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Variance Effective Population Size for Dioecious Species
Author(s) -
Vencovsky Roland,
Chaves Lázaro José,
Crossa José
Publication year - 2012
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2011.07.0360
Subject(s) - biology , population , sex ratio , representativeness heuristic , population size , offspring , reproduction , statistics , germplasm , accession , effective population size , evolutionary biology , demography , genetics , genetic variation , mathematics , botany , european union , pregnancy , sociology , gene , business , economic policy
The concept of effective population size ( N e ) is an important measure of representativeness in many areas. In this research, we consider the statistical properties of the number of contributed gametes under practical situations by adapting Crow and Denninston's (1988) N e formulas for dioecious species. Three sampling procedures were considered. In all circumstances, results show that as the offspring sex ratio ( r ) deviates from 0.5, N e values become smaller, and the efficiency of gametic control for increasing N e is reduced. For finite populations, where all individuals are potentially functional parents, the reduction in N e due to an unequal sex ratio can be compensated for through female gametic control when 0.28 ≤ r ≤ 0.72. This outcome is important when r is unknown. When only a fraction of the individuals in a population is taken for reproduction, N e is meaningful only if the size of the reference population is clearly defined. Gametic control is a compensating factor in accession regeneration when the viability of the accession is around 70 or 75%. For germplasm collection, when parents are a very small fraction of the population, maximum N e will be approximately 47 and 57% of the total number of offspring sampled, with female gametic control, r varying between 0.3 and 0.5, and being constant over generations.