Morphological and molecular insights of root dynamics in rice-fallow lentil (Lens culinaris Medik.)

Lentil is a promising crop for diversifying the vast, untapped rice-fallows of South Asia. However, augmenting lentil productivity in this niche remains a key challenge due to poor soil biophysical properties. Research gap on root trait variation warrants harnessing genotypic variability of lentil root system to shed light on root developmental plasticity. The present study aimed to assess the genotypic variability of 24 lentil genotypes in root traits under differential tillage practices of rice-fallow systems and identify key root traits contributing to root architectural plasticity. Additionally, the role of genes controlling root development in lentil was elucidated. The results revealed substantial genetic variability in root traits and the prospective lentil genotypes had better total root length, surface area, volume, and lateral root numbers. Significant correlations among vital root traits providing a win-win opportunity for the researchers to target these traits for improving resource acquisition in challenging environments. Notably, this study is the first to elucidate the role of triphosphate tunnel metalloenzyme 3 (LcTTM3), and auxin transporter like protein 5 (LcLAX5) in root development, as genotypes with a robust root system exhibited significantly higher transcript-level variation for these genes. Based on a summation rank index, four superior genotypes (2011S 56234-1, ILL-10961, L-1112-19, and ILL-7978) were identified as ideal candidates for cultivation in rice-fallow systems, irrespective of tillage practices. This study provides valuable insights into the genetic basis of root development and its role in nutrient and water uptake efficiency to reduce yield risks and enhance system resilience in lentil.