Phytolith Analysis for Differentiating between Foxtail Millet (Setaria italica) and Green Foxtail (Setaria viridis)

Foxtail millet (Setaria italica) is one of the oldest domesticated cereal crops in Eurasia, but identifying foxtail millets, especially in charred grains, and differentiating it from its wild ancestor, green foxtail (Setaria viridis), in the archaeobotanical remains, is still problematic. Phytolithic analysis provides a meaningful method for identifying this important crop. In this paper, the silicon structure patterns in the glumes, lemmas, and paleas from inflorescence bracts in 16 modern plants of foxtail millet and green foxtail from China and Europe are examined using light microscopy with phase-contrast and a microscopic interferometer. Our research shows that the silicon structure of ΩIII from upper lemmas and paleas in foxtail millet and green foxtail can be correspondingly divided into two groups. The size of ΩIII type phytolith of foxtail millet is bigger than that from green foxtail. Discriminant function analysis reveals that 78.4% of data on foxtail millet and 76.9% of data on green foxtail are correctly classified. This means certain morphotypes of phytoliths are relatively reliable tools for distinguishing foxtail millet from green foxtail. Our results also revealed that the husk phytolith morphologies of foxtail millets from China and Eastern Europe are markedly different from those from Western Europe. Our research gives a meaningful method of separating foxtail millet and green foxtail. The implications of these findings for understanding the history of foxtail millet domestication and cultivation in ancient civilizations are significant

Effet d'un déficit hydrique sur le trèfle blanc (Trifolium repens L.). I. Importance du cultivar

National audienceFour white clover cultivars (Trifolium repens L. Ladino and Hollandicum) were grown in pots placed in a growth chamber. Nine weeks after germination the water supply was suppressed. Dawn water potential, net photosynthetic assimilation and nitrogen fixation were measured. The water stress resulted in a rapid decrease in the dawn water potential. Photosynthesis and nitrogen fixation were also affected. The relationship between nitrogen fixation and soil water content was confirmed. The maximum rate of nitrogen fixation was not reached at the soil water capacity, probably due to a lack of soil aeration. Nitrogen fixation was maximum at 60-70 % and 80-85 % of the soil water capacity with Ladino and Hollandicum respectively. A lack of aeration at the water holding capacity probably caused an inhibition of the nitrogen fixation. Differences in resistance to water deficit were observed between varieties : Crau (Ladino) presented the highest nitrogen fixation, and produced more biomass than other varieties. Huia (Hollandicum) showed the lowest nitrogen fixation and appeared to be the most sensitive variety. Methods for selecting cultivars as regard to their resistance or tolerance to water deficit are discussed.Quatre cultivars de trèfle blanc (Trifolium repens L., Ladino ou Hollandicum) ont été soumis à un déficit hydrique croissant provoqué par l’arrêt total de l’alimentation en eau. L’expérience a été effectuée, en chambre phytotronique, 9 semaines après la germination des plantes. Le déficit en eau entraîne une diminution rapide du potentiel hydrique de base et de l’assimilation photosynthétique nette pour tous les cultivars. Cette étude confirme aussi le lien entre le facteur hydrique et la fixation d’azote, dont l’optimum n’est pas atteint à la capacité au champ, sans doute en raison d’une aération insuffisante du sol à cette humidité, mais correspond à une teneur en eau du sol comprise entre 60 et 70 % de la capacité au champ pour le type Ladino et entre 80 et 85 % pour le type Hollandicum. Des différences intervariétales ont été mises en évidence : Crau (type Ladino) maintient le taux de fixation le plus élevé et produit plus de biomasse aérienne que les autres variétés. Le cultivar Huia (type Hollandicum) présentant la fixation symbiotique la plus basse se montre le moins tolérant au déficit hydrique. L’intérêt de cette étude est discuté dans une optique de criblage de cultivars, sur la base de leur tolérance au manque d’eau

Effet d'un déficit hydrique sur le trèfle blanc (Trifolium repens L.). I. Importance du cultivar

