Plastid inheritance in Oenothera: paternal input may influence transmission patterns

Summary Prior genetic analysis of Oenothera to assess the mechanism(s) controlling differential (biparental) plastid transmission patterns have indicated that the plastome plays an integral role. However, the influence of putative variation in paternal plastid input remains unclear. Pollen collected from Oenothera hookeri plants containing one of four different plastome types (I–IV) in a constant nuclear background (A₁A₁) was examined cytologically by DAPI/ epifluorescence microscopy. The number of plastid DNA aggregates per pollen generative cell was found to differ significantly. Plants containing plastome types I or II displayed an average of about ten plastid DNA aggregates per generative cell whereas plants containing types III or IV displayed, on average, 15 plastid DNA aggregates. The potential paternal plastid contribution to the egg cell at syngamy (III=IV>I=II) differs from the previously determined survival frequencies of the same four plastid types (I>III>II>IV) progeny.Scientific article no. A-5036, contribution no. 8084 of the Maryland Agricultural Experimental Station