Hybrid and true-to-type seed questions

Hello Permie botanists! I'm evolving my garden thinking from that of "maintaining heirloom varieties" to "optimizing crops for my garden". I've been reading Joseph's great posts on landraces and I'm a bit confused about a couple things that I should have learned in high school biology class:

1. I believe that if you plant two C. Pepo squash (ie. pumpkin and acorn squash) near each other they will likely cross-pollinate. On the pumpkin plant you would see and eat pumpkins that taste like pumpkins but the seeds would turn into some hybrid combination of the two. When you plant those hybrid seeds (presumably along with other C Pepo varieties) you'd get curious looking squash with further hybridized seeds in them. If one of those grandbaby squash was the best squash ever (taste, storage, productivity), how would you replicate it? If you save its seeds, aren't they further hybrids that would produce something different from what you liked?

2. I have three types of pole beans to plant this year and I was hoping to put them in the same row. Will they cross pollinate?

3. For those three beans in the same row, how would I be able to separate the harvested dry bean into the various crosses? If I end up with 5 varieties in the fall can I assume that they are identifiable based on size/color/shape of the bean pods and seeds?

4. If I plant one of the cross varieties all by itself would the seed and/or the pod continue to look/taste the same as it did the first year it appeared?

I may be getting mixed up here between crops where you are eating the flesh vs the seed. My goal is to select for plants that do better in my area. If I get cool crosses I'd like to be able to understand, replicate and seed save correctly.

Thanks!!

I'll let Joseph or someone else handle the squash question as he has more practical experience with Cucurbit crossing and varietal/landrace selection and maintenance. That said, we keep our squash pretty separate and still get some likely crossing events across the garden. If you get a tasty derivative that you may wish to maintain and amplify, I think you would have to interpollinate between plants from seeds of the tasty individual and others of the same type of squash, then over the next several generations, keep selecting on that flavor and other characteristics that you like. You may be able to "fix", over time, the flavor and desirable characteristics in your landrace. But again will defer to others' suggestions.

With beans, they are highly self-pollinating. When you mentioned "same row", do you mean the first 1/3 of the row would be variety A, the second 1/3 variety B, and the third 1/3 variety C? That would be more advisable than intercropping the beans....plant A next to plant B next to plant C....repeating all the way down the row. If you want to actually force crosses between them, then the latter would help, but you would not be assured of getting a cross. I'm pretty sure you would need to emasculate the flower of the plant on which you wanted to make the cross and add pollen from a donor plant to this.

Either way, it is not uncommon to get new types of colors and textures in dry beans, even when growing them in isolation, since general mutation will generate variation on its own at a low rate. To maintain a desired variety, keep the seed separate and plant it where you can keep track of it separately and see how variable it is in the next generation....with an inbreeding plant like beans, you should be able to ultimately (over several generations) get to a stable version with the desired characteristics, although there can be some exceptions.

hau Mike, Welcome to the world of Land Race creation.

Botanists divide squash into six main species, four of which are commonly grown as tender annuals.
While squash within any of these species easily cross-pollinate, separate species do not.
By planting a cultivar from one or more of the four species, you can confidently harvest seeds that are true to type.

Common Cucurbita maxima cultivars include “Buttercup,” “Hubbard” and “Turban.”
Cucurbita mixta includes all cushaws except the “Golden Cushaw,” “Orange Cushaw” and “Orange Striped Cushaw,” which belong to Cucurbita moschata.
The Cucurbita moschata grouping also includes “Cheese” and the better-known “Butternut.”
The large Cucurbita pepo group includes all “Acorn,” “Cocozelle,” “Crookneck,” “Gourd” “Scallop,” “Vegetable Marrow” and “Zucchini” squash.

If you want to grow several cultivars from a single species (say, a variety of zucchinis) and you save seeds, hand pollinate.
This allows you to develop seeds uniquely suited to your growing climate.
To prevent insects from getting to the flowers before you do, tape the tips of both male and female flowers shut shortly before the blossoms open.

Only save seeds from open-pollinated or heirloom plants. Seeds collected from hybrid squash produce progeny with a range of characteristics, none of them true to the parent plant.
Select your biggest, healthiest squash, allowing it to ripen on the vine until the stem starts turning brown or until you cannot dent the skin with your fingernail.
Wait three weeks after picking before you harvest the seeds.
Squash seeds continue maturing for 20 days after picking.
When the squash is mature, cut the flesh open, removing the seeds and rinsing them off.
Dry them on a hard surface such as a plate or baking sheet; avoid paper products that can lodge to the seeds as they dry.
Your seeds are dry when they can be cracked in half.
Once they are in an airtight container, seeds can be frozen or stored in a cool, dark place.

Now, to your questions.
1). Yes, if you plant different squash varieties close (within 1/4 mile) to each other, cross pollination will occur and the seeds will not produce True.
To make sure they do produce true you will need to either separate or hand pollinate (I hand pollinate).
When you are trying to create a best taste, landrace variety, you choose the best characteristics and prevent insect caused crosses.

2). If you place 3 varieties of pole beans in the same row, yes cross pollination will occur, just not every flower will be involved in the cross pollination.

