Eco-physiological studies on Indian arid zone plants: I. Photosynthetic characteristics of Pennisetum typhoides (Burm. f.) Stapf & Hubbard and Lasiurus sindicus Henr.

Photosynthetic characteristics of two important grasses of Indian desert have been studied. Pennisetum typhoides, an important cereal crop, known to have 'Kranz'-type leaf anatomy and low CO₂-compensation point, shows the C-4-dicarboxylic acid pathway for photosynthetic carbon reduction. Lasiurus sindicus, a promising forage grass, has also been shown to possess, for the first time, a typical 'Kranz'-type leaf anatomy and a very similar CO₂-fixation pattern like Pennisetum typhoides. It is remarkable that both species after short time exposure to ¹⁴CO₂ show a high labelling not only in malate but also in alanine. This may be due to the activity of an aspartic acid decarboxylase.