Tuesday, August 25, 2015

Making My Own Carrots 3

I've previously posted about my project to breed up my own variety of carrots (the-biologist-is-in.blogspot.com/2014/02/making-my-own-carrots.html) and showed you some photos of the flowers (the-biologist-is-in.blogspot.com/2014/05/making-my-own-carrots-2.html) growing from the mother plants I had selected the previous year and saved over the winter.

I was looking through my photo archive and realized I had taken some photos (left and right) of a couple "mother" plants that decided not to flower with all the others in the second year. Instead they grew lumpy and tortured looking over the year and froze in their second winter. I figured someone might be interested in seeing them, since few people these days will have experience growing carrots beyond the first year.

Perhaps these roots would have bloomed in their third year. Perhaps they would have bloomed in their second if they had been exposed to some environmental trigger lacking in their second year. These were the darkest purple roots I had saved, so the large batch of seed resulting from all the flowers has fewer of those nice intense color genes than I had hoped for in the project. However, I'd rather not have the genetics responsible for the lack of flowers in my carrot population.

This year a friend is hosting an aggressively growing patch of carrots in her garden. I didn't have a garden setup yet and the seeds had to get planted.

I pulled out several sample carrots at midsummer to check on their growth and edibility. I also pulled out some samples of the variety "Scarlet Nantes" to use as a flavor control, since it is known for being a very sweet carrot. My carrots didn't taste very sweet, but the control carrots tasted horrid. I'm blaming the then-hot weather on the poor showing they all had in the flavor department.

The carrots had a range of colors, ranging from white to yellow, orange, pink, and red. There was even a couple roots that seemed to have a thick translucent outer layer (with pink pigment throughout). The reddish ones tasted the worst and the translucent-surface ones tasted the best.

I'll be taking lots of photos and statistics of the larger batch when harvest time comes at the end of fall. Soon after I'll be writing up a nice post with lots of pretty pictures. Somewhere along the way I'll have to decide what selection criteria to have for the next generation.

Part 1: The initial story.
Part 2: Carrot flowers.

Tuesday, August 18, 2015

Wild Carrot Flowers

Wild Carrot (Queen Anne's Lace, Daucus carota) is a common roadside weed/wildflower. The typical flower structure is a flat umbel with hundreds of tiny flowers. The florets at the edge have larger petals on their outer sides. Some of the plants produce a small number of dark purple florets (usually just one) in the center of the umbel, but it isn't clear why it does so. The purple florets are considered sterile (though this photo suggests not always), so there has to be some selective advantage to having them that maintains their presence in the population. Some suggest the dark floret acts as an insect mimic to draw in flying pollinators, but the research is ambiguous at best.

While was taking photographs of one plant, an ant climbing across the surface of one umbel paused to investigate the dark center floret. This started me wondering if the plant might have improved pollination from ants crawling across it with the dark purple center to attract them. More generally, the dark floret could act as a nectar-guide to draw bees and other effective pollinators to the umbel. The impact on insect visitation (and presumably on fertilization) of dark marks has been shown for other plants, so it is reasonable to extrapolate the same adaptive role may be at play in the wild carrot.

Once the dark central floret drew my attention, I looked for variations in the trait within the small population I was walking along. The most pronounced difference I noted was in the height and size of the central floret. In most plants the central floret was held at the same level of all the others. In some few it was held below and in one, a larger central floret was held well above the other florets in the umbel. I thought this was an attractive variation, so I harvested a near-mature seed-head from the plant. I might grow a plant or two in a controlled location some time -- when I'm not trying to get seed from edible carrots (they readily hybridize), that is.

I also noted some variation in color of the central floret. The typical example is a very dark purple, but I also found a few plants with a much lighter pink central floret. I don't really like the aesthetics of the photo at right, but it was the best I got when trying to place the two different colored central florets next to each other for comparison.

The diversity of variations of the central floret in this small population suggest that the trait isn't under strong selection (at least in this small population). If a trait is under strong positive selection, mutations which interfere with it will rapidly be lost. To me, this suggests the dark central floret is a historical anachronism. It was once under strong positive selection, which is why it is so common, but it is not now under such selection (again, at least in the small population I examined). This could mean that in whatever small corner of the world where the plant came from, there is a specialized pollinating insect that likes the dark central floret. When the plant started traveling with humans, it found other pollinators that didn't care if it had the central floret and the trait began to diverge as mutations accumulated. If this hypothesis has any sort of validity, then we would predict that where carrots originally evolved (Afghanistan, Turkey) there would be less variation in this central floret trait.

Once I started looking online for carrot flower color variations, I found a few photos people have taken of wild flowers in shades of pink and purple (in references below). I found a nifty blog post discussing how to dye Queen Anne's Lace using food-coloring. I even found a variety of Queen Anne's Lace being sold commercially that has darkly-colored flowers.


Tuesday, August 11, 2015

Botanizing in Alaska: Yellow Paintbrush

I found this plant growing up at the top of a mountain, where we were starting a four-wheeler trip from. I recognized it as a paintbrush flower (genus Castilleja), though I had never before seen one this pale. The genus contains some 200 species that are often difficult to distinguish. The populations of various species grade into each other, with intermediate forms confusing identification even further.

