Photosynthetic characteristics of three varieties of “Oriental Hybrids” in the central areas of Yunnan Province, China

Abstract

To understand the ecophysiological adaptation of Lilium “Oriental Hybrids”, which are grown for their commercial bulbs, the gas exchange, leaf N and chlorophyll content of the three varieties were investigated in the central areas of the Yunnan Province. Among the three varieties, light-saturated photosynthetic rate at ambient CO₂ (A_max) of Tiber was the highest, while that of Siberia was the lowest. The difference in the A_max was related to the carboxylation efficiency (CE), leaf mass per unit area and leaf N content per mass, which indicated that their photosynthetic capacity was influenced by the activity and/or the quantity of Rubisco. The three varieties had lower photosynthetic saturation points and photosynthetic compensation points, but the photosynthetic rates were not decreased up to 2000 ?molm^-2s^-1 of the light intensity. This indicates that the three varieties had broad adaptability to light intensity. There were significant differences in the photosynthetic optimum temperature among the three varieties. Siberia had the highest photosynthetic optimum temperature (25.5°C–34.9°C), and is likely to grow well in warm areas. Sorbonne had the lowest photosynthetic optimum temperature (19.3°C–25.6°C), and its growth is favored in cool areas. Tiber can maintain a high photosynthetic rate within a wide range of temperature. Therefore, Tiber is the most suitable variety for the climate in the central areas of the Yunnan Province, China.

Keywords

East lily (Lilium & / #8220 / Oriental Hybrids& / #8221 / ) / photosynthesis, carboxylation efficiency / leaf dry mass per area / leaf N content per mass