Monoploid Production Through Chromosome Elimination - Here monoploids are defined as sporophytes with the basic gametic chromosome number. They have a single genome or chromosome set (2n = X = 7 in Hordeum vulgare). Monoploids are generally sterile but by doubling the chromosomes, homozygous diploid fertile plants are produced.

Monoploids can be produced by interspecific hybridization followed by chromosome elimination. The hybridization method consists of crossing cultivated barley, Hordeum vulgare (2n = 2X = 14), With the wild, diploid cross pollinating and perennial H. bulbosum (2n :::: 2X = 14). This technique, the Bulbosum method, consists of the following steps the female gamete of barley is fertilized by the H. bulbosum gamete.

The advantage of monoploids as tools in plant breeding or genetics becomes more apparent when their direct application is visualized:
1) They provide the quickest possible way to complete homozygosis.
2) They may serve to recover recessives
3) Linkage data can be obtained directly by sampling gametes as monoploids.
4) Doubled monoploids give an immediate product of stable recombinants from species crosses.
5) Monoploids can be used to determine homology within a genome and between genomes.
6) They are ideal for the study of mutation frequencies and spectra.
 7) They provide an ideal system for fundamental cell biological problems (i.e., biosynthesis) in cell and protoplast culture.
8) Monoploid cells as protoplasts provide unique material for gene transfer, host pathogen reactions, and cytoplasmic and/or chromosomal incompatibility.