3). Labeling is how you keep track of what is crossed with what. Otherwise you will most likely not be able to tell them apart.

4). Yes, keeping a cross separated will help a great deal with keeping it true.

Hope this helps you out.

Mike: When I find a squash with excellent taste, or an amazing shape that I'd like to turn into a new variety. I plant it separately the next year. Often with seeds from other squash that share the shape or taste. Yes, there are lots of other genetics running around, but the potential and the family resemblance is still there. So over a few years, I move the genetics of the population towards my goal. If I am dealing with a trait like fruit shape, that is obvious very early on, I could cull plants with the non-target shape and thus minimize the amount of non-target pollen early in the growing season. Plant breeders that want to make formal varieties or have the process occur more quickly might manually self-pollinate the plant, for a few years, which speeds up the elimination of non-target genes. As a landrace grower I like genetic diversity, so I take the successive approximations approach. I have about 5 widely separated fields, so I have lots of isolation options. When I only had one field, I would plant squash I wanted to (more or less) isolate into the corners of the field.

Pollination is a highly localized event... A plant is much more likely to be pollinated by it's closest neighbor than by something from further away. So I do things like plant a 300 foot row of squash with one variety on one end, and a different variety on the other, and then I save seeds only from the ends of the row, and not from in the middle. Then I pay attention during the growing season and cull off-types.

The cross pollination rate of common beans is highly dependent on the environment and what pollinators are present. With close plantings, it can be in the neighborhood of 0.5% up to about 5%. Bean hybrids are not observable in the first generation of harvested seeds. The offspring however might have differences in color, or leaf shape, or internode distance, that would allow them to be identified. The seed coat might be a different color.

As an example with beans:

This is the mother variety. A bush bean. The hybrid seed looked the same.


The children of the cross looked like this.


The grandchildren of the cross looked like this. This was the entire harvest of bush beans. There were pole varieties that I didn't harvest. Hint: The pollen donor was a pole bean.


The great-grandchildren of the cross looked like this: Don't read too much into the changes in coloring of the seeds in later years. That probably has as much to do with what I chose to plant as it does with the genetics of the plant or with survival of the fittest. Because they are beans, and highly inbreeding, I could separate the colors at this point, and there'd be around 90% chance that they'd remain true to type.

Out of curiosity, was trying to find a comparison of the relative within-group diversity for Phaseolus (common bean) verus Vigna (mung, adzuki, and others) and came up empty handed. Still the following summary is interesting as it relates to what kind of diversity is available to play with:

Abstract

Economically, legumes (Fabaceae) represent the second most important family of crop plants after the grass family, Poaceae. Grain legumes account for 27% of world crop production and provide 33% of the dietary protein consumed by humans, while pasture and forage legumes provide vital part of animal feed. Fabaceae, the third largest family of flowering plants, has traditionally been divided into the following three subfamilies: Caesalpinioideae, Mimosoideae, and Papilionoideae, all together with 800 genera and 20,000 species. The latter subfamily contains most of the major cultivated food and feed crops. Among the grain legumes are some of mankind's earliest crop plants, whose domestication parallelled that of cereals: Soybean in China; faba bean, lentil, chickpea and pea in the Fertile Crescent of the Near East; cowpeas and bambara groundnut in Africa; soybean and mungbeans in East Asia; pigeonpea and the grams in South Asia; and common bean, lima bean, scarlet runner bean, tepary bean and lupin in Central and South America. The importance of legumes is evidenced by their high representation in ex situ germplasm collections, with more than 1,000,000 accessions worldwide. A detailed knowledge of the phylogenetic relationships of the Fabaceae is essential for understanding the origin and diversification of this economically and ecologically important family of angiosperms.
[Critical Reviews in Plant Sciences, Volume 34, Issue 1-3, 2015 Special Issue: Legumes in Sustainable Agriculture]

See also: http://tolweb.org/Papilionoideae/60240

Thanks everyone for your responses! The progression of squash towards a characteristic you like makes sense to me now. So the grand child of a hybrid may taste wonderful but it's hard to duplicate that exact squash for future years. But if you save its seeds and ones like it and keep planting them and selecting for the ones that taste great you eventually move the gene pool towards that taste. Got it

The beans seem a bit tricky then. I was planning on planting 1/3rd of the row in each type of bean. So the crossing is likely to only happen where the varieties meet. But I won't be able to tell if any crossing occurred that harvest by looking at the beans. Correct me if I'm wrong but a pinto bean flower crossed with a rattlesnake bean would still look like a pinto bean that first year.

Thanks for the beautiful pictures Joseph! So what do you do with 50 hybrids of beans? Mix them together in soup? Or try to grow them out separately and see if they are good for anything in particular? I can only imagine how many different bean meals you'd have to have to find a winner among all the varieties you have to choose from. Or are you selecting beans for other features (pickability, productivity) and the colors are just a byproduct? Or am I getting hung up on the color variation and they are really the same general style of bean?

@Mike J: "Thanks for the beautiful pictures Joseph! So what do you do with 50 hybrids of beans?"

