Új mérési eljárások fejlesztése a növényi antioxidáns státusz meghatározására

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Effect of different sowing times on the plant developmental parameters of wheat (Triticum aestivum L.)

Studies on plant development phases and yield component patterns of wheat are essential for a better understanding of adaptation in wheat. Our main aim was to carry out detailed phenological analyses of 18 wheat genotypes in three sowing times for determining the effect of sowing date on individual phenophases, and yield components. Sowing date had the single greatest effect on the start of intensive stem elongation. The longer vegetation period had a favourable effect on main spike length and on the spikelet number per spike, but had no influence on thousand-kernel weight and grain number per spike. The time between the first node appearance and start of intensive stem elongation had a significant effect on the number of reproductive tillers. A close association (R2 = 0.191) was observed during the second phase of intensive stem elongation between the boot stage-to-heading interval and the number of spikelets per spike. Two-way analysis of variance on the yield components showed that the sowing date, as a main factor, had a weaker effect on the phenophases than on morphological and developmental parameters. The insensitive allele of the Ppd-D1 gene shortened the time required for first node appearance and heading both in autumn and spring sowing

Élelmiszeralkotó egészségvédő növényi hatóanyagok - fitonutriensek - kémiai-biokémiai tulajdongágainak vizsgálata = Chemical and biochemical examination of plant food components - phytonutrients - having health promoting properties

A zöldség- és főzelékfélék, fontos antioxidáns források, a polifenolos vegyületek nagy mennyiségben, egyes vitaminok azonban az eddigi ismert adatoknál kisebb arányban fordulnak elő bennük. Néhány leveles zöldségben flavonoid molekulákat is sikerült kimutatni. Mind a friss zöldségek, mind a zöldséglevek első- és másodrendű antioxidáns tulajdonságai számottevőek. Az állatkísérletek eredményei alapján úgy tűnik, hogy a brokkoli por (2,12-3,1 mg/ttkg) és a magas izoflavonoid-tartalmú szójakivonat (izoflavonoid: 22,4-24,9 mg/ttkg) kismértékű antioxidáns hatást fejt ki alimentáris úton előidézett hiperlipidémiában, ami elsősorban a májban jelentkezik. A növényi hatóanyagok az alkalmazott dózisban a nagy koleszterin, zsír- és telítetlen zsírsav-tartalmú étrend fogyasztásának káros hatásait csak kismértékben képesek visszaszorítani. Állatkísérletben a kontroll táp mellett a nagydózisú (1600-1700 mg/ttkg) izoflavonoid-bevitel 7 nap alatt szignifikáns változásokat eredményezett mind a plazmában, mind a májban, egyes mirigyek tömege kedvezőtlenül változott. Már az alimentáris hiperlipiémia modellben alkalmazott izoflavonoid dózis is a fiziológiás szint fölött volt, de a kontroll kísérletben használt emelt színt extrém magas bevitelnek tekinthető. A két különböző modellben bevitt izoflavonoid-mennyiségnek megfelelő humán bevitel nem képzelhető el hagyományos étrenddel, ezért a tapasztalt káros hatásokkal nem kell számolni, de a kisdózisok hosszú távú hatásait célszerű lenne vizsgálni. | In present study several fresh and dried vegetables and vegetables juices were screened in relation to their antioxidant compounds and antioxidant characteristics. Low level of vitamins, but remarkable amount of polyphenols and antioxidant characteristics could be detected. Two animal experiments were carried out in order to investigate the antioxidant, lipid-lowering and health promoting effect of broccoli and isoflavonoid-rich soy product. In alimentary hyperlipidemy freezed dried broccoli (2,12-3,1 g/kg b.w) and soy extract (22,4-24,9 mg isoflavonoid/kg b.w.) exhibited slight antioxidant properties, especially in the liver. Extremely high dose of soy isoflavonoid (1600-1700 mg isoflavonoid/kg b.w.) in control rats resulted in significant disadvantageous changes in the weight of some glands, and plasma lipid and lipidperoxidation characteristics. Human physiological isoflavonoid intake is less than doses used in present animal experiments thus detrimental effects caused by dietary intake of isoflavonoids are unbelievable. Higher intake could be achieved by food supplements containing soy isoflavonoids. Health effect of lower doses but longer usage could be different. Therefore it is important to carry out long-term animal experiments with doses equivalent to human intake from normal diet and food supplements together to know better the possible health promoting and/or health damaging effect of phytonutrients

