Disease Resistance to Multiple Fungal and Oomycete Pathogens Evaluated Using a Recombinant Inbred Line Population in Pepper

Abstract

Incorporating disease resistance into cultivars is a primary focus of modern breeding programs. Resistance to pathogens is often introgressed from landrace or wild individuals with poor fruit quality into commercial-quality cultivars. Sites of multiple disease resistance (MDR) are regions or "hot spots" of the genome with closely linked genes for resistance to different pathogens that could enable rapid incorporation of resistance. An F-derived F recombinant inbred line population from a cross between 'Criollo de Morelos 334' (CMM334) and 'Early Jalapeno' was evaluated in inoculated fruit studies for susceptibility to oomycete and fungal pathogens: Phytophthora capsici, P. nicotianae, Botrytis cinerea, Fusarium oxysporum, F. solani, Sclerotinia sclerotiorum, Alternaria spp., Rhizopus oryzae, R. stolonifer, and Colletotrichum acutatum. All isolates evaluated were virulent on pepper. Significant differences in disease susceptibility were identified among lines for each of the pathogens evaluated. P. capsici was the most virulent pathogen, while R. oryzae and one Sclerotinia isolate were the least virulent. Quantitative trait loci associated with resistance were identified for Alternaria spp. and S. sclerotiorum. Positive correlations in disease incidence were detected between Alternaria spp. and F. oxysporum, F. solani, and C. acutatum, as well as between C. acutatum and Botrytis spp., F. oxysporum, F. solani, and P. capsici. No sites of MDR were identified for pathogens tested; however, positive correlations in disease incidence were detected among pathogens suggesting there may be genetic linkage among resistance genes in CM334 and Early Jalapeno.

Challenges and Strategies for Breeding Resistance in Capsicum annuum to the Multifarious Pathogen, Phytophthora capsici

“…The NMRILs have been used globally (Brazil, China, Taiwan, and across the United States) to characterize P . capsici for the past decade ( Monroy-Barbosa and Bosland, 2008 , 2010 , 2011 ; Sy et al, 2008 ; da Costa Ribeiro and Bosland, 2012 ; Hu et al, 2013b ; Naegele et al, 2014 , 2017 ; Naegele and Hausbeck, 2014 ; Rehrig et al, 2014 ; Jiang et al, 2015 ; Barchenger et al, 2018 ). The NMRILs provide a host differential to identify the virulence phenotype in a given region at a particular time ( Barchenger et al, 2018 ).…”

Modelos lineares generalizados espaciais mistos aplicados em estudos de insetos

“…Como em todo estudo de campo, perdas amostrais são muito comuns em diversas áreas de pesquisa e estão envidenciadas em Liu et al (2019), Zhang et al (2019), Dai e Müller (2019), Naegele et al (2017, entre outros. Essas interferências na área experimental, diferente de estudos em laboratório com ambientes controlados, nem sempre podem ser previstas e evitadas.…”