Objavljeno: To Maj 10, 2016 4:23 pm
Metuljc hvala za obrazložitev. A meni še vedno ne da miru efekt, ki mislim, da ga sproži mešan prah. Mislim, da se vrtnica, na katero naneseš zmešan prah drugače obnaša, reagira kot drugače. Kar sem dosedaj prebrala, to velja tako za vrtnice kot za ustvarjanje novih sort sadja npr. so stvari zelo podobne. Govori se namreč o izboljšanju sort. Tako na področju cveta kot plodu, če govorimo o sadju. Kot da pride zaradi konkurence oz. drugačnih vrst prahu do drugačnega - hitrejšega odziva pri oploditvi. In če jaz razumem prav spodnje razlage enega izmed strokovnjakov, ki odgovarja na svetovnem forumu za žlahtnitelje vrtnic, prihaja do še nečesa. Efekta na metabolizem, na katerega lahko vpliva tudi drugi prah drugega starša sem prav razumela?
Če gledam samo mojo letošnjo prakso s poizkusom ene sorte recimo ji A, ki sem jo dosedaj večkrat posejala - OP semena in nikoli nič pametnega dobila, sem letos prvič dobila kalitve, lahko rečem kar nekaj, potem, ko sem mešala prah. Več prahu kot sem zmešala, več kalitev imam. Saj razumem, da bi lahko samo en starš bil odločilen, ker je pač dober kot starš, da imam več kalitev, a ta vpliv -efekt mešanice prahu mi ne da miru, da tu ni še nekaj več. Če gledamo pri človeku, kako se je lahko paru - dvema belcema rodil otrok bel, nato drugi dan ali razmak precej ur še en črn. Mati je kasneje priznala, da je isti dan - ali nekaj ur kasneje spala tudi s črncem....
In zakaj je efekt pri vrtnicah boljši - če ga čez 1 ali 2 dni znova oplodiš z dodatnim prahom??? Potem bi to pomenilo, da ima tudi drugi prah še neko dejavnost po oploditvi?
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Re: Using mixed pollen?
by Karl K » Mon Jun 04, 2012 9:14 pm
Pollen mixtures can be useful when attempting to breed with a species. Instead of picking one specimen at random and hoping for the best, grab pollen from several plants.
There is also evidence of a sort of "step father" effect. Only one pollen tube fuses with the ovum, of course, but other pollen tubes traveling down the style at the same time can influence the metabolism of the embryo. Polyakov (1963) wrote, "In 1953-1962 we recommended and used the new method for studying fertilization processes with the help of the pollen labelled with radioactive isotopes S[sup]35[/sup] and P[sup]32[/sup]. For the first time these tests were direct physiological evidence that pollen without taking direct part in double fertilization is active in metabolic processes of growing seeds."
There are various possible interactions between pollen grains and pollen tubes.
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by Karl K » Wed Jun 06, 2012 10:33 am
Pierre,
The mentor effect is important in some crosses. In addition, there is a maternal influence.
The seed parent cannot choose to provide extra nutrition to seeds with a superior genotype, of course. But it can "play the odds" by investing more heavily (supplying more nutrients) to fruit that have been fertilized by genetically diverse pollen.
"Diverse", in this case, implies that the genetic diversity is recognizable. It would not help much to add morning glory pollen when pollinating a rose. But when making remote crosses, some more familiar pollen (from a closer relative) may encourage the seed parent to feed the fruit more than it would if only the remote pollen were used.
An example of this was shown by Mangelsdorf & Reeves: Maize-Tripsacum hybrids (1931), Figure 4
"Some ears set seed almost 100 per cent. The hybrid seeds, however, are very small compared to maize seeds of the same age. A few maize seed near the middle resulted from pollinating with maize 24 hours after pollinating with Tripsacum. Note that some of the hybrid seeds adjacent to the maize seeds are larger than their sibs."
Apparently, the larger hybrid seeds came about when both maize and Tripsacum pollen tubes grew down the same silks. The seed parent recognized the maize pollen tubes and nourished the seeds as if they were "pure" maize, even though the Tripsacum pollen tubes fused with the ova.
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There is evidence that mixed pollen germinates better than pollination by a single specimen. Some of the evidence is scientific (controlled studies), some is anecdotal.
Cook: Hybridizing (1907)
I have several [rose] seedlings, where the pollen was taken from three and four different varieties mixed together, and they are the richest color in red of any I have ever raised.
The New Phytologist 138(3): 481 (March 1998)
Pollen–pollen interactions in Betula pendula in vitro
H. L. PASONEN & M. KÄPYLÄ
Direct pollen interactions, as well as interactions mediated by a recipient, can have a remarkable influence on pollen fertilization ability. Under conditions of pollen competition it could be advantageous if pollen grains interfered with the germination of other pollen. The aim of this study was to find out if there are direct negative or positive pollen–pollen interactions between pollen grains from genetically slightly different donors. The in vitro germinability of the pollen from several Betula pendula Roth clones was investigated. The pollen interactions between the clones were examined pairwise by using equal pollen mixtures. In three of the eight cases the germination percentage of the pollen mixture was significantly higher than the average germination percentage of the separate clones that formed the mixture, which indicates some type of interaction between the pollen populations. We found only positive interactions between the pollen of clones. This study also documented density-dependent germination of pollen grains in vitro (=pollen population effect). Adding an aqueous pollen extract to the incubation medium increased the germination percentages of poorly germinating pollen and small pollen populations. Germination-stimulating effects were found to exist both with fresh and dead pollen. Such direct pollen–pollen interactions could be explained by specific water-soluble substances diffusing from pollen grains.
