Categorization of Chickpea Nodules and Their Relation with Plant Growth

We categorized chickpea nodules based on their size (mm) [large (> 7), medium (2–7), small (< 2)] and position on roots (primary or lateral) to derive relations between nodule categories and plant growth attributes. Large-sized nodules (LSN) were mostly developed on primary roots (83%), where medium-sized nodules (MSN) were observed both on primary and lateral roots, and small-sized nodules (SSN) were mostly found on lateral roots. Plant growth attributes had strong positive correlations with LSN number, but not with MSN and SSN number. Leaf, stem, root, and total plant biomass had positive associations with LSN weight (particularly LSN on primary roots), but not with MSN and SSN weights. Multivariate regression analysis also revealed the same. This nodule fractionation technique could be used to characterize chickpea nodules and to quantify the contribution of nodules towards plant growth. This criterion may be used for screening and identifying efficient nodulating chickpea genotype(s).