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plant reproduction
In article , cra2 deletethis_cra2
@mindspring.com writes So, if I moved a female plant, for example, to an area of the country where no plants of the opposite sex existed, the plant could not reproduce, correct? Yes, but. Many plants can also reproduce vegetatively. Can you name any specific examples? At one point it was believed that there were no locations in the UK where both sexes of wild _Populus nigra_ existed sufficiently closely together. (They've since found a reasonably sized population in the Vale of Aylesbury.) -- Stewart Robert Hinsley |
plant reproduction
Isn't there any number of fruit trees who need to have a 'male' planted
somewhere near them for them to bear fruit? Maybe I can think of them when feeling a little less woozy. PvR cra2 schreef So, if I moved a female plant, for example, to an area of the country where no plants of the opposite sex existed, the plant could not reproduce, correct? Can you name any specific examples? Are there are any commonly known instances of this... where you have to have an "opposite sexed" plant somewhere in your neighborhood or the plant won't reproduce? |
plant reproduction
This is a question for you plant experts out there. :)
I had a trivia question that has now turned into a curiousity I must satiate. There are plants that have both sexes and then other plants that only have one sex or the other, right? In regards to these single sex plants, the females reproduce by having the pollen (sperm) brought to them by bees, wind, etc, right? So, if I moved a female plant, for example, to an area of the country where no plants of the opposite sex existed, the plant could not reproduce, correct? Can you name any specific examples? Are there are any commonly known instances of this... where you have to have an "opposite sexed" plant somewhere in your neighborhood or the plant won't reproduce? Or, is the requirement much more loose than that, and a potential "mate" could be anywhere in the same state? Thanks for your time. Looking forward to hearing back. cra2 "at" mindspring "dot" com |
plant reproduction
In article , P van
Rijckevorsel writes Isn't there any number of fruit trees who need to have a 'male' planted somewhere near them for them to bear fruit? Maybe I can think of them when feeling a little less woozy. PvR Apples for a start, though I wouldn't swear that it applies to all cultivars. Sample URL - http://www.ontarioprofessionals.com/trees.htm -- Stewart Robert Hinsley |
plant reproduction
P van Rijckevorsel writes
Isn't there any number of fruit trees who need to have a 'male' planted somewhere near them for them to bear fruit? Maybe I can think of them when feeling a little less woozy. PvR Stewart Robert Hinsley schreef Apples for a start, though I wouldn't swear that it applies to all cultivars. Sample URL - http://www.ontarioprofessionals.com/trees.htm -- Stewart Robert Hinsley + + + Afraid not. This is an example of a different mechanism, viz self-incompatibility not based on mechanical principles. Self-incompatibilty in apples is linked to genetic make-up, which means that an orchard composed of a single clone (cultivar) won't produce fruit. For that a genetically different apple is necessary (a different cultivar). Not all apple cultivars are equally suitable as pollen producers. PvR |
plant reproduction
That's not a case of unisexual flowers, though, not in the Rosaceae.
It's self-incompatibility. With things in this family (notably cherries), often one cultivar is incompatible with itself and needs a different cultivar. You can get around this sometimes by grafting on a branch or two of a different cultivar. M. Reed Stewart Robert Hinsley wrote: In article , P van Rijckevorsel writes Isn't there any number of fruit trees who need to have a 'male' planted somewhere near them for them to bear fruit? Maybe I can think of them when feeling a little less woozy. PvR Apples for a start, though I wouldn't swear that it applies to all cultivars. Sample URL - http://www.ontarioprofessionals.com/trees.htm -- Stewart Robert Hinsley |
plant reproduction
Plants in many families can make fruit parthenocarpically (seedless fruit is
the result, so for a fruit grower that's still ok, but not reproduction). But if not parthenocarpic, even fruits won't form. Examples of dioecious plants that come to mind a date palms (Phoenix dactylifera) persimmon (Diospyros virginiana, D. kaki) red maple (Acer rubrum) Some hollies (not all) (Ilex spp.) at least some of the ashes (Fraxinus spp) papaya (Carica papaya), which has staminate, pistillate, and perfect-flowered individuals Some grapes, including the southern muscadine (Vitis rotundifolia), which, like papaya, has all three types. fig (Ficus carica), although females are often parthenocarpic, and of course, the syconium is not really "fruit" tissue anyway, in the sense of being an ovary. Brazilian pepper (Schinus terebinthefolia) In most of these examples, except for some horticultural cultivars selected for their parthenocarpy, an isolated pistillate ("female") plant will not bear fruit. |
plant reproduction
To start nitpicking: not all Rosacaeae are guaranteed to have perfect
