摘要
以海岛棉海7124(R1)和Pima 90(R2)为砧木,以冀棉11(S1)和鄂棉22(S2)为接穗,利用贴接法得到嫁接苗(S1/R1,S2/R1,S1/R2和S2/R2),成活率均在60%以上,S2/R2的则达85%,表明选用的海岛棉品种与陆地棉品种具有良好的亲和性。抗性鉴定结果表明,S1/R1、S2/R1对黄萎病表现为抗病;S1/R2、S2/R2表现为高抗,说明利用合适的抗病砧木与感病的陆地棉嫁接,能有效地防治黄萎病。接种黄萎病菌3d后,叶片中SOD、POD活性均有加强,MDA含量均有提高。且砧木叶片中SOD、POD活性最高,接穗叶片中SOD、POD活性最低;4种组合的嫁接苗介于二者之间。而叶片中MDA含量则相反,以接穗中最高,砧木中最低,嫁接苗介于二者之间。表明嫁接增强植株的抗病性可能是通过增强防御自由基和活性氧伤害的酶系统、降低叶片细胞膜脂的过氧化作用、使膜的损伤程度减小而实现的。棉苗感染病原菌后PAL活性明显升高并表现出规律性的变化,即在侵染的第1天,酶活性上升较缓,随后急剧上升,酶活高峰出现在侵染后第3天,之后迅速下降,到第5天后与初始水平接近。不同抗性品种的PAL活性变化有显著差异。鄂棉22(S2)的PAL活性上升缓慢,峰值较小,Pima 90(R2)的PAL活性上升快,峰值最高。S2/R2嫁接棉苗的PAL活性介于两者之间,且峰值与Pima 90(R2)的接近。
Using sea-island cotton 7124 （R1） and Pima 90 （R2） as rootstocks, grafted seedlings S1/R1,S2/R1,S1/R2 and S2/R2 were obtained by the close-joining method with Jimian 11 （S1） and Emian 22 （S2） as the scion. All the grafting survival rates are above 60%, and the survival ratio of S2/R2 reached 85%. Results confirmed that there was favorable affinity among the selected sea-island cotton and upland cotton varieties. The resistance test showed that the grafted seedlings of S1/R1, S2/R1,S1/R2,and S2/R2 were resistant to Verticillium wilt with the relative disease indexes of resistance at 16.1,12. 3,5.4 and 4. 5, respectively. The results indicated that susceptible upland cotton cultivars grafting on appropriate disease-resistant rootstocks can effectively control the Verticillium wilt. The physiological indexes of rootstocks, scion and grafted seedlings were determined on the third day after inoculation of Verticillium dahhae Kleb.. It was found that the activities of SOD and POD in all leaves were enhanced with MDA content increased. The SOD and POD activities in rootstocks leaves were the highest （the SOD and POD activities in R2 leaves are 68.51 and 661.26 U/（mg·min）, respectively）, and the increased amplitudes are 31.5% and 27.7%,respectively; the SOD and POD activities in scion leaves were the lowest （the SOD activity in S1 leaves and POD activity in S2 leaves are 40.80 and 424.48 U/（mg·min）, respectively）,and the increased amplitudes are 15.5% and 5.2% ,respectively; the SOD and POD activities in four grafted seedlings leaves were between them. While the MDA contents in leaves were in the contrast：the MDA contents in scion leaves being the highest, and those in rootstock leaves being the lowest, the MDA contents in grafted seedlings leaves being mediate. The enhancement of dis ease-resistance in plant by grafting can be contributed to the enhancement of the enzyme system which defenses the damage from free radicals and reactive oxygen through reducing the lipid peroxidation in the leaf cell membrane. PAL activity in the leaves of cotton seedling infected by pathogen was significantly elevated and showed regular changes. PAL activity increased slowly in primarily infected the first day followed by a sharp rise, and the activity peak arose at the 3rd day after infection followed by a rapid decline, then the enzyme activity were close to the initial levels at the 5th day PAL activities in different resistant varieties are significantly different. PAL activity in Emian 22 （S2） increases slowly with small peak（32. 41 U/（mg·min））; PAL activity in Pima 90（R2） increases quickly with high peak value （53.65 U/（mg·min）） ; PAL activity in grafted cotton seedlings S2/R2 is mediate, and the peak value （46.13 U/（mg·min）） is more close to that of R2.
出处
《华中农业大学学报》
CAS
CSCD
北大核心
2012年第4期414-418,共5页
Journal of Huazhong Agricultural University
基金
国家科技支撑计划项目(2011BAD35B05)
湖北省自然科学基金项目(2008CDB091)
湖北省教育厅重点项目(D20082701
D20102903)
