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Responses of three arid zone grass species to varying Na/Ca ratios in saline sand culture
Author(s) -
ASHRAF M.,
NAQVI M. I.
Publication year - 1991
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1991.tb01032.x
Subject(s) - shoot , panicum , sodium , zoology , botany , horticulture , chemistry , biology , organic chemistry
summary The effects on three grass species, Cenchrus pennisetiformis Hochst. & Steud., Leptnchloa fusca (L.) Kunth. and Panicum turgidum Forssk., of decreasing Ca 2+ concentration in a saline growth medium were assessed after 7 weeks growth in sand culture. The different Na/Ca ratios of the salt treatment were 24, 49, 99, and 199, at a constant concentration of 200 mol m −3 . Leptuchloa fusca produced the highest fresh and dry biomass, and was able to maintain Na + and Cl − Concentrations in the shoots and roots almost constant at varying external Na/Ca ratios, except that the shoot Na + concentration increased significantly at the highest Na/Ca ratio. In C, pennisetiformis the shoot Na + decreased, whereas the shoot Cl − concentration increased at the highest external Na/Ca ratio. But the root Na + and Cl − concentrations in this species remained unchanged at varying Na/Ca ratios. C. pennisetiformis and L. fusca maintained almost constant K + and Ca 2+ concentrations in both shoots and roots at varying Na/Ca ratios. In P. turgidum the shoot K + and shoot and root Ca 2+ remained almost unchanged at all Na/Ca ratios, whereas the root K + concentration decreased significantly but uniformly at the three, higher Na/Ca ratios. No consistent pattern of increase or decrease was observed in the shoot and root Na/K and Na/Ca ratios of all the species. The shoot selectivity (S k + na ) increased consistently in C pennisetiformis with the increase in Na/Ca ratios and it decreased in L. fusca only at the highest Na/Ca ratio in the growth medium It was established that L. fusca was tolerant, C. penni‐setiformis intermediate and P. turgidum relatively sensitive to low Ca 2+ concentrations of the saline growth medium.