The bacterial community in potato is recruited from soil and partly inherited across generations

Buchholz et al., 2019.

Strong efforts have been made to understand the bacterial communities in potato plants and the rhizosphere. Research has focused on the effect of the environment and plant genotype on bacterial community structures and dynamics, while little is known about the origin and assembly of the bacterial community, especially in potato tubers. The tuber microbiota, however, may be of special interest as it could play an important role in crop quality, such as storage stability. Here, we used 16S rRNA gene amplicon sequencing to study the bacterial communities that colonize tubers of different potato cultivars commonly used in Austrian potato production over three generations and grown in different soils. Statistical analysis of sequencing data showed that the bacterial community of potato tubers has changed over generations and has become more similar to the soil bacterial community, while the impact of the potato cultivar on the bacterial assemblage has lost significance over time. The communities in different tuber parts did not differ significantly, while the soil bacterial community showed significant differences to the tuber microbiota composition. Additionally, the presence of OTUs in subsequent tuber generation points to vertical transmission of a subset of the tuber microbiota. Four OTUs were common to all tuber generations and all potato varieties. In summary, we conclude that the microbiota of potato tubers is recruited from the soil largely independent from the plant variety. Furthermore, the bacterial assemblage in potato tubers consists of bacteria transmitted from one tuber generation to the next and bacteria recruited from the soil.

Initially, seed potatoes of seven potato cultivars (Agata, Agria, Ditta, Fabiola, Fontane, Lady Claire and Hermes) were used for 16S rRNA gene amplicon sequencing (T0) and were grown in parallel in commercial potting soil. At maturity, tubers were harvested and used for 16S rRNA gene amplicon sequencing (T1). Tubers of four varieties (Agata, Fabiola, Hermes and Lady Claire) were planted in pots with five different soil types (commercial potting soil and four different farmland soils). Again, tubers were harvested at maturity and used for bacterial community sequencing (T2). The 16S rRNA gene amplicon sequencing data of different potato tuber generations and potato cultivars were combined to different datasets depending on the research question (datasets 1–4), as indicated by differently colored boxes. 

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0223691
.