Table 3.
Ribitol content, heterocyst frequency and Zn2+-resistant photosynthesis of cyano- and chlorolichens
| Lichen species | Photobionts | Ribitol content (% total carbohydrates)* | Heterocyst frequency (% total cells) | Zn2+-resistant photosynthesis (% original GP) |
|---|---|---|---|---|
| Ps. carpoloma | Chlorobiont + cephalodia | – | 26·2 ± 0·4 | – |
| Ps. lividofusca | Chlorobiont + cephalodia | 37·0 | – | – |
| Ps. chloroleuca | Chlorobiont + cephalodia | – | 25·0 ± 0·3 | – |
| Ps. rufovirescens | Chlorobiont + cephalodia | 42·0 | 26·3 ± 0·1 | 105·0 |
| Sticta latifrons | Chlorobiont + cephalodia | 29·0 | – | – |
| Ps. crocata | Cyanobiont | 40·6 | – | 13·8 |
| Ps. hookeri | Cyanobiont | – | – | 18·5 |
| Ps. lividofusca/cyan | Cyanobiont | 35·0 | 6·2 ± 0·3 | – |
| Ps. rufovirescens/cyan | Cyanobiont | 30·8 | 6·5 ± 0·2 | 0·2 |
| Ps. cinnamomea | Cyanobiont | 1·0 | 3·8 ± 0·4 | 17·6 |
| Ps. dissimilis† | Cyanobiont | 0·2 | 4·8 ± 0·6 | 22·7 |
| Sticta fuliginosa | Cyanobiont | 3·1 | 5·7 ± 0·2 | 12·2 |
| Peltigera dolichorhiza | Cyanobiont | 2·5 | 5·6 ± 0·2 | 1·1 |
| Collema leucocarpum | Cyanobiont | 0·0 | 5·4 ± 0·4 | 6·6 |
* Small carbohydrates are those composed of one or two molecules.
† Data from Snelgar and Green (1981).
–, not measured.