Molecular markers for the discrimination of Triticum turgidum L. subsp. dicoccum (Schrank ex Schübl.) Thell. and Triticum timopheevii (Zhuk.) Zhuk. subsp. timopheevii

The persistent uncertainty on the classification of the “new” glume wheat found in Neolithic and Bronze Age sites from Greece and other European settlements might be resolved only through analysis of its ancient DNA. Tools able to discriminate among different Triticum species on the basis of scarce, very damaged DNA, are therefore essential. While current attempts concentrate on DNA fragments sequencing and comparison, in some instances PCR-based selective amplification techniques might offer a cheaper and quicker alternative. The purpose of this research was therefore the identification of species-specific primers, able to distinguish caryopses of Triticum timopheevii subsp. timopheevii from those of Triticum turgidum subsp. dicoccum. Primers and their working conditions were defined and optimized using DNA from modern accessions. The ribosomal primers ITS1 tim and ITS2 tim, and the nuclear primer acetyl-coenzyme A tim clearly discriminated the sequences of Triticum timopheevii from other species. Finally, Neolithic charred wheat grains found in the sites of Sammardenchia (Pozzuolo del Friuli, Udine) and La Marmotta (Lago di Bracciano, Roma), belonging to the “new” wheat type or to emmer, were tested with the three selected primers. However, the results were not conclusive, because the samples analysed were apparently too degraded to yield useful DNA.     

DNA analysis in charred grains of naked wheat from several archaeological sites in Spain

In the present work we attempt to recover endogenous ancient DNA from cereal grains preserved under different conditions: charred, partially charred and waterlogged. A total of 126 grains from naked wheat and 18 from barley from different sites on the Eastern Iberian Peninsula ranging from the beginning of agriculture in the region to the turn of the Common Era, were studied. Two different extraction protocols were used, a standard phenol–chloroform method and a silica-based DNA extraction procedure implemented for artificially charred seeds. Amplifications were directed to three markers: the large subunit of ribulose 1,5 biphosphate carboxylase (rbcL) and the microsatellite WCT12 in the chloroplast genome and the x and y subunits of the high molecular weight glutenin gene (Glu-1) in the nucleus. The first two were used to assess the preservation status of the samples, while with the third we tried to identify the wheat grains at species level. It was possible to obtain eleven positive amplifications in 8 partially charred seeds but only two amplifications of the Glu-1 gene from a single sample of the Early Bronze age were genome-specific. Different contamination sources were identified and reported. Cloning and alignment of sequenced clones showed a correspondence of the amplified fragment to modern wheat D genome haplotypes. This result suggests that the sample corresponds to hexaploid wheat (Triticum aestivum L.), thus being the first ancient DNA evidence to date for the cultivation of hexaploid wheat in the prehistoric agriculture of the Iberian Peninsula. Moreover, obtained results highlight contamination problems associated to the study of ancient archaeobotanical charred seeds suggest that the combination of a silica-based extraction method together with the amplification of specific targets is a good strategy for recovering endogenous ancient DNA from this kind of material.     

国徽中的图案是谷穗还是麦稻穗

目前关于中华人民共和国的国徽图案有这样两种说法:一是国徽上的图案是谷穗,如《辞海》中指出:中华人民共和国国徽,中间是五星照耀下的天安门,周围是谷穗和齿轮。一是国徽上的图案是麦稻穗,如蒋建华主编的《中华人民共和国资料手册》中指出:中华人民共和国国徽的内容为国旗、天安门、齿轮和麦稻穗。那么,国徽上的图案到底是谷穗还是麦稻穗呢?     

Genetic analysis of wheat landraces enables the location of the first agricultural sites in Italy to be identified

