Volume 3 Special Issue 1 2009
How to reference: Cawoy V, Ledent J-F, Kinet J-M, Jacquemart A-L (2009) Floral Biology of Common Buckwheat (Fagopyrum esculentum Moench). In: Dobránszki J (Ed) Buckwheat I. The European Journal of Plant Science and Biotechnology 3 (Special Issue 1), 1-9
Research Centre of University of Debrecen, Centre of Agricultural Sciences and Engineering, Hungary
CONTENTS AND ABSTRACTS
Valérie Cawoy, Jean-François Ledent, Jean-Marie Kinet, Anne-Laure Jacquemart (Belgium) Floral Biology of Common Buckwheat (Fagopyrum esculentum Moench) (pp 1-9)
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Invited Review: Common buckwheat (Fagopyrum esculentum Moench) is widely cultivated but the floral biology of this auto-incompatible distylous species was poorly documented. This review, based on our recent results obtained with the cultivar ‘La Harpe’ and the literature, summarizes main aspects related to its reproduction: morphogenesis, flowering, nectar, pollination and flower functionality. The activity of the reproductive meristems is potentially endless but the morphogenesis is stopped by the abortion processes. When the plant has one unfolded true leaf, the morphogenesis of the reproductive structures occurs at many nodes and this developmental stage is highly sensitive to environmental stress. Hymenoptera (Apis mellifera L. and Bombus spp.) and Diptera (Syrphidae) are the main visitors. Honeybee appears to be an effective pollinator and the most numerous visitors in Western Europe. At the anthesis, ‘hexoses-dominant’ floral nectar is secreted by unicellular secretory hairs during all the light period even after pollination. Except for the morphology of the reproductive organs, both morphs differ only in the nectar production. Thrum flowers secrete more nectar than pin flowers. Pollinator abundance is an important parameter to secure the yield but even without pollen transfer limitation the seed set is low. Flower fate appears to be dependent on a mechanism internal to the raceme which controls the percentage of flowers able to set a seed. Infertile flowers with an undersized gynoecium and last abortions after fecundation are not frequent. In contrast, flowers with a normal sized gynoecium which do not set seed after compatible pollination are the main contribution to the low seed set. This female organ sterility seems to be the most yield limiting factor throughout the world.
Roman Przybylski, Eliza Gruczyńska (Canada) A Review of Nutritional and Nutraceutical Components of Buckwheat (pp 10-22)
Invited Review: Buckwheat, frequently classified as a pseudocereal, is one of the minor crops cultivated by ethnic groups in developed and developing countries which is an integral part of their diet and culture. When views on food components changed from only a source of basic nutrients into a resource of health promoting compounds, suddenly buckwheat was recognized as a food ingredient offering a variety of unique nutrients and nutraceuticals. The importance of buckwheat components is currently reflected by the large volume of research on nutritional and health aspects of this crop. In this paper we appraise recent findings in the macronutrients, nutraceuticals and unique components with astonishing properties present in buckwheat seed and plant.
Pham Van Hung (Canada/Vietnam), Tomoko Maeda, Naofumi Morita (Japan) Buckwheat Starch: Structure and Characteristics – A Review (pp 23-28)
Invited Review: Buckwheat, which contains high nutritional values of protein, dietary fiber, phenolic compounds and minerals, is a major pseudo-cereal for processing functional foods, especially the Japanese buckwheat noodles (soba noodles). In buckwheat flour, starch is a main component which plays an important role in the functional properties of end-use food products. Buckwheat starch granules were spherical, oval and polygonal in shape and granule size distribution ranged from 2 to 6 µm. The apparent amylose content of buckwheat starches varied from 21.1 to 27.4%, while the actual amylose content ranged from 16 to 18%. X-ray diffraction pattern of buckwheat starches was the typical A-type crystal with 38–51% crystallinity. The gelatinization temperatures of buckwheat starch were 57.8–64.3°C for onset (To), 63.7–70.8°C for peak (Tp) and 70.8–85.8°C for complete (Tc) temperatures, and ΔH values ranged from 2.14 to 15.0 J/g. Buckwheat amylopectin showed longer average chain length and larger amount of long chain than did the cereal amylopectins, while buckwheat amyloses were slightly larger than maize and rice amyloses, but similar to wheat and barley amyloses. The β-amylolysis limits of buckwheat amylopectins and amyloses were similar to those of the other cereals. The pasting characteristic studies showed that buckwheat starches had similar peak viscosity, higher hot and cool paste viscosities and higher resistance to shear thinning than did wheat starch. These characteristics of buckwheat starches are considered to contribute significantly to the texture and quality of buckwheat-based food products.
