Transfer of C4 Photosynthetic Characters through Hybridization of Flaveria Species 1

• Published in: Plant physiology (Bethesda) 1989-08, Vol.90 (4), p.1538-1545
• Main Authors: Cameron, Randall G., Bassett, Carole L., Bouton, Joe. H., Brown, R. Harold
• Format: Article
• Language: English
• Subjects: Metabolism and Enzymology
• ISSN: 0032-0889; 1532-2548

Transfer of C 4 photosynthetic traits was studied through hybridization of Flaveria trinervia (Spreng.) Mohr (C 4 ) and Flaveria brownii A.M. Powell (C 4 -like) with Flaveria linearis Lag. (C 3 -C 4 ) and the C 3 species Flaveria pringlei Gandoger (C 3 ). Fertility was low, based on irregular chromosome pairing and low pollen stainability, except in F. brownii × F. linearis which had bivalent pairing and 76% stainable pollen. Hybrids had apparent photosynthesis values of 71 to 148% of the midparental means, while the CO 2 compensation concentration was similar to the C 4 or C 4 -like parent, except in hybrids having the C 3 species F. pringlei as a parent. Inhibition of apparent photosynthesis by O 2 , and phospho enol pyruvate carboxylase and NADP-malic enzyme activities and subunit levels in the hybrids were closer to the C 3 or C 3 -C 4 parent. The species F. brownii and F. trinervia were equal in their capacity to transfer reduced O 2 inhibition of AP and CO 2 compensation concentration values to hybrids with F. linearis (C 3 -C 4 ), although hybrids with F. trinervia had higher PEPC activity. The O 2 inhibition of AP was correlated with the logarithm of activities of phospho enol pyruvate carboxylase ( r = −0.95) and NADP-malic enzyme ( r = −0.87). These results confirm that C 4 traits can be transferred by hybridization of C 3 -C 4 and C 4 or C 4 -like species, with a higher degree of C 4 photosynthesis than exists in C 3 -C 4 species, and at least in F. brownii × F. linearis , fertile progeny are obtained.