http://repositoriodigital.ipn.mx/handle/123456789/687 Mon, 20 Apr 2026 12:15:51 GMT 2026-04-20T12:15:51Z https://www.repositoriodigital.ipn.mx:443/retrieve/1237/ http://repositoriodigital.ipn.mx/handle/123456789/687 http://repositoriodigital.ipn.mx/handle/123456789/18862 Title: Lenguaje y educación. temas de investigación educativa en México Authors: Carrasco Altamirano, Alma; López-Bonilla, Guadalupe Tue, 01 Jan 2013 00:00:00 GMT http://repositoriodigital.ipn.mx/handle/123456789/18862 2013-01-01T00:00:00Z http://repositoriodigital.ipn.mx/handle/123456789/16418 Title: BIOCONTROL DE Botrytis cinerea A PARTIR DE EXTRACTOS FENÓLICOS DE FRESA Authors: ALVAREZ GÓMEZ, TANIA BELEN Abstract: Michoacan is the first producer of strawberry in Mexico, occupying approximately 4,300 h in the last year. The strawberry crop is susceptible to disease-causing by pathogenic microorganisms, such as, Botrytis cinerea gray mold as causal agent a major disease of this crop. It causes major economic losses, therefore it is usually controlled with agrochemicals, for that reason it requires of new alternative of control. An alternative that is propose in this paper, is the use of biological inputs, as strawberry plants that finished production cycle meant for obtaining plant extracts that present antimicrobial activity and also allow the crop sustainability. Two ethanol extracts of strawberry plants were evaluated. The first extract was obtained using high temperature (EFEC) and the second extract at room temperature (EFES). It performed an in vitro test of the biocontrol activity of the extracts in three different volumes in potato dextrose agar (PDA), and one in vivo test the extracts were sprayed on strawberry fruits; in a similar way it performed a fractionation thin layer chromatography, each one of the fractions was evaluated in vitro; confronting each test with the fungus B. cinerea. The EFES at 125 μL concentrations allowed the inhibition of the production of biomass dry weight basis of the fungus. Another interesting finding was the inhibition of spore formation in both extracts at least one concentration. In vivo evaluation both extracts showed significant inhibition of the development of the disease with a percent inhibition of 73.8% and 66.3% for EFEC and EFES compared to the control (p ≤ 0.05). Regarding the evaluation of the fractions, three of them in each extract, allowed significantly reduce pathogen mycelial growth. This biocontrol activity could be attributed to the presence of flavonoids type compounds. Wed, 12 Jun 2013 00:00:00 GMT http://repositoriodigital.ipn.mx/handle/123456789/16418 2013-06-12T00:00:00Z http://repositoriodigital.ipn.mx/handle/123456789/7789 Title: Producción de Lecanicillium (= Verticillium) lecanii en diferentes sustratos y patogenicidad Authors: Cortez Madrigal, Hipólito Abstract: The conidial production of the fungus Lecanicillium lecanii cultivated in different substrates (nutrition media + supports) and its pathogenicity were determined. The evaluated media were: sorghum, rice grain, broken rice grain (“granillo”), rice polish (“pulido”) and as supports sugar cane leftover “bagazo”, rice husk and corn cob “olote”. The combination of media and supports provided twelve treatments plus a control constituted by rice alone. The production of conidia displayed statistical differences (p≤ 0.05) among treatments; those with larger conidia production were sugar cane leftover (bagazo) + rice (839.7 ± 1.2 x 106 g-1) and sorghum + corn cob (825.8 ± 1.7 x 106 g-1). Although polished of rice was the less efficient medium for production, all combinations where it was included resulted superior to rice alone. Rice showed the smallest production of conidia (265.4 ±1 x 106 g-1). Also, the media and support where it was produced affected the pathogenicity of L. lecanii on Toxoptera aurantii and Aphis gossypii. The aeration favored by the support marked the difference between treatments and the control. Results indicated that the culture medium is important for the massive production of L. lecanii; besides, they indicate that the pathogenicity of the fungus was also affected by the culture medium. Mon, 01 Jan 2007 00:00:00 GMT http://repositoriodigital.ipn.mx/handle/123456789/7789 2007-01-01T00:00:00Z http://repositoriodigital.ipn.mx/handle/123456789/7788 Title: Ocurrencia de hongos y etiología de la secadera de la fresa con diferentes sistemas de manejo agronómico Authors: CejaTorres, Luis F.; Mora Aguilera, Gustavo; Téliz, Daniel; Mora Aguilera, Antonio; Sánchez García, Prometeo; Muñoz Ruíz, Carlos; Tlapal Bolaños, Bertha; De La Torre Almaraz, Rodolfo Abstract: In México, strawberry dry wilt (Fragaria x ananassa) has been associated with a fungus complex in which only the implication of Fusarium oxysporum (Fox) is evident. Therefore, in the present study the association of fungi and pseudofungi with the disease was determined in different systems of agronomical management, and pathogenicity was verified. Two samplings were made in the 2002/03 season and three in 2003/04 in 16 localities of the Valley of Zamora, Michoacán, México, where 2640 sections of roots and 365 of necrotic crowns were sown, along with 400 sections of asymptomatic tissue in potato-dextrose-agar (PDA) culture medium and a selective medium with antibiotics and PCNB (PARPH) fungicide. Fox, F. solani (Fso), Cylindrocarpon sp. (Cyl), Pythium aphanidermatum (Pyt), Phytophthora sp. (Phy), Rhizoctonia fragariae (Rhi), Verticillium albo-atrum (Ver) and Colletotrichum sp. (Col) were associated with the dry wilt. Fox was the most frequent species (p=0.05) and the only one that showed an increase from flowering to fructification of 47 to 62% in root and 77 to 83% in crown. In plantations with plastic mulch and drip irrigation (A + G), Fox decreased by 18% with respect to unmulched soil with gravity irrigation, whereas Cyl increased by 15% in A + G (p=0.05). The clay and clay loam soil contrasted in the detection of Fox (46.8 and 12.4%) and Rhi (9.1 and 43.7%). Symptoms of wilting with necrosis in root and crown and general death were reproduced with individual inoculations of Fox (100%), Pyt (100%), Phy (100%), Rhi (60%) and combinations of Fox with Rhi (100%), Pyt (100%) and Cyl (100%). This is the first report that implies Phytophthora sp., P. aphanidermatum and R. fragariae as causal pathogens of dry wilt in México. The morphological identification of Fox and Rhi was confirmed by sequencing of the intergenic region of the rDNA. Tue, 01 Jan 2008 00:00:00 GMT http://repositoriodigital.ipn.mx/handle/123456789/7788 2008-01-01T00:00:00Z