不同浓度褪黑素对豆瓣菜镉积累的影响

为提高豆瓣菜对镉胁迫抗逆性的同时有效降低其镉含量,采用盆栽试验,研究了在镉(5mg/kg)胁迫下,不同浓度褪黑素(0,25,50,100,150,200μmol/kg)对豆瓣菜生物量、镉含量、光和色素含量、抗氧化酶活性以及土壤酶活性、pH、有效态镉含量的影响。结果表明,与对照相比,褪黑素有效提高了豆瓣菜叶片超氧化物歧化酶、过氧化物酶、过氧化氢酶的活性,且均随着褪黑素浓度的升高呈现上升的趋势。豆瓣菜根、茎、叶的生物量及叶片光合色素(叶绿素a、叶绿素b、类胡萝卜素)的含量均随着褪黑素浓度的升高出现先上升后下降的趋势,并在褪黑素浓度为50μmol/kg时达到最大值;而豆瓣菜根、茎、叶的镉含量随着褪黑素浓度的升高出现先下降后上升的趋势,并在褪黑素浓度为50μmol/kg时最低,分别较对照降低了9.82%,7.42%,8.19%。另外,与对照相比,褪黑素显著提高了种植过豆瓣菜的土壤有效态镉含量及土壤蔗糖酶的活性,且随着褪黑素浓度的升高出现上升的趋势;而随着褪黑素浓度的升高,土壤pH值则出现下降的趋势。综上,适宜浓度的褪黑素可以在提高豆瓣菜对镉胁迫抗逆性的同时有效降低豆瓣菜对土壤镉的吸收,其中褪黑素浓度为50μmol/kg时效果最好,可为镉污染地区豆瓣菜的栽培生产提供参考。

野菜少花龙葵的硒富集特性研究

【目的】为从野菜中筛选出硒富集较高的蔬菜,并对其硒富集特性进行鉴定。【方法】采用盆栽试验,以野菜为研究对象,对5种野菜(养心菜Sedum aizoon、灰灰菜Chenopodium album、马齿苋Portulaca oleracea、马兰Kalimeris indica和少花龙葵Solanum photeinocarpum)进行了硒富集特性的初步研究,发现少花龙葵具有较高的硒富集量,并对少花龙葵进行了进一步的硒浓度梯度鉴定。【结果】少花龙葵根系、茎秆、叶片及地上部分生物量随着土壤硒浓度的增加呈降低的趋势,但未表现出明显的毒害症状。随着土壤硒浓度的增加,少花龙葵各器官的硒含量呈增加的趋势,其大小顺序为:根系>叶片>茎秆>地上部分,其地上部分硒积累量则呈先增后降的趋势(最大值为151.03μg/株);在土壤硒浓度为75 mg/kg时,少花龙葵地上部分硒含量为136.06 mg/kg,大于非硒富集植物的临界值(100 mg/kg)。少花龙葵叶绿素总量、净光合速率和可溶性蛋白含量随着土壤硒浓度的增加呈降低的趋势,而类胡萝卜素含量、气孔导度、胞间CO2浓度、蒸腾速率、SOD活性、POD活性和CAT活性呈先增后降的趋势。【结论】少花龙葵是一种硒富集量较高的野菜,且对硒具有较高的耐性。

壳聚糖对葡萄幼苗生理生态的影响

为筛选出最有利于葡萄生长的壳聚糖浓度,以葡萄幼苗为材料,对其喷施浓度为0、1、2、4和6 g/L的壳聚糖溶液,研究了壳聚糖对葡萄生长及生理的影响。结果表明:喷施不同浓度壳聚糖后,葡萄幼苗生物量、光合色素含量和光合作用均较对照显著增加,且随壳聚糖浓度的增加而呈先增加后减少的趋势,当壳聚糖浓度为4 g/L时,葡萄幼苗生物量、光合色素含量及净光合速率均最大。喷施壳聚糖后,葡萄幼苗叶片抗氧化酶(超氧化物歧化酶、过氧化物酶和过氧化氢酶)活性、可溶性蛋白含量、丙二醛含量及相对电导率均随喷施浓度增大不断提高,且在壳聚糖浓度为6 g/L时达到峰值。经壳聚糖处理后葡萄幼苗各部分可溶性糖含量也有所上升,根系、茎秆可溶性糖含量在壳聚糖浓度为4 g/L时达最高值。因此,壳聚糖能够促进葡萄幼苗生长,在一定程度上提高了葡萄幼苗的抗逆性。

Intercropping with Solanum nigrum and Solanum photeinocarpum from Two Ecoclimatic Regions Promotes Growth and Reduces Cadmium Uptake of Eggplant Seedlings

Soil contamination by heavy metals is a serious environmental problem worldwide, and reduction of heavy metal accumulation in vegetables grown on contaminated land is a matter of urgency. A pot experiment was conducted to study the effects of intercropping with the Cd hyperaccumulators Solanum nigrum and Solanum photeinocarpum from two ecoclimatic regions, Ya'an and Chengdu,Sichuan Province, China, on the growth and cadmium(Cd) uptake of eggplant(Solanum melongena L.). The biomass, photosynthetic pigment contents, and activities of antioxidant enzymes of eggplant were enhanced by intercropping. The biomass of eggplant was the highest after intercropping with S. photeinocarpum from Ya'an, but did not differ significantly from that after intercropping with S. nigrum from Chengdu. The shoot Cd content of eggplant was significantly reduced by intercropping with the hyperaccumulators,which ranked as follows: S. nigrum from Chengdu > S. nigrum from Ya'an > S. photeinocarpum from Chengdu > S. photeinocarpum from Ya'an, with the decreases being 19.60%, 14.36%, 9.66%, and 6.42%, respectively, as compared with the control. The lowest shoot Cd content and translocation factor of eggplant were attained after intercropping with S. nigrum from Chengdu. Therefore, it was feasible to intercrop eggplant with S. nigrum and S. photeinocarpum on Cd-contaminated soil.