AUTHOR=Patel Manoj Kumar , Chaudhary Rajat , Taak Yashpal , Pardeshi Priya , Nanjundan Joghee , Vinod K. K. , Saini Navinder , Vasudev Sujata , Yadava D. K. 

TITLE=Seed coat colour of Indian mustard [Brassica juncea (L.) Czern. and Coss.] is associated with Bju.TT8 homologs identifiable by targeted functional markers

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1012368

DOI=10.3389/fpls.2022.1012368

ISSN=1664-462X

ABSTRACT=<p>Seed coat colour is an important trait in Indian mustard. Breeding for seed coat colour needs precise knowledge of mode of inheritance and markers linked to it. The present study was focussed on genetics and development of functional markers for seed coat colour. F<sub>1</sub>s (direct and reciprocal) and F<sub>2</sub> populations were developed by crossing two contrasting parents for seed coat colour (DRMRIJ-31, brown seeded and RLC-3, yellow seeded). Phenotypic results have shown that the seed coat colour trait was under the influence of maternal effect and controlled by digenic-duplicate gene action. Further, <italic>Bju.TT8</italic> homologs of both parents (DRMRIJ-31 and RLC-3) were cloned and sequenced. Sequencing results of <italic>Bju.TT8</italic> homologs revealed that in RLC-3, gene <italic>Bju.ATT8</italic> had an insertion of 1279bp in the 7<sup>th</sup> exon; whereas, gene <italic>Bju.BTT8</italic> had an SNP (C→T) in the 7<sup>th</sup> exon. These two mutations were found to be associated with yellow seed coat colour. Using sequence information, functional markers were developed for both <italic>Bju.TT8</italic> homologs, validated on F<sub>2</sub> population and were found highly reliable with no recombination between the markers and the phenotype. Further, these markers were subjected to a germplasm assembly of Indian mustard, and their allelic combination for the seed coat colour genes has been elucidated. The comparative genomics of <italic>TT8</italic> genes revealed high degree of similarity between and across the <italic>Brassica</italic> species, and the respective diploid progenitors in tetraploid <italic>Brassica</italic> species are the possible donors of <italic>TT8</italic> homologs. This study will help in the marker-assisted breeding for seed coat colour, and aid in understanding seed coat colour genetics more precisely.</p>