Quatre cultivars de trèfle blanc (Trifolium repens L., Ladino ou Hollandicum) ont été soumis à un déficit hydrique croissant provoqué par l’arrêt total de l’alimentation en eau. L’expérience a été effectuée, en chambre phytotronique, 9 semaines après la germination des plantes. Le déficit en eau entraîne une diminution rapide du potentiel hydrique de base et de l’assimilation photosynthétique nette pour tous les cultivars. Cette étude confirme aussi le lien entre le facteur hydrique et la fixation d’azote, dont l’optimum n’est pas atteint à la capacité au champ, sans doute en raison d’une aération insuffisante du sol à cette humidité, mais correspond à une teneur en eau du sol comprise entre 60 et 70 % de la capacité au champ pour le type Ladino et entre 80 et 85 % pour le type Hollandicum. Des différences intervariétales ont été mises en évidence : Crau (type Ladino) maintient le taux de fixation le plus élevé et produit plus de biomasse aérienne que les autres variétés. Le cultivar Huia (type Hollandicum) présentant la fixation symbiotique la plus basse se montre le moins tolérant au déficit hydrique. L’intérêt de cette étude est discuté dans une optique de criblage de cultivars, sur la base de leur tolérance au manque d’eau.Four white clover cultivars (Trifolium repens L. Ladino and Hollandicum) were grown in pots placed in a growth chamber. Nine weeks after germination the water supply was suppressed. Dawn water potential, net photosynthetic assimilation and nitrogen fixation were measured. The water stress resulted in a rapid decrease in the dawn water potential. Photosynthesis and nitrogen fixation were also affected. The relationship between nitrogen fixation and soil water content was confirmed. The maximum rate of nitrogen fixation was not reached at the soil water capacity, probably due to a lack of soil aeration. Nitrogen fixation was maximum at 60-70 % and 80-85 % of the soil water capacity with Ladino and Hollandicum respectively. A lack of aeration at the water holding capacity probably caused an inhibition of the nitrogen fixation. Differences in resistance to water deficit were observed between varieties : Crau (Ladino) presented the highest nitrogen fixation, and produced more biomass than other varieties. Huia (Hollandicum) showed the lowest nitrogen fixation and appeared to be the most sensitive variety. Methods for selecting cultivars as regard to their resistance or tolerance to water deficit are discussed

Le statut en vitamines anti-oxydantes module les effets de l’activité physique sur le niveau de leptine et sur les caractéristiques métaboliques liées au poids chez l’adolescent

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Modification of sunflower oil quality by seed-specific expression of a heterologous Delta 9-stearoyl-(acyl carrier protein) desaturase gene

The coding sequence of Delta9-stearoyl-(acyl carrier protein) desaturase from Ricinus communis was introduced into sunflower. under the control of seed-specific promoter and terminator sequences of the late embryogenesis abundant gene from sunflower. Hads10. Two independent primary transformants contained three and six copies of the T-DNA. as demonstrated by hybridization using nptII as a probe. The transgene proved genetically stable and was transmitted as a Mendelian trait. Transcript analysis of the heterologous Delta9-stearoyl-(acyl carrier protein) desaturase under control of the Hads10 promoter verified tissue-specific expression in the developing embryos and not in the leaves. Fatty acid composition of the seed oil was followed over five generations under greenhouse and open field conditions. Some of the transgenic lines produced oil with a significantly reduced stearic acid content compared with non-transformed plants under greenhouse and field conditions, However. additional studies need to be performed to assess whether or not physiologically stable lines can be developed from these transgenic lines

Modification of sunflower oil quality by seed-specific expression of a heterologous Delta 9-stearoyl-(acyl carrier protein) desaturase gene

The coding sequence of Delta9-stearoyl-(acyl carrier protein) desaturase from Ricinus communis was introduced into sunflower. under the control of seed-specific promoter and terminator sequences of the late embryogenesis abundant gene from sunflower. Hads10. Two independent primary transformants contained three and six copies of the T-DNA. as demonstrated by hybridization using nptII as a probe. The transgene proved genetically stable and was transmitted as a Mendelian trait. Transcript analysis of the heterologous Delta9-stearoyl-(acyl carrier protein) desaturase under control of the Hads10 promoter verified tissue-specific expression in the developing embryos and not in the leaves. Fatty acid composition of the seed oil was followed over five generations under greenhouse and open field conditions. Some of the transgenic lines produced oil with a significantly reduced stearic acid content compared with non-transformed plants under greenhouse and field conditions, However. additional studies need to be performed to assess whether or not physiologically stable lines can be developed from these transgenic lines