DSpace Communidade: Embrapa Recursos Genéticos e Biotecnologia (CENARGEN)

Sublethal exposure to insecticides disrupts pheromone communication and reduces fertility in the cotton boll weevil (Anthonomus grandis grandis)

2026-01-01T00:00:00Z

Título: Sublethal exposure to insecticides disrupts pheromone communication and reduces fertility in the cotton boll weevil (Anthonomus grandis grandis) Autoria: MARRA, S. O. D. O.; LAUMANN, R. A.; MORAES, M. C. B.; GUEDES, R. N. C.; BORGES, M.; BARBOSA, W. F.; BATISTA, P. S. C.; ZANINE, A. M.; LOURES-FERREIRA, M. Conteúdo: The objective of this work was to evaluate the effects of sublethal exposure to the insecticides malathion and beta-cyfluthrin on the pheromone perception and emission by the cotton boll weevil [Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae)]. The potential impact of sublethal exposure on this species' population growth was also determined using fertility table parameters. Males and females were exposed to malathion (100 g a.i./L) or beta-cyfluthrin (25 g a.i./L) for 1 min in a glass Petri dish. The response of pesticide-exposed and unexposed insects to their aggregation pheromone (grandlure) was evaluated in a Y-tube olfactometer, and pheromone production was assessed. In order to evaluate the possible reproductive effects, the couples remained isolated for 48 h, and the females were subsequently evaluated until their death. For reproductive assays, four mating-pair treatments were established: (1) both sexes unexposed; (2) exposed males paired with unexposed females; (3) exposed females paired with unexposed males; and (4) both sexes exposed. Insects exposed to both insecticides did not respond to their aggregation pheromone during the first 24 h after exposure, whereas unexposed weevils showed a clear behavioral response. However, insecticide-exposed males did not show reduced pheromone production compared to unexposed males. Sublethal insecticide exposure lowered the net reproductive rate (R0) and the intrinsic rate of increase (rm) for the cotton boll weevil. These findings suggest that sublethal insecticide exposure may suppress boll weevil population growth while potentially compromising the reliability of pheromone-based monitoring programs in intensively treated cotton fields.

Fungal peptidogalactomann as a biocontrol agent Against Meloidogyne incognita in cotton.

2026-01-01T00:00:00Z

Título: Fungal peptidogalactomann as a biocontrol agent Against Meloidogyne incognita in cotton. Autoria: LISEI-DE-SA, M. E.; SANTOS-JIMÉNEZ, J. L.; MONTEBIANCO, C. de B.; BERNARDINO, M. C.; SANTOS, M. M.; XISTO, M. I. D. da S.; SANTINO, A. D.; PAGANELLA, M. B.; OLIVEIRA, N. G.; MORGANTE, C. V.; BARRETO-BERGTER, E.; SA, M. F. G. de; VASLIN, M. F. S. Conteúdo: Root-knot nematodes (Meloidogyne incognita) severely limit cotton (Gossypium spp.) productivity, with conventional control methods facing ecological and efficacy challenges. Here, we evaluate a fungal peptidogalactomann (pGM), derived from Cladosporium herbarum (commercially formulated as Hariman), as a novel biocontrol agent that primes plant defenses against nematode infection. Under greenhouse conditions, foliar application of pGM at 100 μg·mL⁻¹ resulted in an 83% reduction gall formation compared to untreated controls and yielded a four-fold increase in resistant plants (gall index = 1.5 vs. 3.2 in controls; *p* < 0.01). Nematode egg production was reduced by 60% at 120 days post-inoculation. pGM triggered a biphasic defense response, evidenced by a remarkable 40,000-fold upregulation of the systemic acquired resistance gene PR1 and transient activation of phenylpropanoid (PAL) and jasmonate (LOX2) pathways. Notably, pGM supported healthy plant growth without phytotoxicity, contrasting with the phytotoxicity often associated with chemical nematicides. These findings indicate that pGM has strong potential as a sustainable alternative for M. incognita management in cotton, primarily by enhancing host immunity rather than exerting direct nematode toxicity. Further field trials are necessary to validate its effectiveness and to evaluate its integration into integrated pest management strategies.

A comprehensive review on food-grade electrospinning of natural biopolymers for cultivated meat applications.

2026-01-01T00:00:00Z

Título: A comprehensive review on food-grade electrospinning of natural biopolymers for cultivated meat applications. Autoria: SILVA, N. M. A. da; SILVA, L. P. da Conteúdo: The production of cultivated meat relies on in vitro animal cell growth and requires the use of scaffolds that structurally resemble key features of the extracellular matrix (ECM), providing mechanical support and biochemical cues for cell adhesion, proliferation, and differentiation. Electrospinning has emerged as a promising technique for manufacturing three-dimensional edible scaffolds because it is robust, versatile, and capable of producing nanofibers with a high surface area-to-volume ratio, tunable porosity, and ECM-like fibrous architectures. Natural biopolymers are promising candidates for the fabrication of electrospun scaffolds, combining biocompatibility, biodegradability, and processing compatibility with food-grade requirements. However, the absence of fully food-grade electrospinning systems, coupled with limited scalable green-processing strategies, remains a critical barrier to industrial translation. In this context, this review presents recent advances in the food-grade electrospinning of natural biopolymers focused on cultivated meat production. Furthermore, scientific gaps in the development of fully edible scaffolds are discussed, along with the need for alternatives to animal-derived materials and synthetic carrier polymers, considering sustainability, consumer acceptance, and the translation from laboratory-scale studies to industrial systems. Finally, this review outlines a strategic roadmap to accelerate the transition from proof-of-concept studies toward scalable, regulatory-compliant, and industrially viable electrospinning technologies for cultivated meat production.

Seed transmission of Cowpea mild mottle virus in common beans in Brazil.

2026-01-01T00:00:00Z

Título: Seed transmission of Cowpea mild mottle virus in common beans in Brazil. Autoria: PINHEIRO-LIMA, B.; VIDAL, A. H.; FELIX, G. P.; ALVES-FREITAS. D. M. T.; LACORTE, C. C.; FARIA, J. C.; ABREU, E. F. M.; PINHEIRO, P. V.; MELO, F. L. de; RIBEIRO, S. da G. Conteúdo: Cowpea mild mottle virus (CPMMV) is a carlavirus that is transmitted by whiteflies and can also be spread through seeds in cowpea, soybean, and common bean. Seed transmission of CPMMV has been described in various countries; however, it was only recently reported in Brazil as a seed-transmitted virus in soybean. CPMMV has spread widely in bean-growing areas in recent years. Most Brazilian farmers use harvested grains as seed for reseeding, increasing the risk of seedborne infection. In this study, we examine seed transmission of CPMMV in two bean cultivars using RT-PCR in combination with nucleic acid hybridization. The plants evaluated were obtained from seeds harvested in commercial and experimental fields and from seeds collected in transmission experiments using either mechanical or whitefly inoculation. The observed seed transmission was estimated between 10 to 45% for ‘BRS FC 401 RMD’ and 13 to 22% for ‘Pérola’. In addition, evidence of secondary transmission (23.3%) by Bemisia tabaci MEAM1 was observed. These results suggest that CPMMV could be spread in bean fields by sowing infected seeds and that germinated plants could serve as an inoculum for whitefly transmission. This is the first report of seed transmission of CPMMV in common bean in Brazil.