Stripe rust (picture)

The DH lines and parents were assessed for adult plant resistance to stripe rust (Puccinia striiformis f. sp. hordei) in field tests at Toluca, Mexico  in 1994, 1995, and 1996 (at two planting dates) and in one test at Celaya, Mexico in 1995. Stripe rust severity was rated as percentage severity on a plot basis. Reaction type was scored using a 0-9 scale (0 = immune, 9 = susceptible). These tests were conducted at ICARDA/CIMMYT by Dr. Hugo Vivar, Dr. Sergio Sandoval-Islas, Ing. Bernardo Ramirez and Ing. Vicente Morales. 

 

• Stripe rust severity (five environments)
• Stripe rust infection type (one environment)

 

Leaf Rust (picture)

The DH lines and parents were assessed for adult plant leaf rust (Puccinia hordei) resistance in field tests at Ciudad Obregon, Mexico in 1994, 1995 and 1996 and in three environments in Equador in 1998.  Tests in Mexico were conducted by Dr. Hugo Vivar, Ing. Bernardo Ramirez and Ing. Vicente Morales. Tests in Ecuador were conducted by Dr. Oswaldo Chicaiza.  Disease was rated by infection type - resistant (R), moderately resistant (MR), moderately susceptible (MS), and susceptible (S) – and percentage severity on a plot basis. For mapping purposes, a rust index was calculated by equating the infection type rating with a numerical score (R= 1, MR = 2, MS = 3, and S = 4) and multiplying this values by the percentage severity.

• Leaf rust; Mexico
• Leaf rust;  Ecuador

 

 

Barley Yellow Dwarf Virus (BYDV) (picture)

The DH lines and parents were assessed for resistance to BYDV-MAV-MEX and BYDV-PAV-MEX serotypes. MAV resistance was characterized using a dwarfness 0-9 score (0 = no height reduction; 9 = severe height reduction ) and a tillering 0-9 score (0 = normal tillering; 9 = no tillering) in four tests at Toluca, Mexico in 1995 and 1996 (two planting dates per year). In 1996, plant height reduction  was also measured. PAV resistance was measured in one test at Toluca in 1996. The same dwarfing and tillering scores used for MAV were used to measure PAV resistance. Tests were conducted by Dr. Hugo Vivar, Ing. Bernardo Ramirez and Ing. Vicente Morales.

• MAV serotype in one environment for dwarfness score.
• MAV serotype for tillering score
• MAV serotype for plant height reduction
• PAV serotype for dwarfness score
• PAV serotype for tillering score

 

Scald (picture)

The DH lines and parents were assessed for adult plant resistance to scald (Rynchospora secalis) in field tests at Toluca, Mexico in 1995 and Toluca, Mexico in 1996 at two planting dates each year. Scald severity was rated as percentage severity on a plot basis. Tests were conducted by Dr. Hugo Vivar, Ing. Bernardo Ramirez and Ing. Vicente Morales.

 

• Scald severity (%)

 

Net Blotch (picture)

The DH lines and parents were assessed for adult plant resistance to net blotch (Pyrenophora teres f. teres) in field tests at Toluca, Mexico in 1996 and Ciudad Obregon, Mexico in 1996 in two planting dates at each location. Net blotch reaction type was scored using 0-9 scale (0 = immune, 9 = susceptible).  Tests were conducted by Dr. Hugo Vivar, Ing. Bernardo Ramirez and Ing. Vicente Morales.

 

• Net blotch reaction type