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Capacidad Germinativa En Semillas Infestadas Por Insectos En Seis Especies Arbóreas Del Bosque De La Sierra De Manantlán, Jalisco

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Capacidad Germinativa En Semillas Infestadas Por Insectos En Seis Especies Arbóreas Del Bosque De La Sierra De Manantlán, Jalisco UNIVERSIDAD DE GUADALAJARA COORDINACIÓN GENERAL ACADÉMICA Coordinación de Bibliotecas Biblioteca Digital La presente tesis es publicada a texto completo en virtud de que el autor ha dado su autorización por escrito para la incorporación del documento a la Biblioteca Digital y al Repositorio Institucional de la Universidad de Guadalajara, esto sin sufrir menoscabo sobre sus derechos como autor de la obra y los usos que posteriormente quiera darle a la misma. Av. Hidalgo 935, Colonia Centro, C.P. 44100, Guadalajara, Jalisco, México [email protected] - Tel. 31 34 22 77 ext. 11959 UNIVERSIDAD DE GUADALAJARA CENTRO UNIVERSITARIO DE LA COSTA SUR DIVISIÓN DE DESARROLLO REGIONAL DEPARTAMENTO DE ECOLOGÍA Y RECURSOS NATURALES VARIACIÓN INTER E INTRAPOBLACIONAL DE LA DEPREDACIÓN DE SEMILLAS POR INSECTOS ENDÓFAGOS EN SEIS ESPECIES ARBÓREAS DE LA RESERVA DE LA BIOSFERA SIERRA DE MANANTLÁN, JALISCO Tesis Presentada por la Sustentante: BIÓLOGA GLORIA IGLESIAS LÓPEZ Como Requisito Parcial para Obtener el Grado de: MAESTRA EN CIENCIAS EN MANEJO DE RECURSOS NATURALES A UTLÁN DE N AVARRO , J ALISCO NOVIEMBRE 20 19 JUNTA ACADÉMICA DE LA MAESTRÍA EN CIENCIAS EN MANEJO DE RECURSOS NATURALES DEPARTAMENTO DE ECOLOGÍA Y RECURSOS NATURALES : DIVISIÓN DE DESARROLLO REGIONAL CENTRO UNIVERSITARIO DE LA COSTA SUR UNIVERSIDAD DE GUADALAJARA PRESENTE Por este medio nos permitimos informar a ustedes que habiendo revisado el trabajo de Tesis de MAESTRÍA , titulada VARIACIÓN INTER E INTRAPOBLACIONAL DE LA DEPREDACIÓN DE SEMILLAS POR INSECTOS ENDÓFAGOS EN SEIS ESPECIES ARBÓREAS DE LA RESERVA DE LA BIOSFERA SIERRA DE MANANTLÁN, JALISCO , que realizó la sustentante Gloria Iglesias López con número de código 21 7915827 , este comité abajo firmante consideramos que el trabajo ha quedado debidamente concluido, por lo que ponemos a su consideración el escrito final para autorizar su impresión y, en su caso, programación de fecha de examen de titulación respectivo. Sin otro particular agradecemos de antemano la atención que se sirva brindar a la presente y aprovechamos la ocasión para enviarle un cordial saludo. Atentamente Lugar y fecha _________________________ Dra. Dra. Martha Susana Zuloaga Aguilar Directora d e la Tesis _____________________ _______________ Dr. Vicente Hernández Ortiz Dr. Luis Ignacio Iñiguez Dávalos Asesor Asesor 2 AGRADECIMIENTOS Agradezco al comité académico por orientarme en la ejecución de éste proyecto (Dra . Susana, Dr. Vicente, Dr. Luis Ignacio) ; por siempre tener las palabras precisas y la mejor actitud para responder a mis inquietudes ; por fortalecer y enriquecer mi conocimiento a partir del de ustedes, gracias por siempre darme soluciones en vez de preocupaciones, todo fluyó de manera bonita. Gracias a los tan especiale s compañeros que tuve durante la maestría, hicieron ameno y muy alegre mí recorrido durante este tiempo, sé que algunos serán grandes amigos de vida. Gracias a mi familia por siempre creer en m í … 3 DEDICATORIA Este proyecto va dedicado a la persona que más me ha influenciado en la vida ; quien hizo de m í un ser aguerrido con ganas de luchar y cons eguir siempre lo que se propone; por hacer de mí una persona sin miedo a nada (solo a veces me susto un poco) ; por no cortarme las alas, al contrario , me enseñ ó a volar alto y lejos; por depositar siempre su confianza en cada proyecto que he emprendido; por inculcarme el valor de la form ación integral ; por enseñarm e que a pesar que el camino es largo y culebrero con esfuerzo se llega al destino. Esto es por ti MAMÁ Te amo! 4 VARIACIÓN INTER E INTRAPOBLACIONAL DE LA DEPREDACIÓN DE SEMILLAS POR INSECTOS ENDÓFAGOS EN SEIS ESPECIES ARBÓREAS DE LA RESERVA DE LA BIOSFERA SIERRA DE MANANTLÁN, JALISCO Gloria Esperanza Iglesias López Resumen Se evaluó la depredación pre - dispersión de semillas por insectos endófitos de seis especies arbóreas en la Sierra de Manantlán, donde se estimó la variación entre poblaciones en (1) la frecuencia y densidad de depredación, (2) su relación con el tamaño y contenido de nutrientes de las semillas y (3) el efecto de la infestación en la geminación . Se seleccion aron tres especies pertenecientes al género Quercus ( Q. nixoniana, Q. acutifolia y Q. praineana ) y tres especies arbóreas del bosque mesófilo de montaña ( Styrax ramirezii, Citharexylum mocinnoi y Persea hintonii ) . Se colectaron frutos directamente del árbo l parental de entre dos y tres pisos altitudinal es ; los frutos se incubaron en condiciones de laboratorio para estimar frecuencia de infestación (porcentaje) y densidad (insectos asoc iados por semilla). U na estimación del contenido de nutrientes de las