混种牛膝菊嫁接后代对树番茄幼苗镉积累的影响

Effects of Intercropping With Post-Grafting Generations of Galinsoga parviflora on Cadmium Accumulation of Cyphomandra betacea Seedlings

以树番茄幼苗和镉超富集植物牛膝菊嫁接后代(砧木:牛膝菊、豨莶、鬼针草和万寿菊,实生后代,依次记为:S_G、S_S、S_B、S_T及S_N)为材料,采用盆栽试验,将树番茄幼苗分别与牛膝菊不同砧木嫁接后代及其实生后代混种于镉污染的土壤上,研究了混种牛膝菊嫁接后代对树番茄幼苗镉积累的影响,以期筛选出既能有效促进树番茄幼苗生长又能降低其镉含量的混种模式。结果表明:与牛膝菊后代混种均显著提高了树番茄幼苗根系、茎秆、叶片的生物量及其光合色素含量。其中,混种S_B对树番茄幼苗生长的促进作用最显著,其总生物量较树番茄幼苗单种提高了312.48%。对树番茄幼苗的镉含量而言,混种牛膝菊嫁接后代(S_G、S_S、S_B、S_T)使树番茄幼苗各器官的镉含量均显著低于其混种牛膝菊实生后代(S_N)及树番茄单种。混种S_B使树番茄幼苗根系、茎秆、叶片的镉含量均达到最低,分别较单种降低了46.30%、36.68%和22.10%。对牛膝菊后代而言,S_N根及地上部分的生物量均显著高于其它牛膝菊嫁接后代,而S_N各器官的镉含量在所有处理中均达到最低。因此,混种牛膝菊嫁接后代能够促进树番茄幼苗的生长,并降低树番茄的镉含量,其中以S_B混种树番茄幼苗效果最佳。

In order to screen out the intercropping mode which could effectively promote the growth of Cyphomandra betacea seedlings and reduce its cadmium content under cadmium stress,the fruit tree C.betacea seedlings and cadmium hyperaccumualtor plant Galinsoga parviflora were used in the pot experiment,and the effects of intercropping with the post-grafting generations of Galinsoga parviflora(the rootstocks of G.parviflora,Siegesbeckia orientalis,Bidens pilosa and Tagetes erecta,and ungrafted,which marked as S_G,S_S,S_B,S_T and S_N)on cadmium accumulation of Cyphomandra betacea seedlings were studied.The results showed that intercropping with generations of G.parviflora not only significantly increased the roots,stems and leaves biomasses of C.betacea seedlings,but also increased the photosynthetic pigment contents in that.Among them,intercropping with S_B had the most significant effect on the growth of C.betacea seedlings,and the total biomass increased by 312.48%,compared with the monoculture.For the cadmium content in C.betacea seedlings,intercropping with post-grafting generations of G.parviflora(S_G,S_S,S_B and S_T)was significantly lower than those of intercropping with S_N and the monoculture of C.betacea seedlings.Intercropping with S_B had the lowest cadmium content in roots,stems and leaves of C.betacea seedlings,which decreased by 46.30%,36.68%,and 22.10%,respectively,compared with the monoculture.For the post generations of G.parviflora,the roots and shoots biomasses of S_N were significantly higher than those of other post-grafting generations of G.parviflora,but the cadmium content in S_N reached the lowest in all treatments.Therefore,intercropping with post-grafting generations of G.parviflora could promote the growth of C.betacea seedlings and decrease the cadmium content in C.betacea seedlings,and the best effect was SBintercropping with C.betacea seedlings.