B. Pezzarossa et al., Uptake and distribution of selenium in tomato plants as affected by genotype and sulphate supply, J PLANT NUT, 22(10), 1999, pp. 1613-1635
Aim of this work was to investigate if the variation among tomato genotypes
in selenium (Se) uptake and accumulation observed in short term experiment
s are maintained over longer growth periods and if there is a positive corr
elation in shoot between sulphur (S) accumulation and Se accumulation acros
s different genotypes or if higher tissue S results in greater feedback inh
ibition of Se uptake. Two experiments were carried out under greenhouse con
ditions and different genotypes of Lycopersicon lycopersicum (UC82B and LA2
711) Lycopersicon pennellii (LA716) and Lycopersicon peruvianum (LA2157) we
re grown until fruit ripening. The results obtained in the two experiments
confirmed that sulphate in the growth solution reduced selenate uptake by p
lants and increased the S content of the leaves. Under low sulphate treatme
nt there was a clear correlation (R-2=0.82) between leaf S content and shoo
t Se content across genotypes in both experiments, indicating that the over
all activity of the S transport systems also determines Se transport. Selen
ium was translocated from shoot to fruit, but the edible portion of the pla
nt contained much less total Se than the inedible plant parts. The differen
ce in Se content between the low and the high sulphate treatments was signi
ficantly higher in shoot than in root, confirming that the Se translocation
from root to shoot is probably more affected by high sulphate supply than
Se uptake by root. In the first experiment the genotype LA716 showed an hig
her Se accumulation together with higher S content in leaves, indicating a
marked ability of this genotype to absorb ions from substrate. In the secon
d experiment UC82B appeared to be more capable to accumulate Se and S rathe
r than LA2711 and LA2157. In both experiments Lycopersicon peruvianum appea
red to be less affected by the high concentration of ions in the growth sol
ution and to be able to reduce ion uptake than Lycopersicon lycopersicum an
d Lycopersicon pennellii.