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Seeking nightshades in South America

48 Posts tagged with the andes tag


The past couple of days have been full of discovery - in the herbarium! Cordoba is a great centre for Solanaceae research, the great solanologist (person who studies nightshades - so wonderful they have their own profession) Armando Hunziker worked here until he sadly died in 2001. He was the director of the institute for 52 years, incredible dedication. His portrait hangs behind where I am working - I hope he approves.


The cupboards are full of treasures - new records for Argentina for little known species, lots of specimens of species that are endemic to Argentina and of which we have not a single collection in London - this is why working with colleagues in other institutes like ours is so incredibly rewarding. Highlights have been many specimens of Solanum endodenium - which we hope to see in the next week - with dark purple flowers with a green "eye"; a duplicate of a type specimen that I thought had been destroyed in the bombing of Berlin in the 1940s, oh and the list goes on. Tiina is figuring out her very complicated plants over in the next room - we keep popping back and forth to trade ideas and questions.


We have been looking at specimens not only for databasing and recording for future work, but more urgently to see where we need to prioritize the trip in order to see as much as possible. We will certainly find surprises though, in the Andes solanums are everywhere, and a beady eye is a must while travelling. Our route will take us to 3000 m elevation and through some fantastic places - can't wait!!




Cordoba, Argentina....

Posted by Tiina Feb 8, 2012



I am here at last; flying over the Andes this morning from Santiago in Chile was amazing - beautifully clear and I could see all the glaciers and snow-capped peaks. Not much snow now because it is summer here....


Cordoba is a beautiful town, a brilliant mixture of old colonial and new. The University where the herbarium is located is near the centre of town, we went over there this afternoon to have a look around. They are experiencing a heat wave in Cordoba - it is approximately 30 degrees and VERY humid! I am catching up on all the adventures Tiina and Gloria have been having last week - I'll had over to her now for the update!




It was great to get Sandy here with us to sort out some issues with Solanum! Like Sandy says, it's extremely hot and humid, which is why we've also had some big storms this week. A few days ago it was raining ice balls - yes I mean ICE BALLS!


I took pictures as proof of how bad it was: we had to mop water from the floor as the roof and windows were leaking in the herbarium! It was a real mixture of ice the size of table tennis balls, and massive rain.


It just goes to show that it's not easy to keep up a museum in tropical countries... While we were busy mopping water from the floor, the storm knocked down a large tree just outside. The sound was tremendous! Gloria and I went out to see the damage afterwards.

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The challenge of the coming days is to fit everything in. We have meetings to talk about our recent results, our work with molecular phylogenetics and taxonomy at NHM, and cytogenetic and taxonomic work here in Cordoba. It's a great chance to throw some ideas around, discuss what we have and plan future work.


We also have to plan the route for our longer trip in the north. We are heading to the big Andes on Friday, to the departments of Jujuy, Catamarca, Tucuman and Salta. There are many species we want to cover, and we can gather localities where to find them from the herbarium and our existing online Solanum database.


During the weekend we did a short 3 day trip around the departments of Cordoba and San Luis and managed to find species which were previously only known from types. The three species we found in the field can now be studied in detail together with the original descriptions to fully understand the species.


Now off to bed, we are gathering strength for what's ahead! Thus far 253 specimens fully databased, c. 400 identified, and more to go!


Setting the scene...

Posted by Tiina Feb 2, 2012

We all like eating tomatoes and potatoes - what could be better than chips with ketchup ! But did you know tomatoes and potatoes are extremely closely related? Although a red juicy tomato looks totally different to a pale yellow potato, the two plants share much of their DNA.


Potato and tomato belong to a group of plants known as Solanaceae - the nightshade family. In actual fact, they are so closely related they belong to the same genus within Solanaceae, known as Solanum. Tomato is called Solanum lycopersicum L. in scientific latin, whilst potato is known as Solanum tuberosum L.



Other well known species in the group include the bell peppers, chili peppers, eggplants, petunias, and tobacco - yes, incredibly this strongly flavoured plant is related to commonly eaten yummy things! South Americans might know more fruits from the family, such as naranjilla (Solanum quitoense Lam.), or tamarillo (Cyphomandra betacea Sendt.) used for making preserves and juice. If you visit Mexico and indulge in local food culture, you come across another species from the family, tomatillo (Physalis philadelphica Lam.) which is used to prepare salsa for buritos, tacos and tortillas.


Below is a lovely phylogeny of the nighshades which illustrates how the species are related within the family. It's based on a small set of DNA data. It is still not complete as it only includes roughly 30% of all the species in the family. Our aim is to add more species as our research progresses. What you can see is that eggplant, tomato, potato and pepino are really closely related, and tobacco is the furthest relative of them all. Solanaceae_large_phylogeny_SMALL_for_blog.jpg



The nightshades were known to be a group of closely related plants before anybody even knew they are related based on their DNA. This is because all species in the group share a set of morphological characters. Some of these are very obvious such as flowers which are generally stellate, with five corolla lobes, and five stamens. The most clear character that unites the family is seeds. Seeds are small – think of tomato seeds! – flattened, kidney-shaped, and have puzzle-piece shaped cells if looked under a microscope. Most of seeds in the nightshade family have curled embryos. If you are curious, try looking at dried tomato seeds closely! You will see the impression of the curled embryo on the seed quite easily.



Other characters of the nightshade family are more hidden. For example, all nightshades have internal phloem which means that sugars produced in leaves via photosynthesis are transported down to roots inside the water transport system known as xylem. Most plants have an opposite type transport system where sugars are transported outside the waterpipe system.



Anyways, why all this ramble? Well, the thing is that we are about to go hunting for nightshades in the Andes! There are an estimated 4,500 species of nightshades in the world, and large number of these is found in the Andes. These are wild relatives of tomatoes and potatoes and such likes, some weirder than other, some with tubers, whilst other climb trees! There are still species remaining to be described, waiting in the forests and mountain sides for discovery. We will be travelling in the northern part of Argentina and in Peru over the next coming 3 months – our aim is to collect as many species of Solanaceae on our way. This time we are targeting the particularly poorly known species of the Morelloid clade in the genus Solanum, a set of roughly 60 species.

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