Despite selection pressure against them some sublethal recessive alleles stay in an open pollinated population?

Yes, despite selection pressure against them, some sublethal recessive alleles can persist in an open-pollinated population due to several factors:

Heterozygote Advantage: In some cases, carriers of recessive alleles may exhibit an advantage when heterozygous (carrying one dominant and one recessive allele). This heterozygote advantage can maintain the recessive allele in the population, as it provides a selective advantage even in the presence of selection pressure against the homozygous recessive genotype.

Frequency-Dependent Selection: The persistence of recessive alleles can also be influenced by frequency-dependent selection, where the fitness of a particular genotype depends on its frequency relative to other genotypes in the population. Rare recessive alleles may escape selection pressure because their frequency is too low to be effectively targeted by natural selection.

Balancing Selection: Balancing selection occurs when multiple alleles at a locus are maintained in the population over time due to various selective pressures. In cases where recessive alleles confer advantageous traits under certain environmental conditions or in specific genetic backgrounds, balancing selection may act to preserve genetic diversity, including sublethal recessive alleles.

Gene Flow: Gene flow, the movement of alleles between populations, can introduce and maintain recessive alleles in a population even if they are subject to selection pressure. Migration from neighboring populations or the introduction of new genetic material through pollen or seed dispersal can replenish the genetic diversity of the population, including recessive alleles.

Mutation-Selection Balance: Mutation is a continuous process that introduces new genetic variation into populations. Even if selection pressure acts against recessive alleles, new mutations may continuously arise, replenishing the pool of recessive alleles and allowing them to persist in the population.

Genetic Drift: Genetic drift, the random fluctuation of allele frequencies in small populations, can also contribute to the persistence of recessive alleles. In small populations, genetic drift may override selection pressure, leading to the fixation or maintenance of recessive alleles by chance alone.

Overall, the persistence of sublethal recessive alleles in open-pollinated populations can be influenced by a complex interplay of genetic, ecological, and evolutionary factors. While selection pressure may act against recessive alleles, various mechanisms can contribute to their maintenance or retention in populations over time.