Summary
Samples of approximately 100 plants from each of 22 populations ofLolium perenne representing 15 cultivars, and from 13 populations ofLolium multiflorum representing six cultivars were scored for iso-zyme variants in five enzyme systems, PGI, GOT, ACP, PGM and 6-PGD. From the individual banding patterns a genetic interpretation of the variation was formulated and population studies of the resulting six polymorphic enzyme loci were performed. No strong indications of partial selfing was found since at four of the six loci,Pgi 2, Got 3, Pgm 1 andPgd 1, the genotypic proportions were in correspondence with the Hardy-Weinberg expectations. This indicated, further, that the genetical interpretations of the banding patterns might be correct. Deviations from Hardy-Weinberg proportions forAcp 1 andGot 2 indicated presumably selection working on the linkage group including these loci. Gametic phase disequilibrium was observed betweenPgi 2 andPgd 1 for populations of one cultivar. These results were discussed in relation to the variation expected within a cultivar.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Allard RW, Kahler AL, Clegg MT (1977) Estimation of mating cycle components of selection in plants. In: Christiansen FB, Fenchel TM (eds) Measuring selection in natural populations. Springer, Berlin Heidelberg New York, pp 81–90
Bishop YMM, Fienberg SE, Holland PW (1980) Discrete multivariate analysis: theory and practice. MIT Press, Cambridge (Mass) London
Brown AHD (1975) Sample sizes required to detect linkage disequilibrium between two or three loci. Theor Popul Biol 8:184–201
Brown AHD (1979) Enzyme polymorphism in plant populations. Theor Popul Biol 15:1–42
Cockerham CC, Weir BS (1977) Digenic descent measures for finite populations. Genet Res 30:121–147
Cornish MA, Hayward MD, Lawrence MJ (1980a) Self-incompatibility in ryegrass. 3. The joint segregation ofS andPgi-2 inLolium perenne L. Heredity 44:55–62
Cornish MA, Hayward MD, Lawrence MJ (1980b) Self-incompatibility in ryegrass. 4. Seed-set in diploidLolium perenne L. Heredity 44:333–340
Curie-Cohen M (1982) Estimates of inbreeding in a natural population: a comparison of sampling properties. Genetics 100:339–358
Elston RC, Forthofer R (1977) Testing for Hardy-Weinberg equilibrium in small samples. Biometrics 33:536–542
Fearon CH, Hayward MD, Lawrence MJ (1983) Self-incompatibility in ryegrass. 5. Genetic control, linkage and seed-set in diploidLolium multiflorum Lam. Heredity 50:35–45
Hayward MD, Gottlieb LD, McAdam NJ (1978) Survival of allozyme variants in swards ofLolium perenne L. Z Pflanzenzücht 81:228–234
Hayward MD, McAdam NJ (1977a) Genetic control of isoenzyme phenotypes inL. perenne. Rep Welsh Plant Breed Stn 1976:28–29
Hayward MD, McAdam NJ (1977b) Isozyme polymorphism as a measure of distinctiveness and stability in cultivars ofLolium perenne. Z Pflanzenzücht 79:59–68
Hayward MD, McAdam NJ, Balls T, Zaruk M (1979) The use of isozymes as genetic markers. Rep Welsh Plant Breed Stn 1978:47–48
Hill WG (1974) Estimation of linkage disequilibrium in randomly mating populations. Heredity 33:229–239
Kidd KK, Stone WH, Crimella C, Carenzi C, Casati M, Rognoni G (1980) Immunogenetic and population genetic analyses of Iberian cattle. Anim Blood Groups Biochem Genet 11:21–38
Larntz K (1978) Small-sample comparisons of exact levels for chi-squared goodness-of-fit statistis. J Am Stat Assoc 73:253–263
Lawrence MJ, Fearon CH, Cornish MA, Hayward MD (1983) The genetical control of self-incompatibility in ryegrass. Heredity 51:461–466
Lewis EJ, Humphreys MW, Caton MP (1980) Chromosome location of two isozyme loci inLolium perenne using primary trisomics. Theor Appl Genet 57:237–239
Nielsen G (1984) The use of isozymes as probes to identify and label plant varieties and cultivars. In: Rarrazzi MC, Scandalios JG, Whitt GS (eds) Isozymes: current topics in biological and medical research. Alan R Liss Inc, New York (in press)
Nielsen G, Østergaard H, Johansen H (1984) Cultivar identification by means of isoenzymes. 2. Genotypic variation at four enzyme loci in diploid ryegrass. Z Pflanzenzücht (in press)
Robbins RB (1918) Some applications of mathematics to breeding problems 3. Genetics 3:375–389
Rust PF (1972) On the estimation of gene frequencies through gene counting. Hum Hered 22:58–65
Scandalios JG (1969) Genetic control of multiple molecular forms of enzymes in plants — a review. Biochem Genet 3:37–79
Shaw DV, Allard RW (1982) Estimation of outcrossing rates in douglas-fir using isozyme markers. Theor Appl Genet 62:113–120
Ward RH, Sing CF (1970) A consideration of the power of theχ 2-test to detect inbreeding effects in natural populations. Am Nat 104:355–365
Weir BS (1979) Inferences about linkage disequilibrium. Biometrics 35:235–254
Author information
Authors and Affiliations
Additional information
Communicated by P. M. A. Tígerstedt
Rights and permissions
About this article
Cite this article
Østergaard, H., Nielsen, G. & Johansen, H. Genetic variation in cultivars of diploid ryegrass,Lolium perenne andL. multiflorum, at five enzyme systems. Theoret. Appl. Genetics 69, 409–421 (1985). https://doi.org/10.1007/BF00570911
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00570911