6/27/2011
Today I worked in the tissue culture lab. In this lab, they propagate Musa spp (bananas and plantains) and Theobroma cacao for maintenance of the germplasm collections and for distribution to researchers and breeders. They use the techniques of tissue culture, in which plants are regenerated from tissues under aseptic conditions in an artificial environment. Many, many disease-free plants can be propagated relatively quickly in a small space.
TARS has live collections of Musa and Theobroma cacao. The former has 148 accessions, including 118 bananas and 30 plantains, and the latter has 193. These accessions are listed in USDA’s GRIN, the germplasm resource information network.
It is important to have a back-up. Puerto Rico is an island in the Caribbean, after all. What if a hurricane destroyed the collections? They also maintain Musa in tissue culture and are working on creating a similar collection for Theobroma cacao. It’s kind of bizarre, seeing miniature banana plants in little plastic baggies (they are actually semipermeable bags).
Musa spp and Theobroma cacao are each propagated in a different manner. Meristematic tissue from young Musa suckers are the raw material for micropropagation. In contrast, flower buds of Theobroma cacao serve as the starting material for somatic embryogenesis. In both methods, the plant material must first be sterilized. In micropropagation, the meristematic tissue is induced to form shoots and then to form leaves and roots. In somatic embryogenesis, the staminodes and petals are induced to produces calluses and then embryos. The embryo is then converted and leaves, stems, and roots are produced. The small plants, whether produced from micropropagation or somatic embryogenesis, must be acclimatized to outdoor conditions.
Today in the lab, we prepared Embryo Development media for somatic embryogenesis. The media includes vitamins and macro and micronutrients, as well as sucrose, glucose, and a gelling substance. It is sterilized in the autoclave before it is poured into petri dishes for later use.
I also helped transfer small musa plants to new propagation media. The transfer was done in sterile conditions in the hood. I had to wear a mask and gloves and constantly sterilize the tools I was using. We also had some high school girls visit. They were touring the station. Some of these girls looked really young to be in high school (I know; I am in no position to say anything…).
6/28/2011
DNA extraction from semi-young mango leaves. Semi-young? What do you mean by semi-young?
We collected these “semi-young” leaves from 6 mango trees on TARS property. We then used a heavy-duty hole-puncher to punch discs from the leaves. We then extracted the DNA using a kit involving a variety of solvents. We even used PVPP, which I have used in the winery. It gloms onto contaminants and brings them to the bottom so you can pour off a supernatant or rack off the wine.
We then determined the concentration and purity of the samples based on absorbancy values. All 6 samples were pretty clean and contained a fair to impressive amount of DNA.
In the afternoon, I read a couple papers, one on sigatoka, a fungal disease of bananas, and one on microsatellite fingerprinting of the cacao germplasm collection.
After work, my parents picked me up and we visited Boqueron. I wished I had brought my bathing suit. The water was so inviting. We got some pizza for dinner. They dropped me off back at TARS and returned to their hotel. They leave for home tomorrow. See you in 2 ½ weeks! Bon voyage!
6/29/2011
We transferred the Musa shoot tips from 3% bleach solution to 10% bleach solution. This is to remove any potential contaminants. Tissue culture is valuable not only because it produces a large number of clones quickly but also because it generates clean planting material.
While the tip was sitting in the 10% solution, I read some of the books in the lab.
I learned that the banana ranks 4th for gross production value, coming in behind rice, wheat, and maize. Bananas are grown on about 4.84 million hectares in 150 countries worldwide and global production is 95.6 million tonnes. India is the largest producer, responsible for more than ¼ of global production. Following India are the Philippines, China, Brazil, and Ecuador. However, the main exporters of bananas are Ecuador, Costa Rica, the Philippines, and Colombia. Asian countries grow bananas mainly for domestic consumption.
We then rinsed off the bleach in sterilized, distilled water, trimmed the leaves and corms, and placed the meristems in test tubes with initiation media. These are placed in the dark for 10 days and monitored for contamination. After this time, they are transferred to propagation media.
6/30/11
I started reading The Screwtape Letters. One of the researchers was kind enough to give us a bag full of books. I’m not Christian, not really religious, but The Screwtape Letters is an intriguing book and I am enjoying it thus far. Though I may not agree with C.S. Lewis in all cases, I think he is a great observer of mankind.
In the lab today, we turned on the autoclave to sterilize diseased plant material before disposing of it. The machine made some funny noises and we decided it was probably best to shut the thing off. (Later, the doctor came in and turned on the machine, no problem. WTF?)
The tech guy showed me the now-defunct library. I love old books! We opened one and someone’s family photos fell out – two white women in 1950s bathing suits standing on the beach. Looked like they had a nice family vacation. I’d love to read Gardens of Madeira, or Date Growing or Nuclear Radiation in Farming and Agriculture or some of the station’s early annual reports. It’s so sad that these books are just sitting there! Does no one use libraries anymore? I certainly do. I mean, the librarian at school knows me! I always considered (and still do, at times) being a librarian. I love books and researching and learning.
