Response to selection with restrictions while considering effective family number

Response to restricted selection (genetic gain) from unrelated families was studied as a function of effective family number. The restrictions applied were maximum limits on the number of families among which selections are allocated, or on the number of individuals selected from a family. Numerical results were calculated for large normally-distributed populations. Effects of different selection methods, selection intensities, restriction intensities, and heritability are demonstrated. Selection with restrictions is a handy alternative for tradeoff between gain and effective number. Restricted phenotypic selection seemed favourable when both gain and effective number are desirable. Optimal-index selection without restriction or with low intensity of restriction on the contributions of families was proposed to produce maximum gain if low effective number is tolerable. The conclusions were verified for a real material.