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

Abstract

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 °Cand 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 low-temperature-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.