胁迫下,研究竹种在胁迫第19天出现伤害症状,由于本研究采用盆栽地被竹,竹鞭受冻害严重,综合评价抗冻性阔叶箬竹>菲白竹>黄条金刚竹;(3)不同竹种在土壤重金属Pb胁迫下研究发现,与对照竹苗相比,低浓度处理(<500 mg·kg-1)的研究竹种长势相对较好,差异不显著;高浓度(>500 mg·kg-1)处理的幼苗随着胁迫浓度的增加受伤害程度增加。3个研究竹种菲白竹对铅的耐性较强,黄条金刚竹和阔叶箬竹蓄积能力较强。因此,冬季采取适当防护措施的情况下,菲白竹可以考虑作为土壤重金属Pb2+含量较高地区的景观植物,阔叶箬竹抗冻性较强,可考虑北方地区的重金属污染区作为修复植物。

Bamboo species are ideal for greening and beautifying landscape. In order to explore the possibility to grow and popularize bamboo in large area in the cities of North China, the photosynthetic and physiological responses to drought, cold and Pb stresses in Pleioblastus kongosanensi, lndocalamus latifolius, Sasa fortunei were comprehensively evaluated. The changes in photosynthetic parameters, chlorophyll fluorescence parameters and biochemical indexes of these bamboo species under drought, stress and Pb stresses were examined. The methods of subordinate function and fuzzy synthetic judgment were used to evaluate their resistance. The results showed that P. kongosanensis, I. latifolius and S. fortunei grew well when the soil water content was ≥ 12%, 16% and 21% and the drought stress duration was more than 17d, 21d, and 21d respectively. P. kongosanensis damaged most quickly and S.fortunei damaged slower than the other species over the process. The drought resistance followed the order of P. kongosanensis 〉 I. latifoliu 〉 S. fortunei. Although, there were no significant difference in their drought tolerance indexes. The rhizomes of the bamboo plants growing in pots were seriously injured under cold stress in winter, their injury symptoms appeared from the 19th day on, and they died at the end. Based on chlorophyll fluorescence and biochemical indexes, their cold resistance followed the order of I. latifolius 〉 S. fortunei 〉 P. kongosanensis. Under the low Pb （ 〈 500 mg·kg-1 ） treatments, the bamboos under test grew well, while under high Pb （ 〉 500 mg kg- 1 ） treatments, the damaged area of the bamboo leaves increased with the increasing Pb concentration, the differences between treatments and control were significant. Their Pb storage capacity were high, especially under high Pb （ 〉 2000 mg kg-1） conditions, S. fortunei was less affected. These indicated that S. fortunei can be planted in high Pb soil, and I. latifoliu can be used as the remediation plants for high Pb soil in North China.