不同砧木对西瓜嫁接苗耐寒性的影响

Effects of different rootstocks on chilling-tolerance of grafted watermelon seedlings

以西瓜(Citrullus vulgarris)郑抗1号为接穗,日本南瓜(C.moschata)、黑籽南瓜(C.ficifolia)、葫芦(Lagenaria siceraia)为砧木,研究了嫁接苗和自根苗在(7.5±0.5)℃低温胁迫下叶片相关耐寒性指标的变化。结果表明:低温处理后嫁接苗丙二醛(MDA)含量、电解质渗透率显著低于自根苗;叶绿素、脯氨酸(Pro)、可溶性糖含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性显著高于自根苗。与处理前相比,12d时日本南瓜砧、黑籽南瓜砧和葫芦砧嫁接苗叶绿素含量分别降低了30.48%、28.48%和52.69%;葫芦砧嫁接苗MDA含量6d时较处理前增加了313.16%;3～12d日本南瓜砧和黑籽南瓜砧嫁接苗电解质渗透率显著低于葫芦砧嫁接苗;低温处理期间,日本南瓜砧嫁接苗可溶性糖含量分别比黑籽南瓜砧和葫芦砧嫁接苗高出24.71%和31.17%,SOD、POD、CAT酶活性高于另外2个组合。综合各项指标显示:3种砧木均能提高接穗对低温的忍耐能力,其顺序为日本南瓜砧>黑籽南瓜砧>葫芦砧。

With the watermelon （ Citrullus chata, C. ficifolia, and Lagenaria siceraia ance of grafted and self-rooted watermelon vulgarris） Zhengkang No. 1 as the scion and C. as the rootstocks, this paper studied the chilling -tolerseedlings under （7.5 ± 0. 5 ） ℃ stress. Under this low temperature stress, the malondialdehyde （MDA） content and electrolyte effusive rate of grafted watermelon seedlings were significantly lower, while their chlorophyll, proline （Pro） and soluble sugar contents and superoxid dismutase （SOD）, peroxidase （POD） and catalase （CAT） activities were significantly higher, compared with those of self-rooted watermelon seedlings. On the twelfth day after low temperature treatment, the total chlorophyll content in the leaves of C. moschata-Zhengkang No. I, C. ficifolia-Zhengkang No. 1, and L. siceraia-Zhengkang No. 1 decreased by 30. 48%, 28.48% and 52. 69%, respectively. The MDA content of L. siceraia-Zhengkang No. 1 changed obviously, with an increase of 313. 16% from 0 to 6 days, and the relative electrolyte effusive rate was significantly higher than that of the other two grafted groups. Under the low temperature treatment, the soluble sugar content of C. moschata-Zhengkang No. 1 was 24. 71% and 31.17% higher than that of C. ficifolia-Zhengkang No. 1 and L. siceraia- Zhengkang No. 1, respectively, and the SOD, POD and CAT activities of C. moschata-Zhengkang No. 1 were significantly higher than those of the two latter grafted groups. The survival rate of C. moschata-Zhengkang No. 1, C. ficifolia-Zhengkang No. 1, L. siceraia-Zhengkang No. 1, and Zhengkang No. 1 was 84. 29%, 79. 24%, 65, 59%, and 45. 12%, respectively. It was suggested that the chilling-tolerance of watermelon seedlings could be improved via grafting with suitable rootstocks. C. moschata-Zhengkang No. 1 had the best chilling-tolerance, followed by C. ficifolia-Zhengkang No. 1, and L. siceraia-Zhengkang No. 1.