Seriously, how does on grow seedless oranges?
How does one cross breed plants? I assume that you can’t just put two seeds together and expect to get one plant.
How does pollination work? In school all they really told us was that bugs carry pollen from one flower to another, but what happens then?
It’s frightening how many crazies think that world is going to end in a few days. All of us smart people know that it’s not ending until next year.
I’ll answer your third question. Pollen includes the flower’s germ cells - that is, the flower’s sperm or egg (I can’t remember which). The bee gets itself all dirty when it drinks nectar, and then goes to another plant, thus spreading the germinating pollen from one plant to another.
This gets around one of the main problems for sexual reproduction in plants; while animals can hop, crawl, fly or whatever over to an appropriate member of the same species, plants are rooted to the spot (so to speak). A plant could reproduce asexually, which isn’t great for population diversity, or it has to find some way to cover the distance to that hot-looking plant down the path. Trees often spread their germ cells by the wind; some low-lying underbrush kinda flora spread theirs in forest-floor waters; flowers enlist the aid of insects, paying them in honey.
When the dirty bee lands at another flower, some of the foreign pollen will be rubbed on the appropriate flower structure (stamen or pistel or pestle or whatever, again I can’t remember). Then, sperm hits egg in a familiar process. So, yes, the bees are performing sex for the flowers.
Second part of the OP:
I think you can just cross-breed plants by taking over for the bees. The two parent varieties would probably never have differentiated if they were close together. That is, if a bee could easily fly from one kind of plant to the other, they would never have become two kinds of plants. (Assuming they are varieties of the same species, otherwize all those germ cells end up wasted in the wrong flower.) So when cross-breeding, you’ll probably take varieties from two separate regions, and take germ cells from the stamen of one and the pistle of the other. So it’s not much different from flying a lion in from Africa to mate with a tiger, thus producing a liger (or a tion, if there is such a thing…?)
How you would cross breed asexual plants is beyond me.
And the master has answered your first question…
http://www.straightdope.com/columns/950407.html
“Drink your coffee! Remember, there are people sleeping in China.”
Dennis Matheson — dennis@mountaindiver.com
Hike, Dive, Ski, Climb — www.mountaindiver.com
Yeah, sticking your nose into a flower is sitcking your nose into their sex organ. whoa.
Cessandra: Most crossbreeding happens between two varieties of similar plants (there are cases of inter-genera cross breeds such as the Fatshedera lizei). Such as two types of roses that have desirable traits. You take the pollen from one, and transfer it to the female part of another plant. Crossbreeding for new varieties can take years as it’s all trial and error. I think it takes at least 20 years (not sure) to come out with new varieties of roses. Crossbreeding is more than just transfering of pollen, it also takes observation and patience to result in plants that produce desireable flowers or fruit reliably.
Another way to get desireable plants is grafting. This is how we get dwarfed fruit trees. Usually a rootstock that will dwarf the fruit bearing stock is used (but doesn’t have desireable fruits). Normally without a dwarfing roostock, the tree will grow full sized (which is why when buying dwarf fruit trees you don’t want the graft under the soil, or the top growth will root and you end up with a big tree).
Just to share further (how often do we get plant questions), almost all “named” plant varieties are grafts or cuttings. Be it seedless grapes and oranges, Autumn Blaze maples, or varigated petunias, to keep the plant “pure” asexual reproduction is a necessity. The reason for this is because most plants don’t hold mutations in flower color, seed production, etc for more than a generation before reverting back to the original. Take some striped petunias, let them go to seed, plant the seeds and you’ll get standard solid color petunias of a pinkish or reddish color (most likely).
(In the “you didn’t ask, but I’m on a roll” department…)
Therefore, as mentioned, you can graft sections of the plant onto another plant of the same species or else cut a sectionn off and force it to grow roots, thus creating a new plant. The major downside of this is a total lack of genetic diversity. So, if one plant in your seedless grape crop was hit by a virus or fungus, it’s about 90% sure that the rest of your plants will be blighted as well since none of them have any chance of resistance. In terms of landscaping, this is prevented (to a point) by mixing genetically diverse species of plants in an area (such as maple, ash, oak, linden, etc and not just maples) so if a maple specific disease comes along, you’ll (A) still have enough trees of other sorts that the neighborhood isn’t defoliated and (B) hopefully the maples will be spaced far enough apart to prevent the rapid spread of the disease.
“I guess one person can make a difference, although most of the time they probably shouldn’t.”
I seem to remember reading somewhere (I think it was in one of Poundstone’s Secrets books) that France lost a large portion of its wine grapes for this reason and wound up having to get new vines from California. Oh, the irony.
“Drink your coffee! Remember, there are people sleeping in China.”
Dennis Matheson — dennis@mountaindiver.com
Hike, Dive, Ski, Climb — www.mountaindiver.com
There’s some disease, or maybe it’s a parasite, that affects “old world” grapes much more than “new world” varieties. However, it only affects the roots, so you can graft old world vines onto new world roots. Is that what you’re talking about, or did they literally have to reimport seeds and vines from California?
And, also in the “You didn’t ask but i’m telling you anyway” category, some plants (tropical fruit trees mostly) have polyembryonic seeds (more than one seedling to a seed). The plants from these seeds actually do turn out to be very close to the parent plant in fruit quality. Mangoes for instance are like this. I’ve read that when growing them from seed, the seeds that produce more than one seedling will most likely have as good quality fruit as the parent plant.