Differences in pathogen resistance between diploid and polyploid plants: a systematic review and meta-analysis

Polyploidy, the state of having more than two full sets of chromosomes, has been hypothesized to provide several evolutionary advantages to flowering plants, including increased ability to resist pathogens and parasites. However, studies comparing pathogen resistance in conspecific and congeneric diploids and polyploids have produced mixed results. While the supposed relationship between polyploidy and pathogen resistance has been commented on in several narrative reviews, it has never been subjected to a systematic meta-analysis. We examined the effect of polyploidy on pathogen resistance by synthesizing 214 effect sizes from 128 studies. We find that, overall, there is no consistent effect of polyploidy on pathogen resistance. Subgroup analyses suggest that polyploids perform significantly better than diploids only in resisting hemibiotrophic pathogens, and autopolyploids tend show greater resistance than allopolyploids. This is surprising given the fact that polyploids possess extra ..., Literature search. We searched for relevant publications using Google Scholar, using individual searches for studies comparing diploids and various cytotypes. These searches returned a total of 1,602 publications, which, after pruning for papers that met our criteria, produced 73 studies able to be analyzed. These were combined with 55 papers found outside our systematic search, for a grand total of 128 publications with 214 individual effect sizes.
Data extraction. For each effect size, we recorded the following information: mean, standard deviation, sample size, and for both the diploid and polyploid groups in each effect size: authors, Linnean family, ploidy level of the polyploid, whether or not the diploids under study were hybrids, whether the polyploids under study were autopolyploids or allopolyploids, whether the species under study were wild or cultivated, whether the polyploids under study were synthetic or established, the type of pathogen with which plants were infected, an...,
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The data in HagenandMason2023_data.xlsx can be opened in Microsoft Excel or an open-source alternative like LibreOffice Calc
The bibliography of papers included in the meta-analysis, included_papers_biblio.docx, can be opened in Microsoft Word or an open-source alternative like LibreOffice Writer