不同抗性砧木嫁接黄瓜幼苗对NaCl胁迫的生理响应

在对系列黄瓜嫁接砧木进行耐盐性鉴定的基础上,选择夏尔巴、新土佐、铁力砧和云南黑籽南瓜4种抗性不同的砧木品种嫁接‘新泰密刺’黄瓜,以自根苗为对照,研究了幼苗对NaCl胁迫的生理响应差异.结果表明:在100 mmol·L-1 NaCl胁迫条件下,嫁接苗的电解质相对渗漏率和丙二醛含量均显著低于自根苗,其中黑籽南瓜嫁接苗最低,其次是铁力砧、新土佐和夏尔巴嫁接苗;NaCl胁迫下嫁接苗叶片中脯氨酸、可溶性糖含量及过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性均显著高于自根苗,其中黑籽南瓜嫁接苗最高,铁力砧和新土佐嫁接苗间无显著差异,夏尔巴嫁接苗最低.NaCl胁迫后,嫁接苗叶片中Na+含量为黑籽南瓜＜铁力砧＜新土佐＜夏尔巴＜自根苗,K+含量在黑籽南瓜、铁力砧和新土佐嫁接苗间差异不大,但均明显高于夏尔巴嫁接苗,自根苗含量最低;嫁接苗Na+/K+显著低于自根苗,以黑籽南瓜嫁接苗最低.

Physiological responses of cucumber seedlings grafted on different salt-tolerant rootstocks to NaCI stress

Based on the salt-tolerance identification of a series of cucumber rootstock varieties, the cucumber cultivar 'Xintaimici' grafted on different salt-tolerant rootstock varieties 'Sherpa', 'Shintosa' , 'Tielizhen' , and 'Figleaf gourd' was selected to study its seedlings physiological responses to NaCl stress, taking the self-rooted ones as the control. Under the stress of 100 mmol NaCl x L(-1), the leaf electrolyte leakage rate and malondialdehyde (MDA) content of the grafted seedlings were significantly lower than those of self-rooted seedlings, and the seedlings grafted on 'Figleaf gourd' showed the lowest electrolyte leakage rate and malondialdehyde (MDA) content, followed by the seedlings grafted on 'Tielizhen', 'Shintosa' , and 'Sherpa'. The leaf proline and soluble sugar contents and peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities of the grafted seedlings were significantly higher than those of the self-rooted seedlings, and the POD, SOD, CAT, and APX activities were the highest for the seedlings grafted on 'Figleaf gourd' and the lowest for the seedlings grafted on 'Sherpa', but had no significant differences for the seedlings grafted on 'Tielizhen' and 'Shintosa'. The leaf Na+ content of the seedlings grafted on different rootstock varieties ranked as 'Figleaf gourd' < 'Tielizhen' < 'Shintosa' < 'Sherpa', while the leaf K+ content had little difference for the seedlings grafted on 'Figleaf gourd', 'Tielizhen', and 'Shintosa' but was significantly higher than that for the seedlings grafted on 'Sherpa'. The self-rooted seedlings had the highest leaf Na+ content but the lowest leaf K+ content. The leaf Na+/K+ ratio of grafted seedlings was significantly lower than that of self-rooted ones, and the seedlings grafted on 'Figleaf gourd' had the lowest leaf Na+/K+ ratio.