Author
PHAM, T - University Of Illinois | |
HILL, C - University Of Illinois | |
MILES, M - Retired ARS Employee | |
NGUYEN, B - Plant Protection Research Institute - Vietnam | |
VU, T - Plant Protection Research Institute - Vietnam | |
VUONG, T - University Of Missouri | |
Vantoai, Tara | |
NGUYEN, H - University Of Missouri | |
Hartman, Glen |
Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/16/2010 Publication Date: 5/8/2010 Citation: Pham, T.A., Hill, C.B., Miles, M., Nguyen, B.T., Vu, T.T., Vuong, T.D., Vantoai, T.T., Nguyen, H.T., Hartman, G.L. 2010. Evaluation of Soybean Germplasm for Resistance to Soybean Rust in Vietnam. Field Crops Research. 117(2010):131-138. Interpretive Summary: Soybean rust, caused by the fungus Phakopsora pachyrhizi, is a severe foliar disease of soybean that occurs throughout most soybean producing regions of the world. Soybean rust may be managed with fungicides, but the utilization of soybean cultivars that are resistant to the pathogen may be more economical and environmentally safe. The objective of this research was to evaluate soybean germplasm selected from the Vietnamese breeding programs for resistance to soybean rust. Soybean rust resistance, assessed by recording soybean rust reaction types and rust severity, was evaluated over the growing season. Genetic resources useful for studies of host plant resistance and breeding for resistance to this pathogen were identified. This information is important to soybean pathologists and breeders that are working on research to improve resistance to soybean rust. Technical Abstract: Soybean rust, caused by Phakopsora pachyrhizi Sydow, is a severe foliar disease of soybean [Glycine max (L.) Merr.] that occurs throughout most soybean producing regions of the world. Soybean rust may be managed with fungicides, but the utilization of soybean cultivars that are resistant to the pathogen may be more economical and environmentally safe. The objective of this research was to evaluate soybean germplasm selected from the Vietnamese breeding programs with accessions selected for resistance to soybean rust in other environments. Sixty-three soybean genotypes were evaluated in an initial field trial in Vietnam during 2005. Three follow-up experiments with selected genotypes, were completed during 2005 through 2007. Plants were spray-inoculated with soybean rust collected from the field, near the location of the study. Soybean rust resistance, assessed by recording soybean rust reaction types and rust severity, was evaluated over the growing season. The area under the disease progress curve (AUDPC) was calculated for each soybean genotype based on four disease assessments taken during the reproductive growth stages. AUDPC among soybean genotypes in each experiment differed (P < 0.05). PI 437323 was among the soybeans with the lowest AUDPC units and was not different from the resistant check, ‘DT 2000’, in three of the four experiments. PI 549017 was among the soybean genotypes with the lowest AUDPC in three experiments and did not differ from DT 2000 in two experiments. PI 398998 had among the lowest AUDPC units in all four experiments and was similar to the resistant checks in three experiments. |