Insights into morphological, anatomical, and molecular traits for superior fiber yield and quality in dark jute

The lignocellulosic fibers obtained from dark jute are of superior strength, but their coarseness often limits their industrial value, and fiber quality estimation processes further complicate plant selection. Therefore, the current investigation was undertaken to identify some high-yielding and fine-fiber-producing dark jute cultivars among a diverse panel based on morphological and anatomical characteristics. Furthermore, the role of lignin and some genes associated with its biosynthesis pathway, which influence fiber quality attributes, were investigated. The pooled analysis of variance over 2 years demonstrated significant variations among the genotypes across the evaluated traits. The genetic parameters, principal component analysis, and correlation studies signified that the assessment of mid-diameter alongside plant height and basal diameter could enhance the selection efficiency for high-fiber-yielding cultivars. Among the bark anatomical traits, the area of the fiber wedge, lumen area, and number of fiber cells per bundle demonstrated the best estimates of fiber yield and quality. The lignin content (%) and the activities of the phenylalanine ammonia-lyase (PAL) and cinnamyl alcohol dehydrogenase (CAD) enzymes revealed significant differences among the genotypes under evaluation, with a positive association between them for fiber strength and fineness. The upregulated activity of the genes PAL, CAD, and 4-coumarate-CoA ligase (4CL) in the genotype BCCO 105 than in its fine fiber-producing counterpart (OIN 95) depicted a critical role of these enzymes leading to disparity in fiber qualities. The high-fiber yielders (BCCO 105, OIN 123) and fine-fiber producing genotypes (OIN 95, OIN 128, BCCO 115, BCCO 120) detected in the present study will not only enrich the breeding materials for future fiber quality enhancements but also fulfill the quest for a superior fiber producing dark jute cultivar that can be utilised in the industrial sector efficiently.