Principles of Plant Genetics and Breeding

92 CHAPTER 6
Table 1 Conservation methods for different categories of diversity rated by their importance for specific group of
diversity (based on Hammer 2004).
Crops Wild relatives Weeds
Importance 1 2 3 4 1 2 3 4 1 2 3 4
Ex situ
Infraspecific diversity x x x
Diversity of species x x x
Diversity of ecosystems x x x
On farm
Developing countries
Infraspecific diversity x x x
Diversity of species x x x
Diversity of ecosystems x x x
Developed countries
Infraspecific diversity x x x
Diversity of species x x x
Diversity of ecosystems x x x
In situ
Infraspecific diversity x x x
Diversity of species x x x
Diversity of ecosystems x x x
1, no importance; 2, low importance; 3, important; 4, very important.
Table 2 Advantages and disadantages of several methods of measuring genetic variation (FAO 1996).
Method 1 2 3 4 5 6 7
Morphology Slight High Small Medium Phenotypical Qualitative/ Low
number characteristic quantitative
Pedigree Medium – – Good Degree of parent – Low
analysis relationship
Isoenzyme Medium Medium Small Medium Proteins Codominant Medium
number
RFLP Medium Low Small number Good DNA Codominant High
(low copy) (specific)
RFLP High Low High number Good DNA Dominant High
(high copy) (specific)
RAPD High to High High number Slight DNA Dominant Medium
medium (random)
DNA High Slight Small number Good DNA Codominant/ High
sequencing (specific) dominant
Seq tag SSRs High High Middle number Good DNA Codominant High
(specific)
AFLPs Medium High High number Medium DNA Dominant High
to high (random)
1, variation found; 2, throughput of samples; 3, examined loci/assay; 4, reproducible on repetition; 5, analyzed character type;
6, inheritance of examined character trait; 7, necessary level of technology.