Effect of drought on yield components of maize hybrids : Zea mays L

When investigating drought tolerance, it must not be forgotten that drought stress is a complex phenomenon exhibiting quite different characters in different years and locations. For this reason, the plant response to drought is also a complex process. In our study, 83 maize hybrids originating from various countries were investigated over a period of two years, under irrigated and non-irrigated conditions. The drought tolerance of plants in the non-irrigated plots was analysed in terms of flowering synchrony and yield components. It could be concluded from the results that in response to long-term water deficit the period between tasselling and silking became longer, while the analysis of yield components revealed the greatest reductions in the number of kernels per ear and in the proportion of seed set. As the degree of proterandry increased, there was a decline in the grain yield, confirming that the analysis of this trait could be a way of predicting drought tolerance. Considerable differences in drought tolerance were observed between the genetic materials included in the analysis, suggesting the presence among these parental lines and hybrids of genotypes resistant to long-term water deficit, suitable for cultivation under dry conditions. An analysis of correlations between the traits revealed that proterandry should be treated as a priority trait when investigating drought stress tolerance, as better predictions can be made of both drought tolerance and potential yields, leading to more reliable selection for higher yields

Root Electrical Capacitance Can Be a Promising Plant Phenotyping Parameter in Wheat

As root electrical capacitance (CR*) was assumed to depend on the stem properties, the efficiency of measuring CR* at flowering for whole-plant phenotyping was assessed in five wheat cultivars in three replicate plots over two years. Linear regression analysis was used to correlate CR* with plant-size parameters and flag-leaf traits (extension and SPAD chlorophyll content) at flowering, and with yield components at maturity. The plot-mean CR* was correlated with the plot leaf area index (LAI), the chlorophyll quantity (LAI×SPAD), and the grain yield across years. At plant scale, CR* was found to show the strongest positive regression with total chlorophyll in the flag leaf (flag leaf area × SPAD; R2: 0.65–0.74) and with grain mass (R2: 0.55–0.70) for each cultivar and year (p < 0.001). Likewise, at plot scale, the regression was strongest between CR* and the LAI×SPAD value (R2: 0.86–0.99; p < 0.01) for the cultivars. Consequently, CR* indicated the total plant nutrient and photosynthate supply at flowering, which depended on root uptake capacity, and strongly influenced the final yield. Our results suggested that the polarization of the active root membrane surfaces was the main contributor to CR*, and that the measurement could be suitable for evaluating root size and functional intensity. In conclusion, the capacitance method can be applied for nondestructive whole-plant phenotyping, with potential to estimate root and shoot traits linked to the nutrient supply, and to predict grain yield. CR* can be incorporated into allometric models of cereal development, contributing to optimal crop management and genetic improvement

Generating Marker-Free Transgenic Wheat Using Minimal Gene Cassette and Cold-Inducible Cre/Lox System

The precise elimination of selectable marker genes is highly desirable, when their function is no longer needed, because their presence raised worldwide public concerns against the release of genetically modified plants. This is the first report of simultaneous application of the minimal gene cassette and cold-inducible Cre/lox recombination system in wheat. The bar selection and cre-recombinase genes were eliminated from T0 and T1 transgenic lines with 44 and 51 % efficiency. This approach provides a new, reasonably effective technique to produce selection gene-free transgenic wheat lines either immediately after tissue culture, or from the subsequent transgenic generation. The advantage of this method is that it does not require any additional cold treatment during the plant regeneration/growing because the transgene elimination is ensured by the vernalisation. Application of this method prevents gene flow by pollen and seed, because the selection and recombinase genes are eliminated before pollen development, therefore reducing the risk of GM plants. © 2014, Springer Science+Business Media New York