Integrated phenotypic and DNA barcoding analysis of Brassica genotypes

Abstract

Brassica junceae (L.) Czern. (Indian mustard) plant is one of the world’s most vital agricultural crops that is also known as cruciferous oilseed crops. This study characterises ten Brassica genotypes from Rajasthan, India, using integrated morphological, biochemical and molecular approaches. Nine morphological traits were assessed using a randomized complete block design (RCBD) with 3 replicates. Biochemical profiling was assessed and quantified for glucosinolates, antioxidants, β-carotene, vitamin E, erucic acid and oil content. The DNA barcoding genes matK and rbcL loci, were analysed through Sanger sequencing following through phylogenetic reconstruction (UPGMA/ML/NJ; Kimura 2-parameter model). Principal component analysis (PCA) further explains 69.2 % morphological variation, with yield components dominating in PC1. Control genotype PM-21 exhibited superior performance (199 siliqua/plant, 5.56 cm siliqua length, 5.485 g yield), while control genotype PM-30 showed relatively high β-carotene (2.315 ppm) and vitamin E (25.17 mg/g). Parallelly glucosinolate content ranges from 15.7–83.7 µmol/g. Genetic parameters revealed moderate to high GCV (16–29 %) and PCV (32–72 %). The DNA barcoding confirms the species identity (99–100 %, GenBank; ON556533-ON556542). This study identifies a promising genotype (PM-21, PM-30) for better yield and nutritional breeding for preliminary single-location characterisation. Future research should integrate these nuclear markers simple sequence repeats (SSRs)/single nucleotide polymorphisms (SNPs) and multi-location trials to translate this variation into practical breeding applications.