Abstract
Three experimental breeding populations, created by pooling four to five natural populations of perennial ryegrass, were used to indicate the effect of samphng and pooling on the retention of genetic variation. Conservation of allelic multiplicity and genotypic frequencies was observed using allelic frequencies measured on six isozyme markers. We observed that by bulking four or five natural populations, represented respectively by 25 or 20 plants, in a large polycross design, the allelic and genotypic frequencies of the original mother-plants were conserved. There was no loss of rare alleles (0.01<p<0.10) in the three experimental populations compared with the original natural populations. Only very rare alleles (p<0.01) were reduced in frequency or lost. The value of such a bulking approach is discussed and presented as a possible alternative to the core collection approach to the management and use of genetic resources of perennial ryegrass.
Similar content being viewed by others
Article PDF
References
Allard, R W. 1992. Reproductive systems and dynamic management of genetic resources. In: Datte, Y., Dumas, C. & Gaflais, A. (eds) Reproductive Biology and Plant Breeding, pp. 325–344. Springer, Berlin.
Balfourier, F, and Charmet, G. 1991. Relationships between agronomic characters and ecogeographical factors in the collection of French perennial ryegrass populations. Agronomie, 11, 645–657.
Balfourier, F, and Charmet, G. 1994. Etude méthodologique de la conservation de ressources génétiques de ray grass anglais par multiplication en pools de populations naturelles. Génét Sél Évol. (in press).
Bonnell, M L, and Selander, R K. 1974. Elephant seals: genetic variation and near extinction. Science, 184, 908–909.
Bray, R A. 1983. Strategies for gene maintenance. In: Mclvor J. G. and Bray R. A. (eds) Genetic Resources of Forage Plants, pp. 157–168. CSIRO Melbourne.
Brown, A H D. 1978. Isozymes, plant population genetic structure and genetic conservation. Theor Appl Genet, 52, 145–157.
Buri, P. 1956. Gene frequency in small populations of mutant Drosophila. Evolution, 10, 367–402.
Charmet, G, Balfourier, E, and Bion, A. 1990. Agronomic evaluation of a collection of French perennial ryegrass populations: multivariate classification using genotype × environment interactions. Agronomie, 10, 807–823.
Charmet, G, Balfourier, F, and Monestiez, P. 1994. Hierarchical clustering of perennial ryegrass populations with geographic contiguity constraint. Theor Appl Genet, 88, 42–48.
Charmet, G, Balfourier, F, and Ravel, C. 1993. Isozyme polymorphism and geographic differentiation in a collection of French perennial ryegrass populations. Genet Res Crop Evol, 40, 77–89.
Cornish, M A, Hayward, M D, and Lawrence, M J. 1979. Self-incompatibility in ryegrass. I. Genetic control in diploid Loliumperenne L. Heredity, 43, 95–106.
Efron, B. 1982. The jacknife, the bootstrap and other resampling plans. CBMS-NSF Regional Conference Series in Applied Mathematics No 38. Society for Industrial and Applied Mathematics, Philadelphia, PA.
Frankel, O H. 1984. Genetic perspectives in germplasm conservation. In: Arber, W., Llimensee, K., Peacock, W. J. and Starlinger, P. (eds) Genetic Manipulation: Impact on Man and Society, pp. 161–170. Cambridge University Press, Cambridge.
Gregorius, H-R. 1980. The probability of losing an allele when diploid genotypes are sampled. Biometrics, 36, 643–652.
Hayward, M D, and McAdam, N J. 1977. Isozyme polymorphism as a measure of distinctiveness and stability in cultivars of Lolium perenne. Z PflZücht, 79, 59–68.
Johnson, M S. 1988. Founder effects and geographic variation in the land snail Theba pisana. Heredity, 61, 133–142.
Kimura, M, and Crow, J F. 1964. The number of alleles that can be maintained in a finite population. Genetics, 49, 725–738.
Lallemand, J, Michaud, O, and Greneche, M. 1991. Electro-phoretical description of ryegrass varieties: a catalogue. Plant Varieties and Seeds, 4, 11–16.
Maruyama, T, and Fuerst, P A. 1985. Population bottlenecks and nonequilibrium models in population genetics. II. Number of alleles in a small population that was formed by a recent bottleneck. Genetics, 111, 675–689.
Nei, M. 1978. Estimation of average heterozygosity and genetic distance from a small number of individuals. Genetics, 89, 583–590.
Nei, M, Maruyama, T, and Chakraborty, R. 1975. The bottleneck effect and genetic variability in populations. Evolution, 29, 1–10.
Ostergaard, H, Nielsen, G, and Johansen, H. 1985. Genetic variation in cultivars of diploid ryegrass, Lolium perenne and L. multiflorum, at five enzyme systems. Theor Appl Genet, 69, 409–421.
Pollans, N O, and Allard, R W. 1985. Inheritance of electro-phoretically detectable variants in ryegrass. J Hered, 76, 61–62.
Pollans, N O, and Allard, R W. 1989. An experimental evaluation of the recovery potential of ryegrass populations from genetic stress resulting from restriction of population size. Evolution, 43, 1320–1324.
Sirkkomaa, S. 1983. Calculations on the decrease of genetic variation due to the founder effect. Hereditas, 99, 11–20.
Swofford, D L, and Selander, R B. 1981. BIOSYS-1: a Fortran Program for the comprehensive analysis of electrophoretic data in population genetics and systematics. J Hered, 72, 281–283.
Tyler, B F, Chorlton, K H, and Thomas, I D. 1984. Characterisation of collected Lolium perenne populations Report of the Welsh Plant Breeding Station 1983, Aberystwyth, UK, pp. 29–32.
Waples, R S. 1990. Conservation genetics of Pacific salmon. II. Effective population size and the rate of loss of genetic variability. J Hered, 81, 267–276.
Weibull, P, Ghatnekar, L, Frykman, I, and Bengtsson, B O. 1986. Electrophoretic variation in Festuca ovina L. Agric Hortique Genetica, 44, 25–37.
Wright, S, and Kerr, W E. 1954. Experimental studies of the distribution of gene frequencies in very small populations of Drosophila melanogaster. II. Bar. Evolution, 8, 225–240.
Yonezawa, K. 1985. A definition of the optimal allocation of effort in conservation of plant genetic resources, with application to sample size determination for field collection. Euphytica, 34, 345–354.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Balfourier, F., Charmet, G. & Grand-Ravel, C. Conservation of allelic multiplicity and genotypic frequency by pooling wild populations of perennial ryegrass. Heredity 73, 386–396 (1994). https://doi.org/10.1038/hdy.1994.186
Received:
Issue Date:
DOI: https://doi.org/10.1038/hdy.1994.186