Field Wars: Revenge of the Rogue Rice

from Wikipedia

Humanity's rise as an intelligent species, and one that today dominates the world, would not have been possible without the grasses. Not only did our species develop in the savannahs those traits that mark us as Homo sapiens during the time when grasslands spread throughout the world, but our very civilization would not be possible without the domestication of various grass species, including wheat, maize (corn), and rice.

The latter of this Big Three directly feeds more than half the people on earth, and was thought to have been domesticated twice, once as Oryza sativa in the Yangtze Valley of China more than 9000 years ago (Molina et al, 2011), and another time  in Africa in the inland delta of the Upper Niger River as Oryza glaberrima between 2000-3000 years ago (Linares, 2002). Amazingly, there is now recent evidence that rice (as a wild Oryza sp) was domesticated in a THIRD continent about 4000 years ago, this time by the mid-Holocene residents of the Monte Castelo shell mound in the Amazon regions in South America (Hilbert et al, 2017)!

Such a tight relationship between humanity and this grass genus would surely mean both benefit greatly from the association, and in fact its mutualistic relationship with people has made rice one of the most common plants in the world. But you would be mistaken to think that all rice has become soft and meek and domesticated.

There are rebels in the midst of the rice paddies, and their effect on the productivity of the Empire of Man is surprisingly substantial. Some estimates put crop losses due to this rebellion at more than 90% in some fields, and in the USA up to 30% of rice fields can be compromised, leading to more than $50 million in annual losses.

These weedy rice have characteristics that differentiate them from their still-domesticated brethren. For example, domesticated rice has non-shattering seedheads, which simply means that the grains do not have a tendency to break off from the plant and scatter. This makes it easier to harvest and prevent significant losses of the crop. In the case of the weedy rice, easy shattering of the seedheads means the rice gets to disperse its seeds, which is obviously the usual goal of any species. 

Another example of a trait that these rebellious rice have gotten is seed dormancy, which allows them to stay dormant in the soil until conditions are optimal for seedling growth. Such a trait has been taken out of their more domesticated compatriots because farmers tend to collect the seeds of plants that don't have dormancy.

Lin-Feng et al, 2017

One interesting thing about these rebellious rice is that not only were they derived from different varieties of rice, but that they arose during different periods of the domestication and improvement history of rice. The way researchers discovered when each weedy rice broke off from being domesticated was by looking at what types of genes they have in common with the domesticated type (Lin-Feng et al, 2017).

How does that work?

Well, remember that as rice developed over the centuries and millennia, it acquired various domestication genes (e.g. genes for non-shattering seedheads), followed by various improvement genes (e.g. popcorn taste, nice aroma, etc). So for example, if rebel rice #1 has the genes for domestication, but not the improvement genes, whereas rebel #2 has both genes for domestication and some improvement genes, then the researchers can deduce that rebel #1 broke off earlier than rebel #2 during the history of rice. In the image above, the BHA (black hull awned) weedy rice diverged earlier in the process than the SH (straw hull) weed.

"But wait!" You might ask. "If they still have the domestication and improvement genes, then how were they able to get all those weedy traits?"

It turns out that these weeds modified other genes to re-acquire the weedy traits  (such as re-enabling shattering of seedheads), and these genes are not scattered throughout the genome but tend to cluster into genomic islands. These genomic islands that re-create similar weedy characteristic are completely different for each weed type, which means that each rice weed evolved the weedy traits independently using different methods.

Amazingly, it seems rice has a tendency to rebel against domestication, and it repeatedly evolves gene islands that allow it to break from its "chains of slavery"! 

How totally ungrateful! *smh*

Literature Cited

Hilbert, L., Neves, E.G., Pugliese, F. et al. Evidence for mid-Holocene rice domestication in the Americas. Nat Ecol Evol 1, 1693–1698 (2017). https://doi.org/10.1038/s41559-017-0322-4

Lin-Feng Li, Ya-Ling Li, Yulin Jia, Ana L Caicedo, Kenneth M Olsen. Signatures of adaptation in the weedy rice genome. Nature Genetics, 2017; DOI: 10.1038/ng.3825

Linares, Olga F. (2002-12-10). "African rice (Oryza glaberrima): History and future potential". Proceedings of the National Academy of Sciences. 99 (25): 16360–16365. 

Molina, J., Sikora, M., Garud, N., Flowers, J. M., Rubinstein, S., Reynolds, A., Huang, P., Jackson, S., Schaal, B. A., Bustamante, C. D., Boyko, A. R., & Purugganan, M. D. (2011). Molecular evidence for a single evolutionary origin of domesticated rice. Proceedings of the National Academy of Sciences of the United States of America, 108(20), 8351–8356. https://doi.org/10.1073/pnas.1104686108

A short history of my obsession with grasses

Bambusa malingensis

I've recently wondered when my interest in grasses first manifested itself.

My fascination with a specific plant group for a long time was confined to Aroids, and I maintained one of the longest running aroid-specific websites on the internet when I started my Thaumatophyllum (at the time, Meconostigma) site in 2005.