I bought a wine at the grocery store today. I usually like to taste first, but I used my Ipod app from Wine Spectator. Centine, a red blend (Sangiovese, Cabernet Suvignon, and Merlot) from Tuscany, Italy. 2007. Banfi. Delish.
Gold star for Stacy! Not only did I pick a fairly good, decently priced wine, I also finished reading the plant breeding text book.
7/1/2011
Happy July! I can’t believe this is the end of my fourth week!
Another strange, strange dream last night. I was so anxious about today that I dreamt that they left for the field station without me!
But, I made it in time this morning, and we set off for Isabela, where the Musa spp. collection is located. The TARS collection has many different varieties of bananas and plantains, however, it is biased in that it contains only those varieties that are of agronomic importance.
On the way to Isabela, I read a bit of The Screwtape Letters.
“Pains and Pleasures…are unmistakably real”
Writes Uncle Screwtape
Screw with my mind
Hammer a nail into my heart
I agree with your dear uncle
The Pain you cause cannot be denied
But I will not forget
The moments of Pleasure
Were they real? I wonder now
Some other quotes I like:
· thousands of humans have been brought to think that humility means pretty women trying to believe they are ugly
· they might as well be proud of their hair
· perpetually in pursuit of the rainbow’s end
We stopped at a café on the way. Verde Verde, it’s called. Like a Saladworks, almost. Over desayuno, I learned a bit about agriculture in Puerto Rico. Across the highway was an old sugar cane mill. Sugar used to be the island’s main agricultural industry. Now, it is dairy cattle. The government prohibited import of dairy, so all the island’s milk is produced on the island. Also a big industry is coffee. Growers producing coffee in designated areas receive government incentives.
At Isabela, we characterized 4 accessions in the Musa collection. The main collection is held in tissue culture in Belgium by a Bioversity.
Also at Isabela:
A trial of mangoes. Seeds were planted from open-pollinated parents. Looking for anthracnose resistance.
Nisporo. Widely consumed in Cuba. These trees are very susceptible to wind and insect damage. To combat the former, they are testing an elephant grass border.
Mama sapote. Widely consumed in Cuba and the Dominican Republic.
A back-up ollection of mangoes containing selected accessions from the Miami station.
Annona collection.
In the afternoon, we cleaned tubes. Some plants in a previous experiment were infected with fusarium, so we had to clean the tubes before they could be used again. Many were clogged with mud and, I soon found out, frogs! I saw a coqui frog, but not the kind that sings at night.
I also saw a spider. “Arana, one of the few Spanish words I know!” I pointed out the arachnid.
“I think he just crawled up your leg!”
Ah!!
Then I was asked to move the pick-up truck. I thought he was joking.
“Can’t you drive?”
Well, yeah…I was so nervous I couldn’t even figure out how to put it in drive. I’ll stick with my little Honda Civic, thanks.
On the way home, I wondered whether he actually enjoyed the music on the radio station or put it on because I was there. Some of the songs we heard included, Grease, Hotel California, and I Need to Know.
Looking forward to a great 4th of July weekend! A little bummed about missing the fireworks, though…
7/2/2011
I went to the mall. Yes. I went to the mall. It was rainy and cloudy and not a good beach day. I never go to the mall in Jersey, but I go in Puerto Rico? Huh?
I know. I’m just as confused as you are.
7/3/2011
Another beach day rained out. A shame. Rainy 4th of July weekend here on the west side of the island. Well, we tried. We sat there for 5 minutes, saw lightning, heard thunder, and skedaddled.
We went to the farmers’ market in the morning. A small market, but I got to buy some okra and tamarind jam, so I was happy. And I made two new friends. I love farmers’ markets because I love meeting new people and talking to strangers…ummm, yeah. Anyway, I spoke with one of the farmers and her assistant. The farmer, a woman about my mother’s age, was very nice and her English was fairly good, so we got along well. She even gave me some extra okra! I learned that she kept a hive of honeybees for pollination and also for therapeutic purposes. The stings, she said, relieved the symptoms of rheumatoid arthritis. Within 3 months, she felt no more pain! She also provides the service to others. I have heard of people doing this, but I never actually spoke with someone who used this practice. Fascinating. In Spanish, she said to her assistant that I looked like I was only 12. I heard something about 12 anos and she was looking at me and plenty of people say I look younger than my age. I know enough of the language and use context clues pretty well – I understood what she was saying. She went on to tell me her daughter also looked young for her age. Her assistant is a young man studying agriculture at RUM (UPR Mayaguez). He told me he was looking to further his studies in entomology and considering attending graduate school in the states, perhaps North Carolina. He had never heard of Cornell. I told him to look it up. (I love their insect collection and their program is amazing.)
