Genetic diversity of Ethiopian bread and durum wheat Varieties and advanced lines as revealed by ssr markers

Abstract

About fifty eight bread and 34 durum wheat varieties have been released in Ethiopia until 2012. However, enough work has not been done on the genetic relationships among these varieties. Hence, the present study was initiated with the aims of determining the genetic variation among wheat varieties released in the country and to assess the achievement of wheat variety development program of Ethiopia in terms of developing genetically diverse varieties. Forty one bread and twenty four durum wheat varieties obtained from different breeding centers were used for this study. DNA was extracted using the CTAB method (Doyle & Doyle, 1990). PCR was conducted using 15 SSR markers, and allele separation was performed using polyacrylamide gel on vertical electrophoresis apparatus. The result showed that the number of alleles per locus ranged from 4-16 and 2-15 for bread and durum wheat varieties, respectively. PIC ranged from 0.16 (Xgwm257) to 0.83 (Xgwm136) with an average of 0.56 among bread wheat and from 0.36 (Xgwm257) to 0.89 (Xgwm292) with an average of 0.63 among durum wheat varieties. The genetic distance between Galema and K-6290 bulk was the lowest (0.07) whereas that of Shina and Bobicho was the highest (0.12) among bread wheat varieties. On the other hand, the genetic distance between Werer and Gerardo was the lowest (0.07) whereas that of Selam and Candidate#4 was the highest (0.14) among durum wheat varieties. Both bread wheat varieties with the lowest genetic distance were obtained from KARC and that of durum wheat were obtained from DZARC. The most distant bread wheat variety (Shina) and durum wheat variety (Selam) were obtained from ADARC. There were three main clusters for both bread and durum wheat varieties. Based on the pair wise comparison in the distance matrix all of bread as well as durum wheat varieties shared more than 88% of their marker alleles, which indicates low genetic diversity among the varieties. It could be concluded that the wheat breeding program in Ethiopia was unable to produce more diverse varieties with a wide genetic base. Therefore, it is recommended that future breeding programs should focus on widening the genetic base of the country’s commercial varieties to minimize risks emanating from biotic and abiotic production constraints.