Contents
Abstract and Acknowledgments
List of tables and figures
The Importance of Wheat Genetic Diversity in the People's Republic of China
Indicators of Genetic Diversity
How biological and social scientists measure gentic diversity
Indicators used in this study and data limitations
The Scope of Wheat Production in China
Evolution of Varieties Grown in Farmers' Fields
Spatial and Temporal Indicators of Genetic Diversity in Farmers' Fields, 1982-1993
Landrace Characteristics and Genetic Contributions to Modern Varieties
General characteristics of Chinese landraces and their use
Major progenitors, their characteristics and descendants
Other important wheat forms and genes
Use of Exotic Germplasm in China
Major introduced cultivars
Semi-dwarf materials
Conclusions
References
New Papers from the Natural Resources Group

Abstract

A preliminary study of wheat genetic diversity in the People's Republic of China is presented. Available evidence and basic data related to the ancestry of leading wheat cultivars and the area distribution of dominant cultivars in farmers' fields are summarized. These data are used to generate some preliminary hypotheses regarding wheat genetic diversity and post-reform patterns of varietal distribution. Evidence from secondary sources and the visual inspection of pedigrees from key lines suggests that the influence of domestic landraces in the gene pool of modern Chinese wheat cultivars may be less important than expected and that the influence of foreign germplasm may be correspondingly more important. Linkages between China's modern wheats and the ancestors of major lines grown in other parts of the world are explored, as are changes in spatial and temporal diversity. Unique Chinese wheat forms that may be important to national and global genetic diversity are discussed.

Acknowledgements

The authors gratefully acknowledge the assistance of Yuan Renjin, Pedro Aquino, and Victor Hernandez. The authors acknowledge as well the reviews of Wei-Ping Lu, Hu Xueyi, Dana Dalrymple, Sanjaya Rajaram, Maarten van Ginkel, and Paul Heisey.

Tables

Table 1. Wheat area, production and yield in China, by province, 1993
Table 2. Characteristics of Chinese cultivars in the 1950s and 1970s
Table 3. Wheat releases most widely grown in China, early 1950s
Table 4. Wheat releases most widely grown in China, late 1950s
Table 5. Wheat releases most widely grown in China, 1960s
Table 6. Wheat releases most widely grown in China, 1970s
Table 7. Wheat releases most widely grown in China, late 1980s to early 1990s
Table 8. Average plant height and weight of major cultivars grown in Shanxi Province, 1950s-1980s
Table 9. Number of wheat cultivars by area planted, China, 1982-1990, 1993
Table 10. The five most widely grown cultivars in China, 1982-1990, 1993
Table 11. Percent of wheat area planted to the top five cultivars in ten major wheat- producing provinces of China, 1982-1990, 1993
Table 12. Major landrace progenitors of modern Chinese wheats and their characteristics
Table 13. Some special Chinese wheat forms
Table 14. Percentage distribution of Chinese landraces by level of crossing ability
Table 15. "Centroparents" in Chinese wheats, their origin and number of progeny
Table 16. Genealogical profile of the top ten cultivars in Zone II, China, 1980s and early 1990s
Table 17. Major parents of 170 Chinese semi-dwarf accessions (70-80 cm)
Table 18. Major parents of 70 Chinese dwarf accessions (shorter than 70 cm)

Figures
Figure 1. Wheat yields in China, 1951-1994
Figure 2. China's wheat production zones
Figure 3. Cultivar concentration in China, ten major wheat-producing provinces
Figure 4. Cultivar concentraion in Pakistan, India, and China
Figure 5. Diffusion paths of China's most popular wheats, 1982-1993
Figure 6. Temporal diversity of Chinese wheats, ten major wheat-producing provinces

© CIMMYT October 1997

* At the time this work was conducted, Ning Yang was a CIMMYT intern and a student at Clemson University. Melinda Smale is a CIMMYT economist. The views expressed in this paper are the authors' and may not necessarily reflect CIMMYT policy.