Assessment of genetic diversity in sorghum bicolor using RAPD markers

摘要

Sorghum is one of the most important cereal crop and ranks fifth among cereals after wheat, rice, maize and barley for economic importance. Because the demand of food is increasing, sorghum will increase in importance as a source of food, feed, fibre, and fuel; specially in the European continent where sorghum is little cultivated, mainly due to the lack of sorghum varieties well adapted to the soil and climate conditions such as photoperiod, cold and drought; for this reason, the genetic diversity analysis, through molecular characterization, is an important requirement to begin a plant breeding program. The analysis was performed in 46 sorghum genotypes obtained from the Czech Plant Gene Bank, Crop Research Institute, Prague. Genetic variability values were estimated, through the genetic distance using Dice’s coefficient, and dendrogram constructed using DARwing software. Four out of fifteen of the primers evaluated were completely polymorphic (100%), A hundred and twenty-six scorable bands were identified and 89% of them were polymorphic, the bands ranged from 200 to 2000 bp. The dendrogram grouped the accession into six clusters. The results indicate the existence of high genetic distance values up to 0.8776 among the evaluated accessions, even if the accessions were collected in the same country, or by the contrary, lower genetic diversity among accessions collected in different countries. It may be due to the existence of five ancient races of sorghum, from which were originated most of the wild and cultivated species known nowadays. Mainly, the migration of people from the origin centre of sorghum, located in Ethiopia and Sudan, explain the spread of the genetic material out of Africa. The information generated by this study should be useful for a better understanding of the genetic diversity from the sorghum germplasm stored in the Czech Plant Gene Bank for future plant breeding program.