Leaf blade structure and C4 acid decarboxylation enzymes in xCynochloris spp. (Poaceae), intergeneric hybrids between species of different C4 type |
| |
Authors: | H. D. V. PRENDERGAST N. E. STONE P. W. HATTERSLEY |
| |
Affiliation: | Taxonomy Unit, Research School of Biological Sciences, The Australian National University, P.O. Box 475, Canberra, A.C. T. 2601, Australia |
| |
Abstract: | PRENDERGAST, H. D. V., STONE, N. E. & HATTERSLEY, P. W., 1988. Leaf blade structure and C4 acid decarboxylation enzymes in x Cynochloris spp. (Poaceae), intergeneric hybrids between species of different C4 type. x Cynochloris macivorii Clifford and Everist and x C. reynoldensis B. K. Simon (Poaceae) are intergeneric C4 hybrids between Cynodon dactylon (L.) Pers., and NAD-malic enzyme (NAD-ME) species, and two different PEP carboxykinase (PCK) species of Chloris . Parental species of each hybrid species have the 'classical' leaf blade structure of their respective C4 acid decarboxylation types. The outline of the photosynthetic carbon reduction (PCR or Kranz) bundle sheath and the position of the PCR cell chloroplasts in x Cynochloris are intermediate between those of the parental species, C. macivorii being more like Cynodon dactylon and x C. reynoldensis more like Chloris spp. The PCR chloroplast shape in x C. macivorii and x C. reynoldensis is like that of Cynodon dactylon and Chloris spp., respectively. Differences between the hybrids in their enzyme activities complement these structural differences: x C. macivorii has more NAD—ME and less PCK activity than x C. reynoldensis , although in both species PCK activity is the greater. Both hybrids, however, have a suberized lamella in PCR cell walls as do Chloris spp. The close taxonomic relationship between Cynodon and Chloris make these genera especially suitable for reciprocal crossing experiments aimed at increasing understanding of the genetic relationships between subtypes of the C4 photosynthetic pathway. |
| |
Keywords: | Chloris xCynochloris Cynodon C4 acid decarboxylation enzymes C4 photosynthetic pathway intergeneric hybrids leaf blade structure Poaceae |
|
|