砧用南瓜幼苗对镉的耐性和积累能力研究

Study on Tolerance and Accumulation Ability of Cadmium in Pumpkin Seedlings for Rootstocks

采用营养液栽培的方法,研究了不同浓度(0、5和10mg·L-1)镉(Cd)对10种砧用南瓜幼苗生长状况、丙二醛(MDA)、地上部Cd含量及转移系数(TF)的影响,利用隶属函数法综合评价其耐Cd能力与Cd吸收积累能力,以期筛选到优良的砧用南瓜。结果表明:(1)‘多美109’、‘鑫力3号’、‘强力1号’、‘黑籽南瓜’和‘云南黑籽南瓜’在2种浓度Cd处理下全株生物量均显著低于对照,并以‘黑籽南瓜’和‘云南黑籽南瓜’下降幅度最大、耐性最差,而‘野木一雄’、‘青佳砧甲’、‘津油108’和‘抗线1号’在Cd处理下均与对照差异不显著,生长势良好,耐性强。(2)在2种浓度Cd处理下,‘津油108’幼苗体内各抗氧化酶活性较高,根系和叶片的MDA含量与对照无显著差异,未受到膜脂过氧化伤害;‘野木一雄’幼苗各抗氧化酶活性较高,MDA含量升高幅度较小,为对照的1.01～1.56倍,受到膜脂过氧化伤害相对较小;而‘多美109’、‘强力1号’和‘云南黑籽南瓜’幼苗在2种浓度Cd处理下,各抗氧化酶活性显著下降,体内MDA含量升高幅度大,分别为对照的1.30～2.46、1.33～3.11、1.45～3.24倍,受伤害程度最大。(3)‘津油108’与‘青佳砧甲’在2种浓度Cd处理下地上部Cd含量和TF均较小,Cd吸收能力最弱,其次是‘野木一雄’,而‘亮丽佳’、‘黑籽南瓜’和‘云南黑籽南瓜’地上部Cd含量和TF最大,Cd吸收能力最强。(4)隶属函数值综合评价结果显示,10种砧用南瓜幼苗对Cd的耐性大小依次为:‘津油108’>‘野木一雄’>‘鑫力3号’>‘青佳砧甲’>‘抗线1号’>‘多美109’>‘黑籽南瓜’>‘亮丽佳’>‘强力1号’>‘云南黑籽南瓜’。研究认为,砧用南瓜品种对镉胁迫的耐受性存在明显差异,并以‘津油108’最佳,其在镉胁迫下生长势良好,耐性强,且镉吸收和转运能力最弱。

In this experiment, the effects of different concentrations of cadmium (0, 5 and 10 mg·L^-1 ) on the growth of 10 kinds of rootstock seedlings squash, the content of malondialdehyde (MDA), the content of Cd in shoots and the transfer coefficient (TF) were studied by means of nutrient solution culture. We used membership function method to comprehensively evaluate its ability and absorption and accumulation ability of Cd in order to screen excellent rootstocks The results showed that:(1) the whole plant biomass of ‘Duomei 109’,‘Xinli 3’,‘Qiangli No. 1’,‘Heizi Nangua’ and ‘Yunnanheizi Nangua’ were significantly lower than that of control under 5 mg·L^-1 and 10 mg·L^-1 Cd treatments, and the biggest decreased were ‘Heizi Nangua’ and ‘Yunnanheizi Nangua’, which were the worst resistance. However, the biomass of ‘Yemu Yixiong’,‘Qingjia Zhenjia’,‘Jinyou 108’ and ‘Kangxian No. 1’ had no difference with the control, and the tolerance was the strongest.(2) Under the two concentrations of Cd treatments, the antioxidase activities in seedlings of ‘Jinyou 108’ was higher, and the MDA contents in roots and leaves were not significantly different from the control, indicating that it was not subjected to membrane lipid peroxidation injury. The antioxidase activity in ‘Yemu Yixiong’ seedlings was higher, and the increase of MDA content was smaller, which was 1.01~1.56 times of the control, indicating that the membrane lipid peroxidation injury was relatively small. The antioxidase activity of ‘Domei 109’,‘Qiangli 1’ and ‘Yunnan Yunnanheizi pumpkin’ seedlings were decreased significantly under the 5 mg·L^-1 and 10 mg·L^-1 Cd treatments, and the MDA content increased greatly, which was 1.30-2.46, 1.33-3.11, 1.45-3.24 times higher than that of the control, respectively, and the most severely affected.(3) The Cd content and TF of ‘Jinyou 108’ and ‘Qingjia Zhenjia’ were lower, and the Cd absorption capacity was the weakest under Cd treatment, followed by ‘Yemu Yixiong’. However,‘Lianglijia’,‘Heizi Nangua’ and ‘Yunnanheizi Nangua’ were the highest, and the Cd absorption capacity was the strongest.(4) The comprehensive evaluation results of the membership function values showed that the tolerance of 10 variety pumpkin seedlings for rootstocks to Cd was as follows:‘Jinyou 108’>‘Yemu Yixiong’>‘Xinli 3’>‘Qingjia Zhenjia’>‘Kangxian No. 1’>‘Duomei 109’>‘Heizi Nangua’>‘Lianglijia’>‘Qiangli No. 1’>‘Yunnanheizi Nangua’. The studies showed that the tolerance of rootstock pumpkin varieties to cadmium stress was significantly different, and ‘Jinyou 108’ was the best, which has good growth potential, strong tolerance, and the capacity of cadmium absorption and transport was the weakest under cadmium stress.