杜鹃花类菌根真菌对桃叶杜鹃幼苗光合性能及叶绿素荧光参数的影响

Effects of inoculation with different ERM isolates on photosynthesis and chlorophyll fluorescence parameter of Rhododendron annae Franch. seedlings

【目的】研究12株杜鹃花类菌根(Ericoid mycorrhiza,ERM)真菌对2 a生桃叶杜鹃无菌实生幼苗促生效应及叶片叶绿素、光合参数和叶绿素荧光参数的影响。【方法】采用温室盆栽试验,ERM真菌菌株由野生桃叶杜鹃根系分离而得。【结果】表明接种苗侵染率较高。接种处理间在幼苗地上部分、地下部分干重与总生物量指标呈极显著差异(P<0.01)。与不接种对照相比,叶片中叶绿素a、叶绿素b、总叶绿素含量、叶片净光合速率Pn、叶片气孔导度Gs和叶片蒸腾速率Tr显著提高,而叶片胞间CO2浓度Ci则降低。接种幼苗叶片中实际量子产量ΦPSⅡ除菌株TY19、TY24和TY34低于对照外,其余均显著增加;PSⅡ电子传递速率ETR、PSⅡ最大光化学量子产量Fv/Fm、潜在活性Fv/Fo和光化学淬灭qP均显著提高;非光化学淬灭NPQ除菌株TY29外其它均高于对照,并与对照差异极显著(P<0.01)。ΦPSⅡ与Pn、Gs的相关性大于Fv/Fm、qP、NPQ;ETR与Fv/Fm、Fv/Fo、NPQ、Pn、Tr的相关性大于qP和Gs;Pn与Gs的相关性大于Tr,与Ci显著负相关(P<0.01)。【结论】通过接种处理,提高了叶片光合性能及叶绿素荧光参数,增强了植株对有效光的利用,显著增加了幼苗生物量。从综合接种效应来看,TY18、TY29、TY35、TY02、TY07和TY12是培育桃叶杜鹃菌根苗优良备选菌株。

[Objectivel Twelve ericoid mycorrhiza （ERM） fungal strain isolates were used to inoculate 2-year-old ornamental Rhododendron annae Franch. sterile seedlings, plant growth, chlorophyll, photosynthetic parameters and chlorophyll fluorescence parameters in plant leaves were investigated. [Methods] Greenhouse pot experiments were conducted in this study to test the effect of 12 ERM strains which were isolated from the roots of wild R. annae. ]Re- sults] The results revealed that the colonization ratio was notably higher. There were substan- tial differences on the aboveground, underground part and total biomass index of inoculated seedlings compared with those of uninoculated seedlings （P〈0.01）. Compared with the control treatment, the chlorophyll a and b, total chlorophyll content, leaf net photosynthetic rate （Pn）, stomatal conductance （Gs） and transpiration rate （Tr） were higher significantly, along with the increase of intercellular CO2 concentration （Ci）. Practical quantum yield （~PS II ） of inoculated seedlings＇ leaves were significantly higher than those of the uninoculated except strain TY19, TY24 and TY34; PS 1I electron transfer rate （ETR）, PS II maximum photochemical quantum yield （Fv/Fm）, potential activity （Fv/Fo） and photochemical quenching （qP） were significantly higher than those of the control plants. Non-photochemical quenching （NPQ） were higher as well, and the difference was very significant except strain TY29. The correlation of （I）PS II and Pn, Gs were significantly greater than those of Fv/Fm, qP and NPQ. The correlation of ETR Fv/Fm, Fv/Fo, NPQ, Pa and Tr were greater than the qP and Gs. The correlation of Pn and Gs were greater than Tr, but it had significant negative correlation with Ci （P〈0.01）. [Conclusion] Through inoculation treatment, photosynthetic parameters and chlorophyll fluorescence parameters in plant leaves were improved, and meanwhile the effective use of light were en- hanced. Thus, there were significant increases in seedling biomass. As for the comprehensive inoculation effects, TY18, TY29, TY35, TY02, TY07 and TY12 are the superior strains isolates to cultivate R. annae mycorrhizal seedlings.