Assessment of Changes in PS I and PS II Function as Affected by Sod Culture in Apple Orchard during Leaf Development

摘要

In order to assess the function of PS II and PS I during leaf development under different soil management, 6-year-old apple plants were used as materials to measure the Chlorophyll a fluorescence transient and 820nm transmission by using Handy PEA and M-PEA from initiation to full expansion of leaves under sod culture (SC) and clean tillage (CT). Results showed that, Fo and Fm in SC and CT were markedly lower than that in mature leaves at the earlier stages. Fv/Fm in SC and CT were slightly lower than that in mature leaves, by 2.7% and 4.1%, respectively. Moreover, Fo, Fm and Fv/Fm of SC were obviously higher than that in CT. Vj and Wk in SC were lower than that in CT during leaf development. In SC and CT, Vo, (pEo, ETo/CSo, RC/CS0 and PICS increased with leaf development; moreover, these parameters in SC were higher than that in CT at the earlier stage of leaf development. The amplitude of transmission at 820nm in SC was higher than that in CT, which increased with leaf developing. In concluding, the function of PS II and PS I could be promoted by SC, with more obvious promoting effect at the earliest stage of leaf development.