谷子（小米）是我国北方重要的粮食作物之一，与中华文明的形成和发展关系密切，由于长期缺少准确区分新石器时代早期腐朽、灰化谷子与其野生祖本青狗尾草遗存的鉴定方法，国际上有关谷子的起源时间、过程存在多种不同的认识。植硅体分析是鉴定早期腐朽植物遗存的最有效手段之一，过去的研究由于受方法和材料限制，学界对能否利用植硅体形态区分谷子与青狗尾草的准确性和可靠性存在质疑。
中科院地质与地球物理研究所新生代地质与环境重点实验室博士后张健平等与中科院地理科学与资源研究所以及中国农业科学院等单位的专家合作，通过对采自国内外不同地区的16种现代谷子、青狗尾草小穗颖片、内外稃片不同部位、不同细胞层的植硅体分析，明确了区分鉴定谷子和青狗尾草植硅体的形态特征和可重复检验的测量标准。研究同时表明，采自东亚地区与西欧的谷子稃壳植硅体存在形态学上显著差异，暗示了可能存在不同的演化路线。同行审稿专家认为，该文章为鉴定考古遗址中的谷子与它的野生祖本提供了可靠的方法，是植物考古学研究方法的突破性进展，有希望在早期考古遗址灰化植物遗存样品的鉴定，以及为世界谷子起源、传播过程研究提供新的视角和证据。
该研究成果近日发表在国际知名的综合类学术期刊《公共科学图书馆—综合》（PLoS ONE）杂志上。
该文章是吕厚远研究员课题组继2009年在PLoS ONE 上发表谷子和黍子的植硅体鉴定方法、在PNAS 上发表东亚旱作农业起源研究进展之后，在该领域的又一重要的基础性研究成果。（生物谷Bioon.com）
生物谷推荐原文出处：
PLoS ONE 6(5): e19726. doi:10.1371/journal.pone.0019726
Phytolith Analysis for Differentiating between Foxtail Millet (Setaria italica) and Green Foxtail (Setaria viridis)
Jianping Zhang,Houyuan Lu,Naiqin Wu,Xiaoyan Yang,Xianmin Diao
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.
