In the Bajío, Guanajuato and southwest in the spring-summer cycle is planted pepper in fresh (Capsicum annum L.), while in the north in the same cycle production is for dry pepper. The area planted to this crop has been reduced by 47% has since grown from 7 583-4 032 ha in the last ten years (^{SIAP, 2014}). This area reduction is due mainly to the pepper wilting disease, causing major yield losses ranging up 100% within the country and 40% in Guanajuato (^{González et al., 2009}; ^{CESAVEG, 2012}).

In Mexico, this problem has been associated to different microorganisms such as Phytophthora capsici, Fusarium oxysporum , F. solani, Rhizoctonia solani, Alternaria spp., Sclerotium rolfsii , Verticillium dahliae, V. albo-atrum, and Pythium spp; and some species of nematode Meloidogyne (^{Rico et al., 2004}; ^{Guillén et al., 2006}; ^{Velásquez et al., 2007}; ^{González et al ., 2009}). The ^{CESAVEG (2012)} reported P. capsici, Pythium spp., Fusarium spp. and Rhizoctonia spp., as major in the State. The management strategy that has worked best for reducing the inoculum of these fungi in soil disinfestation with metam sodium (^{González et al., 2009}); however, its management requires several security measures in case of not taking any risk for human and animal health, cultivation and the environment.

It has been observed that, the traditional application of the disinfestant, injected to the ground, is not completely effective for the control of phytopathogens that can occur at the disease (^{Sumner and Phatak, 1988}; ^{Bedriñana et al., 2009}). When this happens, the use of pesticides or biological agents are the option with curative intent; however, the producer known what microorganisms are causing the disease in their fields so that first requires a phytosanitary diagnosis of diseased plants and soil to know that fungi are present and influence alone or in partnership; this information allows the producer or select specific fungicides for each of the fungi or the necessary antagonists.

Therefore, the objectives of this study were: a) to know the current status of fungi associated with dry wilt or wilt pepper, its presence and distribution in the Bajío, Guanajuato and southwest; b) whether these are alone or in association plots. These objectives were raised as an informational tool for producers of pepper in the State.

In the spring-summer (P-V) 2013 in Celaya, Irapuato, Villagran, Silao, Romita, Pénjamo and Abasolo cycles; and 2014 in Apaseo El Grande, Cortazár, Villagrán, Juventino Rosas, Abasolo, Pénjamo, Guanajuato, Silao and Romita; Collections were made in five of “golds” of 10 diseased plants of pepper plot x cooperating producer. Plants of different varieties and types of pepper such as Crusadier, Don Vicente and Aristotle (serrano type), Imperial, Hungarian, Arista, Tajin and 5807 (Jalapeno) were collected. The collected plants showed typical symptoms of wilt or dry wilt that smaller plants were wilted with erect stems, leaves hanging unchanged in colour and nuts, wrinkled or mature hanging plant. In roots and stems affected two types of decay, a dry brown discoloration were observed; and soft, watery, odorless, a coffee and dark brown to almost black colour.

The collected plants were processed at the Laboratory of Plant Pathology, National Research Institute of Forestry, Agriculture and Livestock - Bajío Experimental Field. The plants were cut foliage and stem and root which was washed with tap water to remove excess soil was used. Of this material portions of 0.5 cm 2 tissue stem and root rots that were disinfected with sodium hypochlorite 5% for 90 s were taken; then washed twice with sterile distilled water and stored in sterile absorbent paper until use. The cuts were planted under the laminar flow hood in potato-dextrose-agar (PDA) + Ac. lactic and incubated at 20-24 °C.

After five to seven days there was a first identification of the fungal colonies and a second 20 days later. To classify the colonies within the genus Fusarium, the main feature observed was the pigmentation of PDA, which was mostly a purple or light purple, red and fuchsia, as the mycelium aged (20 days) it became a dark purple almost black coloration to coincide with those reported by ^{Leslie and Summerell (2006)} and ^{Nelson et al., (1983)}. For Rhizoctonia species, PDA coloration brown in the early days, with dark brown over time was observed; by temporary preparations, hyphae were observed at 90°, constricting them and the formation of the two septa within walking distance of the point of origin of the hyphal branches (^{Sneh et al., 1991})

For Phytophthora we observed a white cottony growth and starred in PDA (^{Drenth and Sendall, 2001}). Re isolations were made using PDA colony hyphae tip for inbred strains. 80, 13 and 2 strains, classified within the genus Fusarium, Phytophthora and Rhizoctonia respectively.

