Elementary plant Biochemistry and Biotechnology (2+1)

Bulbosum technique

Principle

• The fertilization proceeds readily between H. vulgare and H. bulbosum.
  
• Zygote induction is high and chromosomes of H. bulbosum are rapidly eliminated from the cells of developing embryo. This develops for two to five days and then aborts.
  
• In the developing monoploid embryo cells, the division and increment is slower than the diploid cells.
  
• This comparatively slow growth of the monoploid condition, together with the disintegration of the endosperm leads to the formation of small embryos which have to be dissected out of the fruits and provided with nutrients in vitro in order to complete their development.
• Following in vitro embryo culture, the developing plantlets are raised under normal green house conditions and chromosome doubling is induced on established plants.

Advantages

1. The method of hybridization followed by chromosome elimination proves to be of general interest for haploid production in other species of Hordeum and also of hexaploid wheat.
2. It is possible to produce monoploids of barely in a cytoplasm of H. bulbosum by using H. vulgare as male and H. bulbosum as female. Using embryo culture as vehicle, high frequency foreign cytoplasm monoploids can be obtained.
3. Hordeum species is not the only one where chromosome elimination is found in higher plants. In Haplopoppus, monoploids have been examined with only two chromosomes. H. bulbosum need not be the ideal partner for H. vulgare to induce monoploids of barley via somatic chromosome elimination. There can be a range of Hordeum that might be tried as a more efficient pattern than H. bulbosum.