Authors:
Atsushi Ogawa, , Kazuki Amano
, Kyoko Toyofuku
, Maya Matsunami,
,
Chiharu Sone, and Hirohiko Morita
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Abstract:
Rice is an important cereal and very sensitive to salt stress. However, information regarding the
diversity of root traits and their response to salt stress is still limited because the studied cultivars
do not fully cover a wide range of the total genetic diversity. In this study, we aimed to identify
differences in tolerance, root morphological development, physiological characteristics, and
yield components of selected rice cultivars under salt stress conditions. To this end, 56 cultivars
from the Rice Diversity Research Set as well as five check cultivars were grown in a culture
medium with 0 mM NaCl (control) or 50 mM NaCl (salt stress treatment). The dry shoot weight
differed significantly between the stress and control treatments. Two cultivars were selected as
salt tolerant and two others as non-salt tolerant. Salt stress did not affect the total root length of
the two tolerant cultivars, but significantly increased the number of L-type lateral roots. The
sodium content in the shoot of the two tolerant cultivars was lower than that of the two nontolerant
cultivars. Salt stress did not change the leaf water potential of the two tolerant cultivars
and had a little influence on yield. These results suggested that the maintenance of water uptake
due to the growth of the root system, mainly of L-type lateral roots, as well as the inhibition of
sodium accumulation in the shoot were important mechanisms of salt tolerance that finally
reflected in plant yield.
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