Contents - Index

Evaluate host genotypes for their general and specific resistance

This is a function when the biplot is used in visual analysis of host genotype by pathogen strain two-way data. For the evaluation of host genotypes, the following biplot is most informative:

Note this biplot have the following settings (compare with pathogen race evaluation):

1. host genotypes are treated as entries and pathogen strains as testers;

2. tester-centered model (centering = 2);

3. entry-focused scaling (SVP =1); and

4. the average-tester coordination view

Interpretations:

• The red lines points to larger response scores (higher susceptibility). Therefore, the general susceptibility rank is:

H30 > H-Betzes > ... > H33 = Average > ... > H10 = H32 > H16. H30 is most susceptible, and H16 the most resistant.

• H8 and H31 are very unstable: They are highly susceptible to strains S48 and S78 but are resistant to other strains. This suggests strong specific (vertical) resistance.

• The strains fall into two distinct groups: S48 and S78 as one group vs. the others as another group.