Recent Advances in Nano‑Enabled Seed Treatment Strategies for Sustainable Agriculture:Challenges,Risk Assessment,and Future Perspectives

Agro seeds are vulnerable to environmental stressors,adversely affecting seed vigor,crop growth,and crop productivity.Different agrochemical-based seed treatments enhance seed germination,but they can also cause damage to the environment;therefore,sustainable technologies such as nano-based agrochemicals are urgently needed.Nanoagrochemicals can reduce the dose-dependent toxicity of seed treatment,thereby improving seed viability and ensuring the controlled release of nanoagrochemical active ingredients However,the applications of nanoagrochemicals to plants in the field raise concerns about nanomaterial safety,exposure levels,and toxicological implications to the environment and human health.In the present comprehensive review,the development,scope,challenges,and risk assessments of nanoagrochemicals on seed treatment are discussed.Moreover,the implementation obstacles for nanoagrochemicals use in seed treatments,their commercialization potential,and the need for policy regulations to assess possible risks are also discussed.Based on our knowledge,this is the first time that we have presented legendary literature to readers in order to help them gain a deeper understanding of upcoming nanotechnologies that may enable the development of future generation seed treatment agrochemical formulations,their scope,and potential risks associated with seed treatment.

Acute hyperthermia and hypoxia tolerance of two improved strains of nile tilapia(Oreochromis niloticus)

Tilapia production in Ghana has been hit with episodes of stress and pathogen-induced mass fish kills which have anecdotally been linked to the culture of illegally imported Genetically Improved Farmed Tilapia(GIFT)strains of Nile tilapia,Oreochromis niloticus.This study was thus set up to comprehensively assess the stress tolerance of the GIFT strain and a native strain of Nile tilapia(the Akosombo strain)following exposures to hyperthermic and hypoxic stressors.In a series of experiments,oxygen consumption(MO_(2)),aquatic surface respiration(ASR),thermal limits and hypoxia tolerance were assessed.The effects of these stressors on haematological parameters were also assessed.The GIFT strain was less tolerant of hypoxia and performed ASR at higher O_(2) levels than the Akosombo strain.Under progressive hypoxia,the GIFT strain exhibited higher gill ventilations frequencies(fV)than the Akosombo strain.The thermal tolerance trial indicated that the Akosombo strain of O.niloticus has higher thermotolerance than the GIFT strain and this was reflective in the higher LT_(50)(45.1℃)and LT_(max)(48℃),compared to LT_(50) and LTmax of 41.5℃ and 46℃ respectively.These results imply that it is crucial to consider how the GIFT strain performs under various environmental conditions and changes during culture.Particularly,raising the GIFT strain of Nile tilapia in earthen ponds rich in phytoplankton and subject to protracted episodes of extreme hypoxia may have a detrimental physiological impact on its growth and welfare.

As clear as mud： Turbidity induces behavioral changes in the African cichlid Pseudocrenilabrus multicolor

Aquatic biodiversity is being lost at an unprecedented rate. One factor driving this loss is increased turbidity, an en- vironmental stressor that can impose behavioral, morphological, and/or physiological costs on fishes. Here we describe the be- havioral response of a widespread African cichlid, Pseudocrenilabrus multicolor victoriae, to turbidity. We used a split-brood rearing design to test if F1 offspring reared in turbid water, originating from river （turbid） and swamp （clear） populations, behave differently than full-sibs reared in clear water. We examined two facets of behavior： （1） behaviors of fish in full sib groups, in- eluding activity level and social dynamics collected during the rearing period; and （2） male aggressive behavior directed at poten- tial male competitors after fish had reached maturity; this was done in an experimental set-up independent of the rearing aquaria. Regardless of population of origin, fish reared in turbid water were marginally less active and performed fewer social behaviors than those reared in clear water. On the other hand, when tested against a competitor in turbid water, males performed more ag- gressive behaviors, regardless of population of origin or rearing environment, Our results suggest a plastic behavioral response to turbidity that may allow P. multicolor to persist over a range of turbidity levels in nature by decreasing activity and general social behaviors and intensifying reproductive behaviors to ensure reproductive success [Current Zoology 58 （1）： 146-157, 2012].

Interaction between pollution and climate change augments ecological risk to a coastal ecosystem

Pollution and climate change are among the most challenging issues for countries with developing economies,but we know little about the ecological risks that result when these pressures occur together.We explored direct effects of,and interactions between,environmental pollution and climate change on ecosystem health in the Bohai Sea region of Northern China.We developed an integrated approach to assess ecological risks to this region under four scenarios of climate change.Although ecological risks to the system from pollution alone have been declining,interactions between pollution and climate change have enhanced ecological risks to this coastal/marine ecosystem.Our results suggest that current policies focused strictly on pollution control alone should be changed to take into account the interactive effects of climate change so as to better forecast and manage potential ecological risks.