Nullisomics can also be used to identify or assign genes to specific chromosomes. Because of a loss in vigor, nullisomic analyses is less practical than monosomic techniques. Spontaneous haploids occur at a low frequency in many species, both diploid and polyploid. Often naturally occurring haploids can be recognized because they are smaller. Haploid plants can be treated with colchicine to produce diploid sectors or plants and are called doubled haploids.
Haploid plants are useful in mutation studies.
Selection for dominant alleles is easier in haploids. Since haploid, only 1 allele per locus so if dominant, then doubled, the doubled plant has 2 copies of the dominant allele. Otherwise, the dominant allele could mask the recessive allele and generations of selfing may be needed to eliminate the recessive allele from the population. Genetic segregation can be less complex in polyhaploids. Haploids are useful in cytogenetic studies of polyploids because monosomic series can then be derived.