Danuta Zielińska, Henryk Zieliński (Poland) Low Molecular Weight Antioxidants and Other Biologically Active Components of Buckwheat Seeds (pp 29-38)
Invited Review: The biological bases for intake of low molecular weight antioxidants and other biologically active compounds present in the buckwheat seeds in relation to the reduction of risk for chronic diseases have been discussed in this article.
Yakov E. Dunaevsky, Natalya V. Khadeeva, Galina A. Belyakova, Mikhail A. Belozersky (Russia) Properties, Physiological Role and Possible Use in Biotechnology of Proteinase Inhibitor from Buckwheat Seeds (pp 39-44)
Invited Mini-Review: Isolation and detailed investigation of protein proteinase inhibitor BWI-1a from buckwheat seeds has been carried out. The protein obtained was homogeneous and its physico-chemical, kinetic and biological properties were characterized. The molecular mass of BWI-1a inhibitor was 7.7 kDa and it consisted of 69 amino acid residues. Interaction of the studied inhibitor with a number of proteinases secreted by pathogenic filamentous fungi has been studied. The results obtained made it possible to propose that the inhibitor participated in the defense system of buckwheat seeds. Further complete amino acid sequence of BWI-1a inhibitor was established, the gene of the inhibitor was obtained, and genetic engineered constructions were created for transformation of some plants. Finally, transgenic potato and tobacco plants, containing BWI-1a inhibitor gene, were obtained, which demonstrated increased resistance to 2 bacterial phytopathogens Pseudomonas syringae pv. tomatoe and Clavibacter michiganensis sbsp. michiganensis. Biotest consisting in damaging of tobacco plants with white wings butterfly Trialeurodes vaporariorum in the greenhouse also demonstrated the existence of defense effect in transgenic tobacco plants. Thus, obtained results confirmed the proposal on the defense role of proteinase inhibitor BWI-1a and point to the possibility of its use for production of transgenic plants with increased resistance to phytopathogens and insect pests.
Dan Li, Xiaolei Li, Changcheng Gao, Xing Chen (China) Tartary Buckwheat, Fagopyrum tataricum (Linn) Gaertn: A Functional Food Ingredient from Eastern Asia (pp 45-48)
Invited Mini-Review: Tartary buckwheat is widely grown and utilized in western China. In some Asian countries, dietary intake of tartary buckwheat foods is considered to be highly beneficial to human health. Many nutraceutical compounds in tartary buckwheat have been found to play critical roles in its health benefits. This review summarizes findings of recent studies in East Asia on protein, flavonoids, inositol, and inhibition of bitter taste and rutin loss in tartary buckwheat.
Tatiana Bojňanská, Peter Chlebo, Radovan Gažar (Slovak Republic), Aleš Horna (Czech Republic) Buckwheat-Enriched Bread Production and its Nutritional Benefits (pp 49-55)
Original Research Paper: Buckwheat wholegrain flour was added to wheat flour at 10, 20, 30, 40 and 50% (dry weight) to evaluate the technological, organoleptic and nutritional propoerties of the enriched bread. The bread that was produced was generally acceptable when up to 30% buckwheat was added to wheat flour. Regarding the technological quality, an increase in the level of buckwheat led to a decrease of the extensograph energy, resistance, extensibility as well as the ratio number (rheological parameters). Loaves prepared with buckwheat were of lower quality, negatively influencing loaf volume, specific volume, and bulk productivity of the bakery products. From a nutritional point of view, various nutritional parameters, such as rutin content and macro and microelements were determined and compared in the enriched and control bread. The elements which were quantitatively determined (zinc, copper, manganese, nickel) are important biogenic elements. The contents of these elements in bread to which 50% buckwheat was added were significantly higher than in the control wheat bread (from 115% for Mg to 338% for Ni). The rutin content in the bread increased as the amount of buckwheat increased from 14.1 mg.kg-1 DM (10% buckwheat) to 48.9 mg.kg-1 DM (50% buckwheat). The daily consumption of buckwheat-enriched bread (30% buckwheat, 200 g bread, 3.8 g rutin) during the clinical study (four weeks/eight weeks) caused a significantly increase in the iron level in the blood of volunteers and significantly decreased the triglyceride, HDL cholesterol, creatinine, calcium and magnesium levels. The decrease in total cholesterol, urea and chloride levels were insignificantly.
