Tag Archives: lettuce

1249–1260 V. Alle, U. Kondratovics, A. Osvalde and M. Vikmane
Differences in cadmium accumulation and induced changes in root anatomical structures in plants used for food
Abstract |
Full text PDF (719 kB)

Differences in cadmium accumulation and induced changes in root anatomical structures in plants used for food

V. Alle¹*, U. Kondratovics¹, A. Osvalde² and M. Vikmane¹

¹University of Latvia, Faculty of Biology, Department of Plant Physiology, St. Jelgavas 1, LV-1004 Riga, Latvia
²University of Latvia, Institute of Biology, Laboratory of Plant Mineral Nutrition, St. Miera 3, LV-2169 Salaspils, Latvia
*Correspondence: vita.alle@lu.lv

Abstract:

 A rapid urbanization passes all over the world thus the effect of chemicals, including heavy metals, increases on plants. Heavy metal pollution poses a serious hazard to humans’ health, and it uptake into plants is the primary way through which it can enter the food chain. The goal of this study was to investigate the impact of cadmium (Cd) contamination on plant growth responces, Cd uptake, and changes in the root anatomical structures as species-specific reaction to Cd stress. The vegetation experiment was carried out with monocotyledon Hordeum vulgare L. and dicotyledonous Lactuca sativa L. The plants were grown in quartz sand under controlled optimal growth conditions. Changes in the root structure and Cd accumulation were studied at five levels of Cd added as Cd(NO3)2 4 H2O solution in substrate. The level of Cd in the air-dry plant material was estimated by an atomic absorption spectrometer. To identify structural changes in the plant roots which were caused by Cd accumulation cross sections were cut using microtome and stained with Astra Blue/Safranin for observations using a light microscope. Barley and lettuce growth and development were significantly influenced by increasing the amount of Cd in substrate. There were differences in the ability to accumulate Cd in above-ground plant parts depending on a model object. Substrate contamination with Cd caused significant changes in the root anatomical structures. The obtained results confirmed significance of anatomical and physiological studies to reveal species-specific plant response to Cd stress to avoid heavy metal entrance in the food.

Key words:

, , , ,




39–48 M. Järvan and P. Põldma
Content of plant nutrients in vegetables depending on various lime materials used for neutralising bog peat
Abstract |
Full text PDF (160 kB)

Content of plant nutrients in vegetables depending on various lime materials used for neutralising bog peat

M. Järvan¹ and P. Põldma²

¹Department of Field Crops, Estonian Research Institute of Agriculture, Teaduse 13, 75501 Saku, Estonia; e-mail: malle.jarvan@mail.ee
²Department of Horticulture, Estonian Agricultural University, Kreutzwaldi 64, 51014 Tartu, Estonia; e-mail: ppoldma@eau.ee

Abstract:

The trials were performed in the years 1998–2000 in Saku (59°18’N, 24º39’E) in greenhouse conditions. The aim was to establish how lime materials used for the neutralisation of bog peat acidity (oil shale ash, clinker dust, limestone meal, dolomite meal and their mixtures), which changed significantly the contents of available Ca, K and Mg in the peat substrata, affect the mineral composition of vegetable leaves (lettuce, cucumber, tomato, paprika) and the mutual relationships between elements (K, Ca, Mg, P). In the case of all vegetables, a strong Ca and Mg antagonism occurred. The Mg content of plants was very sensitive to the Ca:Mg ratio in the lime material used for peat neutralisation. In the case of limestone meal, the tomato plants contained Mg 0.18–0.24% and cucumber plants 0.36–0.40%; in the case of dolomite meal, 0.66–0.71% and 0.78–0.90, respectively. The Ca and K contents of vegetables were somewhat less affected by the difference of lime materials than the Mg content. Abundant Mg in lime material increased P content in plants, a synergism between Mg and P occurred.
Lettuce grown on substrata neutralised with mixtures of limestone and dolomite meal contained less nitrates than that grown on substrata with clinker dust and oil shale ash. Too high K content in the substrate neutralised with clinker dust had a negative effect on the carotene content of lettuce.

Key words:

, , , , , , , , , , ,