Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 365

 Development of new cultivarsThrough diplodization, haploids are used to generate instant homozygous true breeding lines. It takes only two seasons to obtain doubled haploid plants, versus about seven crop seasons using conventional procedures to attain near homozygous lines. The genetic effect of doubling is that doubled haploid lines exhibit variation due primarily to additive gene effects and additive × additive epistasis, enabling fixation to occur in only one cycle of selection. Heritability is high because dominance is eliminated. Consequently, only a small number of doubled haploid plants in the F1 is needed, versus several 1000s of F2 for selecting desirable genotypes.

 Selection of mutantsAndrogenic haploids have been used for selecting especially recessive mutants. In species such as tobacco, mutants that are resistant to methionine analogue (methionine sulfoxide) of the toxin produced by Pseudomonas tabaci have been selected.

 Development of supermales in asparagusHaploids of Asparagus officinalis may be diplodized to produce homozygous males or females.