Genetic Diversity Study of Lepidiumsativum Population of Ethiopia using ISSR Marker and Morphological Characters
The study was conducted to assess the genetic diversity of Lepidiumsativum populations from Ethiopia using both morphological and ISSR markers. A total of 86 L. sativum genotypes were planted in Complete Randomized Block Design with two replications at Holeta Agricultural Research Center during 2011/2012 cropping season. Ten plants were tagged for morphological data collection and fourteen quantitative traits were recorded. The ISSR fingerprint analysis was conducted at the Genetics Laboratory of Addis Ababa University, Ethiopia. Analysis of variance was computed for 12 morphological traits and significant variation within and between L. sativum populations was recorded. Yield data indicated that accession 205162 (2324.08 kg/ha) and 90020 (2008.46 kg/ha) from Amhara; accession 234828 (1983.4kg/ha) from Oromia observed to give higher yield. The seed color based bulk analysis of oil content also indicated that Brown gave the highest (25%) oil content. Molecular data generated from ISSR bands recorded was used for computing gene diversity, percent polymorphism and Shannon diversity index and AMOVA. Moreover, the ISSR data was used to construct UPGMA, Nj trees. Tigray and Amhara populations showed higher gene diversity (0.24) and Shannon information index (0.35). Nj, UPGMA analysis showed very week grouping among individuals collected from the same regions. Generally, Tigray and Amhara regions showed moderate to high diversity in both morphological and ISSR analysis. High variation was recorded for number of seeds/plant, number of pod/plant, number of secondary branch/plant, and plant height, which indicates the presence of ample variability for L. sativum improvement in Ethiopia. Different geographical regions of Ethiopia, showed different levels of variation; thus conservation priority should be given for those regions that have genetic diversity. This result also indicated the presence of genetic diversity that can be exploited to improve the productivity of L. sativum in Ethiopia.
Key words - Genetic diversity, ISSR, Lepidiumsativum, Morphology