Lucia Brindzová, Mária Takácsová, Lucia Mikušová, Michal Zalibera (Slovak Republic) Antioxidant Capacity and Sensory Evaluation of Wheat Bakery Products Supplemented with Buckwheat and Oat Flour and Barley β-D-Glucan (pp 56-61)
Original Research Paper: Wheat (Tritium aestivum L.) is the most important cereal crop of world in terms of production and consumption. However, wheat is considered nutritionally poor and therefore we decided to supplement wheat flour with whole buckwheat flour (variety ‘Špačinská 1’) and extruded oat flour (variety ‘Avesta’) in three different ratios: ratio of oat to buckwheat 1: 2 (15% addition), 1: 3 (20% addition) and 1: 4 (25% addition). Moreover, we tested the enrichment of bakery products with barley β-D-glucan, important for its hypocholesterolemic and radical scavenging effects. Supplemented bakery products exhibited higher antioxidant capacity evaluated by ABTS (2,2’-azinobis-[3-ethylbenzthiazoline]-6-sulphonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) tests, by EPR (electron paramagnetic resonance) spin trapping assay and β-carotene bleaching method, in comparison to the control wheat product. Total phenolic compounds in four kinds of the representative bakery products were also analysed. The increased ratio of buckwheat flour in bakery products lead to a statistically significant increase in the content of phenolic compounds. Sensory characteristics of suggested bakery products were determined by a panel of 14 judges who evaluated the form of products, crust colour, porosity, tackiness, colour and elasticity of crumb, odour, taste and overall acceptability. All tested characteristics were affected by the buckwheat and oat flour supplementation. The 15 and 20% addition improved positively the overall acceptability of studied products while the 25% addition showed no considerable improves.
Andrea Brunori (Italy), Gergő Sándor (Hungary), Hao Xie (China), Gerardo Baviello (Italy), Bernadett Nehiba, Gyula Rabnecz, György Végvári (Hungary) Rutin Content of the Grain of 22 Buckwheat (Fagopyrum esculentum Moench and Fagopyrum tataricum Gaertn.) Varieties Grown in Hungary (pp 62-65)
Original Research Paper: Nineteen common buckwheat (Fagopyrum esculentum Moench) and three tartary buckwheat (Fagopyrum tataricum Gaertn.) varieties were grown in the summer 2007 at the Research and Experimental Farm of the Corvinus University in Soroksár, Hungary. The rutin content of the grainof F. tataricum, determined by high pressure liquid chromatography (HPLC), resulted several times higher than that of F. esculentum. Among the three varieties of F. tataricum, under investigation, ‘Ishisoba’ presented a significantly (P = 0.05) higher rutin content, although the actual differences of rutin levels remained rather modest. On the contrary, a large variation of the rutin content of the grain appeared among the 19 varieties of F. esculentum when comparing top and least rutin values observed (‘Fukue’ 51 mg/100 g dry weight (DW) and ‘Mancan’ 11 mg/100 g DW). However, the content of rutin of most of the varieties of F. esculentum was confined within a rather narrow range between 15 and 25 mg/100 g DW, values which are to be regarded as typical of this species. In this respect, ‘Fukue’ with 51 mg/100 g DW, for sure, represents a variety of F. esculentum capable of expressing an extremely high rutin content of the grain under the Hungarian environment. The rutin content of tartary buckwheat grain, though somewhat lower than the highest values reported in the pertinent literature, remained decidedly higher compared to that of common buckwheat.
