Memahami biji benih: Generasi F1, F2, F3........

source: google

Need to understand biji benih punya sifat juga...
Reason:

1. jangan salah beli biji benih yg xde kualiti.. biar mahal.. tapi berkualiti
2. jika ada niat nak menjual/ sedekah biji benih drp pokok yg kita tanam... kena paham dulu asal usul benih kita... supaya biji benih yg kita jual tu sama kualiti dgn induk dia

source: google

This brief info is obtained from discussion drp forum http://www.tomatoville.com...
link ke forum http://www.tomatoville.com/showthread.php?t=17088

Happy reading!!!!
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Please explain F1, F2, F3...
I encountered F1 for the first time on my pepper forum, but really don't understand a few points:

1. If I plant F1 seeds, will the seeds from the resultant pods be viable, or do I have to buy more seed?

2. Is an F1 plant hardier than the non F1, in general?

3. Can two different F1's hybridise?

Cheers!


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A little background...

For crosses you have parents (P) and offspring (Filial generations) F1 = children of parents, F2 = grandchildren, F3 = great grandchildren, etc.

At its simplest, vegetable varieties have two sets of chromosomes, one from each parent. The forms of these genes (alleles) can either be the same (homozygouse) or different (heterozygous -e.g.regular leaf/potatoleaf), one type of allele often dominates/masks other forms (regular leaf form masks potato leaf form). Genetically stable open pollinated (self pollinating) varieties have homozygous genes so all of the offspring generations will be identical to the parent generation... i.e. they are genetically stable.

Horticulturally speaking, a hybrid is an F1 having parents of two different varieties, and is thus heterozygous at many genes. When that plant self pollinates creating F2 seeds/plants those seeds/plants are no longer hybrids, but they still have a mix of genes from the parent plants and those genes start to form new combinations.

Parent = potatoleaf X parent = regular leaf --> F1 Regular leaf (with RL+PL allels). F1's offspring (F2) = RL+RL, RL+PL, RL+PL, PL+PL.

So if you grow out seed from a hybrid variety you will get gene segregation for all of the genes that were heterozygous in that hybrid (color, leaf type, flavor components etc.)


Now for your questions

1) You mean if you plant seeds from the fruits of an F1 hybrid, which would be F2 seeds.... They will grow but be different from the F1 and each other.

2) Yes, F1 hybrids are often more vigorous than their open pollinated parents, but not always.

3) Yes, F1aXF1b will work. This is what effectively occurs in all wild populations because individuals are not genetically stable varieties (homozygus at all genes) in those populations. You and I would be classified as horticultural hybrids because we each had dissimilar parents.

However, if you made this cross F1aXF1b they would now be the "P" generation and the offspring would be F1 ... [F1xF1other = F1, F1xF1same = F2].

What is confusing is that biologicaly speaking, a hybrid is the offspring of two different species (Lion x Tiger) and all progeny (F1>>>>F100) will remain hybrids. In most cases this type of cross does not work because the genetic combinations are incompatible either directly (embryo cannot develop), or indirectly (the hybrid offspring get outcompeted by the parent species and cannot form a continuing population) Horticulturally we almost never see biogical hybrids for vegetables (the apricot x prune is one exception) even broccoli x cauliflower = broccoflower is not a biological hybrid because all of the Kale vegetables are of the same species.

source: google