We typed five microsatellite loci in 52 landraces of Italian emmer wheat to determine if genetic analysis of cereals can provide information relevant to the spread of agriculture. Each of the five loci was polymorphic with 43 allele combinations identified in the 52 landraces. The allele combinations fell into two groups. Group 1 comprised 27 genotypes found in 42 landraces and Group 2 comprised 15 genotypes found in 10 landraces. The landraces with Group 1 genotypes showed a strong correlation between geographical and genetic distances (r = 0.601, p < 0.001) but those with Group 2 genotypes did not (r = 0.116, p = 0.244). We inferred that the Group 1 landraces might therefore retain a phylogeographical structure that reflects ancient events. We present a phylogeographical model for the spread of agriculture that enables the point of origin of crop cultivation to be predicted by comparison between the genetic and geographical distances between landraces. We applied this model to the Group 1 landraces by positioning 131 hypothetical points of origin around the coastline and northern border of Italy. The highest correlation coefficients between genetic and geographical distances were seen for hypothetical points of origin located on the coast of northern Puglia. We repeated the analysis with 1040 hypothetical points of origin located within the Italian peninsula. Again, the highest correlation coefficients were located in northern Puglia. These predicted points of origin correspond with the location of the earliest agricultural sites in Italy. The results show that plant genetics can be used to study the spread of agriculture.     

Going Against the Grain: Why Do Canada and the United States Market Wheat So Differently?

At the turn of the twentieth century, private grain exchanges settled the daily prices for North American wheat. By the end of the Second World War, the Canadian and US governments had intervened significantly in these markets. The Canadian government required farmers in its western provinces to deliver their product to the Canadian Wheat Board (CWB), a single-selling-desk agency that, by then, had supplanted private wheat marketing in western Canada. Meanwhile, the United States government subsidized farm incomes with domestic-use taxes and import tariffs, but otherwise preserved private wheat marketing. In this article, I demonstrate that these disparate agricultural policies were broadly defined by immutable economic realities imposed on each country by global wheat-trade patterns and triggered by unprecedentedly severe agricultural crises. That is, amidst the precipitous fall in wheat prices in the early 1930s, each government crafted farm-support policies that reflected its domestic-consumption share of wheat production and the importance of wheat to its overall economy.     

Patterns and Determinants of Historical Woodland Clearing in Central‐Western New South Wales,Australia

We consider the history of woodland clearing in central western New South Wales, Australia, which has led to the present highly cleared and fragmented landscape. A combined approach is used examining available historical land‐use data and using regression analysis to relate the pattern of cleared and wooded areas in the recent landscape to environmental variables, taking into account the contagious nature of clearing. We also ask whether it would be possible to apply a simple simulation modelling approach to reconstruct a credible historical sequence of clearing in the study area. The historical data indicate that annual clearing rates have varied substantially in the study area and selective tree removal (ringbarking and thinning) has been common. These findings make it unlikely that a simple simulation approach would replicate the spatial and temporal sequence of woodland loss. Our regression results show that clearing patterns can be related to environmental variables, particularly annual rainfall and estimated pre‐European vegetation type, but that patterns are dominated by contagion.     

应用EVA热熔胶膜法加固黄缎绣双龙团扇

清代文物黄缎绣双龙团扇外圈织物已经糟朽,修复保护研究中使用的传统黏结材料无法满足加固后的外圈织物需缝合、打褶等特殊需求。将EVA 热熔胶膜应用于此件文物的修复,并对EVA膜加固后织物的拉断、剥离强度和撕裂度等项物理指标进行了测试。测试结果符合要求,修复效果令人满意。     

论西汉中后期冬小麦在关中的推广

在农业发展史上,任何农作物的推广与普及,都离不开适合该作物生长的自然环境,但同时也需要技术与社会条件的推动。西汉中后期冬小麦之所以能在关中地区获得推广,不仅仅因为其具有高产、旱作的特性,还在于它适应了当时关中农业发展的需要,以及防旱保墒技术的完善对其推广过程中技术问题的解决。     

Early Processed Triticeae Food Remains in The Yanghai Tombs,Xinjiang, China

Visible food remains can provide evidence regarding ancient food processing, the spread of cereals and cultural communication. Some desiccated food remains were discovered in the Yanghai Tombs, Turpan district, in Xinjiang, China (2600–2900 bp ). These food remains were analysed by Fourier transform infrared (FT–IR) spectroscopy combined with plant microfossils, including starch grains and cross cells of pericarp from the cereal bran fragments. The results showed that these food remains were cooked dough food made from wheat (Triticum aestivum) and barley (Hordeum spp.). The cross‐sections of these remains look very dense, not porous under a microscope, which suggests that no fermentation had happened, so these foodstuffs may be some kind of flatbread. Although wheat and barley had been introduced into China by at least the third millennium bc , these remains are still the earliest known direct evidence that wheat and barley were ground into flour and then processed as foodstuffs in north‐western China.