Genetic Mapping of the Serrated Leaf Trait in Indian Mustard (Brassica juncea)
Priyansha Singh, PhD scholar, University of Delhi, South Campus
Leaves exhibit amazing variations in shape and size, both of
which result from a complex network of hormone signalling and wide array of
genetic factors. The lobed leaf character is an easily recognisable and unique
morphologic trait in Brassicas, with potential advantages for agricultural
productivity. Brassica juncea var. tumida is quite distinct in leaf morphology
with its serrated margins. For genetic mapping of the serrated leaf character,
tumida was crossed with popular and high yielding B. juncea var. Varuna, which
has smooth margins. The F1 plants showed an intermediate leaf type. A large
number of doubled haploids were raised, and were phenotyped for their leaf morphology
and 11 main agronomic traits. The doubled haploid lines were genotyped with
intron polymorphisms, microsatellite, KASPar and genotyping by sequencing (GBS)
based SNP markers. Twenty-one restriction enzyme combinations were tested using
IgCoverage for in silico evaluation of genomic coverage through GBS. A genetic
map was developed and primary genetic analysis of the serrated leaf character
was performed which mapped it to a 417.5 kb region of B. juncea A10. Fine
mapping in this region is underway for the identification of candidate genes
which will facilitate the cloning and identification of the target gene.
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