GENETIC DIVERSITY FOR AGRO-MORPHOLOGICAL AND NUTRITIONAL QUALITY TRAITS IN SORGHUM [Sorghum Bicolor (L) MOENCH] AND ITS SEED SYSTEMS IN TIGRAY NORTH ETHIOPIA

Abstract

In the present study, frequency distribution, Shannon–Weaver diversity index (H′), and multivariate methods were used to estimate the phenotypic diversity in 110 sorghum genotypes growing in Tigray taking their districts of origin, geographical zones, and altitude classes into considerations for qualitative. Results showed that high and comparable trait distributions among the sorghum genotypes. The H′ computed for individual traits varied from 0.33 for grain form to 0.99 for grain plumpness with a mean of 0.83, which reveals huge diversity within the Farmers’ varieties. The estimated H′ of each trait pooled over districts of origin, zones, and altitude classes was high with an overall mean of 0.71, 0.74, and 0.70, respectively. Based on district of origin, the highest (0.84) and the lowest (0.46) H′ values were recorded for the Tahtay adyabo and Raya azebo districts, respectively. When the zones were considered, the highest (0.80±0.06) and the lowest (0.46) H′ values were recorded for the northwestern zone and southern zone, respectively. With respect to altitude classes, the highest (0.80) and the lowest (0.68) H′ value were recorded for 1001 m.a.s.l, and >1600 m.a.s.l, respectively. Disruptive selection is the most likely reason to maintain the huge diversity in the sorghum Farmers’ varieties. The treasure of diversity suggests the potential for exploitation in sorghum improvement and conservation programs. The ANOVA showed that the mean squares due to H′ values within the districts, geographical zones, and altitude classes were significalntly variable for most of the traits studied. The difference in discriminating the Farmers’ varieties within districts of origin, zones, and altitude classes demonstrate the phenotypic traits have different importance and contribution levels to the total variance explained.