Potential nodule- forming bacteria-
We were not able to isolate Ensifer from any of our historic
specimens, only from the contemporary Medicago . Although E.
meliloti has been described as desiccation tolerant, Ensifer do
not generally produce any spores or cysts (Humann et al. 2009), which
potentially limited their ability to survive in the extreme conditions
of the herbaria. We were able to isolate potential nodule-formingMicrovirga from the nodules of specimens from 2004 and 2015.
Nodule forming Microvirga form nodules in several legume species,
including Listia , Lupinus (Ardley et al. 2012, 2013), andVigna (Radl et al. 2014). Future work will include sequencing the
rest of our culture collection and increasing our temporal resolution by
sampling more specimens, from more dates, allowing us to definitively
say how long Ensifer can survive in herbaria. Additionally, we
will investigate if historic Microvirga isolated from herbaria
nodules can nodulate and benefit Medicago lupulina .