Petunia (DRAFT)
References:
2010A, 2018E, 2019I, 2021L, 2023X, 2023V, 2025L
Figs. from 2019I: Pampas landscape with " sandstone towers". Occurrence of Petunia exserta in the shady caverns (coves) and ridges on these sandstone towers. Along the sun-exposed slopes, the white-flowered Petunia axillaris are prevalent. Although a hybrid origin is widely believed in the literature (Model 1), we prefer Model 5, in which P. exerta repeatedly originates from P. axillaris. We estimate that a superposition effect is governing this process (see quantum superposition hypothesis). Each sandstone tower has its own origin of P. exserta within the nearby P. axillaris population. |  | ||||
 Distribution Petunia exserta (Brazil) |  | ||||
According to the Color-Pattern-Length Model, the probability that a bird-pollinated plant species is red is low at this latitude; it is more likely to have a purplish or orange flower. Petunia exserta, with its purplish-red corolla and the overall length of 45-75 mm, fits well. The hummingbird species pollinating these sandstone towers remains unknown. It could be a bird with a bill of a length up to 40 mm (white arrow). |   | ||||
An estimation of the molecular genetic process by which P. axiliaris evolved into Petunia exserta follows here. Whenever cis- and trans-regulatory mechanisms are involved, one should broaden the perspective to include quantum mechanics. Long-read data have recently been published from wild plants as well as from "hybrid plants". It is useful to have a whole-genome alignment. Unfortunately, the published genome is still "polluted": for example, it comes from an inbred line. Inbred lines generally accumulate thousands or millions of point mutations across the entire genome. Additionally, one should be aware of the hidden heritability of certain MYBs involved in the MBW pathway. It is also useful to have a heat map showing gene activity for the species and the individuals in transition. The current conclusion is that the origin of Petunia exserta is most likely not attributable to hybridization; rather, it is likely the result of superposition. | We believe that species of the Petunia axillaris type, once they reach the shady coves of these sandstone towers, can adapt to the exserta type via internal, preformed mechanisms within a very short time. The system, especially P. exserta populations in those coves, should be phenotypically and genotypically monitored for at least 20 years. It seems to us that mixed phenotypes in these coves approach the exserta type in the long run. The ongoing transition from axillaris to exserta may be less than 100 years old or younger. | ||||
Chloroplast Genome The chloroplast genome is an essential feature when looking for relationships in so-called natural hybrids. As the chloroplast genome is 1) a maternal gift and 2) a slower-evolving genome with respect to the nuclear genome, it can give a hint at what route the evolving process is taking. As soon as we have more essential information about this topic, we will come back for analysis. |
One needs to have the CP genomes of both taxa for an adequate interpretation. We see for P. axillaris an array of intergenetic spacers only. It is very likely that both chloroplast genomes are identical. | ||||
For color measurement, see the Materials and Methods section or use your smartphone. If, in doing so, you become convinced that there is a superposed effect within five years. What kind of hummingbird is visiting these coves? | 05-2026 rolfy | ||||
