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In African sub-Saharan countries, sesame is mostly grown under rain fed conditions where it is
subjected to drought stress. The objective of this study was to identify the drought tolerance sources
in induced-mutants of sesame. Sixteen induced mutants and their three respective parental sources
were evaluated in separate experiments under drought stress and normal conditions in the field over
two years (2010 and 2011). Seven drought tolerance indices including stress susceptibility index
(SSI), stress tolerance index (STI), mean productivity (MP), geometric mean productivity (GMP),
tolerance (TOL), yield index (YI) and yield stability index (YSI) were calculated based on yield
under drought (Ys) and yield in optimal conditions (Yp). Factor analysis (FA) evidenced that first and
second factors accounted for 98.7 and 98.5 % of the variation in the first and second year,
respectively. Biplot and FA evidenced that genotypes LC 164, LC 162, BC 167, EF 147 and MT 169
had the highest grain yield under both DS and NS environments in 2010, whereas in 2011 the best
performers in both environments were HC 108, 32-15, HB 168 and 38-1-7. FA and the mean rank
method discriminated genotypes LC 164, LC 162 and BC 167 as the most drought-tolerant in 2010
whereas in 2011 the combined methods identified 32-15 as the highest drought-tolerant genotype.
Plant height, the number of capsules per plant, and the length of the capsules should be considered
in selection for obtaining high-yielding sesame cultivars in drought-stressed environments.
Keywords: Sesamum indicum L., drought stress, yield, criteria.