I won't speak for him, but I can't resist some bad Friday humor: He's going to knit them into a robe and star in a one man show called "Joseph and the Amazing Technicolor Bean-coat"

Har-har......

Hee Hee I'm thinking you could sell them at Hobby Lobby to jewelry people. Anyone for some organic necklaces?

I plant, harvest, cook, and eat mixed varieties of beans. There are around 7 species of beans in my food grade bean mix. I use them in any recipe that calls for beans: salads, soups, stir-fries, re-fried, chili, etc... I love the variations in texture and taste from bean to bean. Most of them are just beans....

As part of my ongoing trials, I plant and harvest short rows containing perhaps ten plants each of specific varieties. That lets me evaluate the yield of each variety, and compare its growth characteristics to other varieties. Comparisons are easier to do if they are separate. That also makes it easier to spot new hybrids.

Red Kidney Beans are popular here, and productive, so I grow a separate crop of them for the farmer's market. The rest of my bean seeds goes to market as mixed species and mixed varieties.

I am selecting beans for diversity, ease of harvest, easy threshing, productivity, early maturity, bush-ish habit, local-adaptability, etc... Color and shape are important to me, because they are an indication of diversity. If I plant a row of pink beans, and a yellow bean shows up in it, then that indicates that it may be a hybrid, or recently descended from a hybrid. There is one bean that I'd like to isolate to grow as a separate variety. When cooked, it has a texture more like a water chestnut than a bean. There are hundreds of varieties in my beans, and more being generated every year, so I may get it isolated eventually, and it might slip into obscurity.

Here's more photos of what my general bean population looks like:

Earliest harvest in 2014.




This was about 1/13th if my bean harvest last year.


These beans were the earliest of the early harvest in 2015.

Thanks Joseph! It's all making sense now. I think I'll grow my three types and keep the seed separate. Next year I'll do the same and see if anything interesting shows up. I'll also select for plant properties I like along the way. I probably can't call it a landrace since I'm only starting with three varieties but maybe I can call it a landwalk?

I don't eat legumes, but I have a sudden urge to start growing and breeding as many beans as I can find. I never knew there was such an amazing colour variety possible!

Mike Jay wrote: if you save its seeds and ones like it and keep planting them and selecting for the ones that taste great you eventually move the gene pool towards that taste.

If you want to research this idea, look up "Recurrent Mass Selection".

I grew competition pumpkins (the huge ones) for several seasons, and also competition tomatoes.

The MOTHER plant is the one that produces the tasty fruit, you need to propagate the MOTHER PLANT. The seeds of the fruit will carry the genes of the mother and the father, but the delicious tomato you just got the seeds from is the legacy of the mother. So that plant's genes are what gave you the lovely fruit. The mother and father plant's genes are in the seed in the fruit, it is different than the plant that produced the fruit that the seeds are encased in.

I would make sheer window curtain drawstring bags, and bag blooms so I could control the pollination and cross for known genetics in the seeds, but. There would just be POTENTIAL in those seeds. When you grew them out, you didn't know what you were going to get until those plants were mature and producing.

If you want to develop your own strain, you have to cross the parents then take the seeds (F1) and raise them and cross them back for several generations and hand select for the characteristics you want. (a friend has hit generation 8, they are breeding for a specific straight cayenne pepper that is mild and flavorful and their work is now considered a separate variety that breeds true....)

I have indeed, propagated a parent plant of both (giant pumpkins and mostly Delicious genetic tomatoes) to continue breeding efforts with the magic plant that produced the wonderful looking and tasting offspring.

I am currently embarking on pepper breeding, and bringing parent plants in for the winter (I have successfully gotten bloomout, pollenated, and gotten crops during the winter indoors).

Maintaining 'heritage' varieties means that you start from stock with known characteristics. Doing landrace is less intensive, but is still choosing for characteristics that do best in your microclime. I am just more active than that, in expending effort to adapt a plant variety to what works best, or works better, for me in my conditions...

Joseph, your work with legumes is amazing. I need to buy more pie...

For me, developing landrace varieties is much more intensive than any other type of gardening I have done... I might plant a hundred packets of bean seed, and harvest them separately. If I were growing an heirloom bean, I might only plant one packet, and they would all be harvested at once... As a landrace grower, I produce my own seed for every one of the 70 varieties that I am growing. I am always observing, and continuously culling, and putting flags on plants. I am constantly making new hybrids both via natural and manual cross-pollination. If I were growing an heirloom variety, I'd just be watching to make sure that things grew about the same as last year, and that everything in the patch looked approximately the same. Not many decisions to be made, just grow the crop. As a landrace grower I devote tens of hours to seed production for every crop. I can't just buy a $1.59 packet of seeds and thus acquire my heritage seeds for the year.

Some crops are easy for me, others are hard as can be. I just keep muddling along: Determined to develop landrace varieties for every crop that I can coax to grow in my difficult climate.

Decisions. Decisions.


After 7 years, I'm finally getting my preferred phenotype very routinely...


Always making decisions:


Always observing, measuring, and documenting:

Here I was going to gift Joseph as soon as payday happened...

Thank you!

Gorgeous pictures, also!