Of the 80 strains of Fusarium spp., one was selected by locality same as those planted in the medium carnation leaf-Agar (HCLA) and PDA; at the same time seeded, following the same procedure, the certified strains of ATCC^® F. oxysporum (catalog No. MYA-3041), F. oxysporum f. sp. lycopersici (Catalog No. 16605), and F. solani (Catalog No. 16372). Incubated at 20-24 °C, 12 h light and 12 h white black light. After 20 days morphological identification was performed following the taxonomic keys of ^{Leslie and Summerell (2006)} and ^{Nelson et al. (1983)}. For the case of 13 inbred strains of Rhizoctonia, morphological characteristics were corroborated by temporary aided preparations with compound microscope keys used by ^{Sneh et al. (1991)}, ^{Romero (1994)} and ^{Mendoza (1999)}. The two inbred strains of Phytophthora began to grow amid vegetable juice (V8) clarified liquid to stimulate the formation of sporangia, were identified according to ^{Drenth and Sendall (2001)}; ^{Romero (1994)} and ^{Mendoza (1999)}.

In general, of all the collections we isolated Fusarium spp, directly from infected root tissue and stem; was identified F. oxysporum in eight of the 11 municipalities, comparing the morphological characteristics with those of the certified strain F. oxysporum (MYA-3041). The strains studied showed the following characteristics in PDA: white mycelium, sometimes agglomerated or scattered in the Petri dish, medium pigmentation ranged in colour from white (HCLA) to pale or dark, reddish purple and fuchsia. Micro and Macroconidia were hyaline and no sclerotia were observed. HCLA characteristics: some strains were observed in the formation of pale orange sporodochia on carnation leaves.

In most of the strains in this medium pigmentation was pale violet and in some cases creamy white. In all strains were abundant microconidia oval or kidney-shaped, slightly elliptical, mostly with a septa. Macroconidia, presented in PDA and the sporodochia formed in HCLA were mostly slightly curved, thin and with three septa medium length (30-50 microns). The apical cell was conical, curved with a slight hook while the basal cell had a foot-shaped end; coincide with those reported by ^{Leslie and Summerell (2006)}; ^{Nelson et al. (1983)} and APS (2013).

For Rhizoctonia spp., 13 strains were identified as fungus, white hyphae were observed with coffee tones; mycelium hyaline microscope was slightly brown with branches at right angles, often with a slight constriction and septa near each branch, these characteristics match those described by ^{Sneh et al (1991)} for the genus; and ^{Romero (1994)}, ^{Mendoza (1999)} and ^{APS (2003)} for R. solani considering the host where the fungus was isolated in this study. For Phytophthora spp., the clarified liquid V8 medium stimulated the formation of sporangia, in this case, were abundant sporangiophores simple and irregularly branched, sporangia were ovoid (nearly round) and globose; mostly only with a conspicuous papillae. These characteristics are consistent with those reported by ^{Drenth and Sendall (2001)} for the genus of this fungus; and ^{APS (2003)}, ^{Romero (1994)} and ^{Mendoza (1999)} for P. capsici in pepper.

According to fungi found by municipality (Table 1), in the P-V/2013 cycle at 100% of the municipalities was found Fusarium spp., the species F. oxysporum was identified in three municipalities. In three (27%) were identified Rhizoctonia spp., and only one to Phytophthora spp. In the P-V/2014 cycle, 100% of the locations were identified Fusarium spp., and the species F. oxysporum was found in seven municipalities. Rhizoctonia spp was identified in five (56%) and Phytophthora spp., in one. This data overlap with the frequencies reported by ^{González et al. (2002)}, who mentioned that sampled pepper plants with symptoms of wilting, 65% to Fusarium spp., was isolated, 33% to R. solani and 33% P. capsici.

Table 1 Isolated fungi from affected tissue of root and stem collected from municipalities and southwest Bajío, Guanajuato in the spring-summer 2013 and 2014 cycles plants. 

Fu= Fusarium spp.; Fo= Fusarium oxysporum; Rh= Rhizoctonia spp.; Ph=Phytophthora spp.

^{Rico et al. (2001)} by analysing pepper plants with root rot, collected in 118 lots, isolated Fusarium spp., 65% to R. solani 32% and P. capsici in 3%. On the other hand, ^{Guillén et al. (2006)} to analyze soil samples from Dolores Hidalgo, Guanajuato, identified P. capsici in 60% of samples, R. solani in 40%; and F. solani and F. oxysporum in 100% of the samples. In the cases reported above, as in this study, and the three fungi were isolated Fusarium spp., which was the most frequently isolated followed by Rhizoctonia spp., and Phytophthora spp.

Regarding the association of fungi in the P-V/2013 cycle in four municipalities was isolated from plants affected only Fusarium spp., and F. oxysporum; in three were isolated Fusarium spp., and F. oxysporum + Rhizoctonia spp.; while Irapuato was isolated F. oxysporum + Phytophthora spp. In P-V/2014 alone were isolated Fusarium spp., and F. oxysporum in four municipalities; these same four yeast + Rhizoctonia spp., and only in Villagrán all three together were isolated (Table 1).