印度梨形孢对非洲菊幼苗生长及抗旱性的影响

Effects of Piriformospora indica on growth and drought tolerance of Gerbera jamesonii L.seedlings

【目的】探究印度梨形孢对非洲菊(Gerbera jamesonii L.)幼苗生长及抗旱性的影响,明确印度梨形孢对非洲菊干旱胁迫的调节机理。【方法】以非洲菊品种‘云南红’为试验材料,通过浇灌印度梨形孢菌液(处理组)观察幼苗生长变化,设不处理对照组,测定2组幼苗生长指标,观察印度梨形孢在植株根部的定殖情况;然后通过自然干旱胁迫处理,对2组幼苗进行干旱胁迫试验,分析干旱胁迫前后各组幼苗叶绿素荧光参数、光合色素含量、相对含水量、含水量、气孔开放度、抗氧化酶活性和MDA含量,探究印度梨形孢对非洲菊幼苗生长及其抗旱性的影响。【结果】印度梨形孢能定殖在非洲菊幼苗根部,显著提高非洲菊幼苗地上部鲜质量、叶片数、叶柄长度和根部鲜质量、根数、根长(P<0.05)。在干旱胁迫下,处理组非洲菊幼苗叶片的F_(v)/F_(m)与qP分别为0.825,0.655,均显著高于对照组(P<0.05);处理组非洲菊幼苗叶片叶绿素总量、相对含水量、含水量分别为1.36 mg/g,33.73%,73.70%,均显著高于对照组(P<0.05);处理组叶片CAT和SOD活性分别为0.30,876.03 U/g,与对照组均无显著差异(P>0.05),APX活性较对照组显著增加(P<0.05),而POD活性和MDA含量则较对照组显著降低。【结论】印度梨形孢能促进非洲菊生长,在干旱胁迫下,其能保护光系统反应中心,提高叶片的保水能力和APX活性,缓解干旱胁迫造成的光抑制和叶绿素降解,从而增强非洲菊幼苗抗旱能力。

【Objective】 This study explored the effects of Piriformospora indica(P.indica) on growth and drought resistance of Gerbera jamesonii L.seedlings and clarified the regulatory mechanism of P.indica on drought stress of gerbera.【Method】 Seedlings of the gerbera(Gerbera jamesonii L.) variety of ‘Yunnan Red’ were treated with P.indica to examine the growth-related parameters using the seedlings without P.indica treatment as control(CK).Growth parameters and colonization of P.indica in roots of gerbera seedlings were determined.The drought tolerance of seedlings was then assayed by natural drought stress treatment.The chlorophyll fluorescence parameters,photosynthetic pigments,relative water content,water content,stomatal apertures,antioxidant enzyme activities and MDA level were analyzed to study the effects of P.indica on growth and drought tolerance of gerbera seedlings.【Result】 P.indica successfully colonized in roots of gerbera seedlings,and thus promoted fresh weight,leaf number and petiole length of shoots as well as fresh weight,number and length of roots(P<0.05).Under drought stress,the F_(v)/F_(m)and qP values of seedlings treated with P.indica were 0.825 and 0.655,which were significantly higher than those of CK(P<0.05).Chlorophyll(a+b) content,relative water content,and water content of P.indica-treated seedlings were 1.36 mg/g,33.73%,and 73.70%,which were also significantly higher than those of CK(P<0.05).CAT and SOD activities in leaves of P.indica-treated seedlings were 0.30 and 876.03 U/g without significant differences from those of CK(P>0.05),whereas APX activity of P.indica-treated seedlings were significantly increased(P<0.05).Meanwhile,P.indica effectively decreased POD activity and MDA accumulation in seedlings.【Conclusion】 P.indica can promote growth performance of gerbera seedlings.Under drought stress,P.indica can improve the drought resistance of gerbera seedlings by alleviating the photo-inhibition,improving leaf water retention capacity,alleviating chlorophyll degradation,and increasing APX activity.