The effect of heavy metals and thidiazuron on winter wheat (Triticum aestivum L.) seedlings

Abstract We studied the influence of a synthetic cytokinin-like growth regulator thidiazuron (TDZ) and ions of heavy metals (HMs) -Pb , and Ni 2+ on the growth, generation of superoxide anion, concentration of total peroxides, lipid peroxidation, and catalase activity in the leaves of 7-day-old winter wheat plants (Triticum aestivum L. cv. 'Mironovskaya 808'). It was found that 1 mM solution of HMs inhibited the growth of roots in the following sequence: Zn . HMs inhibited the growth of aboveground parts of young wheat plants, too. HMs stimulated superoxide production by a factor of 1.3-4.9. The content of total peroxides in wheat leaves increased in the presence of HMs in the growth medium. Our analyses showed that malonic dialdehyde (MDA) content in leaves increased with increasing Cu 2+ or Ni 2+ concentra tions in the medium and hardly changed with increasing Pb 2+ or Zn 2+ concentrations. HMs enhanced catalase activity in wheat plants 1.1-2.8-fold at all concentrations studied. All these regularities are indications of HMs-induced oxidative stress in wheat plants. In most treatments, TDZ alleviated the HMs-induced oxidative stress and promoted an increase in Wilkinson tolerance index (WTI). This suggests that the wheat seedlings treated with TDZ were more HMs-resistant than the untreated ones

The Response of Baby Leaf Lettuce to Selenium Biofortification under Different Lighting Conditions

Selenium (Se) is an essential microelement for human health and has antioxidant and anticancerous properties. One of the ways to increase its concentration in plants is biofortification through various agronomic practices including artificial lighting. The aim of this study was to determine the responses of baby leaf lettuce to various Se content in hydroponic solution at different ratios of blue (B) and red (R) light of light-emitting diodes (LED) lighting. Lettuce (Lactuca sativa, ‘Little Gem’) was grown hydroponically under B:R light ratios–10%B:90%R, 75%B:25%R. The photon flux density (PFD), photoperiod, temperature, and relative humidity in the growth chamber were maintained at 220 μmol m−2 s−1, 18 h, 21/17 ± 2 °C, and 60 ± 5%, respectively. Two experiments with Se were performed using natrium selenate (Na2SeO4). Results of the first experiment (Se–0, 1, 3 ppm) showed that the content of Se in lettuce was about 15 times higher at 3 ppm compared to 1 ppm. Similar trends were observed for both B and R ratios. However, even the lowest dose of Se in hydroponic solution inhibited lettuce growth and reduced photosynthesis and chlorophyll content. Therefore, a second experiment was performed with lower Se doses (0, 0.5, 1 ppm) at different growth stages (11th and 17th days after sowing (DAS)). It was found that, when Se exposure was initiated at the 17th DAS, the lettuce accumulated a lower content of Se compared to the 11th DAS, but this did not have a negative effect on their growth. The B:R ratio of 10B:90R% resulted in a higher content of Se in the leaves. Overall, these results suggest that properly composed doses of Se, LED lighting and application time could be a suitable way for cultivation of selenium-biofortified baby leaf lettuces without any adverse effects on growth

UA-V radiation influence to growth biometric parameters of different microgreens

The objective of this study was to evaluate the impact of UV-A irradiation on the biometric parameters of Brassica rapa var. chinensis L., ‘Rubi’, Ocimum basilicum L., ‘Sweet Genovese’ and Beta vulgaris L., ‘Bulls Blood’ microgreens. This investigation was performed in the Lithuanian Research Centre for Agriculture and Forestry, Institute of Horticulture. A system of five high-power solid-state lighting modules with the basal 447, 638, 665 and 731 nm light-emitting diodes (LEDs) supplemented with one of three 366, 390 or 402 nm UV-A LEDs were used in the experiments. Photosynthetic photon flux density (PPFD) of UV-A LEDs was 12.4 μmol m-2 s-1 (25 cm from the light source). Total PPFD was 300 μmol m-2 s-1. Biometric parameters of plant growth which were measured include leaf assimilation area, fresh weight, hypocotyl lenght and plant height. The results show that the effect of UV-A irradiation on plants is different and depends on plant species. The most positive effect of supplemental UV-A irradiation in basal illumination was determined on leaf area and fresh weight of red pak choi microgreens, especially under supplemental 366 and 390 nm illumination. No significant effect of UV-A on hypocotyl lenght was observedVytauto Didžiojo universitetasŽemės ūkio akademij

