Login

Join for Free!
118863 members


Hybrids

Genetics as it applies to evolution, molecular biology, and medical aspects.

Moderator: BioTeam

Hybrids

Postby JesnieC » Sat May 14, 2011 2:10 am

"Selective breeding produces different varieties of crops that are homozygous for many genes. This can be disadvantegeous. Organisms that are homozygous for many genes are usually less vigourous than plants that are heterozygous for many genes. If a plant is a homozygous for many genes then there is more chance that it will display a disadvantageous characteristic due to a pair of recessive alleles."

-taken from Biology in Context The spectrum of Life by Peter Aubusson

Why does selective breeding produces different varieties of crops that are homozygous? How?
JesnieC
Garter
Garter
 
Posts: 4
Joined: Wed Apr 06, 2011 10:01 am

Postby Darby » Sat May 14, 2011 2:40 am

The simplified reason is that when you select for certain traits, you do two things: you select for certain alleles, and you are trying to produce a nondiverse population that breeds true. You're more likely to remove the non-preferred alleles, leaving just one type.
Darby
Viper
Viper
 
Posts: 1265
Joined: Thu Mar 02, 2006 5:29 pm
Location: New York, USA

Postby canalon » Sat May 14, 2011 3:07 am

And then the seeds sold are F1 hybrids that are more vigorous than both parents, with the allele that you want.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)
User avatar
canalon
Inland Taipan
Inland Taipan
 
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada


Re:

Postby JesnieC » Sat May 14, 2011 5:30 am

Darby wrote: You're more likely to remove the non-preferred alleles, leaving just one type.


I don't quite understand. If I remove the non-preferred alleles, then how come when a plant has many homozygous genes, its more likely to display bad characteristics due to recessive alleles?
JesnieC
Garter
Garter
 
Posts: 4
Joined: Wed Apr 06, 2011 10:01 am

Postby JackBean » Wed Jun 08, 2011 8:53 am

because you're selecting only some special feature, but with that you can select unwillingly other traits, which may be harmful. Or even your desired traits may be bad in some conditions.
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
User avatar
JackBean
Inland Taipan
Inland Taipan
 
Posts: 5689
Joined: Mon Sep 14, 2009 7:12 pm


Return to Genetics

Who is online

Users browsing this forum: No registered users and 1 guest