PDF《Tansley review》

Tansley review Patterns and processes in crop domestication: an historical review and quantitative analysis of

203 global food crops Author for correspondence: Helen Jensen Tel: +1

514 425

3540 Email: helen.

[email protected] Received:

13 May

2012 Accepted:

15 June

2012 Rachel S. Meyer1,2 *, Ashley E. DuVal3 * and Helen R. Jensen4 *

1 The New York Botanical Garden, Science Division, Bronx, NY 10458, USA;

2 The Graduate Center, City University of New York, Biology Program,

365 Fifth Ave, New York, NY 10016, USA;

3 Yale University, School of Forestry and Environmental Studies,

195 Prospect Street, New Haven, CT 06511, USA;

4 McGill University, Department of Biology,

1205 Dr Pen?eld Avenue, Montreal, QC, Canada H3A 1B1 New Phytologist (2012) 196: 29C48 doi: 10.1111/j.1469-8137.2012.04253.x Key words: center of origin, conservation, domestication, domestication syndrome, ethnobotanical uses, food crops, life history, selection. Summary Domesticated food crops are derived from a phylogenetically diverse assemblage of wild ancestors through arti?cial selection for different traits. Our understanding of domestication, however, is based upon a subset of well-studied '

model'

crops, many of them from the Poa- ceae family. Here, we investigate domestication traits and theories using a broader range of crops. We reviewed domestication information (e.g. center of domestication, plant traits, wild ancestors, domestication dates, domestication traits, early and current uses) for

203 major and minor food crops. Compiled data were used to test classic and contemporary theories in crop domestication. Many typical features of domestication associated with model crops, including changes in ploidy level, loss of shattering, multiple origins, and domestication outside the native range, are less common within this broader dataset. In addition, there are strong spatial and temporal trends in our dataset. The overall time required to domesticate a species has decreased since the earliest domestication events. The frequencies of some domestication syndrome traits (e.g. nonshattering) have decreased over time, while others (e.g. changes to secondary metabolites) have increased. We discuss the in?uences of the ecological, evolutionary, cultural and technological factors that make domestication a dynamic and ongoing process. Contents Summary

29 I. Introduction

30 II. Key concepts and de?nitions

30 III. Methods of review and analysis

35 IV. Trends identi?ed from the review of

203 crops

37 V. Life cycle

38 VI. Ploidy level

40 VII. Reproductive strategies

42 VIII. The domestication syndrome

42 IX. Spatial and temporal trends

42 X. Utilization of plant parts

44 XI. Conclusions

44 Acknowledgements

45 References

45 *These authors contributed equally to this work. Review ?

2012 The Authors New Phytologist ?

2012 New Phytologist Trust New Phytologist (2012) 196: 29C48

29 www.newphytologist.com I. Introduction It is estimated that

2500 plant species have undergone domes- tication worldwide, with over

160 families contributing one or more crop species (Zeven &

de Wit, 1982;

Dirzo &

Raven, 2003). Much of our understanding of the processes driving domestication comes from a subset of well-studied crops, particularly crops of major economic importance and model crops (i.e. crops that have had their genomes analyzed and are transformable). These crops have been critical for developing our fundamental understanding of domestication as a continuum of ongoing processes. In particular, they have been critical for revealing the underlying genetic mechanisms responsible for the suite of phenotypic changes associated with domestication that comprise the domestication syndrome. They have also contributed to our knowledge of useful crop breeding traits, such as pathogen resistance, and of fundamen- tal biological processes, such as polyploidization. However, information on such well-studied crops contributes dispropor- tionately to the literature on domestication. In order to explore global trends and historical patterns in domestication, large datasets are required that consider a broad selection of species, including understudied crops and crops of minor eco- nomic importance, in addition to well-studied major global crops. Often, the data relevant to the history of use, selection and domestication of a particular crop are scattered across the literature of diverse disciplines. For many minor food plants, information relevant to domestication history may be dif?cult to access, if it is available at all. Most reviews have not included all the major agricultural regions but rather have concentrated on regional subsets of crops (Duke &