ARTICLE | doi:10.20944/preprints202008.0608.v1
Online: 27 August 2020 (09:43:59 CEST)
Bacterial collections are invaluable tools for microbiologists. However, their practical use is compromised by imprecise taxonomical assignation of bacterial strains. This is particularly true for soft rotting plant pathogens of the Pectobacterium genus. To solve this difficulty, we analyzed the taxonomic status of 265 Pectobacterium strains deposited at CIRM-CFBP collection from 1944 to 2020. This collection gathered Pectobacterium strains isolated in 27 countries from 32 plant species representing 17 botanical families or from non-host environments. MLSA approach completed by genomic analysis of 15 strains was performed to update the taxonomic status of these 265 strains. Results showed that the CIRM-CFBP Pectobacterium collection harboured at least one strain of each species to the exception of P. polonicum. Yet, 6 strains could not be assigned to any of the described species and may represent at least two new species. Surprisingly, the P. versatile species, recently described in 2019, is the most prevalent species among CIRM-CFBP strains. Analysis of P. versatile strains revealed that this species is endemic all over the world on various host plants and environments. At the opposite, other species gathered strains isolated from only one botanical family or exclusively from fresh water environment. Our work also revealed new host plants for several Pectobacterium spp.
ARTICLE | doi:10.20944/preprints202111.0574.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Zantedeschia aethiopica; X-ray mutagenesis; cultivation; Pectobacterium; mutation breeding
Online: 30 November 2021 (14:42:05 CET)
The development of new cultivars is important for the profitability of the floriculture industry. There are a limited number of cultivars of Zantedeschia aethiopica, an iconic ornamental cut flower, garden plant, and potted plant, due to the incompatibility of interspecific crossings within the genus. Most present-day varieties are the result of spontaneous mutations or classical breeding within the species, followed by a long selection process. Breeders are very interested in the development of a time- and cost-effective method for producing new Z. aethiopica cultivars with novel characteristics. Here, Z. aethiopica mutants were generated by treating seeds with 100 Gy of X-ray radiation. The resulting putative mutants were selected based on particular flowering parameters and compared to non-irradiated, control plants. Over two growing seasons, characteristics such as early flowering, flower size and shape, yield and response to soft-rot disease were monitored and considerable variation was observed among the mutated lines. Out of 319 mutants, 20 lines were selected based on their phenotypes and then propagated and further analyzed. Within this group, only two phenotypes displayed at least five improved flowering properties under natural, Mediterranean conditions. The rest displayed two to four desired combinations of flowering traits, some with great commercial potential.