Stability analysis for yield traits and association mapping of quality traits in oat (Avena sativa L.)
Loading...
Date
2023-03-09
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CSK HPKV, Palampur
Abstract
Population growth, hunger and climate change are the major problems in the world.
Therefore, a paradigm shift in agriculture is required to explore neglected and underutilized
crop species that possess agronomic, nutritional and climate-resilient traits. Harnessing
diverse oat genetic resources and development of stable cultivars are the sustainable solution
to overcome these problems to some extent. Therefore, experiment was carried out to identify
yield stable oat genotypes in organically and conventionally managed fields in the North
Western Himalayas using AMMI and GGE biplot analysis and facilitate genetic dissection of
quality traits employing ddRAD based GWAS approach. Ninety-six diverse oat genotypes
were tested in five environments (year-production system combinations) using 12×8 alpha
lattice design with three replications. Pooled ANOVA showed significant genotypic,
environmental and GEI effects, suggesting GEI can be assessed in this population.
Conventional system had higher yield over organic system across years. Environment and
GEI were the major source of variation for all traits except dry matter percentage. Seed yield
per plant showed positive significant association with biological yield per plant and harvest
index whereas green fodder yield per plant exhibited positive significant association with
number of leaves per plant and dry matter yield per plant. Genotypes SKO-190, UPO-119,
OS-92, HJ-8, Choripatti and EC-523890 for seed yield per plant and HFO-878, HFO-502 and
PLP-14 for green fodder yield per plant were found to be widely adapted. On the basis of
polygon view of the GGE biplot, two mega-environments (MEs) were identified with winning
genotypes ADG-96 and IG-03-205 in ME-1 and SKO-190, EC-605837, PO-1 and KUE in
ME-2 for seed yield per plant whereas JPO-38, IG-03-205 and UPO-119 in ME-1 and SKO 28, RO-19, UPO-102 and JHO-99-2 in ME-2 for green fodder yield per plant. Genome-wide
35,262 SNP markers were used for the identification of genomic loci associated with five
grain and forage quality traits phenotyped in different production systems across years.
Distribution of SNPs ranging from 998 (chromosome 6D) to 2945 (chromosome 1A) with
SNP density ranged from 1.94 per Mb to 5.60 per Mb window size. Population structure and
kinship matrix analysis divided population into three groups with some admixtures indicating
sufficient genetic variation. Total 31 significant marker-trait associations were detected across
twenty one chromosomes for five quality traits. Out of which 6, 3, 9, 9 and 4 were identified
for ADF, NDF, β-glucan content, crude protein content and crude protein yield per plant,
respectively and explained 0.18 to 17.87% of total phenotypic variation. Twenty putative
genes were found to be associated with QTLs linked with quality traits (100 Kb either side).
Out of 31 QTLs, 10 QTLs explained more than 10% of total phenotypic variation thus these
can be considered as major QTLs indicating a potential for using these markers in genomic assisted oat breeding programme.