低温胁迫下梁山慈竹体细胞突变体植株叶绿素荧光响应

Responses of Chlorophyll Fluorescence in Two Somaclone Mutants of Dendrocalamus farinosus under Low Temperature Stress

以冷驯化的两种梁山慈竹(Dendrocalamus farinosus)体细胞突变体植株及梁山慈竹实生植株为材料,研究了梯度降温处理(依次为4、0、−5、−10和−15℃)对其叶绿素荧光参数的影响。结果表明,实生植株在−5℃胁迫下死亡,而突变体植株No.101-1b和No.101-1c直到−15℃胁迫下才出现死亡。低温胁迫后,突变体植株和实生植株的最大光化学效率(Fv/Fm)、光系统Ⅱ有效光量子产量(YⅡ)和光化学淬灭系数(qP)均有降低,下降幅度排序为实生植株>No.101-1b>No.101-1c。非光化学猝灭系数(NPQ)显著高于胁迫前,以No.101-1c表现最为突出。品系和温度2个因素及两者交互作用对叶绿素荧光的影响均达到显著水平。总结得出,突变体植株No.101-1c具有较高的耐寒性,本研究可为耐寒梁山慈竹体细胞突变体植株的筛选提供科学依据。

The cold tolerance of three Dendrocalamus farinosus strains(seedling plant and two somaclone mutants)which have been cold-acclimated were compared in terms of their chlorophyll fluorescence responses.The cultivation temperature was set at 4,0,−5 and−10℃in turn and each temperature was kept for 90 minutes.The results showed that the seedling plants died under the stress of−5°C,while the mutant plants No.101-1b and No.101-1c survived at 0°C and died under the stress of−15°C.The ratio of variable fluorescence to maximum fluorescence(Fv/Fm),effective photon yield of optical system II(YII)and photochemical quenching coefficient(qP)values were generally decreased in all Dendrocalamus farinosus strains after exposed to low temperature stress,and the descending order was seedling plants>No.101-1b>No.101-1c.Comparatively,the non-photochemical quenching coefficient(NPQ)values of lowtemperature-treated plants were mostly higher than those before stress,especially No.101-1c.The effects of two factors(strain and temperature)and their interaction effect on chlorophyll fluorescence parameters were all significant.It is concluded that the mutant No.101-1c was the most cold-resistant species.The present study can provide scientific basis for screening cold-tolerant somatic mutants of Dendrocalamus farinosus.