Impact of electromagnetic fields on morphogenesis and physiological indices of tomato

The impact of electromagnetic fields of the power of 1800 Am-1 (=H), 1000 Am-1 (~H), 1500 Am-1 (~H), 200 Am-1 (~H) on the morphological and physiological parameters of tomato plants which were affected directly during the whole vegetation by these fields, and in the first and second generation after effect, was studied in vegetation trials in the glass greenhouses of the phytotron complex. When tomatoes were affected with electromagnetic fields directly during the whole vegetation period, seedlings developed rapidly, and formed the biggest leaf area and grew up the highest when affected by the electromagnetic field of 1500 Am-1 (~H). The leaves of tomatoes affected by electromagnetic fields of 1000 Am-1 (=H) and 1500 Am-1 (~H) accumulated the highest content of pigments. The most intensive photosynthesis occurred under the effect of electromagnetic fields of 1800 Am-1 (=H) and 1500 Am-1 (~H). Electromagnetic field of 200 Am-1 (~H) mostly impeded the formation of pigments and decreased the yield. The greater negative effect of electromagnetic fields was established for germination energy of seeds chosen from tomatoes which were affected directly during the whole vegetation period. The effect of electromagnetic field of the power of 1000 Am-1 (=H) and 200 Am-1 (~H) was distinguished most notablyVytauto Didžiojo universitetasŽemės ūkio akademij

Azoto trąšų poveikis skirtingų žieminių kviečių veislių grūdų kokybės rodikliams

Vytauto Didžiojo universitetasŽemės ūkio akademij

The effect of nitrogen fertilisers for the photosynthetic indicators of different cultivars of winter wheat

Darbe tirtas azoto trąšų poveikis skirtingų žieminių kviečių veislių fotosintetinių rodiklių dinamikai. Lauko eksperimentas vykdytas 2012–2013 m. Aleksandro Stulginskio universiteto Bandymų stotyje, karbonatingame sekliai glėjiškame išplautžemyje Calc(ar)i-Epihypogleyic Luvisol. Tyrimo objektas – gerų kepimo savybių žieminių kviečių veislės ‘Kovas’, ‘Olivin’. Sėjos metu kviečiai buvo tręšti vienanarėmis fosforo, kalio trąšomis (P60K60), o pavasarį, atsinaujinus vegetacijai, – amonio salietra (N60). Papildomai per lapus tręšti karbamido tirpalu (N30, N40) bamblėjimo ir (N15, N30) pieninės brandos tarpsniais. Tyrimų metu nustatyta, kad papildomas tręšimas N30 ir N40 azoto normomis vėlyvaisiais augalo vystymosi tarpsniais skatino fotosintezės pigmentų kaupimąsi ir prailgino aktyvios fotosintezės periodą. Veislės genetiniai ypatumai turėjo įtakos pigmentų kaupimuisi nepriklausomai nuo tręšimo azoto trąšomis. Gerų kepimo savybių kviečių veislė ‘Kovas’ linkusi kaupti didesnius fotosintezės pigmentų kiekius. Didžiausias pigmentų kiekis nustatytas pieninės brandos pradžioje prieš papildomą tręšimą N15, N30 trąšų normomis. ‘Olivin’ veislės žieminiai kviečiai turi didesnį grynąjį fotosintezės produktyvumo potencialą nei ‘Kovas’ veislės kviečiai. Intensyviausiai ‘Olivin’ veislės augalų fotosintezė vyko nuo vamzdelėjimo iki pieninės brandos tarpsnio (BBCH 43–74), tręšiant N60 + N40, o ‘Kovas’ veislės kviečių – N60 + N30 azoto normomisThe work investigates the effect of nitrogen fertilisers on the dynamics of photosynthetic indicators of different cultivars of winter wheat. The field experiment was conducted in the period between 2012 and 2013 at the Experimental Station of Aleksandras Stulginskis University in carbonate shallow gleyic leached soil Calc(ar)i-Epihypogleyic Luvisol. The object of the investigation was the cultivars of winter wheat ‘Kovas’ and ‘Olivin’, which have good baking properties. During the sowing time the wheat was fertilized with single-element phosphorus and potassium P60K60 fertiliser, and in spring, after the vegetation had renewed, the wheat was treated with ammonium nitrate N60. Additionally, foliar fertilizer urea solutions N30 and N40 at the booting stage and N15 and N40 at the milk ripening stage were applied. The investigation revealed that additional fertilization with N30 and N40 during the late stages of plant development induced the accumulation of photosynthetic pigments and prolonged the period of active photosynthesis. Genetic peculiarities of a certain cutivar had influence on the accumulation of pigments irrespective of treatment with nitrogen fertilisers. Cultivar ‘Kovas’, which has good baking properties, tends to accumulate larger amounts of photosynthetic pigments. The largest amount of pigments has been found in the wheat at the beginning of the milk ripening stage before additional fertilization with N15 and N30. The winter wheat of cv. ‘Olivin’ has a higher potential for photosynthetic productivity than the winter wheat of cv. ‘Kovas’. Photosynthesis was the most intensive in the plants of cv. ‘Olivin’ from the time when the flag leaf begins to grow to the milk ripening stage (BBCH 43–74) when they were fertilized with N60 + N40, and in the wheat of cv. ‘Kovas’ when they were treated with N60 and N30Lietuvos agrarinių ir miškų mokslų centrasVytauto Didžiojo universitetasŽemės ūkio akademij

