Mechanisms and resistance sources of Pisum spp. collection against Uromyces pisi
| Autor: | Osuna-Caballero, S., Rispail, Nicolas, Rubiales, Diego |
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| Rok vydání: | 2021 |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Trabajo presentado en Legume Science and Practice 2, celebrado online del 1 al 3 de spetiembre de 2021. Pea rust disease is a major disease worldwide. In temperate climates it is caused by Uromyces pisi, whereas in tropical areas of India it has been ascribed to U. viciae-fabae (Barilli et al., 2009a). Large screenings of pea germplasm for rust resistance have been described before, but only moderate levels of quantitative resistance were identified against U. pisi with no complete resistance or hypersensitive response detected so far (Barilli et al., 2009b). To complement these studies, here we show the response of 320 accessions including both cultivated pea and wild relatives, inoculated with a highly virulent isolate of U. pisi under field and controlled condition, in addition to histological assessment to discern the underlaying resistance mechanisms. Response of adult plants under field conditions was assessed in three consecutive field seasons by recording disease severity (DS) at 30 days post inoculation (dpi). Response of inoculated seedlings was accessed under controlled conditions recording daily from on 7 to 14 dpi the number of rust pustules in a marked area, allowing calculation of latency period (LP 50) and area under disease progress curve (AUDPC). At 14 dpi DS, infection frequency (IF) and infection type (IT) was recorded. From field and seedlings evaluations large variations were detected between accessions in most of the studied traits with partial resistance detected in both cases. However, no correlation was detected between variation in rust germination on the leaf surface before substomatal-vesicle formation events and the resistance to U. pisi. Consequently, the five more resistant, tolerant, and susceptible accessions were studied for post-appressorium events including colony size, hyphae number and haustoria number. This study identified new partially resistant pea accession that harbour a lower level of symptoms which was associated with smaller rust colonies due to a reduction in the number of haustoria and hyphal tips per colony. These findings demonstrate that screening pea collections continues to be a necessary method in the search for complete resistance against the pathogen U. pisi. In addition, the great phenotypic diversity contained in the study collection will be useful for further association analysis and for breeding perspectives. |
| Databáze: | OpenAIRE |
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