breeding surprises in V. unguiculata (yard-long bean/cowpea)

[mskrieger]

Bean diseases and devastating bean beetle predation are pretty common around here, so I grow yard-long beans as a green bean. They're a different genus entirely (Vigna) and seem unattractive to both the insects and diseases around here. They also do fine without irrigation in my climate (we get 3-4 inches of rain per month in the summer, with daytime temps in the 80s-90sF (27-38C). And they are mighty tasty.

The variety I'd been growing was Gita, purchased from Johnny's Selected Seeds in 2012. I noticed that some plants grew just one bean from each flower, and some grew two beans. Appeared identical in all other respects. I liked the idea of doubling my beans for the same number of plants, so I decided to save seed from the double-podded plants and grow them out in another part of the property. I don't know how outbreeding V. unguiculata is under my conditions, but I have plenty of pollinator pressure and wanted to provide some isolation.

This is my first season growing them out...I suppose you could call it the F1 generation, though I did no intentional crosses. Already things are getting weird. I had one plant that bloomed two weeks before the others (early--good) but its beans are nothing like what I expected. Only a single pod grows from each flower. The beans are short, about the size and look of Phaseolus vulgaris (common bean), develop peas much faster than Gita, have short bristly hairs on the outside of the pods that give them an unpleasant velvet-bristle texture, and they don't taste as good as yard-longs usually do.

I did include seed from one, unusually long single-podded plant, because it had super long pods and that was a trait I liked and wanted to preserve. Could that odd man out have been an unintentional cross in the foundation seed?  Or could it be that Gita itself is actually a hybrid (even though Johnny's doesn't mark it as F1, and they are normally good about that kind of thing) and weird things are segregating out in what is effectively an F2 generation? Or does V. unguiculata naturally have quite a bit of variability in it? (This is my first time growing out my own seed from this species, so I have nothing to use as comparison.)

All thoughts, ideas and wild speculation are eagerly appreciated!

[littleminnie]

Very interesting. I know little about this species. I am just trying yard long beans for the first time this year.

I am trying to gather info on just how much crossing is expected in legumes. I am starting a pole bean thread now but I also am growing out edamame of 2 cultivars I let grow together.

[ferdzy]

Beans are never sold as "F1 hybrids" because they would have to pollinate every bean by hand... a difficult and time-consuming proposition, which would only provide a small handful of seeds. That would include even yard-long beans, I would think. Still, it is possible for accidental cross pollination to take place, and you may just have been the lucky recipient of that.

I would say you are on the right track with your seed-saving thoughts, but you should probably be prepared to discard much of this batch, since it isn't what you are looking for (or all that good in any useful way). You might want to re-order and start again, or, if you are getting at least some plants that are "on type", save seed from them and continue with just those. Small genetic pools aren't really a problem for beans, although I am not very familliar with vigna unguiculata so I hate to make sweeping statements about them.

I know with phaseolus vulgaris I have had immediate, next generation leaps in productivity with just one year of selection. The one time I tried growing vigna unguiculata the first year was dismal, but the few seeds I managed to save produced far, far better the next year.

[blueadzuki]

Hard to say. It sounds like you have seed with a lot of crossing so a lot of hidden stuff is coming out. The hairy one almost sounds like a throwback, hairy pods is a wild trait for V.ungiculata, I think.
Quick question does the seed in the hariy one still look like yard long seed, or has it reverted to looking more like standard cowpea (with cowpeas a lot of the long ones have seed that is also longer and more kidney shaped, while that of the normal podded ones is usually shorter and more blocky/linear). \
I'm not sure about the length thing. Of the six times I've managed to get a cowpea to full term here, the one of them that MIGHT have been a yardlong got a lot shorter with the one pod it made (the pods I got it out of I bought in Chinatown were probably 18-24 inches long, the pod it made, maybe 5-6) whether it would have gotten longer had it reached maturity I do not know (I made a mistake of identification, and the pod got harvested WAAY to early to bear viable seed)
Even fairly uniform seed can have a lot of variability. Three of my standard cowpeas look more or less exactly the same as seed (short, wide jet black) and plants (large leaves smooth, waxy more bush than pole flower when fairly short, large morning opening flowers (can't remember if they are all blue flowered, all bicolor yellow and purple, or a mix)....UNTIL the pods show up. One of them makes deep purple pods that are very skinny and a little rugose (wrinkly) like some long beans are (looks almost like a mummified finger) One makes greenish pods that are similar to those of a standard bean. And the third makes very fat fleshy pods that are wax bean yellow (saving that one for snap bean experiments). All came from a simliar source; black cowpeas sold for soup for SE asia (the purple and white from Vietnam, the green from Thailand (though I think it's the same strain). If I ever do any more throwouts of black cowpeas (that's where all three of those came from, leftovers I tossed around to feed the animals or rot into fertilizer, of which a few make it though to maturity.)I fully expect all kinds of other variations.

[mskrieger]

You guys have all made interesting comments. It's too early to say whether this batch of seed is all bad--I saved from a whole bunch of plants and mixed it together (because I am just not anal retentive enough to label every bean's produce individually). The only criteria was "two pods from a flower".

This oddball plant is the only one that has fruited yet--the others are just beginning to flower. Beautiful purple flowers that open in the morning, close by afternoon. 

I inspected another one of the odd beans...the peas inside look like typical immature yard long bean seeds--like green black-eyed peas but a touch more elongated and flattened than black eyed peas would be. And they are well spread in the pod with pod flesh between them, not crowded like 'crowder peas'. I wonder if this bean just had a random mutation in something that controls pod shape and skin texture. 

