外源水杨酸对低温胁迫椰子幼苗生理特性的影响

Effects of exogenous salicylic acid on physiological charac-teristics of Cocos nucifera L. young seedlings under cold stress

  • 摘要: 目的研究外源水杨酸(SA)对低温胁迫下不同品种椰子幼苗抗寒生理指标的影响,为提高椰子幼苗抗寒能力及选育抗寒椰子新品种提供参考依据.方法以1年生文椰78F1、文椰2号、文椰3号和文椰4号幼苗为研究材料,分别喷施100.0、150.0、200.0和250.0 mg/L外源SA,测定分析其4℃低温胁迫1~5 d叶片的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性及丙二醛(MDA)和脯氨酸(Pro)含量.结果4个外源SA处理的椰子幼苗在4℃低温胁迫5 d内,叶片的SOD、CAT和POD活性及Pro含量均高于相应的清水对照(CK),且总体上均呈先上升后下降的变化趋势;MDA含量均低于CK,且呈先下降后上升的变化趋势;4℃胁迫第2 d,喷施150.0 mg/L SA的文椰78F1、文椰2号、文椰3号和文椰4号幼苗叶片SOD、CAT和POD活性及Pro含量最高,均显著高于相应的CK和其他浓度处理(P<0.05,下同),MDA含量最低,均显著低于相应的CK和其他浓度处理,其中以文椰78F1幼苗的SOD、CAT和POD活性及Pro含量更高,MDA含量更低.同一低温胁迫时间不同浓度SA处理中,总体上也以150.0 mg/L SA处理各椰子品种幼苗的SOD、CAT和POD活性及Pro含量最高,MDA含量最低,在4个椰子品种中,以文椰78F1幼苗的SOD、CAT和POD活性及Pro含量更高,MDA含量更低,其次为200.0和250.0 mg/L SA处理,100.0 mg/L SA处理的5个抗寒指标变化不明显.结论喷施150.0 mg/L外源SA能提高椰子幼苗的抗寒性,尤其对文椰78F1幼苗的抗寒效果更佳,可在椰子抗寒育苗及抗寒椰子新品种选育中推广应用.

     

    Abstract: ObjectiveThe present study was conducted to investigate the effects of exogenous salicylic acid(SA)on physiological indexes of Cocos nucifera L. young seedlings of different varieties under cold stress in order to provide refe-rence for improving cold resistance of C. nucifera young seedlings and breeding new cold resistant C. nucifera varieties.MethodOne-year-old seedlings of Wenye 78F1,Wenye II,Wenye III and Wenye IV were used as materials,and sprayed with different concentrations of SA(100.0,150.0,200.0 and 250.0 mg/L). Activities of superoxide dismutase(SOD),cata-lase(CAT),peroxidase(POD)and contents of malonaldehyde(MDA)and proline(Pro)in leaves under cold stress of 4℃for 1-5 d were determined and analyzed.ResultThe results showed that,after being treated with four different concentra-tions of SA at 4℃,SOD,CAT,POD activities and Pro content of C. nucifera young seedlings were higher than those of clear water control(CK)within 5 d,and these indexes increased firstly and then decreased on a whole. But MDA content was lower than that of CK,decreasing firstly and then increasing. SOD,CAT,POD activities and Pro content in seedling leaves of Wenye 78F1,Wenye II,Wenye III and Wenye IV at 4℃were the highest on the 2nd day,significantly higher than those in CK and in other SA treatments(P<0.05,The same below). But MDA content was the lowest,significantly lower than that in CK and under other concentrations of SA. Among which,SOD,CAT and POD activities and Pro concent of Wenye 78F1 young seedlings were the highest and MDA concent was the lowest. When treated with different concentra-tions of SA at the same cold stress time,SOD,CAT and POD activity and Pro content of C. nucifera young seedlings of various varieties treated by 150.0 mg/L SA were the highest and the MDA content was the lowest,among which,SOD, CAT and POD activity and Pro concent of Wenye 78F1 seedlings were the highest and MDA concent was the lowest on the whole. The effects of 200.0 and 250.0 mg/L SA treatments were weaker than those of 150.0 mg/L SA treatment. There were no obvious changes in the five cold resistant indexes in seedlings treated with 100.0 mg/L SA.ConclusionSpraying 150.0 mg/L exogenous SA can improve cold resistance of C. nucifera young seedlings,it especially has optimal effects on Wenye 78F1 cold resistance. Therefore,this method can be applied in breeding cold resistant C. nucifera seedlings and cold resistant C. nucifera new varieties .

     

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