Open AccessDecrease in Nitrate Concentration in Leafy Vegetables Under a Solid-state Illuminator
Author(s) -
G. Samuolienė,
A. Urbonavičiūtė,
Pavelas Duchovskis,
Z. Bliznikas,
P. Vitta,
A. Žukauskas
Publication year - 2009
Publication title -
hortscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.518
H-Index - 90
eISSN - 2327-9834
pISSN - 0018-5345
DOI - 10.21273/hortsci.44.7.1857
Subject(s) - lactuca , nitrate reductase , nitrate , chemistry , horticulture , photosynthesis , photosynthetic pigment , botany , biology , organic chemistry
We report on a substantial reduction of nitrate concentration in leafy vegetables that were subjected to short-term preharvest treatment by narrow-bandwidth red light of high photosynthetic photon flux density generated by a solid-state illuminator. Lettuce ( Lactuca sativa cv. Grand rapids), marjoram ( Majorana hortensis , Moench.), and green onions ( Allium cepa , L. cv. Lietuvos didieji) were grown to harvest time within a greenhouse under daylight with supplementary lighting provided by standard high-pressure sodium lamps (130 μmol·m −2 ·s −1 ). A subsequent 3-day treatment within a phytotron under 638-nm light-emitting diodes (500 μmol·m −2 ·s −1 ) resulted in the reduction of nitrate concentration by 44% to 65%. The reduction of nitrates was accompanied by an increased concentration of nutritionally valuable carbohydrates, which is also in line with stimulation of expression of nitrate reductase by photosynthetic metabolites. Another indicator of nutritional quality, the content of vitamin C, exhibited some variation that was not directly correlated with the nitrate reduction rate that may be attributed to carbohydrate content variation and leaf tissue aging.