semillas y su morfometría fue relacionada con la frecuencia de infestación. Finalmente se evaluó la viabilidad de las semillas infestadas en contraste con las no afectadas aparentemente por insectos. Se iden tificaron 13 morfo - especies de insectos de los órdenes Lepid óptera y Col eóptera consumiendo las semillas de las seis especies hospederas, además de una especie de parasitoide de la familia Ichneumonidae (Hymenoptera) . Se encontraron diferencia s significativas en la frecuencia de infestación entre pisos altitudinales para todas las especies hospederas con excepción de Q. acutifolia . Se encontró que la depredación de semillas fue mayor en los pisos más bajos . Contrario a lo anterior para C. mocinnoi hubo un aumento en la frecuencia d e infestación a mayor altitud. D iferencias significativas en el tamaño y peso fresco de los frutos fue hallado entre pisos altitudinales con una relación negativa con respecto a la altitud . El 100 % de las semilla s infestadas de encinos y S. ramirezii no presentaron germinación . Aunque para C. mocinnoi y P. hintonii hubo germinación en semillas infestadas, éste también resultó ser un factor que afecta negativamente la germinación . En este trabajo se comprobó que la infestación a semillas por insectos representa una baja en el potencial reproductivo de las plantas, ya que hay poca probabilidad de germinar y en consecuencia de contribuir con nuevos individuos a la población . 5 TABLA DE CONTENIDO CAPÍ TULO I: INTRODUCCIÓN GENERAL ................................ 8 Hipótesis ................................ ................................ ............................. 10 METODOLOGÍA GENERAL ................................ .............................. 11 Área de estudio ................................ ................................ ................................ ......... 11 Selección de poblaciones de especies hospederas ................................ .................. 11 Descripción de las especies hospederas ................................ ................................ .. 12 Caracterización sitios de muestreo ................................ ................................ ........... 15 Recolección de frutos ................................ ................................ ............................... 17 LITERATURA C ITADA ................................ ................................ ...... 18 CAPÍ TULO II ................................ ................................ ............. 25 USO DE SEMILLAS POR INSECTOS ENDÓFAGOS Y SU VARIABILIDAD POBLACIONAL EN UN GRADIENTE ALTITUDINAL Y ENTRE ESPECIES ARBÓREAS DEL BOSQUE DE MANANTLÁN ................................ ................................ ...... 26 Resumen ................................ ................................ ............................ 27 INTRODUC CIÓN ................................ ................................ ............... 29 MATERIALES Y MÉTODOS ................................ .............................. 32 Densidad de depredación. ................................ ................................ ........................ 32 Frecuenc ia de infestación de semillas/frutos ................................ ............................. 33 Características morfológicas y recursos de reserva de las semillas .......................... 34 Análisis de datos ................................ ................................ ................................ ....... 34 RESULTADOS ................................ ................................ ................... 36 Especificidad planta – insecto y densidad de depredación. ................................ ....... 36 Frecuencia de infestación ................................ ................................ ......................... 37 Características morfológicas y recursos de reser va de las semillas .......................... 39 DISCUSIÓN ................................ ................................ ....................... 40 CONCLUSIONES ................................ ................................ .............. 48 LITERATURA CITADA ................................ ................................ ...... 50 CAPÍ TULO III: ................................ ................................ ........... 73 6 CAPACIDAD GERMINATIVA EN SEMILLAS INFESTADAS POR INSECTOS EN SEIS ESPECIES ARBÓREAS DEL BOSQUE DE LA SIERRA DE MANANTLÁN, JALISCO ................................ .. 74 Resumen ................................ ................................ ............................ 75 INTRODUCCIÓN ................................ ................................ ............... 76 MATERIALES Y MÉTODOS ................................ .............................. 78 Incubación de semillas ................................ ................................ .............................. 78 Análisis estadístico ................................ ...............................
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