flowers. It is the rule but exceptions can be found. My local flora states that Sanguisorba can have 'male' flowers only PvR Monique Reed schreef That's not a case of unisexual flowers, though, not in the Rosaceae. It's self-incompatibility. With things in this family (notably cherries), often one cultivar is incompatible with itself and needs a different cultivar. You can get around this sometimes by grafting on a branch or two of a different cultivar. M. Reed P van Rijckevorsel writes Isn't there any number of fruit trees who need to have a 'male' planted somewhere near them for them to bear fruit? Maybe I can think of them when feeling a little less woozy. PvR Stewart Robert Hinsley wrote: Apples for a start, though I wouldn't swear that it applies to all cultivars. Sample URL - http://www.ontarioprofessionals.com/trees.htm -- Stewart Robert Hinsley |
plant reproduction
On Tue, 14 Jan 2003 08:18:17 GMT, "P van Rijckevorsel"
wrote: "P van Rijckevorsel" wrote: Isn't there any number of fruit trees who need to have a 'male' planted somewhere near them for them to bear fruit? Maybe I can think of them when feeling a little less woozy. PvR d buebly schreef ginkgo Actually this was just what I did think of but did not want to say. Opinions vary if this is a useful 'fruit'. The Chinese like it, but in Western cities there is a proscription to planting female trees because the 'fruits' have a reputation of smelling badly. I have heard of cases where female trees were planted in busy streets but nobody noticed the 'fruits'. Perhaps these only smell badly in (sub)tropical araes where they will rot more easily? Also Ginkgo's are gymnosperms and thus do not have true fruits! ;-) PvR a male and a female were planted right outside the main library entrance at our college, and in the spring, dog shit smell eminated from the crushed fruits. They finally moved the entrance to the library in a large remodeling. The fruits looked somewhat like an apricot, though the flesh was thinner and the seed inside was less stoney. (it has been many years) |
plant reproduction
MMMavocado schreef
Yes, avocados are synchronously dichogamous (great dinner-party term to throw around!), but they don't really fit into this discussion, since the flowers are anatomically perfect. + + + Thanks. I will try and practice saying "synchronously dichogamous" as if it is an everyday term (will take some doing!). I would say the avocado fits right in this theme PvR + + + They simply mature their sexual whorls at different times. Always female first, then male. Type "A" trees open female in the morning, then close around noon, wait until the following day, and open after noon functionally male. Type "B" trees open the first day in the afternoon, as females, close for the night, and open the following morning functionally male, then close by noon. They do make mistakes, though. Some varieties can self-pollinate by not having the stigma/style undergo senescence until well into the male stage. Others can self-pollinate if the night-time temperature goes low enough to stop the female flowers from closing. |
plant reproduction
I had assumed you ;-) would refer to the avocado, of which some plants are
female in the morning and male in the afternoon, while others are just the reverse, with both groups needing to be present for fruit to set? PvR BRBR Yes, avocados are synchronously dichogamous (great dinner-party term to throw around!), but they don't really fit into this discussion, since the flowers are anatomically perfect. They simply mature their sexual whorls at different times. Always female first, then male. Type "A" trees open female in the morning, then close around noon, wait until the following day, and open after noon functionally male. Type "B" trees open the first day in the afternoon, as females, close for the night, and open the following morning functionally male, then close by noon. They do make mistakes, though. Some varieties can self-pollinate by not having the stigma/style undergo senescence until well into the male stage. Others can self-pollinate if the night-time temperature goes low enough to stop the female flowers from closing. |
plant reproduction
I had assumed you ;-) would refer to the avocado, of which some plants are
female in the morning and male in the afternoon, while others are just the reverse, with both groups needing to be present for fruit to set? PvR MMMavocado schreef Plants in many families can make fruit parthenocarpically (seedless fruit is the result, so for a fruit grower that's still ok, but not reproduction). But if not parthenocarpic, even fruits won't form. Examples of dioecious plants that come to mind a date palms (Phoenix dactylifera) persimmon (Diospyros virginiana, D. kaki) red maple (Acer rubrum) Some hollies (not all) (Ilex spp.) at least some of the ashes (Fraxinus spp) papaya (Carica papaya), which has staminate, pistillate, and perfect-flowered individuals Some grapes, including the southern muscadine (Vitis rotundifolia), which, like papaya, has all three types. fig (Ficus carica), although females are often parthenocarpic, and of course, the syconium is not really "fruit" tissue anyway, in the sense of being an ovary. Brazilian pepper (Schinus terebinthefolia) In most of these examples, except for some horticultural cultivars selected for their parthenocarpy, an isolated pistillate ("female") plant will not bear fruit. |