I ate lunch at El Meson, Puerto Rico’s own fast food chain. Not bad, not bad.
I spent a few hours reading my plant pathology textbook and some more time reading Sherlock Holmes. It’s been a quiet weekend.
July 4, 2011
I finished Screwtape Letters and embarked upon The Double Helix, James Watson’s account of the discovery of the structure of DNA. I just had to put the book down to share with you all this great quote: “in contrast to the popular conception supported by newspapers and mothers of scientists, a goodly number of scientists are not only narrow-minded and dull, but also just stupid” (Watson, p. 18-19). Oh gosh, Watson, you are funny…”in France, where fair play obviously did not exist…”
Okay, so why did you, “from a distance,” call Rosalind, “Rosy?” Is that some cute pet name? Sounds demeaning and sexist. Especially since he added in that bit about doing so only “from a distance.” Arg, sometimes...she “might have been quite stunning had she taken even a mild interest in clothes.” What???!!! “She had a good brain. If she could only keep her emotions under control…” I do not understand. “The best home for a feminist was in another person’s lab.” I beg to differ.
Some comfort for those of you out there who are not too fond of organic chemistry: Watson did not delve into difficult chemistry courses until after earning his PhD.
Thank you, Andrew Zimmerman, for offering free episodes on Itunes. I now want to go to Syria and try some ice cream and pistachio candies and pastries. I think I’ll pass on the camel, though. I’m not a big fan of camels after my experience riding one. It spit and pissed and tried to cut the other camels. And then another camel tried to chew the saddle off…so scary.
7/5/2011
I am in the entomology lab this week! And one of the projects is pollination! I can’t control myself I’m so excited. Ah, the wheels in my mind are turning.
On the way to Isabela, I finished The Double Helix. I was glad to see that Watson somewhat made up for his unkind words about Rosalind Franklin. In the epilogue he acknowledged the importance of her work and the challenges women in science face. When he was a young man listening to her speak, he said he “wondered how she would look if she took off her glasses and did something novel with her hair.” But, in his epilogue, he writes that his “initial impressions…were wrong” and that he realizes “the struggles that the intelligent woman faces to be accepted by a scientific world which often regards women as mere diversions.” Thank you, Watson.
At Isabel, we first collected yellow sticky traps which were set to catch aphids. The goal is to determine whether more aphids visit papaya trees surrounded by a windblock compared to those not surrounded. Aphids transmit papaya ringspot virus.
We then collected flowers from Atemoya, a hybrid of Cherimoya, commonly referred to as custard apple, (Annona cherimola) and sugar apple (A. squamosa). Annonas are native to tropical America, with A cherimola originating in the Andes in Peru and Ecuador and A squamosa native to the West Indies, Central America, and northern South America. I think I tried cherimoya once. Delicious Orchards was selling them for $10/lb. Before I spent that much money, I needed to know exactly what I was buying, so I asked. The kind gentleman pulled a slightly damaged one from the box and cut it for me to taste. Delicious! If you ever see them in the store, go for it. Better than any custard, I swear.
Atemoya flowers are white and have only 3 petals. As the flowers are first female and then male, a pollinator is required. A few small beetle species seem to do the job. However, I have to wonder how much pollen they can carry! And what are they looking for in the flower? Pollen? Nectar? Sufficient pollination is necessary if one wants full, perfectly-shaped fruits. Flowers are typically hand-pollinated. This seems like a lot of work to me. But the fruit is very good.
On one of the Atemoya trees, we saw a beautiful black and white bird. Long black tail feathers, longer than the body! And a small vibrant red-orange bill. Too bad I couldn’t get a photograph.
We went to a vegan restaurant for lunch. How does one find all these vegetarian/vegan places and why did I not know about them earlier? There was lots of traffic, but we eventually got there. And I got plantains, so I think it was a good day.
After work, I went to see “Bad Teacher” at the town center. Only $3.50 for a movie! What would that get me in Jersey, an extra-small popcorn?
7/6/11
Today we went to Guanica, the dry forest, to check on the fruit fly traps there. They are trying to prove that the dry forest acts as a natural barrier and that fruit flies cannot cross it.
Again, my coworker brought cocoa-dusted almond. When I get home, I’m buying some nice cocoa powder and using it to dust almonds and popcorn…oh the possibilities! And combining it with other spices, like cinnamon! Yum…
I started reading Omnivore’s Dilemma. I swore I wouldn’t, simply because everyone says it’s so great and I’ve already read so much Pollan, but it was in the lab, so I figured I’d give t a shot. Not bad, so far. Of course he started by discussing corn. Did I expect any less?
No comments:
Post a Comment