Resistance Rating System :
Indicates when a variety is resistant to a specific disease or pest.
- For varieties with soybean cyst nematode (SCN) resistance, it is specified which races of nematodes the line is resistant to.
- In the case of Phytophthora, it indicates the gene conveying the resistance.
Phytophthora Race Resistance
The following information correlates gene resistance to the actual races of Phytophthora the plant is protected from:
Rps1a = Resistant to races
1, 2, 10, 11, 13–18, 24, 26, 27, 31, 32, 36, 38
Rps1c = Resistant to races
1–3, 6–11, 13, 15, 17, 21, 23, 24, 26, 28–30, 32, 34, 36, 38, 44
Rps1k = Resistant to races
1–11, 13–15, 17, 18, 21–24, 26, 36–38, 44
Rps3a = Resistant to races
1–5, 8, 9, 11, 13, 14, 16, 18, 23, 25, 28, 29, 31–35, 39, 44, 45
Rps6 = Resistant to races
1–4, 8, 9, 10, 12, 14–16, 18–21, 25, 28, 33–35, 38, 39, 44, 45
Phytophthora Field Tolerance
- Usually not as complete as race-specific resistance, but it offers general protection.
- Resistance is not expressed in early stages of plant development.
Numerical rating scale of 1 – 9:
1 = Excellent
9 = Poor
Soybean Cyst Nematode (SCN)
1, 3, 5 and/or 14 = specific race of soybean cyst nematode
R = Resistant
MR = Moderately Resistant
S = Susceptible