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Soil salinity results in reduced productivity in field peas, making soil salinity tolerance a critical breeding objective. In this study, four pot experiments were carried out in semi-controlled environments over four consecutive years to assess the contribution of seedling vigour to salinity tolerance at the seedling stage. Split-plot designs were used to assess the effect of salt stress (sodium chloride solution at 16 dSm−1) and control conditions. Extensive sets of advanced breeding lines were used in 2018–2020 to assess growth differences in relation to the treatment, with elemental analysis used on a subset of 15 lines in 2021. A salt tolerance index (STI) was defined as a proportion of shoot biomass under salt stress (DWstress) relative to the shoot dry weight under control (DWctrl). Visual scores of salt stress were recorded on a 1–10 scale (1 = tolerant, 10 = susceptible) from salt stress treatments. The consistent positive and significant correlations (p < 0.01) between shoot DWctrl and DWstress indicated that vigorous genotypes maintained higher shoot DWstress. Both the shoot DWctrl and shoot DWstress had negative and significant (p < 0.01) correlations with visual scores of salt stress. Shoot DWstress showed strong positive correlations with STI (p < 0.01). Both the shoot DWctrl and Shoot DWstress had negative correlations (p < 0.01) with shoot Na+ whereas shoot DWstress had a positive correlation (p < 0.05) with root Na+ concentration. The results indicated that seedling vigour (measured as shoot DWctrl) contributed to salinity tolerance by maintaining improved shoot DWstress, limiting Na+ deposition in shoot and enduring less tissue damage in field pea seedlings. Additional field evaluations are required to establish the correlations of tolerance at seedling stage with yield under saline conditions. The insights obtained from this study may assist field pea breeders in identifying salt-tolerant parent plants, offspring, and breeding lines during the initial growth phases. [ABSTRACT FROM AUTHOR]

Future productivity increases of lentil in the face of changing climates and their expansion into areas traditionally considered marginal for commercial production will require greater tolerance to a range of abiotic constraints, particularly in relation to edaphic conditions. Variation in root system architecture presents a possible means of addressing these constraints. Whilst considerable attention has been paid in the past to above-ground traits; little attention has been given to how root traits can improve adaptation to new environments and productivity. This study aimed to characterise the diversity in root traits present in the Australian lentil germplasm and how breeding may have impacted these traits. The study examined 36 genotypes of lentil registered over the past 27 years in Australia. The experiments were carried out under glasshouse conditions in 2021 and in the field in 2020 and 2021. Results showed a significant variation in both shoot and root traits. Late maturing genotypes accumulated more root biomass, which was associated with a negative impact on yield, harvest index and 100 grain weight. Root traits that varied substantially among genotypes included root biomass, length, depth, surface area, root: shoot ratio and diameter below 60 cm. Geneotypes were catergoised into two major root forms based on root length distribution, 'Shallow' and 'Deep'. Assessment of genotypes registered since the inception of the breeding program showed an indirect selection for smaller roots with early maturity and increasing yield. Lentil varieties released for broadacre cropping in Australia have been selected for shoot architecture and yield, which has inadvertently resulted in variation in root architecture. Thus, these variations and plasticity in root architectural responses can be directly targeted for the future development of climate-ready crops. • Lentil breeding has produced genotypes with early maturity and greater yields. • Breeding for better shoot and yield traits has indirectly selected smaller roots. • Genotypes differed significantly in both shoot and root traits. • Late maturing genotypes accumulated more shoot and root biomass. • Root biomass had a negative impact on yield traits under optimum conditions. [ABSTRACT FROM AUTHOR]