番茄嫁接苗根穗互作对其耐冷性的影响

Effects of Rootstock and Scion Interaction on Chilling Tolerance of Grafted Tomato Seedlings

以耐冷性强的番茄‘060112’(R)和冷敏感番茄‘060911’(S)为试材,采用靠接法进行嫁接,形成双根双穗嫁接苗RS/RS,嫁接苗成活后,通过断根或断穗,设RS/RS、RS/R、RS/S、R/RS、R/S、R/R、S/RS、S/R、S/S共9个处理,置于光强22 klx、光周期12 h/12 h的光照培养箱内,测定昼夜温度10℃/3℃低温胁迫9 d及25℃/15℃常温恢复3 d过程中嫁接苗的冷害指数、根系活力、电解质渗透率及渗透调节物质含量,探讨番茄根系、接穗及其互作效应对嫁接苗耐冷性的影响。经统计分析表明,低温胁迫过程中,具"R"根系或接穗的嫁接苗组合中,以R/R处理冷害指数较低,而具"S"根系或接穗的嫁接苗组合中,以S/S处理的冷害指数较高,同时R/R的叶片及根系电解质渗透率最低,可溶性糖及脯氨酸含量最高,R/RS、RS/R、RS/S、S/RS等处理的冷害指数、电解质渗透率、可溶性糖及脯氨酸含量均介于R/R与S/S之间,表明冷敏感的S根系或接穗均降低了嫁接苗中R的耐冷性,而耐冷性强的R根系或接穗均提高了嫁接苗中S的耐冷性。RS/RS处理的耐冷性高于S/RS而低于R/RS,表明根系在增强嫁接苗耐冷性中的作用大于接穗;而具"RS"根或穗的嫁接苗中,以RS-R的耐冷性显著高于RS-S,且互作效应的P值小于0.01,表明根、穗对嫁接苗耐冷性存在显著的互作效应。低温胁迫处理前,不同耐冷性番茄根系活力、根系及叶片电解质渗透率、可溶性糖及脯氨酸含量等无显著差异,但低温胁迫9 d后,常温恢复3 d时,不同处理间均表现出显著差异。

In order to investigate the effect of tomato rootstock,scion and their potential interaction on chilling tolerance,we grafted chilling-sensitive tomato cultivar‘060911＇（S）and chilling-resistant tomato cultivar‘060112＇（R）. We then selectively removed rootstock or scion from the grafted seedlings RS/RS,and incubated the newly formed 9 kinds of seedlings,i.e.,RS/RS,RS/R,RS/S,R/RS,S/RS,S/R,R/S,R/R,S/S in the growth chamber with light intensity of 22 klx and photoperiod 12 h/12 h. The seedlings were treated with low temperature at 10 ℃/3 for 9 days and recovered at 25℃ ℃/15 for ℃3 days. Chilling injury index,root activity,electrolyte leakage and osmotic adjustment substances were measured after the chilling treatment and after the recovery. Grafted seedlings behaved similarly in root activity,electrolyte leakage of root and leaf,soluble sugar and proline content before the chilling treatment,but showed significant difference after the chilling treatment and after the recovery. Among these 9 kinds of grafted seedlings,S/S seedlings displayed the highest while R/R seedlings displayed the lowest chilling injury index. Meanwhile,R/R seedlings showed the lowest electrolyte leakage,and the highest content of soluble sugar and proline. Meanwhile,R/R seedlings showed the lowest electrolyte leakage,and the highest content of soluble sugar and proline. While R/RS,RS/R,RS/S,S/RS seedlings were intermediate between R/R and S/S regarding the chilling injury index,electrolyte leakage,soluble sugar and proline content. Results indicated that both rootstock and scion are important for chilling tolerance. We further found that rootstock conferred higher chilling resistance than scion,due to the fact that the chilling tolerance of RS/RS was higher than that of S/RS,but lower than R/RS. Moreover,the chilling tolerance of RS-R was significantly higher than that of RS-S,and the P value of interaction was less than 0.01. The results showed that rootstock and scion had significant interaction effect on the chilling tolerance of grafted seedlings.