Background Root-knot nematodes are known to cause significant damage to eggplants. New approaches by green silver nanoparticles (GSN) are used to control plant-parasitic nematode to avoid chemical nematicide hazards. Objectives Analyses of the incorporation of different concentrations of nanoparticles on two different algae (Ulva lactuca and Turbinaria turbinata) were carried out. Furethermore, the effect of GSN on the eggplant DNA profile was studied using RAPD and EST molecular markers. Materials and Methods Green Silver Nanoparticles (GSN) have been synthesized and characterized using the algal extract solution prepared from two algal genera. Nematicidal effect of the GSN was evaluated in greenhouse on eggplants (Solanum melongena cv. Login). Genomic DNA was extracted for use in molecular analysis. Both RAPD and EST molecular markers were used to study the GSN effect on eggplant DNA modification. Results GSN (17 mg.mL-1) obtained from U. lactuca was more effective in reducing second-stage juveniles (J2s) of M. javanica (69.44%) population in soil. All treatments improved eggplants growth parameters. Change in DNA profile using of both RAPD and EST markers was noted. Conclusions GSN (12.75 mg.100 mL-1) were effective on controlling the root-knot nematode (both T. turbinata and U. lactuca algae), similar to chemical control in eggplants. GSN did not cause any phototoxicity in eggplants under treatment.

No abstract

Banana production is severely hindered by plant-parasitic nematodes (PPNs) worldwide. Chemical nematicide, oxamyl is a systematic compound widely applied for the control of PPNs. Because of increase pests' problems, harmful effects on human and environment caused by chemical pesticides and also increased consumer requirements for safe crops have encouraged research on bio-pesticides production. So, the effect of different stress of the yeast, Saccharomyces cerevisiae and blue green algae (cyanobacteria), Spirulina platensis were examined on banana plants infected with root-knot nematodes, Meloidogyne incognita. All tested treatments were effective methods to manage M. incognita in soil samples and banana roots. Notably, the usage of S. cerevisiae and S. platensis in combination treatment revealed the greater antagonistic action on M. incognita in potted banana. In addition it has an avail advantage over artificial nematicides by having several means to attack the RKN and mainly enhanced plant growth compared to any other treatments. Yet, the previous treatment had increased catalase (CAT) enzyme activity and reduced pectin methyl esterase (PME) activity in banana plant that leads to inhibit the count of the RKN. Generally, our results supply a novel knowledge to understand of PPNs management as a new approach for applying bio-fertilizer and bio-control of the parasitic nematodes.

We appraised the use of zinc oxide nanoparticles, (ZnO-NPs) and zinc oxide bulk (ZnO-bulk) or zinc acetate, as a natural nematocide, alone or in combination with oxamyl in vitro and in vivo trials in order to improve systems for root-knot nematode (RKNs) control in banana plants. Especially, ZnO-NPs were biosynthesized from the alga, Ulva fasciata. In general, all applications of ZnO-NPs were more effective to control RKNs than ZnO-bulk as well oxamyl alone (chemical control). In in vitro conditions, ZnO-NPs with oxamyl showed 98.91% second stage juveniles2 (J2s) mortality of Meloidogyne incognita after 72 hrs, while 72.86% mortality was observed at the same NPs treatment without oxamyl at the same exposure time. The same treatment was the most effective in diminution of J2s community (82.77%) in soil and galls number (81.87%) in roots under in vivo conditions. In contrast, the highest weight and height of the shoot was observed in Zn-bulk treatment in combination with oxamyl as well oxamyl only (nematocides check). Scanning electron microscopy (SEM) reports displayed the distributions and accumulations of ZnO-NPs on the nematode (J2s) body under direct exposure, which might be the reason of NP-mediated toxicity and disruption for M. incognita. HighlightsZno-NPs biosynthesis by macrogreen alga Ulva fasciata and give nanorode particles. Biogenic ZnO-NPs were used as nematocidal against root-knot nematodes (RKNs) solely and in combination with oxamly in vitroand in vivo.ZnO-NPs exhibited high nematocidal activity in vitroand in vivo.Banana plants infected with RKNs and treated with ZnO-NPs in combination with oxamly showed high growth. Statement Of NoveltyThis study offers importance of green technology for the development of biosynthesis ZnO-NPs, and in combinations with oxamyl in control RKNs (in vivo and in vitro). Moreover, it is possible using biosynthesis ZnO-NPs in alternative to pesticide and also to enhancement the plant yields. nematode body with magni cation 500x, f) ZnO-NPs attached to the nematode body with magni cation 1500x.

No abstract