Welcome to Acta Prataculturae Sinica ! Today is Share:

Acta Prataculturae Sinica ›› 2017, Vol. 26 ›› Issue (8): 104-112.DOI: 10.11686/cyxb2016425

Previous Articles     Next Articles

Effects of temperature on flower bud differentiation, pigment contents, and photosynthesis of male and female Humulus scandens

GUO Hai-Yan1, DUAN Jing1, LIU Jin-Ping1, *, YOU Ming-Hong2, XIE Rui-Juan1   

  1. 1.China West Normal University and Key Laboratory of Education on Southwest China Wildlife Resoureces Conservation, Nanchong 637009, China;
    2.Academy of Sichuan Grassland Science, Chengdu 611731, China
  • Received:2016-11-14 Online:2017-08-20 Published:2017-08-20

Abstract: In this study, we evaluated the effects of temperature on the physiology of male and female plants of the dioecious climbing herb, Humulus scandens. Seeds of H. scandens were sown in pots, and the pots were moved to artificial climate incubators set at 15, 20, or 25 ℃ when the seedlings had one to two true leaves. These temperatures were selected based on the average temperatures of the areas where the wild resource are concentrated. We determined the duration of vegetative growth, growth accumulated temperature, number and characteristics of leaves, pigment contents, biomass, and photosynthetic parameters of the male and female seedlings. The effects of temperature on photosynthetic production, net photosynthetic rate (Pn), photosynthetic efficiency, transpiration rate (Tr), intercellular CO2 concentration (Ci), and gas exchange (Gs) were also analyzed. The results showed that, 1) temperature and gender had significant effects on growth duration and accumulated temperature (P<0.01). Flower buds differentiated earlier in male plants than in female plants at all three temperatures (P<0.05). Flower bud differentiation was affected by temperature and was optimal at 20 ℃. Growth accumulated temperature differed between males and females, but was not related to growth duration. Temperature significantly affected all of the measured leaf traits (P<0.05), with the strongest effect on leaf number per plant>leaf area per leaf>leaf width>leaf length. The pigment contents did not differ significantly between males and females (P>0.05). Temperature significantly affected the contents of all pigments except for chlorophyll b (P<0.05) with the strongest effect on carotenoids>chlorophyll (a+b)>chlorophyll a/b>chlorophyll a>chlorophyll b. Pigment contents were significantly lower at 20 ℃ than at the other temperatures. Photosynthetic parameters differed significantly between males and females and among temperatures (P<0.05). The temperature affected photosynthetic parameters in the order Pn>Ci>Tr>Gs. The parameters Pn, Ci, and Tr were mainly affected by temperature, but Gs was mainly affected by gender. The biomass and root biomass distribution were significantly higher in female plants than in male plants (P<0.05). Temperature significantly affected biomass accumulation and allocation in the following order: root>leaf>stem (P<0.01). Biomass per plant significantly decreased as the temperature decreased (P<0.05). The highest biomass allocation to the root and stem was at 25 ℃ and the highest biomass allocation to leaves was at 15 ℃.