Of course, I have almost always been involved with one species of grass, Oryza sativa (rice), which I have grown almost every year for more than a decade as something like a ceremonial ritual. But I think this interest did not extend beyond to other grasses until Summer of 2011, when I obtained my first ornamental grass, Imperata cylindrica 'Red Baron' (Japanese Blood Grass, but more well known in its wild form as Cogon grass).

Imperata cylindrica 'Red Baron' (Japanese Blood Grass)

This started my first love affair with grasses, and that JBG is still with me and thriving wildly to this day. In fact, it interested me so much that I bought a few more grasses in 2012, including a Miscanthus sinensis 'Gold Bar', which I unceremoniously stuck below the front passenger seat after I bought it ;-)

Miscanthus sinensis 'Gold Bar'

I also remember 2012 was when we went on a road trip to Florida, and I took several pictures of grasses that we met along the way.

Cortaderia selloana (Pampas grass)

The first were specimens of Cortaderia selloana (Pampas grass) in the Carolina Premium Outlets on the outskirts of Raleigh, North Carolina.

There were some truly impressive specimens of this species in that outlet, with a central plant near the entrance rising perhaps 3-4 meters high. The outlet had also planted them on the islands next to the parking lots, and I had a field day taking photos of the grass while waiting for my wife to finish shopping.

Miscanthus sinensis cultivar

In addition, the outlet had a few Miscanthus sinensis specimens scattered about, although I was admittedly less impressed with these than the flowering Cortaderia.

Bambusa malingensis

Once we got to Florida, we visited The Fairchild Botanical Garden in Miami, where I admired the huge bamboo groves, and on the way back home, we also visited Myrtle Beach, where I marveled at the tall Sea Oats (Uniola paniculata) waving in the sea breeze,

Uniola paniculata at Myrtle Beach

Spikelets of Uniola paniculata

It was at this point that for some reason my interest in grasses wavered then waned, and for about 6 years I barely thought about them due to a rising interest in Banyan Trees (Ficus spp).

This changed in Summer of 2018, and it had to do with Cogon grass (Imperata cylindrica) again. This time, I became interested in the invasive wild form, and my fascination with this one species started to slowly encompass other species in the Poaceae.

During our trip to Baanf National Park in Canada in Fall 2018, I took quite a lot of pictures of grasses in that area, and by the next Summer, I had been enmeshed enough in the family to start this site.

Hordeum jubatum in Lake Louise (Baanf National Park)

In a way, it was a case of positive feedback, where my interest in grasses pushed me to write articles and take pictures of them, while the solid presence of my work provided an impetus for me to write even more and study them even more.

This coming July will mark the first year anniversary of this site. I have enjoyed the journey immensely and I am hoping that my ramblings and photos will encourage others to be just as fascinated by this plant family as I am.

Rice Paddy Art

(c) Captain76 - Wikipedia

There are some grasses whose very existence is honored and celebrated.

Such is the case for rice (Oryza sativa), which is by far the most important human food crop in the world, and directly feeds several billion people.

This species is so important to some cultures that it shows up not only in their religion, but also in their arts.

I have always been fascinated by rice paddy art, which I learned about several years back, where people use different varieties of rice to create pictures that can be seen from the air due to the different colors of the rice plants as they mature.

Perhaps the most famous town that does this is the town of Inakadate in Japan, which started the annual event in the early 1990s as a way to attract tourists.

Here is a video of the town and its work:

Growing rice (Oryza sativa) in the Northeast USA

Some people are surprised to discover that you can actually grow rice to seed in the Northeast, and that it's fairly easy to do so.

I have been growing container pots of this grain every year for many years now, and the sense of accomplishment when I harvest the rice at the end of the growing season is always welcome.

The main problem is actually the short growing season here, and I sometimes bump into the colder temps of October before barely managing to produce the rice.

Germinating rice from brown rice

All you need to do is buy some brown rice of the variety that you'd like to grow, soak  them overnight (with diluted hydrogen peroxide or bleach), then drop onto culture media (usually potting soil or better).

Rice in larger permanent containers

Once the rice seedlings have grown, just transfer to a larger container and keep the soil moist.

Time for pollination!

Varieties that are ready in 90 days are great, but I've also grown those that take 120 days to harvest.

Full  grown rice plant laden with ripening grain

Obviously, there's no way for you to actually grow enough to feed yourself for the year, but growing the grain does give you a better appreciation for the work of the farmers who supply us with our food.

So, go ahead and try it. It's easy and fun!

Macrophotography of Rice (Oryza sativa) Ligules and Auricles

I have recently started taking macro shots using a new lens that I bought. Diving into macro has opened up an entirely new world, one which has revealed the beauty of barely visible objects that I would normally not even give a second glance.

My equipment is fairly basic since I am a beginner, and includes the somewhat basic Nikon D3400 DSLR and a Tokina at-X PRO M 100mm F2.8 D Macro Lens with a Nikon mount.

As you can see from the images, it's  now possible for me to take quite nice photos of even the rice ligules and auricles.

I do have one big warning for people trying to use the D3400 with the Tokina 100 mm Macro Lens. You cannot use autofocus at all with this combination, and so you need to be able to work with manual settings. I believe the reason is that neither lens nor camera has a built-in auto-focus motor.

Old Rice Grains