Indian Society of Genetics & Plant Breeding
Sorghum (Sorghum bicolor (L.) Moench) is considered as
a model species for drought tolerance due to its inherent
drought tolerant characteristics. The accessions were
grouped into 27 major clusters elucidating a high level of
genetic diversity which will be useful for identifying
suitable genotypes for drought tolerance breeding. The
best characterized form of drought tolerance during crop
growth is the non-senescence or “stay-green” trait. Genetic
diversity analysis carried out with 100 sorghum genotypes
for drought tolerance using 13 stay-green specific
polymorphic SSR markers revealed high level of
polymorphism among the genotypes. A total of 56 scorable
alleles were generated of which 55 were polymorphic. The
number of alleles produced by different primers ranged
from two to seven with an average of 4.0 alleles per primer.
The polymorphic loci clearly discriminate all the
genotypes. The similarity coefficients based on 13 SSR
markers ranged from 0.02 to 1.00. Among the 100
accessions three genotypes viz., IS 29389, IS 29393 and
IS 29496 and two other genotypes IS 23392 and IS 23397
showed the highest similarity index (1.00), and the
genotypes IS 22005 and IS 24693, showed the least
similarity index (0.02). The dendrogram, which classified
the hundred sorghum accessions into twenty-seven major
clusters and discriminated the drought tolerant genotypes
with susceptible genotypes. Cluster analysis categorized
the drought resistant and drought susceptible genotypes
in to separate clusters. Most of the genotypes in the cluster
IV had the better stay-green score. The stay-green specific
genes may be present in most of these genotypes and
classified as drought tolerant. In general, the genotypes
B 35, IS 22212, IS22335, IS 22697, IS 29323, IS 22243, IS
23418, IS 22794, IS 21756 and IS 22339 exhibited drought
tolerance phenomenon and were grouped as drought
tolerant under molecular level of genetic diversity.
Keywords: Genetic diversity, Sorghum bicolor, drought tolerance, stay-green, SSR markers
Year: 2011
Volume: 71
Issue: 1
Article DOI: N/A
Print ISSN: 0019-5200
Online ISSN: 0975-6906
K. Rajarajan and K. Ganesamurthy info_circle
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