Agrobotanic characterization of Avena sativa germplasm collection at Plant Gene Resources of Canada

A. Diederichsen and D. J. Williams

Plant Gene Resources of Canada, Agriculture and Agri-Food Canada,

107 Science Place, Saskatoon, SK, S7N OX2, Canada

Introduction

Plant Gene Resources of Canada (PGRC) maintains a unique germplasm collection of the genus Avena L. with more than 27,000 accessions (Diederichsen et al., 2001). The four major groups are: cultivated hexaploid oat (Avena sativa L., including red oat, A. byzantina C. Koch, 11,380 accessions), animated oat (Avena sterilis L., 11,332 accessions), slender oat (A. barbata Pott ex Link, 2,020 accessions), and wild oat (A. fatua L., 579 accessions). A particular strength of the PGRC collection is the representation of 26 species of the genus Avena (Diederichsen et al. 2001), which are an important source of rare genes (Loskutov, 2001). In the early 1960’s, Canadian scientists began collecting oat germplasm in the Mediterranean area and in the Middle East (Baum et al., 1975; Baum, 1977). To increase the usefulness of the germplasm, PGRC initiated, in 1998, a project to rejuvenate and agrobotanically characterize the oat collection. This report gives examples for A. sativa characterization data using a few characters. The complete characterization data is in the process of being made available on the PGRC website (http://www.agr.gc.ca/pgrc-rpc).

Methods

In consultation with Canadian and international oat breeders, a descriptor list using phenological, morphological and agronomic characters was generated according to international genebank standards. Accessions of A. sativa were planted in the field in single rows at Saskatoon. Two Canadian oat cultivars (‘AC Assiniboia’ and ‘CDC Pacer’) were planted in several replications for data standardization.

Results and Discussion

Regeneration and characterization was completed for more than 10,000 accessions of cultivated hexaploid oat (A. sativa) and seeds are available for distribution. Orders can be made by mail or via Internet (http://www.agr.gc.ca/pgrc-rpc). The phenotypic characterization is useful to structure the wide range of diversity, because single character expressions and combinations of character expressions can be used to define certain phenotypic groups within the species. One example in this direction is the distinction between hulled and hulless oat. This is important for targeted access to the germplasm collection by genebank clients. Examples of panicle and grain characteristics are shown in Table 1 and Figure 1.

Table 1. Selected panicle characters and their frequencies in the PGRC A. sativa collection

Panicle character	Class	Absolute frequency	Relative frequency (%)
Panicle type	equilateral	7,900	77.7
	intermediate	1,982	19.5
	unilateral	284	2.8
	Total	10,166
Panicle erectness	drooping	1,377	13.6
	semi-erect	7,439	73.2
	erect	1,350	13.3
	Total	10,166
Panicle density	lax	628	6.2
	intermediate	8,862	87.2
	dense	675	6.6
	Total	10,165

The lemma colour has a wide range from black to nearly white and the panicle can vary considerably in shape. Some character expressions are rare and it is important to preserve such germplasm. A character like the lemma colour is a phenotypic genetic marker and its expression is relatively independent from environmental influences. Other characters, for example, plant height, are strongly influenced by environment and data standardization to reduce year effects is needed.

Conclusions

The characterization data increase the usefulness of the PGRC oat collection for plant breeders and other scientists. The data are also useful for scientific investigations of infra-generic and infra-specific diversity. The agrobotanic characterization of A. sativa germplasm will be completed in 2003. Detailed data analysis, including character correlations and geographic relations, will be conducted. This project represents a major contribution to international efforts to preserve the genetic diversity of agricultural crops and their wild relatives. Molecular characterization of selected groups of the PGRC Avena collection has been initiated (Dr. Y. B. Fu) and will contribute to a better understanding of the genetic diversity in cultivated and wild oat.

Collaboration

Collaboration with oat pathologists at the Cereal Research Centre, Agriculture and Agri-Food Canada, Winnipeg, Manitoba, is ongoing (for details see Diederichsen et al., 2001). In 2001 PGRC received results for stem rust resistance screening conducted by Drs. T. Fetch and J. Gold for 6,800 accessions.

Germplasm rejuvenation was supported by Dr. B. Rossnagel, Crop Development Centre, University of Saskatchewan, Saskatoon.

PGRC received 79 accessions of Avena sativa (incl. A. byzantina) landraces from the N. I. Vavilov All Russian Research Institute for Plant Industry (VIR) through collaboration with Dr. I. Loskutov, St. Petersburg, Russia.

Acknowledgements

Funding for this project was provided by: Agricultural Development Fund Saskatchewan, Quaker Oats Company of Canada Ltd., Can-Oat Milling Products, Emerson Milling, Inc., and the Matching Investment Initiative, Agriculture and Agri-Food Canada. The cooperation of Dr. B. Rossnagel, University of Saskatchewan, is greatly appreciated.

References

Baum, B. R., 1977: Oats: wild and cultivated, a monograph of the genus Avena L. (Poaceae). Canada Department of Agriculture, Ottawa.

Baum, B. R., T. Rajhaty, J. W. Martens and H. Thomas, 1975: Wild oat genepool, a collection maintained by the Canada Department of Agriculture. Canada Department of Agricutlture, Ottawa.

Diederichsen, A., E. Timmermans, D. J. Williams, and K. W. Richards, 2001: Holdings of Avena germplasm at Plant Gene Resources of Canada and status of the collection. Oat Newsletter 47, 35-42. (http://wheat.pw.usda.gov/ggpages/oatnewsletter/v47/ - PGR).

Loskutov, I. G., 2001: [Interspecific crosses in the genus Avena L.]. (Russ.). Genetika (Moskva) 37, 581-590.