Geographical distribution, diversity and gap analysis of East African sorghum collection conserved at the ICRISAT genebank

Abstract

The aim of the investigation was to assess the geographical distribution, diversity and gaps in sorghum collection from East African countries conserved at the ICRISAT genebank. The collection represents a total of 12,750 accessions including 11,672 landraces, 877 breeding materials, six improved cultivars, and 195 wild accessions. Passport data and FloraMap, a GIS software were used to assess geographical distribution and identify gaps. Range, mean, variance and phenotypic diversity index were estimated using GENSTAT 13.1. to assess the diversity in the collection. Cultivated sorghums classified into races and intermediate races based on spikelet and panicle morphology differed significantly, and races showed more variation than intermediate races for days to 50% flowering in postrainy season, plant height in rainy season, basal tillers per plant, panicle length, seed width and 100 seed weight. A total of 153 districts located in 50 provinces of 10 East African countries were found as the geographical gaps. Probably due to large variation for maturity, timing of collecting mission, and accessibility to the area under sorghum cultivation, both North and South Sudan were found as the major gaps with seven and 50 districts, respectively. The wild sorghum collection from East African countries belongs to S. bicolor, S. halepense, S. lanceolatum, S. macrochaeta, S. purpureosericeum and S. versicolor. Remaining species of genus sorghum were considered as taxonomic gaps. The gaps identified in the present study need to be explored on a priority basis to collect and conserve most diverse sorghum germplasm.