Effects of Copper-Carbon Core-Shell Nanoparticles on Bald Cypress Seedlings, Bipolaris sorokiniana and a Cinara sp.

摘要

Nanotechnology and the development of new nanomaterials have opened up the potential uses and novel applications in agriculture and biotechnology. As a new generation of renewable composite nano-material, the Copper-Carbon Core-Shell Nanoparticles (CCCSNs) possess many unique properties. Because of their low cost, unique stability, and demonstrated performance against Formosan termite and some fungal diseases, the CCCSNs show a great promise to be utilized as a pest control measure in agriculture, forestry and forest product industries. However, much research is needed to understand the interaction between CCCSNs and living organisms and the impacts of CCCSNs on living organisms before this product can be commercialized.;This study selected three representative living organisms, a tree species, bald cypress (Taxodium distichum), a plant pathogen ( Bipolaris sorokiniana), and a conifer aphid (Cinara sp.) and studied their interactions with CCCSNs. Specifically, the objectives were (1) to quantify the effects of a series of low level of CCCSNs (with equivalent pure Cu concentrations of 0, 73, 147, and 223 ppm) on the physiology of two-year-old bald cypress seedlings during a 20-month treatment, (2) to quantify the effects of a series of high level of CCCSNs (with equivalent pure Cu concentrations of 0, 750, 1500, 3000 ppm) on the physiology of one-year-old bald cypress seedlings during a 3-month treatment through greenhouse experiments, (3) to quantify the effects of CCCSNs on control of a aphid insect, Cinara sp., in comparison with two commercial insecticides (a formulated cleansing concentrate and an insect killing soap) through an in-vitro experiment, and (4) to quantify the effects of CCCSNs on control of the plant pathogen, Bipolaris sorokiniana, in comparison with four other copper based products: copper-gold nanoparticles (Cu-Au-Nps), copper-silver nanoparticles (Cu-Ag-Nps), cupric oxide (CuO), and cuprous oxide (Cu2O), through a series of in-vitro examination.;The results showed that the CCCSNs treatments applied through soil trenching promoted uptake of Cu in bald cypress seedlings. Root system accumulated more Cu than the shoot parts. CCCSNs treatments also induced variations in uptakes of other nutrients, such as N, P, K. However, the CCCSNs treatments at both the series of low levels and the series of high levels did not show negative effects on leaf gas exchange rates, biomass, and growth in both two-year-old and one-year-old bald cypress seedlings.;The aphid experiment indicated that application of CCCSNs slurry as topical spray at concentration as high as 1%, has little insecticidal effect on the Cinara sp, while the two commercial insecticides are most effective in controlling the giant conifer aphid, the Cinara sp.;The fungus experiment showed that both CCCSNs and Cu-Ag-Nps treatments at concentration of 1 g/L had the strongest antifungal effects on the plant pathogen, B. sorokiniana than the Cu-Au-Nps, CuO, and Cu 2O treatments. It is concluded that CCCSNs have a potential to be utilized as a fungicide for managing diseases in the fields of agriculture and forestry.;This research provided baseline information that is fundamental to understanding of the interactions between CCCSNs and living organisms. Such information will be useful in evaluation of the biological functions of engineered nano-materials. Because of the application potentials of the CCCSNs, more research is needed in the future to study the interactions between the CCCSNs and various plant species, insect species, microorganisms, and the environment.