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Effects of
salinity stress on seedlings
growth, mineral nutrients
and total chlorophyll of some tomato (Lycopersicum
esculentum L.) cultivars
V. D. Taffouo1*, A. H. Nouck1,
S. D. Dibong1 and A. Amougou2
1Department
of Botany, Faculty of Science, University of Douala, P. O.
Box 24157 Douala-Cameroon.
2Department
of Biology and Plant Physiology, University of Yaoundé I, P.
O. Box 812 Yaoundé –Cameroon.
*Corresponding authors. E-mail:
dtaffouo@yahoo.com.
Accepted 22 July, 2010 |
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In this study, six cultivars of tomato (Lycopersicum
esculentum L. var. Jaguar, Xewel, Nadira, Lindo, Mongal
and Ninja) were evaluated. They were subjected to salt
stress during vegetative growth. Three concentrations of
salt solution 50, 100 and 200 mM NaCl and the control (Wacquant
nutrient solution) were used in irrigation. The total
chlorophyll, the dry weight of seedlings (roots dry weight,
stems dry weight and leaf dry weight), the plant height and
the mineral nutrient concentrations (Na+, K+
and Ca2+) were determined. The results showed
that the salt treatments increased significantly Na+
concentrations in roots, stems and leaves of plants, whereas
K+ and Ca2+ concentrations and K+/Na+
selectivity ratio of plants were decreased in all tomato
cultivars. The results also revealed after six weeks of salt
treatments that the dry weight partitioning and the plant
height decreased significantly in Jaguar, Xewel, Nadira and
Mongal with increasing salinity. Jaguar, Xewel, Nadira and
Mongal can therefore be considered as salt-sensitive
cultivars which tolerance level ranges from 0 to 50 mM NaCl.
The Lindo and Ninja plant height was less affected by salt
stress than the four other cultivars. In Ninja, the
moderately salt-tolerant cultivar, the growth parameters
were significantly reduced at 100 mM NaCl. The supply of
mineral nutrient solution with NaCl did not affect
significantly leaf total chlorophyll content and plant
organs dry weight of Lindo at 100 mM NaCl suggesting that it
was relatively more tolerant in saline medium than other
cultivars studied. The Lindo cultivar could be cultivated in
environments with relatively moderate salinity.
Key words:
Growth, Lycopersicum esculentum, tolerance, mineral
nutrients, plant organs. |
