Abstract
Genetic and phenotypic diversity among randomly selected 36 downy-mildew-resistant sorghum accessions were assessed, the former using 10 simple sequence repeat (SSR) marker loci and the latter using 20 phenotypic traits. The number of alleles (a j ) at individual loci varied from five to 14 with an average of 8.8 alleles per locus. Nei's gene diversity (H j ) varied from 0.59 to 0.92 with an average of 0.81 per locus. High gene diversity and allelic richness were observed in races durra caudatum (H j = 0.76, a j = 4.3) and guinea caudatum (H j = 0.76, a j = 3.8) and in east Africa (H j = 0.78, a j = 7.2). The regions were genetically more differentiated than the races as indicated by Wright's F st. The pattern of SSR-based clustering of accessions was more in accordance with their geographic proximity than with their racial likeness. This clustering pattern matched little with that obtained from phenotypic traits. The inter-accession genetic distance varied from 0.30 to 1.00 with an average of 0.78. Inter-accession phenotypic distance varied from 0.01 to 0.55 with an average of 0.33. Eleven accession-pairs had phenotypic distance of more than 0.50 and genetic distance of more than 0.70. These could be used as potential parents in a sorghum downy mildew resistance-breeding program.
This is a preview of subscription content, access via your institution.
References
R.W. Allard, Predictive methods for germplasm identification. In: H.T. Stalker and J.P. Murphy (eds.) Plant Breeding in the 1990s. UK: CAB International (1992) pp. 119-146
S. Audilakshmi, J.W. Stenhouse, T.P. Reddy and M.V.R. Prasad, Grain mould resistance and associated characters of sorghum genotypes. Euphytica 107 (1999) 91-103
A.M. Bowcock, A. Ruiz-Linares, J. Tomfohrde, E. Minch, J.R. Kidd and L.L. Cavalli-Sforza, High resolution of human evolutionary trees with polymorphic microsatellites. Nature 368 (1994) 455-457
S.M. Brown, M.S. Hopkins, S.E. Mitchell, M.L. Senior, T.Y. Wang, R.R. Duncan, F. Gonzales-Candelas and S. Kresovich, Multiple methods for identification of polymorphic simple sequence repeats (SSRs) in sorghum (Sorghum bicolor (L.) Moench). Theor. Appl. Genet. 93 (1996) 190-198
Crow J.F. and Kimura M. 1970. An Introduction to Population Genetics Theory. N.Y. Harper and Row.
R.E. Dean, J.A. Dahlberg and M.S. Hopkins, Genetic redundancy and diversity among ȁ8Orangeȁ9 accessions in the US National Sorghum collection as assessed with simple sequence repeat (SSR) markers. Crop. Sci. 39 (1999) 1215-1221
C. De Oliveira Antonio, Todd Richter and L. Bennetzen Jefferey, Regional and racial specificities in sorghum germplasm assessed with DNA markers. Genome 39 (1996) 579-587
M. Deu, D. Gonzalles-de-Leon, J.C. Glaszmann, I. Degremont, J. Chantereau, C. Lanaud and P. Hamon, RFLP diversity in cultivated sorghum in relation to racial differentiation. Theor. Appl. Genet. 88 (1994) 838-844
Duncan R.R., Bramel-Cox P.J. and Miller F.R. 1991. Contributions of introduced sorghum germplasm to hybrid development in the USA. Crop Science Society of America – Use of Plant Introductions in Cultivar Development. Special Publ. Part 1. CSSA No. 17.
J.C. Gower, A general coefficient of similarity and some of its properties. Biometrics 27 (1971) 857-871
C. Grenier, M. Deu, S. Kresovich, P.J. Bramel-Cox and P. Hamon, Assessment of genetic diversity in three subsets constituted from the ICRISAT sorghum collection using random vs non-random sampling procedures B: using molecular markers. Theor. Appl. Genet. 101 (2000) 197-202
L. Kong, J. Dong and G.E. Hart, Characteristics, linkage-map positions, and allelic differentiation of Sorghum bicolor (L.) Moench DNA simple-sequence repeats (SSRs). Theor. Appl. Genet. 101 (2000) 438-448
Marshall D.R. and Brown A.H.O. 1975. Optimum sampling strategies in genetic conservation. In: Frankel O.H. and Hawkes J.G.(eds) Crop Genetic Resources for Today and Tomorrow. Cambridge Univ. Press, Cambridge, UK, pp. 53–80
Miller M.P. 1997. Tools for Population Genetic Analysis (TFPGA) 1.3: A Windows Programme for the Analysis of Allozyme and Molecular Population Genetic Data.
W.C. Morden, J. Doebley and K.F. Schertz, Allozyme variation in old world races of Sorghum bicolor (Poaceae). Am. J. Bot. 76 (1989) 245-255
M. Nei, Molecular Evolutionary Genetics. New York: Columbia University Press (1987).
M. Nei and W.H. Li, Mathematical model for studying genetic variation in terms of restriction endonucleases. PNAS (USA) 76 (1979) 5269-5273
Pande S., Bock C.H., Bandyopadhyay R., Narayana Y.D., Reddy B.V.S., Lenne J.M. and Jeger M.J. 1997. Downy Mildew of Sorghum. Information Bulletin No. 51 Patancheru 502 324, A.P., India.
Payne R.W.(eds) 2002. The guide to Gen, Stat Release 6.1. Part 2: Statistics.
J.S. Rogers, Measures of genetic similarity and genetic distance. In: Studies in Genetic VII. Austin: University of Texas Publication no. 7213 (1972).
F.J. Rohlf, NTSYS-pc: Numerical Taxonomy and Multivariate Systemversion 2.1.1.. Setauket, New York: Exeter Software (1994).
D.J. Schoen and A.H.D. Brown, Conservation and allelic richness in wild crop relations in aided by assessment of genetic markers. PNAS 90 (1993) 10623-10627
S. Sivaramakrishnan, K. Seetha, A. Nageshwar Rao and Singh Laxman, RFLP analysis of cytoplasmic male-sterile lines of pigeon pea (Cajanus cajan (L.) Millsp.) developed by interspecific crosses. Euphytica 93 (1997) 307-312
Snedecor G.W. and Cochran W.G. 1967. Statistical Methods. Oxford and IBH Publishing Co.
D. Tautz, M. Trick and G.A. Dover, Cryptic simplicity in DNA is a major source of genetic variation. Nature 322 (1986) 652-656
B.S. Weir and C.C. Cockerham, Estimating F-statistics for the analysis of population structure. Evolution 38 (1984) 1358-1370
Author information
Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kamala, V., Bramel, P.J., Sivaramakrishnan, S. et al. Genetic and Phenotypic Diversity in Downy-mildew-resistant Sorghum (Sorghum bicolor (L.) Moench) Germplasm. Genet Resour Crop Evol 53, 1243–1253 (2006). https://doi.org/10.1007/s10722-005-5678-7
Received:
Accepted:
Published:
Issue Date:
Key words
- Downy mildew
- Genetic diversity
- Microsatellite markers
- Phenotypic diversity
- Sorghum bicolor