Phytophthora sojae Kauffmann and Gerdemann is a potential threat for soybean which deteriorates the quality of crop and causes huge crop loss all over the world. It is an oomycete pathogen which attacks on the susceptible varieties of soybean plants Glycine max (L.) and causes root and stem rot which is known as Phytophthora root and stem rot (PRR). It is reported that an average annual loss from 1996 to 2014 due to PRR is more than 1.1 million tons1.
Cultivation of soybean has been elevated in paddy fields that are usually wet because of poor drainage2. Soil borne pathogen such as P. sojae is more likely to persist in paddy soils. This pathogen rapidly colonize root and stem tissues of susceptible plants by producing oospores3. Seedling damping-off, roots and stem rot, yellowing of leaves and wilting are the characteristics symptoms produced by the attack of this pathogen in soybean plants which ultimately leads to the death of plant4.
Resistance R-gene is extensively used in developing resistant varieties in soybean growing countries like China, Japan, Brazil and US. It has been observed that soybean varieties that possess resistance R-gene quickly develop a hypersensitive response within hours after infection and provide protection to soybean plants against pathogen P. sojae5.
PRR was first identified in South Korea but the interaction between soybean and P. sojae is completely unknown which urge the scientists to study the presence of Rps resistance against four isolates in twenty universal soybean cultivars planted in South Korea. Therefore, a new study was designed by Jang et al., 2020 published in The Plant Pathology Journal in order to identify the genomic location of a gene conferring resistance to P. sojae isolate 2457 in the recombinant inbred line population developed by a cross of Daepung × Daewon.
The results from this study exhibited that 50% of the evaluated cultivars were susceptible, only few cultivars such as Korean soybean cultivar Daewon showed resistance to P. sojae. Single Marker Analysis detected that 20 single nucleotide polymorphisms associated with resistance to the P. sojae isolate 2457. Daewon contributed a resistance allele for the locus and this region is a well-known location for Rps1 and Rps7.
To put it succinctly, the identified R-gene locus would be beneficial in developing resistant varieties of soybean against P. sojae in the future.
- Wrather J. A. and Koenning S. R. 2006. Estimates of disease effects on soybean yields in the United States 2003 to 2005. Nematol.38:173-180.
- Ministry of Agriculture, Food and Rural Affairs. 2019. Crop production area. In: Agriculture, food and rural affairs statistics yearbook, ed. by Director Information & Statistics & Policy Division, Director-General for Policy Planning Bureau, Sejong, Korea. 64-88 pp.
- Dorrance A. E. 2018. Management of Phytophthora sojaeof soybean: a review and future perspectives. J. Plant Pathol. 40:210-219.
- Schmitthenner A. 1985. Problems and progress in control of Phytophthora root rot of soybean. Plant Dis.69:362-368.
- Staskawicz B. J., Ausubel F. M., Baker B. J., Ellis J. G. and Jones J. 1995. Molecular genetics of plant disease resistance. Science268: 661-667.