Journal ArticleDOI
Dimensions of Diversity in Modern Spring Bread Wheat in Developing Countries from 1965
Melinda Smale,Matthew P. Reynolds,Marilyn L. Warburton,B. Skovmand,Richard Trethowan,Ravi P. Singh,Ivan Ortiz-Monasterio,José Crossa +7 more
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TLDR
The hypothesis of increasing genetic uniformity in modern spring bread wheat (Triticum aestivum L.) cultivars from 1965 is tested by assessing changes in the diversity of leading progenitors over three decades, in terms of several dimensions of diversity.Abstract:
Diverse and varied crop genetic resources are necessary (though not sufficient) for adequate food production in a rapidly changing world. Since the scientific community first raised public concern several decades ago, modern cultivars have been viewed as the cause of declining diversity in the world's crop genetic resources. This paper tests the hypothesis of increasing genetic uniformity in modern spring bread wheat (Triticum aestivum L.) cultivars from 1965, a year which marks the release of some of the first modern semidwarf cultivars carrying Rht1 and Rht2 genes in the developing world. Results from previously published studies are summarized. Preliminary molecular analyses, and new analyses of cultivar numbers, areas, ages, and genealogies are presented. An estimated 77% of the spring bread wheat area in the developing world today is sown to CIMMYT-related wheats, but this does not imply that they are genetically uniform. The hypothesis of increasing genetic uniformity is tested by assessing changes in the diversity of leading progenitors over three decades, in terms of several dimensions of diversity. Latent dimensions include genetic distance and genealogies. Apparent dimensions include performance with respect to yield potential, maintenance and stability across management (input use), and growing environments. The data are not consistent with the view that the genetic diversity of modern semidwarf wheat grown in the developing world has decreased over time. Moreover, since national programs in developing countries cross CIMMYT lines with their own materials before releasing them, the genetic diversity in their cultivars is at least as great as that present among CIMMYT lines.read more
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Book ChapterDOI
The Contribution of Breeding to Yield Advances in maize (Zea mays L.)
TL;DR: Maize (Zea mays L.) yields have risen continually wherever hybrid maize has been adopted, starting in the U.S. corn belt in the early 1930s, and genetic gains may have to bear a larger share of the load in future years.
Journal ArticleDOI
Achieving yield gains in wheat.
Matthew P. Reynolds,John Foulkes,Robert T. Furbank,Simon Griffiths,Julie King,Erik H. Murchie,Martin A. J. Parry,Gustavo A. Slafer +7 more
TL;DR: Crop development should favour spike fertility to maximize harvest index so phenology must be tailored to different photoperiods, and sensitivity to unpredictable weather must be modulated to reduce conservative responses that reduce harvest index.
Journal ArticleDOI
Wheat genetic diversity trends during domestication and breeding
Jochen C. Reif,P. Zhang,S. Dreisigacker,Marilyn L. Warburton,M. Van Ginkel,David Hoisington,Martin O. Bohn,Albrecht E. Melchinger +7 more
TL;DR: The results indicate that breeders averted the narrowing of the wheat germplasm base and subsequently increased the genetic diversity through the introgression of novel materials.
Journal ArticleDOI
Dissecting a wheat QTL for yield present in a range of environments: from the QTL to candidate genes
Steve Quarrie,S. Pekic Quarrie,Radenko Radošević,Dragana Rančić,A Kaminska,Jeremy Barnes,M Leverington,Carla Ceoloni,Dejan Dodig +8 more
TL;DR: Comparisons with rice identified AINTEGUMENTA and G-protein subunit genes affecting lateral cell division at locations homologous to the wheat 7AL yield QTL, and it is likely that the yield gene(s) on 7AL affects plant productivity.
Journal ArticleDOI
Genetic erosion in crops: concept, research results and challenges.
TL;DR: The different approaches in the recent literature to measure genetic erosion in crops are reviewed and the most likely scenario of diversity trends during modernization is a reduction in diversity due to the replacement of landraces by modern cultivars, but no further reduction after this replacement has been completed.
References
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Journal ArticleDOI
AFLP: a new technique for DNA fingerprinting.
Pieter Vos,René Cornelis Josephus Hogers,Marjo Bleeker,Martin Reijans,Theo van de Lee,Miranda Hornes,Adrie Friters,Jerina Pot,Johan Paleman,Martin Kuiper,Marc Zabeau +10 more
TL;DR: The AFLP technique provides a novel and very powerful DNA fingerprinting technique for DNAs of any origin or complexity that allows the specific co-amplification of high numbers of restriction fragments.
Journal ArticleDOI
Ribosomal DNA spacer-length polymorphisms in barley: mendelian inheritance, chromosomal location, and population dynamics.
TL;DR: It is concluded that the rDNA sl variants and/or associated loci are under selection in CCII, which demonstrates that Rrn1 and Rrn2 are useful as new genetic markers.
Journal ArticleDOI
Coefficients of Inbreeding and Relationship
TL;DR: The importance of having a coefficient by means of which the degree of inbreeding may be expressed has been brought out by Pearl' in a number of papers published between 1913 and 1917.
Journal ArticleDOI
Abundance, variability and chromosomal location of microsatellites in wheat.
Marion S. Röder,Jens Plaschke,Susanne U. König,Andreas Börner,Mark E. Sorrells,Steven D. Tanksley,Martin W. Ganal +6 more
TL;DR: It was found that wheat microsatellites are relatively long containing up to 40 dinucleotide repeats, and more variation was detected with the micros satellite markers than with RFLP markers with, on average, 4.6 different alleles per microsatellite.
Journal ArticleDOI
Physiological and Morphological Traits Associated with Spring Wheat Yield Under Hot, Irrigated Conditions
TL;DR: Sixteen spring wheat genotypes were grown under hot, irrigated, low latitude conditions, during the 1990-1991 and 1991-1992 winter cropping cycles in Mexico, Egypt, India and the Sudan, and in the 1990 and 1991 winter cycles in Brazil.