I have a bibliography of various other reports.
http://www.bulbnrose.org/Heredity/King/ ... tures.html
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Tu ni vse zajeto, kar sem prebirala a sedaj bi mogla iskati, kje sem to brala, mogoče imam celo shranjeno. Mogoče pa je to že dovolj in bo pomagalo. Torej bega me še efekt mešanega prahu na sejance._________________Usmerimo se k soncu in sence bodo ostale za nami.
Če gledam samo mojo letošnjo prakso s poizkusom ene sorte recimo ji A, ki sem jo dosedaj večkrat posejala - OP semena in nikoli nič pametnega dobila, sem letos prvič dobila kalitve, lahko rečem kar nekaj, potem, ko sem mešala prah. Več prahu kot sem zmešala, več kalitev imam. Saj razumem, da bi lahko samo en starš bil odločilen, ker je pač dober kot starš, da imam več kalitev, a ta vpliv -efekt mešanice prahu mi ne da miru, da tu ni še nekaj več. Če gledamo pri človeku, kako se je lahko paru - dvema belcema rodil otrok bel, nato drugi dan ali razmak precej ur še en črn. Mati je kasneje priznala, da je isti dan - ali nekaj ur kasneje spala tudi s črncem....
In zakaj je efekt pri vrtnicah boljši - če ga čez 1 ali 2 dni znova oplodiš z dodatnim prahom??? Potem bi to pomenilo, da ima tudi drugi prah še neko dejavnost po oploditvi?
------------------------------------------------
Re: Using mixed pollen?
by Karl K » Mon Jun 04, 2012 9:14 pm
Pollen mixtures can be useful when attempting to breed with a species. Instead of picking one specimen at random and hoping for the best, grab pollen from several plants.
There is also evidence of a sort of "step father" effect. Only one pollen tube fuses with the ovum, of course, but other pollen tubes traveling down the style at the same time can influence the metabolism of the embryo. Polyakov (1963) wrote, "In 1953-1962 we recommended and used the new method for studying fertilization processes with the help of the pollen labelled with radioactive isotopes S[sup]35[/sup] and P[sup]32[/sup]. For the first time these tests were direct physiological evidence that pollen without taking direct part in double fertilization is active in metabolic processes of growing seeds."
There are various possible interactions between pollen grains and pollen tubes.
----------------
by Karl K » Wed Jun 06, 2012 10:33 am
Pierre,
The mentor effect is important in some crosses. In addition, there is a maternal influence.
The seed parent cannot choose to provide extra nutrition to seeds with a superior genotype, of course. But it can "play the odds" by investing more heavily (supplying more nutrients) to fruit that have been fertilized by genetically diverse pollen.
"Diverse", in this case, implies that the genetic diversity is recognizable. It would not help much to add morning glory pollen when pollinating a rose. But when making remote crosses, some more familiar pollen (from a closer relative) may encourage the seed parent to feed the fruit more than it would if only the remote pollen were used.
An example of this was shown by Mangelsdorf & Reeves: Maize-Tripsacum hybrids (1931), Figure 4
"Some ears set seed almost 100 per cent. The hybrid seeds, however, are very small compared to maize seeds of the same age. A few maize seed near the middle resulted from pollinating with maize 24 hours after pollinating with Tripsacum. Note that some of the hybrid seeds adjacent to the maize seeds are larger than their sibs."
Apparently, the larger hybrid seeds came about when both maize and Tripsacum pollen tubes grew down the same silks. The seed parent recognized the maize pollen tubes and nourished the seeds as if they were "pure" maize, even though the Tripsacum pollen tubes fused with the ova.
-----------------------------
There is evidence that mixed pollen germinates better than pollination by a single specimen. Some of the evidence is scientific (controlled studies), some is anecdotal.
Cook: Hybridizing (1907)
I have several [rose] seedlings, where the pollen was taken from three and four different varieties mixed together, and they are the richest color in red of any I have ever raised.
The New Phytologist 138(3): 481 (March 1998)
Pollen–pollen interactions in Betula pendula in vitro
H. L. PASONEN & M. KÄPYLÄ
Direct pollen interactions, as well as interactions mediated by a recipient, can have a remarkable influence on pollen fertilization ability. Under conditions of pollen competition it could be advantageous if pollen grains interfered with the germination of other pollen. The aim of this study was to find out if there are direct negative or positive pollen–pollen interactions between pollen grains from genetically slightly different donors. The in vitro germinability of the pollen from several Betula pendula Roth clones was investigated. The pollen interactions between the clones were examined pairwise by using equal pollen mixtures. In three of the eight cases the germination percentage of the pollen mixture was significantly higher than the average germination percentage of the separate clones that formed the mixture, which indicates some type of interaction between the pollen populations. We found only positive interactions between the pollen of clones. This study also documented density-dependent germination of pollen grains in vitro (=pollen population effect). Adding an aqueous pollen extract to the incubation medium increased the germination percentages of poorly germinating pollen and small pollen populations. Germination-stimulating effects were found to exist both with fresh and dead pollen. Such direct pollen–pollen interactions could be explained by specific water-soluble substances diffusing from pollen grains.
I have a bibliography of various other reports.
http://www.bulbnrose.org/Heredity/King/ ... tures.html
---------------------
Tu ni vse zajeto, kar sem prebirala a sedaj bi mogla iskati, kje sem to brala, mogoče imam celo shranjeno. Mogoče pa je to že dovolj in bo pomagalo. Torej bega me še efekt mešanega prahu na sejance._________________Usmerimo se k soncu in sence bodo ostale za nami.
? Si mislim, da to pomeni, da se kuja.
_________________