plant reproduction
"P van Rijckevorsel" wrote:
Isn't there any number of fruit trees who need to have a 'male' planted somewhere near them for them to bear fruit? Maybe I can think of them when feeling a little less woozy. PvR d buebly schreef ginkgo Actually this was just what I did think of but did not want to say. Opinions vary if this is a useful 'fruit'. The Chinese like it, but in Western cities there is a proscription to planting female trees because the 'fruits' have a reputation of smelling badly. I have heard of cases where female trees were planted in busy streets but nobody noticed the 'fruits'. Perhaps these only smell badly in (sub)tropical araes where they will rot more easily? Also Ginkgo's are gymnosperms and thus do not have true fruits! ;-) PvR |
plant reproduction
Xref: 127.0.0.1 sci.bio.botany:18769
From: "cra2" So, if I moved a female plant, for example, to an area of the country where no plants of the opposite sex existed, the plant could not reproduce, correct? Sean Houtman schreef in berichtnieuws To pick a nit, the plant could not reproduce sexually. It could still propagate asexually with cuttings, sprouts, rhizomes, divisions, or other methods of spreading about. Sean + + + To pick more nits: it is debatable if the option to be propagated still is reproduction. IIRC there is a species of Cycad of which only a 'female' specimen is known (perhaps it is in Kew?), so as a species it is just about extinct. PvR |
plant reproduction
From: "cra2"
So, if I moved a female plant, for example, to an area of the country where no plants of the opposite sex existed, the plant could not reproduce, correct? To pick a nit, the plant could not reproduce sexually. It could still propagate asexually with cuttings, sprouts, rhizomes, divisions, or other methods of spreading about. Sean -- Visit my photolog page; http://members.aol.com/grommit383/myhomepage Last updated 08-04-02 with 15 pictures of the Aztec Ruins. Address mungled. To email, please spite my face. |
plant reproduction
On Mon, 13 Jan 2003 19:09:23 GMT, "P van Rijckevorsel"
wrote: Isn't there any number of fruit trees who need to have a 'male' planted somewhere near them for them to bear fruit? Maybe I can think of them when feeling a little less woozy. PvR cra2 schreef So, if I moved a female plant, for example, to an area of the country where no plants of the opposite sex existed, the plant could not reproduce, correct? Can you name any specific examples? Are there are any commonly known instances of this... where you have to have an "opposite sexed" plant somewhere in your neighborhood or the plant won't reproduce? ginkgo |
plant reproduction
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plant reproduction
The cycad you refer to is actually a "male" clone of Encephalartos
woodii. It is apparently extinct in the wild but the surviving clone has been propagated and as many as 500 specimens exist in botanic gardens and private collections. There are efforts to propagate E. woodii by tissue culture, to induce a sex change to produce a "female" clone, and to breed a "female" by first crossing with a closely related species and then repeatedly backcrossing to the "male" clone. Some people question whether E. woodii was ever a widespread species. It may have been a single individual that arose as a intergeneric hybrid. So maybe they never were any "females." Reference SEX CHANGE IN CYCADS - HOPE FOR WOODII? http://www.plantapalm.com/vce/biology/sexchange.htm David R. Hershey "P van Rijckevorsel" wrote in message ... + + + To pick more nits: it is debatable if the option to be propagated still is reproduction. IIRC there is a species of Cycad of which only a 'female' specimen is known (perhaps it is in Kew?), so as a species it is just about extinct. PvR |
plant reproduction
Thanks. This looks like it. Nice link!
PvR ============== David Hershey schreef The cycad you refer to is actually a "male" clone of Encephalartos woodii. It is apparently extinct in the wild but the surviving clone has been propagated and as many as 500 specimens exist in botanic gardens and private collections. There are efforts to propagate E. woodii by tissue culture, to induce a sex change to produce a "female" clone, and to breed a "female" by first crossing with a closely related species and then repeatedly backcrossing to the "male" clone. Some people question whether E. woodii was ever a widespread species. It may have been a single individual that arose as a intergeneric hybrid. So maybe they never were any "females." Reference SEX CHANGE IN CYCADS - HOPE FOR WOODII? http://www.plantapalm.com/vce/biology/sexchange.htm David R. Hershey |
reproduction
This sort of thing happens in botany too. A somewhat similar case is that of
the St Helena redwood (extinct in the wild) and the St Helena ebony (down to two specimens in the wild), of which hybrids are doing well http://home1.swipnet.se/~w-17282/endemic/ebony.html http://home1.swipnet.se/~w-17282/endemic/redwood.html PvR ============= to breed a "female" by first crossing with a closely related species and then repeatedly backcrossing to the "male" clone. Iris Cohen schreef I understand similar efforts are underway to preserve a species of bird of which there is only one left. Iris, |
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