I too have heard the word that the Fabaceae family are all inbreeders, easy to save seed from, etc. But since fava beans and garbanzos have shown that to be untrue in a pollinator-rich North American garden, I'm starting to wonder about V. unguiculata too. Blue Adzuki, it sounds like you got an awful lot of variation from just one sample of seed you picked up in a Chinese market--am I reading you right? That seems kind of crazy unless V. unguiculata does outcross quite a bit and the farmer was growing more than one variety and relies on professional breeders for seed. Hm. I wish I knew some yardlong bean farmers. No one here grows them commercially, I think it's a daylength issue. Johnny's Selected specifies that the Gita and Red Noodle varieties it sells are specifically selected to perform well in the temperate daylengths. Johnny's also claims the beans grow 16-20". I rarely get 16", 12" is more like it (though still impressive. And it may be because I grow them without irrigation.)  

In a week or two I'll have pods from the other plants that are just starting to flower and I'll let you know what I find!

[philagardener]

I grew the Chinese Red Noodle from Baker Creek with great success a few years back. I found it freezes well compared to string/snap beans. The plants seemed to sit there forever at the start of the season, but then took off once the real hot and humid weather set in. I had 18 inch pods but they were best picked on the young side before the seed started to fill.

[blueadzuki]

Well you have to take into accout we are talking about a BIG sample. The original Vientamese bag was probably 12oz, the Thai one probably that again over. That's something on the order of severalthousandbeans. Plus being food product, it was probably the product of MANY farmers fields, not just one. I also imagine that, if you are growung the plants for dry beans, the color of the pod is probably irrelvant in your book, since no one is normally ever going to see it except you. It's much like the fact that a lot of black skinned soybeans sold in Asian markets can have beans that are yellow inside and ones that are green inside mixed in in the same packages (it's the same gene/gene group that does the green/yellow crossover for peas; a LOT of legumes have it) Since most recepies for using black soybeans culinarily in asia use them without taking the seed coats off, the end products color doesn't change much, so no one bothers to seperate them or rouge one or the other out (though the amount of green has gone steadily up over the years, so someone may be actively pulling yellows out (again like peas, yellow is dominant over green, so for green to go up yellow has to be being removed; left on it's own, in crosses, yellow will domainate a population.)
Speaking about green insides, one of my main griefs from those platings is that, with all of the starter material that was out there, I DIDN'T get a cowpea with green cots. The Vietmanese bag had quite a few that had that trait. At least, I think it did (green cots in cowpeas tend to be a lot paler than peas or soy since the opposite cot color is more white than yellow so seeing it is a bit harder). But none of the two that made it had it, and I haven't been able to get any more of that brand of cowpeas since (I can get all that Thai I want, but they don't seem to have that trait; it's one of the very few DIFFERNECES between the two stocks.)
I should have mentioned at least one of the three (the white podded one) is also a black on black like Gita seems to be (that is a cowpea that has a black eye that, when mature becomes crytic because the seed coat is ALSO black). I think it's pretty common for black skinned cowpeas, like having a small number of seeds that develop brick red speckles.
Actually there may be a fourth member of the trio (or if I am right quartet) ont it's way this year. There's one simialr looking cowpea plant in this years garden; a survivor from my one by one plantout (wether or critters got all the others) The flat I planted was sown from my cowpea bean box so it had a LOT of odds and ends of varying colors and shapes. But the sown stuff DID contain some black Thai cowpeas, though a different brand (Sailboat) than the last one which was Red Cock, the commonest one (I may no longer feel legally confortable buying thier whole coriander, based on what I found mixed into it. But the rest of thier stuff is probably safe enough.)So theoretically I may get a fourth member of this iteration (though I have seen no sign of flower buds yet.)
Actually you propose an interesting experiment to try at some point. Since Yard longs tend to have long loosely placed, extended seeds, I wonder what happens when you cross one with a crowder (which has compressed seeds) do you get one whose seeds are long AND compressed (like little rectangles) or do the two forces cancel each other out giving you typical rounded cowpea seeds. I'd especially like to know if the crowder in question was one of the few "super crowders" I have seen in my hunts (I have one or two small cowpea seeds which show such extreme compression that I intially didn't recognize them AS cowpeas; the compression had actually deformed the hilum!)

[12540dumont]

Save the seeds from the ones with 2 seeds in a pod. You will increase the number of 2 seeded pods in future years.

[mskrieger]

OK guys, I have a new hypothesis: Maybe I mixed up the seeds, and planted my saved double-podded batch in the 'eating' patch and the original seed in the 'experimental' patch.

Why do I think this? Because the 'eating' patch has an awful lot of double-podded beans, while the 'experimental' patch is mostly single-podded. Huh. I guess nothing to do but save seed from the double pods in both patches. I'll save the experimental and eating patch material separately, and mark them when I plant them next year, and we'll see...

Meanwhile, the yard-longs have been super happy this year, and I'm getting plenty of delicious 16-20" long beans. No other weird ones besides that first super-early hairy podded thing.

[ferdzy]

Ah! Makes sense. I got all excited about crosses in my peas this year, but I have decided that 2 of them are just seeds in the wrong place. Fortunately, I do seem to have 1 genuine cross to grow out and keep me entertained next year.

[raymondo]

I always think I'm very careful about saving seed, labelling them correctly and so on but I invariably get a few surprises so I'm obviously not as careful as I like to think I am.