嫁接对铜胁迫下甜瓜幼苗光合特性与矿质元素吸收的影响

Effects of Grafting on Photosynthetic Characteristics and Mineral Elements of Melon Seedlings under Copper Stress

为探索嫁接对铜胁迫下甜瓜幼苗光合特性与矿质元素吸收的影响,选择了南瓜京欣砧三号为砧木,薄皮甜瓜IVF09与厚皮甜瓜IVF117为接穗,以自根苗为对照,采用基质栽培法研究了铜胁迫下甜瓜嫁接苗和自根苗的光合特性与矿质元素吸收。结果表明:在铜胁迫条件下,甜瓜幼苗生物量下降、光合作用受抑制、矿质元素吸收平衡破坏。但在同一胁迫条件下,嫁接苗的生物量大于自根苗,光合色素含量高于自根苗,净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)显著大于自根苗,气孔限制值(Ls)小于自根苗;嫁接改善了矿质元素吸收,有效增加K、P、Na等的含量,减少Cu含量,IVF09嫁接苗叶片Cu含量在800μmol/L Cu2+胁迫下显著低于自根苗,仅为自根苗的70.11%;而IVF117在400μmol/L Cu2+胁迫下Cu含量显著低于自根苗,为自根苗的86.61%。因此,嫁接减弱了铜胁迫对甜瓜幼苗光合特性与矿质元素吸收的抑制作用,缓解了铜胁迫对甜瓜幼苗的毒害作用。

The effects of grafting on photosynthetic characteristics and mineral elements of melon seedlings under copper stress in this study. Pumpkin Jingxinzhen NO. 3 was carried out as stock,melon IVF09 and muskmelon IVF117 as cion,and ungrafted seedlings as control. Here,we found that,under copper stress,the biomass of melon seedlings was decreased,photosynthetic characteristics was inhibited and the absorption of mineral elements balance were destructed. But under the same stress conditions,the biomass and photosyntheic pigment content of grafted seedings were greater than that of ungrafted seedings. The net photosynthetic rate（ Pn）,transpiration rate（ Tr）,stomatal conductance（ Gs） and intercellular CO2concentration（ Ci） were significantly higher than that of ungrafted seedlings,but Ls was lower. Grafting to improve the absorption of mineral elements,effectively increase the content of K,P,Na,reduce the content of Cu,Cu content of IVF09 grafting seedlings in leaf was significantly lower than that ungrafted seedlings under the 800 μmol /L Cu^2 ＋stress,since only that in 70. 11%,the IVF117 grafting seedlings was significantly lower than that of ungrafted seedlings under 400 μmol /L Cu^2 ＋stress,since 86. 61%. The test results showed that the grafting reduced photosynthetic characteristics and mineral elements absorption inhibitory effect on melon seedlings under copper stress,relieve the toxic effect on copper stress of melon seedlings.