Post by sarraceniaseagull on Apr 6, 2016 19:26:07 GMT -5
Ok so I have heard varying reports on the viability of Sarracenia hybrids, with some people telling me the hybrids are fully sterile, and then I have seen multistep hybrids, the existence of which would have to mean that these hybrids can reproduce. Now, I am aware that exceptions can occur and sometimes you get fertile hybrids when you expected sterile ones, but I also am aware that sometimes hybrids occur naturally without issue. For example, in the moth genus Hyalophora, hybrid blend zones occur where ranges of 2 different species overlap, and the species H. kasloensis is a result of hybridogenesis. In Canada, H. cecropia and H. columbia are always hybridizing and you get individuals who look like at some point several generations back, there was a hybridization. I worked with hybrids of the genus Antheraea, having obtained supposedly sterile Antheraea polyphemus x oculea cocoons and having females successfully mate with wild male polyphemus (I am outside the oculea range) and over several generations and successive crossings of the hybrids with pure polyphemus, the oculea part of the offspring became more and more diluted. Larvae of later generations started performing better on maple (a good host for the polyphagous polyphemus but not the oak-loving oculea's favorite snack) and after 6 generations (before I finally offed the line because I was sick of them), they were indistinguishable from a pure polyphemus. I don't know if natural hybrid blend zones occur with Sarracenia, but it could explain some of the odd variants we come across from time to time. Maybe some of the plants in the wild have a great-great grandparent belonging to a different species.
Anyway, my inquiry is fairly simple. In biology, there are several barriers to hybridization, classified as either pre-zygotic or post-zygotic. Pre-zygotic barriers are things such as differences in geographical range, differences in breeding times, physical incompatibility among the 2 species (could be as simple as species A is too large to mate with species B or as complex as the genitals of species A are shaped so differently that a mating simply cannot occur), differences in breeding strategies, and chemical incompatibility between gametes. These barriers often work across taxa and is why birds and mammals cannot breed together. Closer species have what are known as post-zygotic barriers, implying fertilization did occur. These are things such as miscarriage/abortion of embryo due to some chemical disturbance, reduced hybrid viability (weak or sickly offspring that cannot live very long or well) or reduced hybrid fertility (sterile hybrids or hybrids that may produce less gametes, may be unable to pair with other hybrids and only can mate back with a parent species, or may only be compatible with other hybrids). What hybridization barriers exist between Sarracenia? Is it mostly a matter of flowering time/speed? Yes, geographical ranges may be different too, but plenty of bogs have numerous Sarracenia in the same area. Does anyone have any insights into this??
Anyway, my inquiry is fairly simple. In biology, there are several barriers to hybridization, classified as either pre-zygotic or post-zygotic. Pre-zygotic barriers are things such as differences in geographical range, differences in breeding times, physical incompatibility among the 2 species (could be as simple as species A is too large to mate with species B or as complex as the genitals of species A are shaped so differently that a mating simply cannot occur), differences in breeding strategies, and chemical incompatibility between gametes. These barriers often work across taxa and is why birds and mammals cannot breed together. Closer species have what are known as post-zygotic barriers, implying fertilization did occur. These are things such as miscarriage/abortion of embryo due to some chemical disturbance, reduced hybrid viability (weak or sickly offspring that cannot live very long or well) or reduced hybrid fertility (sterile hybrids or hybrids that may produce less gametes, may be unable to pair with other hybrids and only can mate back with a parent species, or may only be compatible with other hybrids). What hybridization barriers exist between Sarracenia? Is it mostly a matter of flowering time/speed? Yes, geographical ranges may be different too, but plenty of bogs have numerous Sarracenia in the same area. Does anyone have any insights into this??