| Abstract: | Every breeding program that aims to create new and improved cultivars with desired traits mostly relies on
information related to genetic diversity. Therefore, molecular characterization of germplasms is important to obtain target
cultivars with desirable traits. Sweet potato Ipomoea batatas (L.) Lam] is widely considered the world’s most important crop,
with great diversity in morphological and phenotypic traits. The genetic diversity of 20 sweet potato germplasms originating
from Bangladesh, CIP, Philippines, Taiwan, and Malaysia were compared, which was accomplished by genetic diversity
analysis by exploring 20 microsatellite DNA markers for germplasm characterization and utilization. This information was
effective in differentiating or clustering the sweet potato genotypes. A total of 64 alleles were generated using the 20 primers
throughout the 20 germplasm samples, with locus IBS97 having the highest number of alleles (5), whereas locus IbU33 had
the fewest alleles (2). The alleles varied in size from 105 (IbU31) to 213 base pairs (IBS34). The Polymorphism Information
Content (PIC) values for the loci IbL46 and IBS97 varied from 0.445 to 0.730. IBS97 has the highest number of effective
alleles (3.704), compared to an average of 2.520. The average Shannon’s diversity index (H) was 1.003, ranging from 0.673 in
IbU3 to 1.432 in IBS97. The value of gene flow (Nm) varied between 0.000 and 0.005, with an average of 0.003, whereas
genetic differentiation (FST-values) ranged between 0.901 and 1.000. The sweet potato germplasm included in this study had
a broad genetic base. SP1 vs. SP9 and SP12 vs. SP18 germplasm pairings had the greatest genetic distance (GD = 0.965),
while SP1 vs. SP2 germplasm couples had the least genetic diversity (GD = 0.093). Twenty genotypes were classified into two
groups in the UPGMA dendrogram, with 16 genotypes classified as group “A” and the remaining four genotypes, SP10,
SP18, SP19, and SP20, classified as group “B.” According to cluster analysis, the anticipated heterozygosity (gene diversity) of
Nei (1973) was 0.591 on average. In summary, SSR markers successfully evaluated the genetic relationships among the sweet
potato accessions used and generated a high level of polymorphism. The results of the present study will be useful for the
management of germplasm, improvement of the current breeding strategies, and the release of new cultivars as varieties. |
