2019 118 Vitus Ikechukwu Obi Evaluation of tolerance to brown rot caused by Monilia Iaxa (Aderhold and Ruhland) Honey, in peach germplasm (Prunus persica (L.) Batsch) Departamento Ciencias Agrarias y del Medio Natural Director/es BARRIUSO VARGAS, JUAN JOSÉ GOGORCENA AOIZ, YOLANDA Reconocimiento – NoComercial – © Universidad de Zaragoza SinObraDerivada (by-nc-nd): No se Servicio de Publicaciones permite un uso comercial de la obra original ni la generación de obras derivadas. ISSN 2254-7606 Tesis Doctoral EVALUATION OF TOLERANCE TO BROWN ROT CAUSED BY MONILIA IAXA (ADERHOLD AND RUHLAND) HONEY, IN PEACH GERMPLASM (PRUNUS PERSICA (L.) BATSCH) Autor Vitus Ikechukwu Obi Director/es BARRIUSO VARGAS, JUAN JOSÉ GOGORCENA AOIZ, YOLANDA UNIVERSIDAD DE ZARAGOZA Ciencias Agrarias y del Medio Natural 2018 Repositorio de la Universidad de Zaragoza – Zaguan http://zaguan.unizar.es PhD thesis Evaluation of tolerance to brown rot caused by Monilinia laxa (Aderhold and Ruhland) Honey, in peach germplasm (Prunus persica (L.) Batsch) Vitus Ikechukwu Obi Zaragoza, 2018 PhD Supervisors: Yolanda Gogorcena (Dr.) Juan Jose Barriuso (Dr.) INFORME FAVORABLE DE LOS DIRECTORES DE LA TESIS Los abajo firmantes Dra. Yolanda Gogorcena Aoiz y Dr. Juan J. Barriuso Vargas, como co- directores de la tesis doctoral realizada por Vitus Ikechukwu Obi con el título “EVALUATION OF TOLERANCE TO BROWN ROT CAUSED BY MONILINIA LAXA (ADERHOLD AND RUHLAND) HONEY, IN PEACH GERMPLASM (PRUNUS PERSICA (L.) BATSCH)” Informan favorablemente: que el contenido de esta tesis doctoral se corresponde con el proyecto de tesis aprobado en su momento. Los objetivos planteados se han alcanzado satisfactoriamente, y el trabajo realizado cumple los requisitos de calidad y originalidad que establece la normativa vigente. Y los resultados obtenidos son de interés académico, práctico y científico y las conclusiones obtenidas pueden servir de base para futuras líneas de investigación teórica y aplicada. Todo lo cual se hace costar a los efectos de la admisión a trámite de la tesis doctoral. En Zaragoza a 30 de mayo de 2018 Fdo. Dra. Yolanda Gogorcena Aoiz Fdo. Dr. Juan J. Barriuso Vargas ACKNOWLEDGMENTS My special thanks go to Drs Yolanda Gogorcena and Juan Jose Barriuso both of whom accepted to direct and supervise this thesis. I thank Dr. Marian Moreno for her assistance in the course of the project. I acknowledge the roles of Dr. Jesús Val Falcón, director of Aula dei CSIC and Sr. Jose Antonio Dominguez, director of CITA for their administrative roles in the success of the project. To Dr. Sergio Sánchez (CITA), Dr. Joaquín Aiber (UNIZAR) and Dr. Jesus Carlos (Mecohisa) once more I expressed my immense gratitude. I must not fail to acknowledge the inputs of the secretary of the department, Madam Yolanda Ubieto and Dr. Ana Olaizola, especially towards the most difficult period of the thesis. I appreciate the company of my colleagues, both at CITA and Aula Dei, including persons like Alex, Maria, Luis, Karina and Rosa. The requisite role, of the members of my family, especially from my lovely spouse, Chinwe; children, Chike and Chinenye; and nephew, Chibuike to the accomplishment of the mission is highly treasured. I express my gratitude to Barr. C.N.Obi (Big daddy) of Obiukwu chambers and Chief (Hon.) A.C.Obi of ASCON pharmacy for their steady show of concern and love at all times. Finally I want to thank Prof. (Dr.) C. E. Akujor (FUTO) for his invaluable counsel and inspiration. This study has been supported by a research grant, (AGL2014-52063R and AGL2017-83358-R) by the MINECO / the Government of Aragón and FEDER / ESF, respectively, through Dr. Yolanda Gogorcena; I can`t thank them enough. El que no ama no ha llegado a conocer a Dios, porque Dios es amor (1 Juan 4:8). INDEX OF CONTENTS Index of tables------------------------------------------------------------------------------------------------ iii Index of figures----------------------------------------------------------------------------------------------- iv Summary------------------------------------------------------------------------------------------------------- 1 Resumen------------------------------------------------------------------------------------------------------- 3 General introduction--------------------------------------------------------------------------------------- 5 Review: Peach brown rot: Still in search of an ideal management option------------------- 7 1. Introduction----------------------------------------------------------------------------------------------- 7 2. The Peach--------------------------------------------------------------------------------------------------- 9 2.1. Geography and ecological requirement of peaches------------------------------------------- 9 2.2. Botany and susceptibility of peach----------------------------------------------------------------- 10 2.3. Economic significance of peach--------------------------------------------------------------------- 12 3. Brown rot--------------------------------------------------------------------------------------------------- 14 3.1. Monilinia spp.