Cranberries are grown in sunken bogs that can be flooded to harvest the fruit. (photo by Vinson Doyle)
Plants and fungi have an intimate relationship. Some fungi, like mycorrhizal fungi which help a plant’s roots use soil resources more efficiently, are beneficial to plants, while others, like powdery mildew on squash leaves, are obviously harmful. However there are many fungi that exist somewhere on the continuum between friend and foe. To further complicate the matter, whether an individual fungus is beneficial, neutral, or antagonistic may change over time such that apparently harmless fungi can become pathogenic.
Cranberries infected with pathogenic fungi. Many different species of fungi are responsible for causing cranberry fruit-rot, but Colletotrichum is one of the most prevalent in cultivated cranberries. (photo by Vinson Doyle)
Studying these fungi can be difficult; they do not always make their presence obvious. Imagine tracking an elephant through the forests of East Africa to understand what it eats, where it travels, and how it selects a mate. Now, imagine tracking an individual you can’t see in the wild, or if you can see it, you can’t tell it apart from its siblings. Tracking these wild fungi would have been impossible a decade ago, but with the advances being made in modern genetic methods both here at The New York Botanical Garden and around the world, we are finally able to address the big questions surrounding these tiny organisms.
My work focuses on understanding the genetic diversity of a single fungal species, Colletotrichum gloeosporioides. C. gloeosporioides is a sneaky fungus that is capable of shifting its place on the continuum between harmless and pathogenic to cranberry. The main focus of my research involves understanding how the spores of C. gloeosporioides are dispersed, what other plants it is associated with, and how it reproduces. I hope that a fuller understanding of this fungus will help cranberry growers formulate effective management plans.
But before we can find answers we have to find the fungus.
Flowering cranberries. While these plants are healthy, there are fungi living under the surface of the plant tissue. (photo by Vinson Doyle)A pure isolate of Colletotrichum growing on agar that was isolated from cranberry. Ascospores produced in the laboratory by a Colletotrichum species isolated from cranberry. (photo by Vinson Doyle)
My field work begins in the cultivated and wild cranberry bogs of North America in the hope that by finding the plant, we will find the fungus. In some cases, it is readily obvious that the plants have been infected by a pathogenic fungus. However, we frequently can’t determine which fungus has infected them, so we collect fruits, stems, and leaves and bring them back to the lab for further study. In other cases, we find plants that look perfectly healthy, but we suspect there are fungi lurking beneath the surface. So we take the material back to the Pfizer Plant Research Laboratory for more research. The hunt continues!
In order to study plant-associated fungi, that is, fungi that live within a plant such as C. gloeosporioides does, we must first coax the fungi out of the plant. To do this we place the plant pieces on a suitable growth medium that encourages the fungus to emerge from the plant and to populate the medium; in this way we are able to isolate the fungus and study it more carefully. Inevitably, many different species of fungi emerge onto the growth medium, which means we must isolate and identify each one.
A high elevation cranberry bog in the Monogahela National Forest in West Virginia. Cranberries are in flower along the banks of the stream (photo by Vinson Doyle)
Once we have isolated all the individual fungal strains, we use methods similar to those used in forensics to identify each one. In the Cullman Lab, we use DNA markers that allow us to identify each individual fungal strain within a single species in the same way that forensics specialists use DNA markers to establish whether an individual was at the scene of a crime.
Modern genetic methods have helped us determine that fungal strains are likely moving undetected (disguising themselves as harmless fungi) inside cranberry vines used to establish new farms in disparate regions before revealing themselves as harmful pathogens. This finding will hopefully allow researchers and farmers in the future to better understand the sources of disease epidemics. This knowledge should help farmers implement preventative measures and may lead to new methods for establishing cranberry bogs.
Ed. note: Larry Lederman, photographer and friend of the Garden (he’s a member of our Advisory Board), has a beautiful exhibit of large-scale tree photographs up right now in the lobby of the amazing Four Seasons restaurant in Manhattan. We wanted to learn more about Larry and his amazing photographs, so we asked him a few questions.
What is the title of the Exhibit at the Four Seasons?
Spring.
How did you choose the photographs for the Exhibit?
To show the presence of trees in our lives. As you walk in the door of the Four Seasons you will first see the pleached Sycamores. It is a striking image: the Sycamores are just beginning to bud, and their severely pruned geometric structure is almost like an x-ray. There is no escaping “the hand of man” expressing a formal sense of beauty on ordinarily unruly Sycamores.
Alongside the Sycamores are the Cherry Trees of Pilgrim Hill in Central Park, showering cherry blossoms like snow. There is no constraint here, no geometry. These trees are over a hundred years old, placed on a hill by Olmsted’s plan to be seen and enjoyed. They express their longevity and the wonder of renewal. And directly opposite the photograph of the Cherry Trees is the photograph of the view of the Native Forest in The New York Botanical Garden, expressing the exuberance of spring.
The fifty-acre Forest is kept native through careful attention–as authentic as Colonial Williamsburg and as diligently cared for–to transport us to an earlier time, our American Eden. The other two images also show us spring’s joy in cultivated trees planted for pleasure. Trees reflect our culture, our communion with nature, without having to retreat to wilderness.
How did you get into taking photographs?
