增刊 章元明等：大豆地方品种种质保持中适宜样本容量的研究 分 8 Frankel O H,E Bennett.Genetic resource in plants:their exploration and conservation.Blackwall,Oxford.1970 9 Frankel O H,J G Hawkes.Crop genetie resource for today and tomorrow.Cambridge univ.Press.1975 10 Fraser A S.Simulation of genetic system by automatic digital computers.Austranlin J.Biol.Sci.1957,10:484~491 11 Omolo E,W A Russell.Genetic effects of population size in the reproduction of two heterogeneous maize populations.lowa State J.Sci.1971,45:449-512 12 Yonezawa K.A definition of optimal allocation of effort in conservation of plant genetic resource with application to sample size determination for yield collect.Euphytica.1985,34:345~354 A STUDY ON SUITABLE SAMPLE SIZE IN THE CONSERVATION OF LANDRACE OF SOYBEANS Zhang Yuanming Gai Junyi (Soybean Reseurch Institde,Nanjing Agricultral Linersity,Nanjing 210095) ABSTRACT Mixtures of a yellow-seeded and a green-seeded (marker genotype)soybean cultivars were used to imitate soybean landraces composing of two homozygous genotypes.Five populations with frequencies of marker genotype 0.5,0.3,0.1,0.05 and 0.01,respectively for each of two cultivar pairs were formed.To confirm the results from the field experiments,the Monte Carlo computer simulation was carried out.The suitable sample size varied with the frequency of marker genotype,and a sample size with 250~330 seeds for planting,and 150~200 plants in the field could fit most of the situation of the tested frequencies of marker genotype except the frequency of rare genotype was too small,for example 0.01 or less.The variation of marker genotype frequency and the frequency of extinction of a marker genotype increased with the advance of generation.In addition,the purity of a germplasm was disturbed due to the introduction of offtypes,which was getting more serious with the advance of generation. Key words:Soybean;Germplasm conservation;Suitable sample size;Monte Carlo simulation 1994-2009 China Academic Journal Electronic Publishing House.All rights reserved.hup:/ww.cnkinet© 1994-2009 China Academic Journal Electronic Publishing House. All rights reserved. http://www.cnki.net