Lepidium meyeniiWalp. （Maca）, a perennial herbaceous plant with narrow distdbution in the Andean region, was cultivated by local residents as early as 1600 B.C. It has high nutritional values and multiple medicinal ...Lepidium meyeniiWalp. （Maca）, a perennial herbaceous plant with narrow distdbution in the Andean region, was cultivated by local residents as early as 1600 B.C. It has high nutritional values and multiple medicinal effects. In recent years the plant source of Maca has been greatly scarce since Maca products are increasingly becoming popular in the world. This makes the study urgent on the identification and quality evaluation of Maca materials. In present work, four Mace samples of different origins or handlings and three other natural plants, including radish, odental ginseng and American ginseng, were investigated. Their essential oils （steam distillates） of the hypogeal parts were weighed and analyzed by GC/MS. Through comparison of the characteristics of their chromatograms, it was found that the essential oil of Maca had unique GC/MS behaviors, and the characteristic peaks produced by the major essential oil components （Phenylacetonitrile, Benzaldehyde, 3-Methoxyphenylacetonitrile, etc） were distinct. Furthermore, the chromatograms of several Maca samples showed a similar qualitative pattern except for some differences in the quantitative composition, and the percentage of total essential oils in the samples varied from 0.88 % to 1.59 %. These behaviors and technologies can be applied to the identification of Maca materials in the markets and be a supplement to assess the quality of Maca matedals.展开更多
Recently,Chen and colleagues from Shanghai Institute of Plant Physiology and Ecology of Chinese Academy of Sciences,in collaboration with scientists from Nanjing Agricultural University and from the US,have identified...Recently,Chen and colleagues from Shanghai Institute of Plant Physiology and Ecology of Chinese Academy of Sciences,in collaboration with scientists from Nanjing Agricultural University and from the US,have identified a homeodomain（HOX）-containing transcription factor that plays a central role in controlling cotton fiber elongation.展开更多
文摘Lepidium meyeniiWalp. （Maca）, a perennial herbaceous plant with narrow distdbution in the Andean region, was cultivated by local residents as early as 1600 B.C. It has high nutritional values and multiple medicinal effects. In recent years the plant source of Maca has been greatly scarce since Maca products are increasingly becoming popular in the world. This makes the study urgent on the identification and quality evaluation of Maca materials. In present work, four Mace samples of different origins or handlings and three other natural plants, including radish, odental ginseng and American ginseng, were investigated. Their essential oils （steam distillates） of the hypogeal parts were weighed and analyzed by GC/MS. Through comparison of the characteristics of their chromatograms, it was found that the essential oil of Maca had unique GC/MS behaviors, and the characteristic peaks produced by the major essential oil components （Phenylacetonitrile, Benzaldehyde, 3-Methoxyphenylacetonitrile, etc） were distinct. Furthermore, the chromatograms of several Maca samples showed a similar qualitative pattern except for some differences in the quantitative composition, and the percentage of total essential oils in the samples varied from 0.88 % to 1.59 %. These behaviors and technologies can be applied to the identification of Maca materials in the markets and be a supplement to assess the quality of Maca matedals.
文摘Recently,Chen and colleagues from Shanghai Institute of Plant Physiology and Ecology of Chinese Academy of Sciences,in collaboration with scientists from Nanjing Agricultural University and from the US,have identified a homeodomain（HOX）-containing transcription factor that plays a central role in controlling cotton fiber elongation.
