Osmotic adjustment, gas exchanges and chlorophyll fluorescence of a hexaploid triticale and its parental species under salt stress.
The effect of salt stress (NaCl 85.7 or 110 mmol/L) was investigated in the triticale T300 and its parental species, Triticum dicoccum farrum (Triticum df) and Secale cereale cv. Petkus. Triticum df and T300 were more salt-tolerant than the rye (110 mmol/L NaCl was the highest concentration allowing rye growth to the three-leaf stage). Na+, K+ and Cl- ions accounted for almost half of the osmotic adjustment in Triticum df and T300, and up to 90% in rye. Salinity decreased the net photosynthesis and transpiration rates of the three cereals as compared to control plants, but induced no significant change in chlorophyll a fluorescence parameters. Water-use efficiency (WUE) increased with salinity. In the presence of 110 mmol/L NaCl, the K+/Na+ ratio decreased markedly in rye as compared to the other two cereals. Proline concentration, which increased in Triticum df and T300, could have protected membrane selectivity in favour of K+. Proline content remained low in rye, and increasing soluble sugar content did not appear to prevent competition between Na+ and K+. The salt sensitivity of rye could be due to low K+ uptake in the presence of a high NaCl concentration.
Laboratoire de Physiologie et Biochimie Végétales, Faculté des Sciences et Techniques, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans cedex 9, France. Annick.Manceau@univ-lemans.fr
Annick
A
Morant-Manceau
Elisabeth
E
Pradier
Gérard
G
Tremblin
D002734:Chlorophyll / Q000737:chemistry / Q000378:metabolism*; D005453:Fluorescence; D005740:Gases / Q000378:metabolism*; D009997:Osmotic Pressure; D012965:Sodium Chloride; D014908:Triticum / Q000378:metabolism*
D005740:Gases; D002734:Chlorophyll; D012965:Sodium Chloride