Twenty-four start codon targeted (SCoT) markers were used to assess genetic diversity and population structure of indigenous, introduced and domesticated ramie (Boehmeria nivea L. Gaudich.). A total of 155 genotypes from five populations were investigated for SCoT polymorphism, which produced 136 amplicons with 87.5% polymorphism. Polymorphism information content and resolving power of the SCoT markers were 0.69 and 3.22, respectively. The Indian ramie populations exhibited high SCoT polymorphism (> 50%), high genetic differentiation (GST = 0.27) and moderate gene flow (Nm = 1.34). Analysis of molecular variance identified significant differences for genetic polymorphism among the populations explaining 13.1% of the total variation. The domesticated population exhibited higher genetic polymorphism and heterozygosity compared to natural populations. Cluster analysis supported population genetic analysis and suggested close association between introduced and domesticated genotypes. The present study shows effectiveness of employing SCoT markers in a cross pollinated heterozygous species like Boehmeria, and would be useful for further studies in population genetics, conservation genetics and cultivar improvement.

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In jute (Corchorus spp.), phenylpropanoid biosynthesis pathway is associated with lignocellulosic bast fibre development and production of various phytochemicals. Development of phenylpropanoid‐related genic markers is thus a key component of gene‐specific precision molecular breeding in jute. We identified a total of 12,772 SSRs in 10,041 unigenes and designed genic SSR markers associated with phenylpropanoid biosynthesis from bast transcriptome of Corchorus capsularis cv. ‘JRC‐212’. A total of 39 and 14 SSR markers were developed from key genes of phenylpropanoid biosynthesis and bast fibre formation, respectively. Further, we developed 457 SSR markers associated with different regulatory gene sequences. Of these, 137 markers were for transcription factors such as WRKY, MYB, MYB‐related, bHLH and zinc finger, which are key regulators and/or modulators of the biosynthesis of phenylpropanoids. Additionally, 600 SSR primer pairs were also designed for other unigenes containing SSR. Diversity analysis based on a set of 41 genic SSR markers in 35 genotypes revealed high polymorphism. The genic SSRs described here are expected to be useful for molecular breeding targeting fibre quality, phytochemical‐related and stress tolerance traits in jute.

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