Ramasamy Perumal, Sorghum Breeder, at KSU Field Day
The major focus of the sorghum research program in the semi-arid regions of Kansas is increased yield potential through the development of elite parental lines with drought resistance (pre-flowering and post-flowering resistance), herbicide tolerance, cold/heat tolerance, non-lodging and disease resistance (Fusarium stalk rot, charcoal rot, anthracnose, and ergot). Insect resistance (green bug) and forage quality are secondary priority areas. The program also evaluates exotic germplasm to find new genetic sources for use in the development of improved lines. Collaborative research efforts will be made using molecular breeding for the traits of economic importance with special emphasis on exotic germplasm characterization and development of mapping populations for QTL and association mapping analyses for graduate research programs.
Current Research Projects
Sorghum Breeding: The sorghum-breeding program develops improved parental lines with major emphasis on developing lines with increased yield, improved tolerance to environmental stresses particularly pre- and post-flowering drought and cold tolerance and herbicide tolerance. The next priority is on the development of lines with disease (charcoal rot and fusarium wilt) and insect (green bug) resistance. The program also evaluates exotic germplasm to find new genetic sources for priority traits for use in the development of improved lines.
Pre and post-flowering drought tolerance: Adaptation of sorghum to the range of environmental conditions in semi-arid regions has resulted in the evolution of extensive genetic variation for drought tolerance in sorghum (Blum 1979; Doggett 1988). However, water stress at both pre-flowering and post-flowering stages of development has the most adverse effect on yield. Hence, productivity enhancement under drought conditions is a challenging task because of the unpredictable nature of most periods of drought stress prevailing in sorghum growing areas in Kansas and gaps in our knowledge of drought biology. These difficulties arise from the diverse strategies adopted by sorghum plants themselves to combat drought stress depending on the timing, severity and stage of crop growth. The research focus at this center will be primarily on the development of drought tolerant parents using conventional breeding methods and through estimating the genetic parameters and character association for some valuable morpho-physiological traits, which have been extensively utilized for screening of pre- and post-flowering drought tolerance.
Cold Tolerance: Sorghum is sensitive to low-temperature stress in the range of 20° to 32° F and suffers chilling injury when subjected to non-freezing temperatures below 50-68° F (Peacock, 1982). Development of cold tolerant sorghum lines is a priority objective to take advantage of early season moisture, minimum tillage and a longer growing period. This would help expand the area of coverage and increase the possibility of two crop seasons for producers. Enhanced germination and emergence at low temperatures would facilitate early planting and adaptation to cooler days between the end of April and May in Kansas. Focusing on important seedling cold tolerance traits like emergence percentage, emergence index, seedling height, shoot and root dry weight and vigor score are being made in collaboration with crop physiologists to identify cold tolerant lines for further hybrid development.
Herbicide Tolerance: Research has shown that heavy weed infestations can reduce grain sorghum yields by 50 percent. In addition, weeds may decrease grain quality, increase insect and disease pressure, and increase harvest difficulty. Segregating progenies are being evaluated in collaboration with weed scientists to select sorghum lines tolerant to acetolactate synthase (ALS) and acetyl coenzyme A carboxylase (ACC) herbicides.
Non-lodging and Diseases Resistance: Charcoal rot [caused by Macrophomina phaseolina (Tassi) Goidanich] incidence is much higher when sorghum plants are exposed to prolonged drought and high stress during grain development. Fusarium stalk rot (caused by Fusarium spp.) is typically more severe when drought and high temperature stress occurs during grain development followed by wet, cool conditions near physiological maturity. Development of genotypes not affected by late-season drought will help reduce susceptibility to stalk rot diseases. Greenbug: The greenbug is the most widespread insect pest of sorghum. Several biotypes of the greenbug presently exist and each new biotype reduces the number of sorghum lines with resistance . Exotic germplasm will be continuously screened in collaboration with entomologists for the identification of resistance/tolerance sources and to use the same for further breeding programs.
