| dc.description.abstract | Turmeric (Curcuma longa L.) commonly known as golden spice is an
economically important spice crop. Turmeric genotypes exhibit wide intraspecific
variation for the biologically active principles coupled with morphological variation.
Given the large influence of the environment on phenotypic variability, there is no
clear understanding about the relation of genetic base with the observed phenotypic
variability. Here, we have studied the genetic diversity in turmeric diversity panel
comprising 93 genotypes by examining the phenotypic variability alongside the
molecular genetic variability to find marker-trait associations.
Phenotypic characterization revealed significant genetic variation among 93
genotypes. Flow cytometric analysis revealed that among the 93 genotypes, majority
were triploids (84) and nine were tetraploids. Most of the tetraploids have origins as
seedling progenies while few are germplasm collection. It was found that triploids
and tetraploids differ significantly in their plant height, number of shoots, number of
leaves on main shoot, petiole length, leaf length, length of mother rhizome, length of
primary rhizomes, length of secondary rhizomes, girth of secondary rhizomes, inner
core diameter of primary rhizome, weight of mother rhizomes per plant, weight of
primary rhizomes per plant, total rhizome weight per plant and dry rhizome weight
per plant. Genetic variability analysis revealed that characters; number of shoots per
plant, length of mother rhizome, total weight of mother rhizomes per plant, total
weight of rhizome per plant and dry weight of rhizome per plant were the most
important traits for selection across ploidy levels.
Here, we have utilized molecular marker based genotyping as well as NGS
based genotyping to study the genetic relationship of the genotypes under study.
Although, reliable and reproducible, the inherent limitations of molecular marker to
achieve the requisite resolution for association studies led us to proceed with NGS
based genotypic data. Here, we have optimized a bioinformatics pipeline or
workflow for variant calling which have resulted in discovery of 30438 SNP
variants. Further, we have analysed the population structure of genotypes understudy (to avoid false positive marker trait associations in downstream analysis) and
have found that there are three subpopulations. Further the association mapping for
three key traits has revealed nine significant marker trait association for : curcumin
content (1), rhizome length (5), and rhizome girth (3). Most marker trait associations
were from chromosome 4. Zingiber officinale MADS-box transcription factor 34-
like (LOC122034397) can be a putative locus involved in rhizome length
morphology. Thus, results obtained here will add onto the understanding of genetic
base of these complex traits in turmeric and to further crop improvement efforts in
turmeric | en_US |
