Studies On Photosynthetic Characteristics Of Paeonia Lactiflora Cultivars Under Greenhouse Cultivation Mode

Herb peony (Paeonia lactiflora Pall.) is a traditional flower in China and also an important new cut flower in international flower market. To extend peony viewing period, people try to study and use facility cultivation techniques. For broadening ideas of selecting Paeonia lactiflora cultivars from field into greenhouse, photosynthetic characteristics of Paeonia lactiflora cultivars in greenhouse were studied. In the paper, choosing Paeonia’Da Fu Gui’、Paeonia ’Duo Ye Zi’、Paeonia’Tao Hua Fei Xue’as materials, refering with open field mode, we studied the greenhouse cultivation mode responsed to the growth and photosynthetic characteristics of peony cultivars. Used the method of membership function synthetical evaluation to select peony cultivars. The results are as follows:1、Under greenhouse cultivation mode, Peony cultivars showed that the height incresed, stem diameter and the number of flowering reduced, the number of abortive bud increased and dry biomass accumulation decreased. On growth and flowering, greenhouse cultivation mode impacted’Da Fu Gui’most, while’Duo Ye Zi’least.2、Compare with open field cultivation mode, photosynthetic capacities of peony had changed under greenhouse cultivation mode. In bud stage, photosynthetic capacities of peony in greenhouse were stronger than that in open field. Photosynthetic capacity and LCP of peony declined, while AQY increased in flowering and after flowering stages in greenhouse.3、Compare with open field cultivation mode, the chlorophyll a and b contents increased and the chlorophyll a/b declined under greenhouse cultivation mode. After cultivating under greenhouse mode for three years, the metabolism of the peony photosynthetic products changed. Soluble protein contents of peony in the flowering stage significantly increased and soluble sugar and starch contents in the leaves of peony after flowering stage increased.4、Dynamical changes of Rubisco activity in the leaves of peony were different under greenhouse and open field cultivation mode. In greenhouse dynamical changes of Rubisco activity of peony gradually declined, but in open field the dynamical changes of Rubisco activity of peony was the single-peak type, the spikes was in the flowering period.5、Rubisco activities and net photosynthetic rate of peony were related. Relationship between Rubisco activities and net photosynthetic rate of corresponding leave positions in’Duo Ye Zi’were significantly related and the highest Rubisco activity in’Duo Ye Zi’was in middle leave positions. But Rubiseo activities and net photosynthetic rate for above and middle leave positions in’Da Fu Gui’ and’Tao Hua Fei Xue’were linearly related. Rubisco activity of below leave positions in’Da Fu Gui’ and’Tao Hua Fei Xue’were the highest.6、Rubisco activities and carboxylation efficiency were less related. Carboxylation efficiency was not constrainted by Rubisco activity. In open field Rubisco activities and starch contents of peony were positively correlated, but under greenhouse cultivation mode they were negatively correlated. The relationship between Rubisco activities and starch contents was impacted by different cultivation modes.7、After cultivating under greenhouse mode for three years, suitability of’Tao Hua Fei Xue’ was the strongest in bud stage and after flowering stage. Suitability of’Duo Ye Zi’was the strongest in the flowering stage. But suitability of’Da Fu Gui’was the weakest.The results showed that photosynthetic capacities and the metabolism of photosynthetic products of three peony cultivars had changed under greenhouse cultivation mode.’Duo Ye Zi’had better growth and flowering with higher Pnmax、AQY、LSP and CE. LCP and AQY after flowering stage and Rubisco activities in the flowering stage can be chosen as screening index for suitable greenhouse cultivation mode of peony cultivars.