Virus Complex: The major viruses attacking sorghum include johnsongrass mosaic virus, maize dwarf mosaic virus, sugarcane mosaic virus, and sorghum mosaic virus. These diseases account for 2-5% loss in grain yield each year. Our plant pathologist has already identified a resistance source to this virus complex. Research efforts are underway to use the same to introgress the trait into other breeding lines and thus into hybrids. Publications Perumal, R., Tesso, T., Kofoid, K. D., Prasad, P.V.V., Aiken, R.M., Bean, S.R., Wilson, J.D., Herald, T. J. and Little. C.R. 2015. Registration of Nine Grain Sorghum Seed Parent (A/B) Lines. Journal of Plant Registrations 9:244–248
Adeyanju, A., Perumal, R. and Tesso, T. 2015. Genetic Analysis of Threshability in Grain Sorghum [Sorghum bicolor (L) Moench]. Pant Breeding 134, 148–155
Kapanigowda, M., Perumal, R., Aiken, R., Herald, T., Bean, S. and Little, C.R. 2013. Analyses of sorghum [Sorghum bicolor (L.) Moench] lines and hybrids in response to early season planting and cool conditions. Can. J. Plant Sci. 93: 773-784.
Kapanigowda, M., Perumal, R., Maduraimuthu, D., Aiken, M.R., Prasad P.V.V., Tesso. T., and Little, C.R. 2013. Genotypic variation in sorghum [Sorghum bicolor (L.) Moench] exotic germplasm collection for drought and disease tolerance. SpringerPlus. 2:650. DOI: 10.1186/2193-1801- 2-650. URL: http://www.springerplus.com/content/2/1/650
Prom, L. K*., Perumal, R*., Erattaimuthu S. R., Little, C.R., No, E. G., Erpelding, J. E., Rooney, W.L., Odvody, G. N., and Magill, C. W. 2012. Genetic diversity and pathotype determination of Colletotrichum sublineolum isolates causing anthracnose in sorghum. Eur J Plant Pathol. 133:671–685. (* Authors with equal contributions)
Kofoid, K. D., Perumal, R., Reese, J.C. and Campbell, L.R. 2012. Registration of Twelve Sorghum Germplasm Lines Tolerant to Greenbug Feeding Damage. Journal of Plant Registrations 6(1):1-3.
Prom, L. K*., Perumal, R*., Erattaimuthu, S. R., Erpelding, J. E., Montes, N., Odvody, G. N., Greenwald, C., Jin, Z., Frederiksen, R., and Magill, C. W. 2011. Virulence and molecular genotyping studies of Sporisorium reilianum isolates in sorghum. Plant Dis. 95:523-529. (* Authors with equal contributions)
Katilé, S*., R. Perumal, *, W.L. Rooney, L.K. Prom, and C.W. Magill. 2010. Expression of pathogenesis-related protein PR-10 in sorghum floral tissues following inoculation with Fusarium thapsinum and Curvularia lunata. Molecular Plant Pathology. 11(1): 93–103 (* Authors with equal contributions)
Perumal, R., M.A. Menz, P.J. Mehta, S. Katile, L.A. Gutierrez Rojas, R.R. Klein, P.E. Klein, L.K. Prom, J.A. Schlueter, W.L. Rooney, C.W. Magill. 2009. Molecular mapping of Cg1, a gene for resistance to anthracnose (Colletotrichum sublineolum) in sorghum. Euphytica 165 (3): 597-606.
Perumal, R., P. Nimmakayala, S. Erattaimuthu, E.G. No, U.K. Reddy, L.K. Prom, G.N. Odvody, D.G. Luster, C.W. Magill. 2008. Simple Sequence Repeat Markers Useful for Sorghum Downy Mildew (Peronosclerospora sorghi) and Related Species. BMC Genetics 9: 77 (doi:10.1186/1471-2156-9-77).
Perumal, R., K. Renganayaki, M.M. Menz, S. Katile, J. Dahlberg, C.W. Magill, W.L. Rooney. 2007. Genetic Diversity among Sorghum Races and Working Groups Based on AFLP and SSRs. Crop Sci. 47: 1375-1383.
Perumal, R., T. Isakeit, M.A. Menz, S. Katile, E.G. No, C.W. Magill 2006. Characterization and genetic distance analysis of isolates of Peronosclerospora sorghi using AFLP fingerprinting. Mycol Res. 110(4):471-478.