Identification of QTLs linked to early maturity and yield-related traits in horsegram (Macrotyloma uniflorum).
Loading...
Date
2019-07-23
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CSK HPKV, Palampur
Abstract
Macrotyloma uniflorum is an important, self pollinated diploid (2n=2x=20) food
legume with probable genome size of 400Mbps. Limited genomic resources and lack of
genetic variation are major constrains in its genetic improvement. Further, horsegram
production is hampered due to twining growth habit, longer days to maturity, photosensitivity
and indeterminate growth habit. The present study was aimed to construct linkage map of an
intraspecific F8 RILs population of 162 individuals derived from HPKM249×HPK4 of
horsegram and identification of genomic regions linked to early maturity and yield related
traits. Two thousand and eleven molecular markers were screened for parental polymorphism
and 493 (25.42 %) were found to be polymorphic among the parents. Of these, 295 were
mapped on ten linkage groups at LOD 3.5 spanning 1541.7 cM with an average marker
density of 5.20 cM.
Analysis of variance of 162 RILs revealed significant differences for all the measured
traits. Phenotypic data from the RILs were used to identify QTLs for early maturity and yield
related traits by composite interval mapping (CIM). A total of 27 QTLs (LOD ≥ 2.5) were
detected across the three environments (Palampur 2016, Palampur 2017, Bajaura 2017) and
combined data) for 24 traits. Among these, 15 were major QTLs with PVE greater than ten
per cent and five were stable QTLs across locations and years. Phenotypic variation explained
(PVE) by QTLs ranged from 6.4 to 53.4 per cent. The highest phenotypic variation (53.4 %)
was explained by the QTLs for root length.
In conclusion, it is envisaged that the present linkage map, fortified with 295 SSR
markers and 27 QTLs for early maturity and yield-related traits would provide genomics tools
to breeders for further genetic enhancement of this crop species. Thus, the current study will
serve as a strong foundation for further validation and fine mapping of QTLs for utilization in
horsegram breeding programs.
Description
Keywords
null