Chinese Bulletin of Botany ›› 2022, Vol. 57 ›› Issue (4): 434-443.DOI: 10.11983/CBB21136

• EXPERIMENTAL COMMUNICATIONS • Previous Articles     Next Articles

Effects of UV-B on Photosynthetic Function and Chloroplast Ultrastructure of Peach Leaves Grown in Greenhouse

Li Chen, Liu Jianting, Fan Yongxin, Zhao Xuehui, Xiao Wei, Chen Xiude, Fu Xiling, Li Ling(), Li Dongmei()   

  1. Shandong Collaborative Innovation Center for Fruit & Vegetable Production with High Quality and Efficiency/State Key Laboratory of Crop Biology/College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an 271018, China
  • Received:2021-08-16 Revised:2021-11-17 Online:2022-07-01 Published:2022-07-14
  • Contact: Li Ling,Li Dongmei
  • About author:First author contact: These authors contributed equally to this paper.

Abstract: After supplementing appropriate amount of UV-B to the nectarine (Prunus persica var. nectarine cv. ‘Zhong- you5’) cultivated in the greenhouse, we analyzed the effects of UV-B on photosynthesis and chloroplast ultrastructure of the Zhongyou5 leaves. We found that the content of leaf pigments was increased under UV-B treatment, particularly the content of chlorophyll b and the net photosynthetic rate (Pn) being greatly increased. Compared with the peach trees without UV-B supplementation (control), UV-B treatment did not affect the Fv/Fm ratio significantly. However, the Fv'/Fm' ratio, the photochemical quenching coefficient (qP), the non-photochemical quenching coefficient (qN), and PSII actual photochemical quantum efficiency (ΦPSII) were all significantly improved. Transmission electron microscopy analysis also showed that under UV-B treatment, the chloroplast stroma lamellae had small voids and were tightly stacked, and the chloroplast outer membrane edge was clearer than those in control. These data suggest that appropriate UV-B supplement in the greenhouse can optimize the ultrastructure of leaf chloroplasts, thereby improving photosynthesis. Our study provides a theoretical basis for the improvement of photosynthetic performance of fruit trees by using proper UV-B irradiation in greenhouse.

Key words: greenhouse peach, UV-B, chloroplast ultrastructure, photosynthetic performance, photosystem (PS)