Tręšimo įtaka skirtingų žieminių kviečių veislių grūdų kokybės rodikliams

Vytauto Didžiojo universitetasŽemės ūkio akademij

Impact of elektromagnetic field on morphological and physiological parameters of tomato in the first and second generations after effect

Vytauto Didžiojo universitetasŽemės ūkio akademij

Lapų indekso ir fotosintezės pigmentų dinamika įvairaus tankumo pluoštinių linų pasėlyje

Tyrimai vykdyti 2005-2007 m. Lietuvos žemdirbystės instituto Upytės bandymų stotyje bei Lietuvos sodininkystės ir daržininkystės instituto Augalą fiziologijos laboratorijoje. Šio bandymo tikslas - nustatyti optimalų pluoštinių linų (Limim usitatissimum L.) pasėlio tankumą pagal lapų indekso dinamiką vegetacijos metu bei fotosintezės pigmentų kiekį linų lapuose. Bandymuose sėti pluoštiniai linai 'Hermes' įvairiomis normomis nuo 10 iki 34 mln. daigių sėklų ha' (pasėlio tankumas nuo 700 iki 2 380 vnt. m ). Nustatyta, kad pluoštinių linų lapų indeksas nuosekliai didėja vegetacijos metu ir didžiausias būna žydėjimo-žaliosios brandos tarpsniu. Esant nepalankioms meteorologinėms sąlygoms (2007 m.), augalų vegetacija užtrunka, linai formuoja Šoninius ūglius, todėl lapų indeksas didėja ir žaliosios brandos tarpsniu. Pasėlio tankumas neturi įtakos linų lapų fotosintezės pigmentų kaupimui. Tačiau stiebų pigmentų sistema jautriai reaguoja į konkurencinę įtampą ir tankinant pasėlį pigmentų kaupiasi mažiau, nors chlorofilų a ir b santykis yra palankesnis vykti fotosintezei. Pagal linų asimiliacinio ploto dinamiką ir fotosintezės pigmentų kiekį, vegetacijos metu pluoštinių linų optimalus tankis turėtų būti 1 540 vnt. m'2 ir nuo 1 820 iki 2 100 vnt. m"" auginant atsparias išgulimui veislesExperiments were conducted during 2005-2007 at the experimental crop rotation of the Lithuanian Institute of Agriculture's Upyte Research Station and at the Lithuanian Institute of Horticulture's Laboratory of Planl Physiology. The objective of this study was to estimate the dynamics of leaf area index during the growing season and to measure the content of photosynlhetic pigments in the flax (Linuin usitatissitnum L.) variety 'Hermes' stands of different density ranging from 700 to 2,380 plants rn'. Experimental evidence indicated that the leaf area index was increasing steadily during the growing season and reached the maximum at the 'flowering' - 'green maturity' stages. Under adverse weather conditions, which occurred in 2007, fibre flax growing season was longer, plants produced lateral shoots and leaf area index increased also at ihe "green maturity' stage. Plant stand density did not have any effect on the accumulation of ilax leaf photosynthetic pigments. However, the stem pigment system responded sensitively to the competitive tension, and with increasing stand density the accumulation of pigments tended to go down, although the ratio of chlorophyll a and b was more favourable for the occurrence of photosynthesis. According to flax leaf assimilating area dynamics and content of photosynthetic pigments, the optimum fibre flax stand density during the growing season should be 1,540 plants m'2 and from 1,820 to 2,100 plants m~2 for lodging - resistant varietiesVytauto Didžiojo universitetasŽemės ūkio akademij