Judit Dobránszki (Hungary) Role of Cytokinins and Explant Type in Shoot Multiplication of Buckwheat (Fagopyrum esculentum Moench) in Vitro (pp 66-70)
Original Research Paper: The main objective of micropropagation after in vitro culture establishment is to work out an efficient and reliable method for shoot multiplication. The effect of isoprenoid (2-iP) and aromatic cytokinins (BA, BAR, KIN, TOP) were tested in experiments aimed on shoot multiplication. Beside the evaluation of the effects of different types and concentrations (1 to 20 μM) of cytokinins, the influence of explant type (shoot tip, nodal segment) on efficient multiplication was also assessed. Both type and concentration of applied cytokinins and the type of explants had a strong effect on the shoot multiplication and on growth type of in vitro shoots. A very tight relationship between the cytokinins and explant types was observed. If meta-topolin was applied between 5 and 15 μM and shoot tips were used as initial explants, high multiplication (3.05-3.49 shoots and 13.26-14.42 nodes per explant) could be achieved and the mean length of shoots was satisfactory (> 40 mm). Results obtained may contribute to the development of an efficient micropropagation protocol for common buckwheat.
Nailya Maksyutova, Ekaterina Galeeva, Alexander Mukhitov, Natalya Rumyantseva, Larisa Viktorova (Russia) Changes in the Growth of Tartary Buckwheat (Fagopyrum tataricum (L.) Gaertn.) Calli with Different Ability for Morphogenesis Induced by Salicylic Acid (pp 71-74)
Original Research Paper: The effect of salicylic acid (SA) on the growth processes of tartary buckwheat calli (Fagopyrum tataricum (L.) Gaertn) with different morphogenic potential have been studied. The changes of biomass and mitotic index of two callus types refer to a high sensitivity of non–morphogenic callus to the SA treatment. The different sensitivity of calli to SA may be connected with different activity of enzymes being parts of oxidative metabolism in these calli.
Jolanta Slawinska, Stella K. Kantartzi, Ralph L. Obendorf (Hungary) In Vitro Organogenesis of Fagopyrum esculentum Moench (Polygonaceae) as a Method to Study Seed Set in Buckwheat (pp 75-78)
Original Research Paper: In vitro organogenesis may provide a method to reduce the very large number of observations required for in planta studies on seed set in Fagopyrum esculentum. Plants were regenerated from leaf petiole explant tissue of buckwheat seedlings. Maximum shoot regeneration was induced on Murashige and Skoog (MS) medium containing Gamborg’s vitamins, 6-benzylaminopurine (BA), 6-γ,γ-dimethylallylamino-purine (2iP) and 2,3,5-triiodobenzoic acid (TIBA) at 1 mg L-1 each, and sucrose at 30 g L-1. Whole plants were obtained at high frequencies (up to 98%)when the shooting explants were transferred to half-strength MS media without growth regulators for rooting and then to vermiculate followed by soil mix in greenhouse conditions. Regenerated plants were studied for vegetative, floral and seed characteristics in comparison with buckwheat plants developed from seeds. Plants regenerated by organogenesis were 33% shorter than those developed from seeds, with lower pollination frequency and smaller seeds but the number of seeds per raceme and percentage of seed set did not show any significant differences. In addition, the number of aborted seeds per raceme was significantly lower (by 40%) in plants developed from in vitro organogenesis than those grown from seeds. This regeneration system may be valuable for studying the problem of low seed set in common buckwheat.
Danuta Zielińska, Dorota Szawara-Nowak, Henryk Zieliński (Poland) Antioxidative and Anti-glycation Activity of Bitter Buckwheat Tea (pp 79-83)
Original Research Paper: Unhusked tartary buckwheat and green tea with mint leaves were used for the preparation of ready-to-drink bitter buckwheat tea and green tea with mint. An 80% methanol extract of dry unhusked tartary buckwheat and bitter buckwheat tea were characterized for total phenolic contents (TPC), flavonoids profile, DPPH radical scavenging activity (DPPH RSA) and antioxidative capacity by the cyclic voltammetry (CV) assay, whilst the anti-glycation activity of bitter buckwheat tea was evaluated in vitro in a bovine serum albumin (BSA)-glucose model. The antioxidative and anti-glycation activities of bitter buckwheat tea were compared to those of green tea with mint. The dry unhusked tartary buckwheat showed 5 times lower TPC content when compared to that of green tea leaves with mint. The analysis of flavonoids in dry unhusked tartary buckwheat showed a high content of rutin followed by a moderate level of quercetin and low contents of flavone C-glucosides. Rutin was the main bitter buckwheat tea flavonoid, while quercetin was not detected. The bitter buckwheat tea showed about 5 times lower antioxidative capacity determined with DPPH RSA (5 times) and with the CV assay (two-fold) than green tea with mint. The ready-to-drink bitter buckwheat tea showed 69% inhibition of the formation of AGEs, whereas that noted for green tea with mint reached 98%. Therefore, unhusked tartary buckwheat may be used for tea preparation as the main single tea ingredient or as a mixed component of other tisanes.
