Field evaluation and components of peanut rust resistance of newly developed breeding lines

Abstract

Field, greenhouse, and growth chamber experiments were conducted to determine the level of resistance to Puccinia arachidis Speg. in newly developed breeding lines of peanut (Arachis hypogaea L.). These lines were developed in the UF150 project of the Peanut Collaborative Research and Support Program (Peanut CRSP) as part of the United States Agency for International Development (USAID). Field experiments were carried out in Citra, FL and Tifton, GA from 2010 to 2013. Five genotypes Tifrust-10 and Tifrust-13, and CRSP breeding lines PTBOL3-3, 97x36-HO2-1-B2G-3-1-2-2, and BOL3-7 had the lowest standardized area under the disease progress curve and final disease severity score for rust. The CRSP breeding lines 97x36-HO2-1-B2G-3-1-2-2 and BOL3-7 also appeared to be highly resistant to late leaf spot, caused by Cercosporidium personatum (Berk & M. A. Curtis Deighton). In growth chamber studies, genotypes with longer latent periods generally had lower infection frequencies at 7, 11, and 16 d after inoculation, and smaller percent diseased areas. Latent period and percent diseased area were significantly correlated with stAUDPC. CRSP breeding lines 97x36-HO2-1-B2G-3-1-2-2 and BOL3-7, and plant introductions PI562530, PI568164, and PI298115, were among the genotypes with the lower scores for these components. Several genotypes with multiple disease resistance in different environments and under high disease pressure were identified in these studies. These results indicate sources of rust resistance in the CRSP breeding lines, including several genotypes that could be used as parents in peanut germplasm enhancement programs, and indicate that latent period, percent diseased area, and lesion diameter may be used as indicators for rust resistance in growth chamber studies.

Comparative Transcriptome Analysis Identified Candidate Genes for Late Leaf Spot Resistance and Cause of Defoliation in Groundnut

“…Defoliation reduces healthy leaf area and affects the rate of photosynthesis and weakens the stems and pegs causing pods to fall off during up-rooting. If the leaf spot is not controlled in initial stage of disease development, defoliation level exceeds 50 percent and yield loss also exceeds 50 percent or more [ 36 ]. In the present study, we found genes responsible for senescence showing downregulation in susceptible genotypes (TAG 24) as compared to resistant genotype (GPBD 4) ( Table S18; Figure S3 ).…”

Resistance to rust (Puccinia arachidis Speg.) identified in nascent allotetraploids cross-compatible with cultivated peanut (Arachis hypogaea L.)

“…Fávero et al (2009) also found sporulation on six accessions of A. stenosperma, two accessions of A. valida, and one accession of A. magna, which were not tested in this study. So far, high resistance to rust has not been identified in A. hypogaea germplasm (Power et al, 2019;Subrahmanyam et al, 1982;Pande and Rao, 2001;Fávero et al, 2009). The lack of high resistance to rust in cultivated germplasm was contributed in part by having a highly susceptible progenitor as well as the ploidy barrier between allotetraploid peanut and its diploid, highly resistant Arachis relatives.…”

“…A major limitation to breeding rust-resistant cultivars is that only moderate levels of resistance have been identified in A. hypogaea germplasm (Power et al, 2019). Fortunately, high resistance to rust has been identified in numerous wild Arachis species, including the readily U.S.ble A-and B-genome Arachis species, and resistance can be introgressed into cultivated peanut (Subrahmanyam et al, 1982(Subrahmanyam et al, , 1983Pande and Rao, 2001;Fávero et al, 2009).…”

Early Interactions of Rust Pathogen Puccinia arachidis (Speg.) with Groundnut Genotypes Varying in Resistance

“…It is controlled in monogenic, digenic and trigenic manners (Daudi et al, 2021a). Further, resistance to rust has been identified in wild relatives, elite inbred lines, recently developed breeding lines and commercial cultivars (Pande and Rao, 2001, Favero et al, 2015, Sudini et al, 2015, Han et al, 2018, Power et al, 2019. However, there is limited understanding on the histopathological differences among the genotypes that might have led to the visual differences in signs and symptoms including lesion and sporulation levels.…”