I was interested in and enjoyed trees. It was that interest the got me into photography; the subject preceded the medium. But once I learned how to use the camera, I expanded my subjects. For example, I have spent the last five years doing landscapes evocative of the Hudson River School of painters, among other things. Last year I had a show at Olana, the home and studio of Frederic Edwin Church, one of the founders of the Hudson River School.
When did you start and how did you learn?
I started about nine years ago with film and then moved to digital photography. I largely taught myself, which is the way I like to learn. But teaching yourself requires a lot of reading and many museum visits. It also allows you make a lot of mistakes and to develop bad habits, which you have to watch out for and correct. I find that it is necessary to take a few courses from time to time.
How did you come to exhibit at the Four Seasons?
They had seen the calendars that I have been doing for the Garden over the past five years.
Your photographs are very large, some are 6×9 feet!
Images of trees and forests show very well when they are large. Photographs help you to see structure and form in a way that is difficult to see otherwise. When they are large there is an emotional impact that informs your sense of the divine. It is the way that I see the images when I take them. For me, photography is an emotional experience.
How often do you photograph?
Almost every day, even when it rains and snows. And I am at the Garden at least two or three times a week, following the changes in the light and the seasons.
I understand that you are working on a book with the Garden?
We are doing a book to be called Magnificent Trees of The New York Botanical Garden. We expect that it will be published in 2012, in time for Christmas.
I also understand that the proceeds from the sales of the photographs at the Four Seasons will go to the Garden.
That is correct. The Garden has been an inspiration for me.
When will the exhibit at the Four Seasons begin?
It is up now through at least June 20, possibly through the end of June. It is in the lobby, which is a landmarked room, and you can visit the exhibit without going upstairs to the restaurant.
The peonies that line Perennial Garden Way are getting set to explode into a riot of color and aroma. There are a few out, and hundreds more just waiting for the perfect weather to burst forth into a profusion of petals. Here’s a few of the early peonies to get you set for peony prime time!
‘Do Tell’
‘Kevin’ – Isn’t it great that there’s a peony named Kevin?
‘John Harvard’ – This peony which bears the colors of the Ivy League school founded by the man it is named for was one of the first to open this year, and is still going strong.
Spanish Paradise: Gardens of the Alhambra doesn’t open to the public until tomorrow, but today, Members get a first look, or maybe I should say first sniff, at our latest exhibition. Why first sniff? Because this exhibition in the Enid A. Haupt Conservatory smells AMAZING! And it sounds pretty good, too. The tinkling of water, soft strains of guitar music, and bird tweets meld together with the heady perfume and sublime gardens to create a true paradise on earth.
Ed. note: Selena Ahmed, ethnobotanist and author of the gorgeous new book Tea Horse Road will be at the Garden for a book signing this Saturday, May 21 at 3 p.m at Shop in the Garden. I first saw Selena’s book in a colleague’s office. The absolutely stunning photographs, taken by Michael Freedman, drew me in, but it is Selena’s tales that bring this fascinating book to life. We are currently working with Michael, who is traveling China, to put together a post of his photographs, so stay tuned. But why wait? Pick up a copy of Tea Horse Road this Saturday. You won’t be disappointed.
My new book, Tea Horse Road: China’s Ancient Trade Road to Tibet, with photographer Michael Freeman explores lives and landscapes along the world’s oldest tea trading route. Our journey starts in tropical montane forests in China’s southern Yunnan Province. This is the birthplace of the tea plant, Camellia sinensis (Theaceae). The cultural groups of Yunnan including the Bulang, Akha have produced and consumed tea for centuries for its well-being and stimulant properties. They traditionally grew tea plants as trees of several meters tall without the use of chemical fertilizers, pesticides and herbicides.
While tea cultivation spread where climatic conditions allowed, the practice of drinking tea reached far beyond. During the 7th century, the Tibetan kingdom to the north of Yunnan came into contact with tea, and the drink soon became central to the Tibetan people’s diet. Tea functioned to reduce the oxidative stress of Tibet’s high altitudes and as a dietary supplement in an environment with limited fruit and vegetable production. These same extreme conditions mean that tea has remained an imported item from tropical and sub-tropical areas in China’s Yunnan and Sichuan provinces. The demand for tea led to the creation of a network of trails extending more than 3,000 kilometers, carved through forests and mountains, with Lhasa at its core. This network collectively became known as the South West Silk Road or Cha Ma Dao, the Tea Horse Road.
However, tea was only one side of the trade equation: China was in constant search for warhorses that made its armies more mobile allowing the kingdom to maintain control over the empire. Abundant natural resources along with tea and horses were exchanged on the Tea Horse Road over the course of 2 millennia, linking cultures and natural resources beyond their surroundings. In its day, the Tea Horse Road touched the lives of many. These were the tea farmers on the southern mountains, the caravan leaders, the Tibetan lados skilled at traversing high passes and the porters with 100-kilo loads on their backs. This book is their story, narrated against the backdrop of some of the world’s most rugged and powerful landscapes.
Trade along the Tea Horse Road declined in the 20th century as horses ceased to have a major military use. Roads were paved allowing for more efficient transport, and policies and markets transitioned. As the Tea Horse Road acquires a historical presence, it is easy to forget its vital former role of maintaining community health, sustainable agriculture, livelihoods, and cultural exchange.
If ever there were a spring day so perfect,
