In vivo fixation of CO₂ by attached pods of Brassica campestris L.

Abstract

In vivo net CO₂ exchange characteristics of attached Brassica pods were studied during the entire period of their growth and development after anthesis. ¹⁴CO₂ was fed both from the external atmosphere and internally through the pod cavity, and the anatomy of the pod-wall was examined microscopically. Stomata were observed in the outer epidermal layer of the pod wall. Net in vivo CO₂ fixation by the pods was observed throughout the period of their development and was maximum on day 42 after anthesis (DAA). Compared to the internal feeding experiments, ¹⁴CO₂ fixation from the external environment was very high. Apparent translocation of fixed carbon from the pod wall to seeds was rapid. Pod photosynthesis contributed substantially to seed growth.