Development of robust nurseries through cyanobacteria as seed priming or nursery media amendment options and their interactions with tomato cultivars

• Robust nurseries were generated by cyanobacterial priming of potting media or seeds. • Anabaena torulosa BF1 or Anabaena laxa RPAN8 explored in three tomato cultivars. • Differential modulation of vigor indices, nutrients availability and PLFA profiles. • A. laxa was the top performer in cv.’PC1’ and A. torulosa in cv. ‘NS4266’. • Potting media amendment with A. laxa was the most promising intervention. Establishing healthy nurseries via soilless media is highly important for promoting protected cultivation as a commercial horticultural venture; however, the use of microbes and their cultivar-specific interactions are rarely considered. The enrichment of potting media (mix of cocopeat: vermiculite: perlite at a 3:1:1 ratio) or seed priming with the C N-fixing cyanobacteria Anabaena torulosa BF1 or Anabaena laxa RPAN8 was envisaged as a means of stimulating seedling growth. A comparison of the performance of three tomato cultivars, cv. ‘Pusa Cherry 1′ (PC1), cv. ‘Pusa Roma’ and cv. ‘NS4266’ (different genetic backgrounds), revealed that A. torulosa performed better than A. laxa in cv. ‘PC1’, recording 97.3 % seedling emergence, but performed statistically at par with cv. ‘NS4266’ . Anabaena laxa effectively increased the vigour indices by 23.6–43.8 % in ‘PC1’ and’NS4266’cvs . ‘PC1’ cultivar grown in A. laxa primed media presented 18 % and 39 % greater values of leaf pigments than did cv. ‘Pusa Roma’ and cv. ‘NS4266’ cultivars , respectively. Seed priming with A. laxa in cv. ‘NS4266’ led to a 1–2-fold greater accumulation of glomalin-like proteins and polysaccharides, with PLFA-based profiles illustrating the enrichment of copiotrophic communities in the potting medium. A significant increase in leaf glutamine synthetase and PEP carboxylase activities, over hydropriming was recorded. A cultivar-wise comparison of the performance of different treatments revealed that A. laxa was the top performer in cv. ‘PC1’ and A. torulosa in cv. ‘NS4266’, whereas cv. ‘Pusa Roma’ responded equivalently to both cyanobacterial treatments . The treatments involving potting media amended with A. laxa were distinctive and identified as the most promising interventions for generating robust nurseries.