László Léder, János Falusi, András Tomcsányi (Hungary) Improvement and Maintenance of Buckwheat (Fagopyrum esculentum Moench.) Variety ‘Oberon’ and its Major Characteristics (pp 84-85)
Short Communication: We have been dealing with the improvement of buckwheat since the middle of the last decade. Our aim was to develop a variety with rich crops and a high 1000-seed weight and smaller harrowing loss. Improvement was carried out with the Ohio method, which is frequently used with open-pollinated varieties. The types that best suited our purposes were propagated in isolation. As a result of our work, var. ‘Oberon’ was registered by the state in 2006. Maintenance of variety occurs with the Ohio method and by eliminating the divergent types before flowering. The 1000-seed weight of this variety is 30-35 g, i.e. higher than average.
Pasquale Martiniello (Italy) Adaptability of Lucerne, Cocksfoot and Tall Fescue Genotypes in Mediterranean Environment under Different Application of Water Supply (pp 86-96)
Original Research Paper: Dry matter of perennial species in Mediterranean environments depends on agronomic management, weather conditions and edaphic habitus of growing plants. Experiments on genotypes of perennial legume (lucerne, Medicago sativa L.; and graminaceous, cocksfoot, Dactylis glomerata L. and tall fescue, Festuca arundinacea Schreb.) were established, from 1996 to 2001, in an environment (Foggia, southern Italy) with a typical Mediterranean climate. The genotypes of three species were evaluated under rainfed and irrigated conditions. Irrigation integrated 80% of water lost by evapotranspiration from the lucerne, cocksfoot and tall fescue genotypes. Forage defoliation of the genotypes was performed when 45-50% of stems in the plot had flowered. The experimental design was a combined split-plot in time and factorial design replicated four times. The parameters assessed in the study were dry matter (t ha-1), stem height (cm), stems m-2 and leaf: stem ratio (%). Irrigation treatment, in comparison to rainfed, doubled the time of agronomic utilization of the crops (3 vs. 6 years) and increased the dry matter yield by 24.35 t ha-1 in lucerne, 11.71 t ha-1 in cocksfoot and 14.67 t ha-1 in tall fescue. The adaptability of genotypes within crops to growing conditions were determined by cluster analysis which identified genotypes with superior fitness and adaptability to weather resources. Tall fescue was the crop with highest percentage of genotypes in all traits of the selected homogeneous group. Furthermore, because the genotypes Coussouls, Equipe, Lodi and Romagnola in lucerne; Cesarina and breeding population in cocksfoot; Maris Kasba and Tanit in tall fescue are included in more than one selected cluster group, they are endowed by physiological mechanisms able to better adapt and perform in weather conditions of Mediterranean climate.
Mehmet Serhat Odabas, Hüseyin Celik, Ali Islam (Turkey) Non-Destructive Leaf Area Prediction Model for “Kiraz” Cherry Laurel (Laurocerasus officinalis Roem.) (pp 97-99)
Research Note: The objective of the present study was to develop a leaf area prediction model for “Kiraz” cherry laurel (Laurocerasus officinalis Roem.). To achieve this objective, a total of 200 leaves were selected randomly from “Kiraz” cherry laurel in Turkey. Leaf width, length and leaf area were measured. The actual leaf area of the plant was measured by a PLACOM Digital Planimeter and multiple regression analysis with SAS was performed. The leaf area model developed was LA= (-55,5877) + (19,98318 x W) + (-0,83723 x W2) + (0,143132 x L2) where LA is leaf area, L is leaf length, and W is leaf width. The R2 value (0.95) and standard error were found to be significant at p<0.001.