Fe. Prado et al., Effect of NaCl on germination, growth, and soluble sugar content in Chenopodium quinoa Willd. seeds, BOTAN B A S, 41(1), 2000, pp. 27-34
The influence of NaCl on germination rate, growth, and soluble sugar conten
t in quinoa (Chenopodium quinoa Willd.) seeds and seedling components (coty
ledons and embryonic axes) during early germination was investigated. Under
saline conditions germination decreased markedly. The delay in germination
rate was not linear. In presence of 0.4 M NaCl, the percentage of germinat
ion was only 14% after 14 h, whereas the control at the same time reached m
aximum germination (87%). The percentage of aborted seeds after 14 h in NaC
l was lower than in distilled water (7% and 16%, respectively). A high perc
entage (67%) of the ungerminated seeds from saline treatment germinated aft
er washing with distilled water. Fresh weight was reduced by salinity in bo
th embryonic axes and cotyledons. The highest increase in fresh weight was
observed in embryonic axes, where an increase up to 3-fold higher occurred
in distilled water than in saline conditions after 10 h of development. The
water content of embryonic axes in distilled water increased considerably
for the first 10 h, then remained constant thereafter. In saline conditions
, no significant changes were observed in water content. NaCl did not stron
gly inhibit dry mass production in either embryonic axes or cotyledons. Tot
al soluble sugar content increased markedly in distilled water, peaking aft
er 6 h for both embryonic axes and cotyledons. Reduced glucose and fructose
contents were found in embryonic axes in the presence of NaCl. However, in
the cotyledons, the glucose and fructose contents did not differ significa
ntly. Levels of sucrose were higher in NaCl-treated cotyledons than in cont
rol seeds. The relationships between germination, water content, seedling g
rowth, and soluble sugar content in relation to salt stress are discussed.