Crop Genebank Knowledge Base

Articles

Chapter 22: Collecting vegetative material of forage grasses and legumes

J. Hanson
International Livestock Research Institute, Addis Ababa, Ethiopia
E-mail: j.hanson(at)cgiar.org

M. van de Wouw
Centre for Genetic Resources (CGN), Wageningen University and Research Centre, The Netherlands
E-mail: markvandewouw(at)yahoo.co.uk

	2011 version (0.3 MB)	1995 version (0.3 MB)
	Open the full chapter in PDF format by clicking on the icon above.

This chapter is a synthesis of new knowledge, procedures, best practices and references for collecting plant diversity since the publication of the 1995 volume Collecting Plant Diversity; Technical Guidelines, edited by Luigi Guarino, V. Ramanatha Rao and Robert Reid, and published by CAB International on behalf of the International Plant Genetic Resources Institute (IPGRI) (now Bioversity International), the Food and Agriculture Organization of the United Nations (FAO), the World Conservation Union (IUCN) and the United Nations Environment Programme (UNEP). The original text for Chapter 22: Collecting Vegetative Material of Forage Grasses and Legumes, authored by N. R. Sackville Hamilton and K. H. Chorlton, has been made available online courtesy of CABI. The 2011 update of the Technical Guidelines, edited by L. Guarino, V. Ramanatha Rao and E. Goldberg, has been made available courtesy of Bioversity International.

Please send any comments on this chapter using the Comments feature at the bottom of this page. If you wish to contribute new content or references on the subject please do so here.

Back to list of chapters on collecting

References for this chapter


	Different forage grasses and legumes in a field genebank. (Photo: ILRI)

Abstract

Recent literature on forage collection has focused on seed collection, site selection and sampling strategy. New approaches using ecogeographical information and GIS mapping techniques have improved site selection targeting, sampling design and capture of more representative diversity from natural populations.

Introduction

While the reasons outlined in the original chapter for collecting forage grasses and legumes remain valid, a review of current literature comes up with very few references that cover collecting methods for vegetative material of forage grasses and legumes. As mentioned in the original chapter, the collection of vegetative material poses problems related to sample size, speed and transport due to the weight and bulk of vegetative cuttings compared to seeds. In addition, vegetative samples require more careful handling to avoid damage to the material before reaching the home base. This has led most collectors to focus on seed collection whenever possible and to avoid vegetative material by carefully timing collections to coincide with peak seed ripeness before shattering. Vegetative collection is usually restricted to those cases where it is the only practical option, such as for grass species that rarely or never produce seeds or for fodder trees that might take many years to flower and seed or when material is urgently required.

Current status

Recent advances in forage collection have focused on the use of targeting to better identify the areas and timing for collection. For example, the use of modelled ecogeographic attributes has been applied to the collection of forage germplasm in Southern Russia (Hart et al. 1996; Greene et al. 1999). The strategy for this collection was to make decisions on area and taxa for collection using map analysis combined with observations to improve the efficiency and effectiveness of the sampling design. This approach allowed better targeting of sampling gradients across collection-site habitats in order to acquire forage germplasm adapted to a broad range of environmental conditions. It can be used for either vegetative or seed-producing species.

Several collections that have been made for forage legumes and grasses over the past 15 years have been reported in the Plant Genetic Resources Newsletter. The most recent of these are reports on collection of forage legumes in Greece (Shackle et al. 2001), Medicago in Kazakhstan (Greene et al. 2005), Centrosema, Stylosanthes and Desmodium in Venezuela (Guenni et al. 2006) and forage legumes and grasses in the Carpathian Mountains in Ukraine (Diederichsen et al. 2007). However, most have focused on seed collections, and the reports do not address collecting methodologies. Several do address the use of mapping and GIS to determine sampling strategy and site selection to maximize the capture of genetic diversity within target species. It is now common to use GIS datasets to identify areas with specific soil types or climatic conditions within the distributional range of a species in order to target specific collection sites with a high probability of finding genotypes with specific adaptations to edaphic factors, or to maximize landscape diversity in collections, as described in detail by Greene et al. (2005).

Future challenges/needs/gaps

The major challenge in the collection of forages as vegetative material is to find ways to use new developments in modified atmosphere packing to improve storage conditions during transport and to reduce the weight and bulk of cuttings but to still have sufficient material to increase survival rates during shipping back to base. If this challenge could be overcome, the advantages of collecting vegetative cuttings (which provide more rapid growth and establishment than seeds) could be realized.

Conclusions

Improved targeting using ecogeographical information and GIS mapping techniques have been applied to forage collection to improve sampling design and the capture of more representative diversity from natural populations. However, there have been few advances in the collecting methodology and practical methods of handling vegetative material in the field.

Back to list of chapters on collecting

References and further reading

Diederichsen A, Boguslavskij RL, Halan MS, Richards KW. 2007. Collecting plant genetic resources in the eastern Carpathian Mountains within the territory of Ukraine in 2005. Plant Genetic Resources Newsletter 151:14–21.

Greene SL, Hart TC, Afonin, A. 1999. Using geographic information to acquire wild crop germplasm for ex situ collections: I. Map development and field use. Crop Science 39:836-842.

Greene SL, Hannan R, Afonin A, Dzyubenko NI, Khusainov A. 2005. Collecting wild crop relatives in the northwestern steppes of Kazakhstan. Plant Genetic Resources Newsletter 141:1–6.

Guenni O, Calles T, Gil JL, Fariñas J, Rodríguez I, Espinoza F, Sanabria D, Schultze-Kraft R. 2006. Surveying and collecting native Centrosema, Stylosanthes, and Desmodium germplasm in Venezuela. Plant Genetic Resources Newsletter 148:38–43.

Hart TS, Greene SL, Afonin A. 1996. Mapping for germplasm collections: site selection and attribution. In: Proceedings of the Third International Conference on Integrating GIS and Environmental Modeling. National Center for Geographic Information and Analysis, Santa Barbara, CA. Available online (accessed 3 October 2011): www.ncgia.ucsb.edu/conf/SANTA_FE_CD-ROM/sf_papers/hart_thomas/thart.html.

Shackle HS, Bennett SJ, Snowball R, Samaras S, Francis C, Maxted N. 2001. The ecogeography and collection of forage legumes in the east Aegean Islands, Greece. Plant Genetic Resources Newsletter 128:55–63.

Back to top