Colby Witherup

Candidate for Master's Degree 
Graduate Program in Plant Biology and Conservation 
Northwestern University
and Chicago Botanic Garden

Research Interests: crop genetics, ethnobotany, tropical agriculture, sustainable agriculture, grazing systems

Current Research


Jackfruit tree growing near Rajshahi, Bangladesh

Saplings raised at Lawachara National Park, Sylhet Division, Bangladesh

Shopping at a Jackfruit market, Jessore, Bangladesh


Artocarpus heterophyllus (Jackfruit) is one of two economically important crops in the genus Artocarpus (with A. altilis, or breadfruit) in the mulberry family (Moraceae). Jackfruit is a monoecious tree that contains sticky, white latex throughout all of its parts, including the fruit, which is the largest tree-borne fruit structure in the world. Jackfruit has been cultivated for millennia and is now so widely cultivated that it is unclear in which region it is indigenous and which region holds its greatest diversity. Today it is found in cultivation at low elevations throughout Southeast Asia and has been introduced in the Philippines, Australia, and throughout Africa and the Neotropics.

Jackfruit is the national fruit of Bangladesh, a country whose natural areas are severely threatened by overpopulation and climate change. There is evidence that the country harbors rich jackfruit diversity, but very few studies have focused on jackfruit there.  In Bangladeshi villages, jackfruit trees are grown in almost every yard and are considered the second most important fruit tree after mango. It is feared that genetic variation is being lost due to deforestation, a decline in seed propagation, and the introduction of high-yielding, uniform cultivars.

Loss of crop diversity, especially Plant Genetic Resources that farmers use when breeding and improving crops, is an issue of international concern. Crop wild relatives often contain important traits for improving agricultural production and maintaining sustainable agroecosystems, including resistance to pests and diseases, tolerance of drought, salinity and other abiotic stresses, and the ability to achieve higher yields and quality. The demand for genetic material for breeding new adapted cultivars relies on diverse germplasm from both wild and modified sources. Under-utilized crops receive particular attention from scientists who would like to conserve these genetic resources. In Southeast Asia, international organizations (Global Facilitation Unit for Underutilized Species, International Centre for Underutilized Crops, International Plant Genetic Resources Institute) are looking to jackfruit (Artocarpus heterophyllus, Moraceae) to provide a new level of food security and income.

I collected almost 400 jackfruit leaf samples during my recent trip to Bangladesh with my advisor, Dr. Nyree Zerega.  Samples were collected from several sites throughout Bangladesh, along with DBH and a list of ethnobotanical questions, including propagation method, age, fruiting season, fruit texture, etc.  Using DNA fingerprinting, my research will give a broad view of jackfruit diversity in Bangladesh.  By analyzing my lab results in connection to my ethobotanical data, I will investigate claims of genetic erosion and attempt to identify possible causes.


2011 Honorable Mention, National Science Foundation, Graduate Research Fellowship Program

2010 Plant Biology and Conservation Travel Award, Chicago Botanic Garden

2010 Dr. John N. Nicholson Fellowship, Northwestern University

2010 Rogers McVaugh Graduate Student Research Grant, American Society of Plant Taxonomists

2010 Plant Biology and Conservation Research Award, Chicago Botanic Garden

2009 Alumnae of Northwestern University Fellowship

2009 Shaw Fellowship for Plant Biology and Conservation, Chicago Botanic Garden

2008 B.A. Conservation Policies and Methods, Northwestern University

2007 Natural/Cultural Resources Intern, Apostle Islands National Lakeshore, Wisconsin


Witherup, C.E., N. Zerega, and M.I. Zuberi. 2011. Measuring and preserving diversity in a Bangladeshi food crop: Jackfruit (Artocarpus heterophyllus, Moraceae). Oral presentation at Botany 2011, St. Louis, MO, July 11, 2011.


Dr. Nyree Zerega

Artocarpus Pages

Fairchild Tropical Botanic Garden


May 8, 2013