低温胁迫下梁山慈竹体细胞突变体植株叶绿素荧光响应

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。

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

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.