Biopriming of sunflower (Helianthus annuus L.) seed with Pseudomonas fluorescens for improvement of seed invigoration and seedling growth

Abstract

Biopriming treatment is potentially able to promote rapid and more uniform seed germination and plants growth associated with bacterial coatings. In this study, we report application of some effective biological agents on sunflower seed and their impact on seedling. We investigated the effects of 30 strains of Pseudomonas fluorescens on improving sunflower seed germination and promotion of seedling growth. After selection of efficient strains, efficacy of biopriming seed treatment was compared with seed inoculation and priming treatments. Two strains, including UTPf76 and UTPf86, were selected for next experiments because they enhanced seed factors such as germination index, germination percentage, germination rate and vigor index and also seedling growth indices including root length, shoot height, dry and wet weight of seedlings and numbers of lateral roots. In biopriming, the selected strains were applied to the seed during osmopriming with NaCl. Biopriming was significantly improved by the capability of these strains and the highest amount (P= 0.01) of shoot height (28.2 cm), root length (35.9 cm) and seedling weight (8.9gr) reached, in comparison with other treatments and the control. As a conclusion, biopriming with Pseudomonas fluorescens UTPf76 and UTPf86 have provided very well establishment and adherence of bacteria to the seed, before planting, and thus is suggested as a proper treatment for enhancement of seed indices and improvement of seedling growth.