Abstract
Genetic shifts are predicted to be greatest when highly diversematerial originating from an arid environment is bulk multiplied inirrigated and fertilised conditions. This is a key problem if largequantities of quality native seed are needed for restorationpurposes. In Presaharian Tunisia, we investigated two intermingledyield aspects of irrigated seed multiplication of Stipalagascae R. and Sch.: (1) nitrogen fertilisationand (2) selection for vegetative vigour. We set up twocontiguous nitrogen fertilisation trials, one withnon-selected seeds (from a nearby locality), and onewith selected seeds (48 clonal lines seeded in replicatedrows), and compared straw yields. Both selected and unselectedmaterial did not respond to more than 50 kg of nitrogenper ha. Unfertilised yields of both trials were similar,but the straw yield of fertilised selected material was more than100% higher than the straw yield of fertilised unselectedmaterial. In the trial with selected material, we collected straw andleaf yields per row, and scored each row for vigour and for phenologyduring three successive growing seasons. Genotypic differences inseed output and in mortality were large and mainly driven byvariation in potential straw for leaf ratios.The compromise between high yields and high genetic variation couldconsist of the following principles. (1) Create driergrowing conditions so that the actual straw forleaf ratio stays below the genotypic potential. (2) Useinstead fertilisation and selection to enhance seed yields.(3) Avoid bulk multiplication.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Aamlid T.S., Heide O.M., Christie B.R. and McGraw R.L. 1997. Reproductive development and the establishment of potential seed yield in grasses and legumes. In: Fairey D.T. and Hampton J.G. (eds), Forage Seed Production 1, Temperate Species. CAB International, Oxon, New York, pp. 9–44.
Ahring R.M., Taliaferro C.M. and Morrison R.D. 1974. Seed production of several strains and hybrids of bermudagrass, Cynodon dactylon (L.) Pers. Crop Science 14: 93–95.
Apfelbaum S.I., Bader B.J., Faessler F. and Mahler D. 1997. Obtaining and processing seeds. In: Packard S. and Mutel C.F. (eds), The Tallgrass Restoration Handbook for Prairies, Savan-nas and Woodlands. Island Press, Washington, DC, pp. 99–126.
Black A.L. and Reitz L.L. 1969. Row spacing and fertilisation influences on forage and seed yields of intermediate wheatgrass, Russian wildrye and green needlegrass on dryland. Agronomy Journal 61: 801–805.
Elgersma A. and van Wijk A.J.P. 1997. Breeding for higher seed yields in grasses and forage legumes. In: Fairey D.T. and Hampton J.G. (eds), Forage Seed Production 1, Temperate Species. CAB International, Oxon, New York, pp. 243–272.
Ewing M.A. 1999. Annual pasture legumes: a vital component stabilizing and rehabilitating low-rainfall Mediterranean eco-systems. Arid Soil Research and Rehabilitation 13: 327–342.
Floret C. and Pontanier R. 1982. L'aridité en Tunisie Présaharienne. ORSTOM, Paris, France.
Franois L.E. and Maas E.V. 1994. Crop response and management on salt-affected soils. In: Pessarakli M.P. (ed.), Handbook of Plant and Crop Stress. Marcel Dekker Inc., New York, pp. 149–181.
Gates R.N. and Burton G.W. 1998. Seed yield and seed quality response of Pensacola and improved Bahiagrasses to fertilisation. Agronomy Journal 90: 607–611.
Gomez K.A. and Gomez A.A. 1984. Statistical Procedures for Agricultural Research. John Wiley & Sons, Singapore, The Philippines.
Gordon D.R. and Rice K.J. 1998. Patterns of differentiation in wiregrass (Aristida beyrichiana): implications for restoration efforts. Restoration Ecology 6: 166–174.
Griffiths D.J., Lewis J. and Bean E.W. 1980. Problems of breeding for seed production in grasses. In: Hebbletwaithe P.D. (ed.), Seed Production. Butterworths, London, Boston, pp. 37–49.
Haase P., Pugnaire F.I. and Incoll L.D. 1995. Seed production and dispersal in the semi-arid tussock grass Stipa tenacissima L. during masting. Journal of Arid Environments 31: 55–65.
Hampton J.C. and Fairey D.T. 1997. Components of seed yield in grasses and legumes. In: Fairey D.T. and Hampton J.G. (eds), Forage Seed Production 1, Temperate Species. CAB International, Oxon, New York, pp. 45–69.
Kassel P.C., Mullen R.E. and Bailey T.B. 1985. Seed yield response of three switchgrass cultivars for different manage-ment practices. Agronomy Journal 77: 214–218.
Knapp E.E. and Dyer A.R. 1998. When do genetic considerations require special approaches to ecological restoration? In: Fiedler P.L. and Kareiva P. (eds), Conservation Biology, 2E: For the Coming Decade. Chapman and Hall, New York, pp. 345–363.
Le Floc'h E., Neffati M., Chaïeb M. and Pontainer R. 1995. Un essai de réhabilitation en zone aride. Le cas de Menzel Habib (Tunisie). In: Pontainer R., M'Hiri A., Aronson J., Akrimi N. and Le Floc'h E. (eds), L'homme peut-il refaire ce qu'il a défait? John Libbey Eurotext, Paris, pp. 139–160.
Rolston M.P., Rowarth J.S., Young W.C. III and Mueller-Warrant G.W. 1997. Grass seed crop management. In: Fairey D.T. and Hampton J.G. (eds), Forage Seed Production 1, Temperate Species. CAB International, Oxon, New York, pp. 105–126.
Sokal R.R. and Rohlf F.J. 1981. Biometry. 2nd edn. W. H. Freeman and Company, San Francisco.
Visser M., Nasr N. and Zaâfouri M.S. 1997. Quelle recherche en écologie (agro)pastorale face aux mutations agraires en Tunisie aride? In: Bourbouze A., Msika B., Nasr N. and Zaâfouri M.S. (eds), Pastoralisme et foncier: Impact du régime foncier sur la gestion de l'espace pastoral et la conduite des troupeaux en régions arides et semi-arides. CIHEAM/IRA, Montpellier, France, pp. 227–251.
Warringa J.W. and Marinissen M.J. 1996. The effect of light intensity after anthesis on dry matter distribution and seed yield of Lolium perenne L. Grass and Forage Science 1996: 103–110.
White L.M., Cooper C.S. and Brown J.H. 1972. Nitrogen fertilisa tion and clipping effects on green needlegrass (Stipa viridula Trin.): Development, growth, yield and quality. Agronomy Journal 64: 328–331.
Young W.C. III, Chilcote D.O. and Youngberg H.W. 1999. Spring applied nitrogen and productivity of cool-season grass seed crops. Agronomy Journal 91: 339–343.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Visser, M., Reheul, D. Producing native seed of Stipa lagascae R. and Sch. inPresaharian Tunisia: high yields, high genetic variation orboth?. Genetic Resources and Crop Evolution 49, 583–598 (2002). https://doi.org/10.1023/A:1021298521846
Issue Date:
DOI: https://doi.org/10.1023/A:1021298521846