BLOG #12

Wheat is a major food crop that contributes significantly to the world food supply. Its production is vulnerable to climatic and environmental conditions. However, industry advancements have improved productivity and yield stability under unfavorable conditions.   In the article “Coating seeds with endophytic fungi enhances growth nutrient uptake, yield and grain quality of winter wheat,” Colla et al.1 (2015)presented a study which assessed the effects of arbuscular mycorrhizae (Glomus intraradices BEG72 and G. mosseae) and Trichoderma atroviride MUCL 45632 delivered as a seed coating on winter wheat based on the hypotheses that “seed coating of wheat with a microbial consortium based on the arbuscular mycorrhizal fungi and Trichoderma spp. improve seedling establishment, yield and grain quality.”

The use of beneficial microorganisms has been a topic of interest due to their many demonstrated benefits to the soil and crop production, and their contribution to sustainable agriculture - including improvements in resource use efficiency. Arbuscular mycorrhizae (AM) is one of the most prevalent fungi that maintains a symbiotic association with plant roots, providing benefits to soil structure and fertility, and improvements in plant functions such as nutrient uptake and stress response. Trichoderma is the most common fungi of the rhizosphere that feed on nonliving organic matter and has shown biocontrol effectiveness and improvements in the solubility of some soil micronutrients.

Experiment 1 of the study was conducted in a growth chamber to verify the capability of seed coating with AM fungi and Trichoderma atroviride to promote the emergence and plant growth of wheat seedlings. Experiment 2 was conducted in-field over two growing seasons with varying environmental conditions, to assess the effects of seed coating with the AM fungi and Trichoderma atroviride on SPAD index, chlorophyll fluorescence, plant growth, yield, grain quality, and mineral composition of winter wheat.

In Experiment 1, the mean emergence time was reduced, and the SPAD index, number of leaves, and shoot and root dry biomass was significantly higher as compared to non-coated seeds. (figure 1)

Air temperature and total precipitation varied between the two seasons (2011-12 and 2012-13) in Experiment 2. The percentage of AM colonization at the anthesis growth stage was higher in both seasons as compared with the uncoated seeds, and the dryer season of the two had higher mycorrhizal root colonization. The number of Trichoderma colonies found in the soil and roots for the coating treatment were also higher as compared to the control.

There were many favorable benefits identified in the study for coated seeds:

  • In conclusion, the authors stated that “coating seeds with a microbial inoculum containing intraradices BEG72, G. mossae and T. atroviride MUCL 45632 enhanced the mean emergence time and shoot biomass of wheat seedlings, through an increase in root dry weight.”
  • Their results also “demonstrated that coated seeds with Glomus and Trichoderma had improved grain quality (protein, P, K, Fe concentration), yield and yield stability among the two growing seasons.”
  • The authors associated the improvement in grain yields and yield stability in the coated seeds to “a higher chlorophyll concentration, higher photochemical activity of PSH, and to a better nutritional status (higher leaf N, P, K, Fe, and Zn concentration) of wheat.”

Interested in reading the specifics? You may view the entire study here:

(1)Colla, Giuseppe & Rouphael, J. & Bonini, Paolo & Cardarelli, Mariateresa. (2015). Coating seeds with endophytic fungi enhances growth, nutrient uptake, yield and grain quality of winter wheat. International Journal of Plant Production. 9. 171-189.