Physiological descriptors for salt stress susceptibility in Mangifera (mango) plant genetic resources.
Schmutz U., Lüdders P.
Author Affiliation: Humboldt University Berlin, Section Fruit Science, Nahmitzer Damm 26, D-12277, Berlin, Marienfelde, Germany.
Plant Genetic Resources Newsletter : 7-11
Abstract : This paper describes an attempt to gain more detailed stress susceptibility descriptors under controlled environment conditions. Two different Mangifera species (M. indica cv. 13-1 and M. zeylanica) were characterized in an environment-simulation laboratory. During increasing levels of NaCl salinity (15 to 60 mM) physiological description data (CO2 assimilation, root respiration, carbon gain) were simultaneously recorded over a period of one month. At the end of the experiment mineral composition was measured in various plant parts. At 60 mM NaCl the average CO2 assimilation rate (Aav) was 7.9 µmol m-2s-1 in M. zeylanica, whereas it was only 2.8 µmol m-2s-1 in M. indica 13-1. Root respiration was increased more in M. zeylanica. M. zeylanica had lower Na+ and Cl- contents in leaves but higher K+ contents in roots and higher Ca2+ and Mg2+ contents in leaves, compared with M. indica 13-1. There were also higher K+/Na+ ratios in all plant parts, especially in roots of M. zeylanica. From this data it was concluded that the M. zeylanica type examined may have a relatively higher saline tolerance than M. indica 13-1.