There are three Castilleja species noted as living in Alaska: "Yellow Paintbrush" (C. unalaschensis), "Mountain Paintbrush" (C. parviflora), and "Scarlet Paintbrush" (C. miniata). C. parviflora and C. miniata are generally found in shades of red or pink, so I'm pretty sure I found an example of C. unalaschensis. The "Yellow Paintbrush" grows through much of southern Alaska, where it is typically seen in shades of yellow to pale orange. It seems to be closer to white around Fairbanks, however.

Paintbrush flowers, in all their shades, are lovely wildflowers. The most interesting thing about them to me, however, is that they're parasites. They have specialized roots called haustoria that grow into the roots of other plants to steal moisture and nutrients from the victimized plant. They're not a seriously aggressive parasite and could theoretically live on their own, but they definitely get a boost by feeding off a neighbor (who does suffer from the process). This Paintbrush could have been feeding on all the other plants visible in the photo, as they don't specialize on one type of plant.

I reached out to a Castilleja specialist hoping to get some better idea of the identification for the plant I found. I was surprised at how quickly he responded with very useful information.
Hi Darren,

You mentioned in your blog that there are three Castilleja species in AK, but that is not correct. Besides the three you listed, there are C. pallida, C. elegans. C. raupii, C. chrymactis, and C. hyperborea. Your plant is either C. unalaschensis or C. pallida (also known as C. caudata in some Alaska references). It matches C. unalaschensis (which is usually yellowish) in the somewhat compact inflorescence, but the color is closer to that of C. pallida. It's definitely one of those two, but I can't offer a definitive without more photos, particularly close up ones. If I had to choose, I'd call it an unusually pale form of C. unalaschensis.

Best wishes,

His response highlights the need to take excellent photos for identification purposes. It helps to know what the key parts of the plant to photograph are in advance as well. I didn't even recognize this plant as a Paintbrush until I was reviewing my photos, well after the trip was over. Next time I promise to get better and more-informed photographs.

Thanks again, Mark!


Tuesday, August 4, 2015

Novel Vegetable: Black Raddish

Lately I've been writing a series of posts about plants I found on a trip to central Alaska (the-biologist-is-in.blogspot.com/search/label/Alaska). I realized last night that I had enough posts on the topic written up or planned to fill out much of the next few months at my every-Tuesday-plan. So instead of this becoming the Its-Tuesday-Alaska-Time blog, I'll swap posts on other topics into the schedule as I see fit. I might even double up and push through more than one Alaska post a week. We shall see.

On a whim, this year I grew a patch of black radish from seed ordered online. Some time after ordering, the radish seeds and those for a few other root vegetables arrived in a package with Slovenian postage. I had no idea I was ordering from Slovenia. You can end up ordering from surprising places sometimes.

As our garden was still being built, I didn't have a place to grow the radish until a couple of good friends stepped up and donated the space in one of their garden beds for the season for several experimental vegetables.

The radish plants started up quickly and thrived, producing lots of huge green leaves. I had read that they were a larger and longer-season type of radish than the typical small-red radish I find in local stores. I wasn't sure when to harvest the roots, so I let them go (and grow) until they [the plants] told me it was time. On recent trips to the garden, I noted more and more of the plants have been bolting. Each time I pulled out the flowering plants, to prevent any early-flowering genetics from making it into the next generation. I tried eating some of the culled roots and found them to be very pungent, but also somewhat wooden. I know radishes become less ideal as food when they start blooming, so perhaps I should have culled a random good plant for sampling instead.

I finally gave in and harvested what remained of the crop a few days ago (27-July-2015). There were many small-rooted plants in the mix, which I promptly discarded so to select out the loser genetics they represented. (The plants that didn't fight their way to the top aren't the ones I want to save seed from, even if they could have done much better with more thinning.) As I was pulling the plants out, I realized a minority of the population had developed a lovely purple color on their stems. The photo at right shows the result of my rough sorting of the plants by size and color as I went.

The purple-colored plants didn't produce the largest roots, which was one of my final selection criteria, but I decided I really wanted the color mixed into the next generation. I chose two of the most colorful plant, as well as two of the largest rooted plants, for my final population to produce seed for next year.

All four plants have been replanted in a large pot, where they can mature further. The plants look really sad right now, but I'm confident that they will recover and produce a batch of seeds.

All of the sizable culled roots went to a neighbor of the host gardener. She is using them to prepare a lacto-fermented condiment that is somewhat similar to sauerkraut. The root is relatively fibrous and highly pungent, leading to it best being used like one would use horseradish. The grating and fermentation will break up the fibers and temper the pungency somewhat. This is a traditional European recipe from the era before refrigeration and is one of the ways black radishes are typically used where they are more commonly grown in Europe.

After looking into radish recipes a bit, I'm thinking about making chips from the black radish next year. As you might imagine horseradish chips would be a problematic food item, I expect black radish chips will take a few trials to get right.