Detección de tristeza, psorosis, exocortis, cachexia y eneanismo en lima persa (Citrus latifolia) en Veracruz, México.

Abstract

La lima persa (Citrus latifolia) es el principal cítrico que exporta México y Veracruz es el principal productor. En las plantaciones se han observado síntomas como; agrietamientos, descortezamiento del tronco y ramas, lo cual conduce al deterioro y bajos rendimientos del cultivo. Sin embargo se desconocen las causas asociadas a los síntomas antes descritos. Por ello se planteó determinar la presencia y distribución de tristeza [Citrus tristeza virus (CTV)], psorosis [Citrus psorosis virus (CPsV)], exocortis [Citrus exocortis viroid (CEVd)], cachexia [Citrus viroid II (CVd-II)] y enanismo [Citrus dwarfing viroid (CVd-III)] en siete municipios productores y exportadores de lima persa en Veracruz, México. Se realizó extracción de ácidos totales con Concert™ Plant RNA Reagent (Invitrogen™) y de RNA total con TRIzol® Reagent, en la PCR para CTV se usaron los iniciadores CPKF y CPKR. RT-PCR para CPsV el Ps66 y Ps6. En el caso de CEVd el CEVd-h y CEVd-c. Para CVd-II se utilizaron CVd-II-h y CVd-II-c. Por ultimo para CVd-III el CVd-III-h y CVd-III-c. Se detectó a CTV en 12 muestras de las 22 analizadas (54.5%) pertenecientes a los municipios de Martínez de la Torre (MT), Atzalan (AT), Cuitláhuac (CT) y Amatlán de los Reyes (AR). 18 muestras amplificaron para CPsV (81.81%) de MT, AT, SR, CT y AR. Resultaron positivas 20 de las 22 muestras a CEVd (90.9%), de Cazones (CZ), SR, MT, Misantla (MS), AT, CT y AR. En el caso de CVd-II 16 muestras de las 22 resultaron positivas (72.7%), el único municipio donde no se detectó fue Misantla. En el caso de CVd-III se tuvo amplificación en 11 muestras (50%) de MT, AT, SR, CT y AR. El exudado gomoso que se genera en las plantas por la infección de Phytophthora spp. es el síntoma más notorio para los productores, quienes asocian la muerte de las plantas a dicho oomyceto, sin saber que pueden haber otras causas. Con esta investigación podemos decir que la muerte de las plantas de lima persa en Veracruz se debe a más de un patógeno. Este es el primer reporte de la presencia de CTV, CPsV, CEVd, CVd-II, y CVd-III en lima persa en Veracruz, México. _______________ DETECTION OF TRISTEZA, PSOROSIS, EXOCORTIS, CACHEXIA AND ENANISM IN PERSIAN LIMA (Citrus latifolia) IN VERACRUZ, MEXICO. ABSTRACT: Persian lime (Citrus latifolia) is the main citrus exported by Mexico and Veracruz is the main producer state. On Persian lime plantations in Veracruz, symptoms such as Cracking, barking of the trunk and branches, which leads to deterioration and low crop yields have been observed. However, the causes associated with the symptoms described above are unknown. The aim goal of this reserch was to determine the presence and distribution of tristeza [Citrus tristeza virus (CTV)], psorosis [Citrus psorose virus (CPsV)], exocortis [Citrus exocortis viroid (CEVd)] and dwarfism [Citrus dwarfing viroid (CVd-III)] in seven producing and exporting Persian lime counties in Veracruz, Mexico. Total nucleic acid was obtained with Concert ™ Plant RNA Reagent (Invitrogen ™) and total RNA with TRIzol® Reagent. CPKF and CPKR primers were used in PCR for CTV. RT-PCR for CPsV the Ps66 and Ps6. In the case of CEVd the CEVd-h and CEVd-c. For CVd-II, CVd-II-h and CVd-II-c were used. Finally for CVd-III the CVd-III-h and CVd-III-c. CTV was detected in 12 samples of the 22 analyzed (54.5%) belonging to the counties of Martínez de la Torre (MT), Atzalan (AT), Cuitláhuac (CT) and Amatlán de los Reyes (AR). 18 samples amplified for CPsV (81.81%) of MT, AT, SR, CT and AR. 20 of the 22 samples were positive to CEVd (90.9%), of Cazones (CZ), SR, MT, Misantla (MS), AT, CT and AR. In the case of CVd-II, 16 samples from 22 were positive (72.7%), the only county where it was not detected was Misantla. In the case of CVd-III amplification was performed in 11 samples (50%) of MT, AT, SR, CT and AR. The gummy exudate that is generated in the plants by the infection of Phytophthora spp. is the most notorious symptom for the producers, who associate the death of the plants to said oomycete, without knowing that there may be other causes. With this research we can say that the death of the Persian lime plants in Veracruz is due to more than one pathogen. This is the first report of the presence of CTV, CPsV, CEVd, CVd-II, and CVd-III in Persian lime in Veracruz, Mexico.