A total of 130 flax accessions of diverse morphotypes and worldwide origin were assessed for genetic diversity and population structure using 11 morphological traits and microsatellite markers (15 gSSRs and 7 EST–SSRs). Analysis performed after classifying these accessions on the basis of plant height, branching pattern, seed size, Indian/foreign origin into six categories called sub-populations viz. fibre type exotic, fibre type indigenous, intermediate type exotic, intermediate type indigenous, linseed type exotic and linseed type indigenous. The study assessed different diversity indices, AMOVA, population structure and included a principal coordinate analysis based on different marker systems. The highest diversity was exhibited by gSSR markers ( SI = 0.46; He = 0.31; P = 85.11). AMOVA based on all markers explained significant difference among fibre type, intermediate type and linseed type populations of flax. In terms of variation explained by different markers, EST-SSR markers (12%) better differentiated flax populations compared to morphological (9%) and gSSR (6%) markers at P = 0.01. The maximum Nei's unbiased genetic distance ( D = 0.11) was observed between fibre type and linseed type exotic sub-populations based on EST-SSR markers. The combined structure analysis by using all markers grouped Indian fibre type accessions (63.4%) in a separate cluster along with the Indian intermediate type (48.7%), whereas Indian accessions (82.16%) of linseed type constituted an independent cluster. These findings were supported by the results of the principal coordinate analysis. Morphological markers employed in the study found complementary with microsatellite based markers in deciphering genetic diversity and population structure of the flax germplasm.

Tossa jute is an important natural fiber crop of Southeast Asian countries including India, Bangladesh, China, Thailand, Myanmar etc. Traditional industrial application of jute fiber is limited to the packaging products like hessians, sacks, etc. and the fiber found unsuitable for textile industries largely due to significantly high lignin content. Therefore, understanding genetic factors underlying lignin biosynthesis in tossa jute holds promise for jute based product diversification. The major limiting factor in undertaking such study is unavailability of efficient protocol for RNA extraction at secondary growth active stage of tossa jute. Here we report a simplified, swift and cost effective protocol for isolating fairly good quality RNA from bark tissue of 65-days-old field grown tossa jute plant with active secondary growth. The purity, concentration and integrity of extracted RNA ascertained. To confirm downstream amenability, isolated RNA samples were reverse transcribed and PCR analysis done by using CCoAMT1 primer. Results established that method of RNA extraction presented here is an improvement over the other methods, particularly for bark tissue of field grown tossa jute at advance developmental stage. Therefore, present study will enhance our ability to understand expression pattern of fiber formation and maturation related genes in mature bark tissue that holds key for much talked genetic manipulation of fiber quality via lignin optimisation in the crop.