Cyanobacteria-coated seeds for improved productivity and seed storability in direct-seeded and transplanted rice
摘要
The potential of cyanobacterial seed coating as a sustainable strategy was explored to enhance rice productivity. With Direct Seeded Rice (DSR) gaining significance as a resource conserving strategy, the coated seeds were evaluated to compare their performance in a field experiment with both DSR and Transplanted Rice (TPR) systems. Diazotrophic, plant growth promoting cyanobacterium Anabaena laxa RPAN8 was delivered to the seeds, through carriers containing vermiculite (V) alone or mixed (PV) with paddy straw compost (P), along with gum arabic + 1% FeSO4, as sticker and additive respectively. Significant enhancement was recorded in the activity of key plant enzymes with cyanobacterial treatments, particularly, RPAN8-PV. Grain and straw yields were significantly higher (p < 0.05), than control, with increase of 37.8 and 37.4%, respectively. Cyanobacterial treatments and DSR/TPR systems brought about significant, yet differential, enrichment of micronutrients in grains, through greater uptake and mobilization of Fe and Zn from soil to leaves to grains (husk, bran, kernels). Several-fold increase in cyanobacterial treatments were recorded in terms of soil microbiological indices linked to metabolic activities such as dehydrogenase activity and biological nitrogen fixation. Redundancy analyses highlighted strong correlation of these attributes with plant metabolic traits. Furthermore, the superiority and storability of the cyanobacteria-coated seeds was evidenced by the significantly higher germination and vigour indices, and viability of the cyanobacterium on seeds, after 12 months of storage. Overall, cyanobacterial seed coating can be promoted as an effective, eco-friendly and nutrient-enriching strategy to improve rice productivity, particularly for promoting DSR, as a viable option.