Single and combined effects of fertilization, ectomycorrhizal inoculation, and drought on container-grown Japanese larch seedlings

Abstract

Climate change can intensify drought in many regions of the world and lead to more frequent drought events or altered cycles of soil water status. Therefore, it is important to enhance the tolerance to drought and thus health, vigor, and success of transplantation seedlings used in the forestry by modifying fertilization and promoting mycorrhization. Here, we sowed seeds of Japanese larch (Larix kaempferi) in 0.2-L containers with 0.5 g (low fertilization; LF) or 2 g (high fertilization; HF) of slow-release fertilizer early in the growing season. One month later, we irrigated seedlings with non-sterilized ectomycorrhizal inoculum (ECM) or sterilized solution (non-ECM), and after about 2 months, plants were either kept well watered (WW; 500 mL water/plant/week) or subjected to drought (DR; 50 mL water per plant/week) until the end of the growing season. HF largely stimulated plant growth and above- and belowground biomass production, effects that are of practical significance, but caused a small decrease in stomatal conductance (Gs390) and transpiration rate (E390), which in practice is insignificant. ECM treatment resulted in moderate inhibition of seedling growth and biomass and largely canceled out the enhancement of biomass and foliar K content by HF. DR caused a large decrease in CO2 assimilation, and enhanced stomatal closure and induced senescence. DR also largely depleted foliar Mg and enriched foliar K. Although DR caused a large decrease in foliar P content in LF, it moderately increased P in HF. Likewise, DR increased foliar K in HF but not in LF, and decreased foliar P in ECM plants but not in non-ECM plants. Conversely, ECM plants exhibited a large enrichement in foliar P under WW and had a lower water potential under DR when grown in LF. These results indicate that the drought tolerance and health and vigor of Japanese larch seedlings can be modified by soil fertility and soil microorganisms. This study provides a basis for new multifactorial research programs aimed at producing seedlings of superior quality for forestation under climate change.

Leaf UV-B Irradiation and Mycorrhizal Symbionts Affect Lettuce VOC Emissions and Defence Mechanisms, but Not Aphid Feeding Preferences

“…AMF are widely spread in natural and agricultural ecosystems, and their symbiotic relationship with most land plants provides important ecological services, e.g., increasing plant nutrition and tolerance to both abiotic and biotic stresses, including herbivorous pests [ 13 ]. The mycorrhizal status of plants is also a key factor leading to changes in plant physiology, e.g., nutrient dynamics and secondary metabolism [ 14 , 15 , 16 , 17 ], thus affecting the quality of plants as suitable hosts for insect pests [ 18 ]. AMF and UV-B may be involved in the modification of the emission of volatile organic compounds (VOCs), which are responsible for the communication of plants with the surrounding environment [ 19 , 20 ].…”

Effects of Seedling Size, Stock Type, and Mechanical Site Preparation Method on Initial Survival and Growth of Japanese Larch (Larix kaempferi) Seedlings

“…It has been reported that the small container-grown seedlings do not grow taller than bareroot seedlings after planting [14,15]. Some studies have recently been conducted on methods to produce high-quality container-grown seedlings; however, knowledge regarding what characteristics contribute to the effective performance of container-grown Japanese larch seedlings after planting is still insufficient [16][17][18][19].…”

Green Synthesis of Hyperbranched Spermine-Coated Fe3O4 Nanoparticles and Their Effect on Corn Seedlings under Copper Oxide Stress

“…In addition to the important function of micronutrients in enhancing plant germination and growth, under abiotic stress conditions, polyamines (PAs) have a significant effect on enhancing tolerance to abiotic stresses . PAs are small organic polycations that are commonly prevalent in living organisms and are now regarded as a new class of growth substances that include spermidine, spermine, and their obligate precursor putrescine, which play a key role in regulating plant developmental and physiological processes .…”