------------------------------------------------------------------------------------------ 14 3.2. Geographical distribution of the species of Monilinia----------------------------------------- 15 3.3. Life cycle of the species of Monilinia-------------------------------------------------------------- 16 3.4. Ecological requirements of Monilinia species--------------------------------------------------- 17 3.5. Characterization and identification of Monilinia species------------------------------------- 18 3.5.1. Classical methods------------------------------------------------------------------------------------ 18 3.5.2. Molecular methods---------------------------------------------------------------------------------- 20 3.5.3. Limitations of molecular methods--------------------------------------------------------------- 22 4. Host-pathogen interactions--------------------------------------------------------------------------- 23 5. Other management strategies to control brown rot in peach ------------------------------ 25 5.1. Biological control--------------------------------------------------------------------------------------- 25 5.2. Conventional fungicide treatments---------------------------------------------------------------- 27 5.3. Limitations in the use of conventional fungicides---------------------------------------------- 28 5.4. Botanical fungicides------------------------------------------------------------------------------------ 28 5.5. Physical measures to control brown rot in peaches------------------------------------------- 29 5.6. Host Resistance and Genetic Management ----------------------------------------------------- 31 6. Breeding for Tolerant Cultivars or Genotypes --------------------------------------------------- 31 6.1. In-situ and ex-situ screening methods to evaluate brown rot tolerance----------------- 33 6.2. Plant parts and screening for disease tolerance------------------------------------------------ 34 6.3. Procedures for spore production and inoculation in lieu of brown rot susceptibility screening------------------------------------------------------------------------------------------------------- 34 7. Conclusions------------------------------------------------------------------------------------------------ 36 8. Compliance with Ethical Standard------------------------------------------------------------------- 36 9. References------------------------------------------------------------------------------------------------- 37 General objectives------------------------------------------------------------------------------------------- 49 General conceptual framework-------------------------------------------------------------------------- 53 Chapter I. Optimizing protocols to evaluate brown rot (Monilinia laxa) susceptibility in peach and nectarine fruits (Australasian Plant Pathology 46:183-189) ------------------- 57 Abstract-------------------------------------------------------------------------------------------------------- 59 i I-1. Introduction---------------------------------------------------------------------------------------------- 59 I-2. Materials and Methods------------------------------------------------------------------------------- 60 I-2.1. Plant material------------------------------------------------------------------------------------------ 60 I-2.2. Pathogen culture------------------------------------------------------------------------------------- 61 I-2.3. Conidia production and inoculation-------------------------------------------------------------- 61 I-2.4. Incubation and brown rot evaluation------------------------------------------------------------ 62 I-3. Results----------------------------------------------------------------------------------------------------- 64 I-4. Discussion------------------------------------------------------------------------------------------------ 64 I-5. Conclusions----------------------------------------------------------------------------------------------- 66 I-6. Acknowledgments-------------------------------------------------------------------------------------- 67 I-7. References------------------------------------------------------------------------------------------------ 67 Chapter II. Effects of pH and titratable acidity on the growth and development of Monilinia laxa (Aderh. & Ruhl.) in-vitro and in-vivo (European Journal of Plant Pathology)----------------------------------------------------------------------------------------------------