促生小菇属菌株M23对黑果腺肋花楸光合作用的影响

以黑果腺肋花楸为试验材料,设置5个处理组,分别为阴性对照(CK)、阳性对照(PCK)、大田条件下根施低剂量T₁(每株50 g)、中剂量T₂(每株100 g)和高剂量T₃(每株200 g)3个水平的小菇属菌株M23,分析各处理组黑果腺肋花楸的农艺性状、叶绿素含量和生理指标,并利用Li-6400便携式光合仪测定光合特性日变化。结果表明: 黑果腺肋花楸净光合速率(P_n)呈双峰曲线,在13:00时叶片的气孔导度(g_s)和蒸腾速率(T_r)均明显下降,而胞间CO₂浓度(C_i)却显著升高,出现由非气孔限制因素引起的光合“午休”现象。加菌处理可成功避免光合“午休”现象,与13:00时对照组黑果腺肋花楸的平均值相比,加菌组的平均P_n、g_s、T_r、水分利用率(WUE)和光能利用率(LUE)提高了113%、91%、50%、48%和117%,且日均P_n、g_s、T_r和LUE显著高于对照组,分别约是对照组平均值的1.5、1.9、1.4和1.5倍。在加菌处理组中,高剂量的作用效果显著优于中、低剂量,株高是中、低剂量组的1.2倍。高剂量组黑果腺肋花楸的所有生长指标、光合参数和抗性指标均优于其他组。表明菌株M23可以通过提高黑果腺肋花楸的光合特性、增强对外界环境的适应能力等促进植株生长,且以每株200 g作用效果最佳。

Effects of growth-promoting strain Mycena sp M23 on photosynthesis of Aronia melanocarpa

The agronomic traits, chlorophyll content, physiological indices of Aronia melanocarpa were compared in five treatments, namely negative control (CK), positive control (PCK), low dose of microbial inoculant (T₁, 50 g per seedling), moderate dose of microbial inoculant (T₂, 100 g per seedling), high dose of microbial inoculant (T₃, 200 g per seedling) in field. The diurnal variation of net photosynthetic rate was measured by Li-6400 portable photosynthesis system. The diurnal variation of net photosynthetic rate (P_n) of A. melanocarpa showed a pattern of bi-modal curve with photosynthetic “noon break” phenomenon, which occurred at 1:00 pm. At that time, stomatal conductance (g_s) and transpiration rate (T_r) of A. melanocarpa showed a dramatic decline, while intercellular CO₂ concentration (C_i) significantly rose. It was a photosynthetic “noon break” phenomenon caused by non-stomatal limitation. Application of inoculant to A. melanocarpa successfully avoided the photosynthetic “noon break” phenomenon. Compared with average value of CK and PCK, P_n, g_s, T_r, water use efficiency (WUE) and light utilization efficiency (LUE) of inoculation groups increased by 113%, 91%, 50%, 48% and 117% at 1:00 pm. Daily mean of P_n, g_s, T_r and LUE of inoculation group was 1.5, 1.9, 1.4 and 1.5 times as that of average value of CK and PCK. The inductive effect of high dose of microbial inoculant treatment was the best among inoculation treatments, with the seedling height 1.2 times as that of the moderate and low inoculant groups. All growth indices, photosynthetic parameters and resistant physiological indices of high dose group were superior to other groups. Our results suggested that fungi M23 could improve the adaptability of A. melanocarpa to environmental stresses and promote its growth by increasing photosynthesis, with the inductive effect of high dose being the best.