Leaf gas exchange and fluorescence of two teosinte species: Zea mays ssp. parviglumis and Z. diploperennis.

TLDR: This study compared the leaf blade characteristics, pigment composition, photosystem II (PSII) photochemistry, and photosynthetic rates (P) of a multi-stemmed annual and a perennial teosinte species growing in a glasshouse under analogous nutritional and environmental conditions to show similar chlorophyll contents and ratios.

Abstract: This study compared the leaf blade characteristics, pigment composition, photosystem II (PSII) photochemistry, and photosynthetic rates (P) of a multi-stemmed annual (Zea mays ssp. parviglumis Iltis & Doebley) and a perennial (Z. diploperennis Iltis, Doebley & Guzman) teosinte species growing in a glasshouse under analogous nutritional and environmental conditions. Similar chlorophyll contents and ratios implied comparable efficiencies of photon energy capture and electron flow through PSII in both species. Maximum photochemical efficiency (Fv/Fm) was about 0.75 at predawn and declined linearly to a minimum at midday of about 0.65, implying down-regulation of photosynthesis. By contrast, maximum P (Pmax) was 11.5% higher in the annual compared to the perennial teosinte, signifying that wild maize germplasm could potentially be used for improving the photosynthetic efficiency of cultivated maize. Future studies, however, should assess a larger number of teosinte species for their differences in leaf area per plant, growth habit, grain yield, and leaf photosynthesis.