RFLP diversity in cultivated sorghum in relation to racial differentiation

• Published in: Theoretical and applied genetics 1994-08, Vol.88 (6-7), p.838-844
• Main Authors: Deu, M, Gonzalez-de-Leon, D, Glaszmann, J.C, Degremont, I, Chantereau, J, Lanaud, C, Hamon, P. (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement, Montpellier (France))
• Format: Article
• Language: English
• Subjects: ADN; AFRICA; AFRIQUE; Agronomy. Soil science and plant productions; Biological and medical sciences; Classical genetics, quantitative genetics, hybrids; ENZIMA DE RESTRICCION; ENZYME DE RESTRICTION; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; MARCADORES GENETICOS; MARQUEUR GENETIQUE; POLIMORFISMO GENETICO; POLYMORPHISME GENETIQUE; Pteridophyta, spermatophyta; SECUENCIA NUCLEOTIDICA; SEQUENCE NUCLEOTIDIQUE; SORGHUM BICOLOR; VARIACION GENETICA; VARIATION GENETIQUE; VARIEDADES; VARIETE; Vegetals
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/BF01253994

Careful assessment of the comparative diversity for molecular markers and for potentially-useful morpho-agronomic traits is paramount to the analysis of a genome through the mapping of favorable genes. Sorghum (Sorghum bicolor ssp. bicolor) varieties are traditionally classified into five races on the basis of morphological traits, especially panicle and grain traits. Isozyme diversity has provided a new insight into genetic diversity, and showed a marked geographic structure. RFLP analysis was performed on 94 varieties, chosen to represent the main cross combinations (race x geographic origin), using 35 maize probes that detect polymorphism with at least one of the two restriction enzymes Hind3 and Xba1. A total of 50 polymorphic probe-enzyme combinations yielded 158 polymorphic bands. The bicolor race appeared highly variable and included many rare markers. Among the other races multivariate analysis of the data differentiated six clusters corresponding, by decreasing magnitude of divergence, to: the margaritiferum types (a sub-race of race guinea); the Guinea forms from western Africa; race caudatum; race durra; race kafir; and the guinea forms from southern Africa. The apparent geographic differentiation was related to the contrasting distribution of these races and to a higher similarity between races localized in southern Africa. The data agree with the current hypotheses on sorghum domestication but reveal associations between neutral markers and traits probably highly subjected to human selection. Whether such associations will be observed with other useful traits, and to what extent they are maintained by genetic linkage, is worth exploring.