Upload
muruganjey
View
453
Download
5
Embed Size (px)
Citation preview
Three line system of hybrid seed
production
A.Murugan
Bsc.,agri
Hybrids
It begins at 20th centuary.
First generation offspring of a cross between the genetically diverse parents .
Always heterozygous.
100% cross pollination.
100% seed set is not possible.
Three line system
A line
Stable Sterility.
Well developed floral traits for outcrossing.
Easily, widespectum, strongly restored.
B line
Maintainable line.
Well developed floral traits with large pollen load.
Good combining ability.
A &B – nucleus should be same only cytoplasm
will vary.
R line
Able to restore / fertile the male fertility character.
Good combining ability.
Taller than A line.
Large pollen load, normal flowering traits.
No extra parents need for R line multiplication.
Success of hybrid seed production
• Choice of location.
• Selection of seed fields.
• Isolation.
• Cultural practices.