RAPID SCREENING METHOD TO DETECT POTENTIAL BIPARENTAL INHERITANCE OF PLASTID DNA AND RESULTS FOR OVER 200 ANGIOSPERM SPECIES

Abstract

We have developed a diagnostic method to screen rapidly for plant species potentially capable of biparental inheritance of plastid DNA using the DNA fluorochrome 4′,6‐diamidino‐2‐phenylindole (DAPI) in conjunction with epifluorescence microscopy. Pollen shed from 235 plant species (including about 50 of agronomic importance) representing 80 families were screened. Putative plastid DNA was detected in the generative and/or sperm cells of pollen from 26 genera (43 species) representing 15 families. Plastid DNA was not detected in the generative or sperm cells of pollen from 192 plant species, thereby strongly suggesting that these species have only maternal inheritance. Our cytological diagnosis corroborated the known genetic evidence in 42 plant species and conflicted with the genetic reports in five species, which are discussed. The data suggest that biparental inheritance of plastids is rare; overall, it may occur in about 14% of flowering plant genera, examples of which are scattered among 19% of the families examined. This methodology also readily reveals whether pollen is bi‐ or trinucleate.