genetic diversity

A new study by researchers at the University of California, Davis, has found that under the right circumstances, disease-resistant corals can rescue corals that are more vulnerable to disease.

The researchers monitored a disease outbreak at a coral nursery in the Cayman Islands. They tracked the presence of disease in 650 coral fragments in various arrangements over a period of five months. They found that some corals are more resistant to disease just by being around other corals that are particularly resistant. In general, when there are only corals of the same genetic makeup, they are more vulnerable to disease than corals that grow among a mixture of genotypes. But beyond that, some vulnerable corals become more resistant to disease just by being around other corals that are particularly resistant. Proximity to the resistant genotypes helped to protect the susceptible corals from the effects of disease.

These findings provide new evidence that genetic diversity can help reduce disease transmission among corals and furthermore, it is important to consider how corals are arranged in coral nurseries or in reef restoration projects.

The ability of resistant coral to help protect vulnerable individuals appears to be similar to how vaccinations work among humans. Vaccinated individuals resist a disease, which effectively erects a barrier that weakens a disease’s ability to move through a population.

The researchers hope that the findings of this study will be integrated into coral nursery and reef restoration projects. By intentionally arranging corals with mixtures of genotypes, it will help rebuild coral resilience and help those corals that are vulnerable to disease to thrive.

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Corals Saving Corals

Photo, posted December 30, 2014, courtesy of NOAA’s National Ocean Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

In the United States, cotton is a $7 billion annual crop grown in 17 states. Cotton plants in the largest producing countries in the world – India, China, and the U.S. – are genetically very similar and, like other crops that lack diversity, can be at risk.

Cultivated cotton around the world has been bred to look and act very similar. It is high yielding and easy to harvest using machines. But it is also wildly unprepared to fight disease, drought, or insect-borne pathogens.

Researchers are looking beyond breeding for ways to combat the low genetic diversity of cultivated cotton. There are new approaches that combine breeding with elements of genetic modification. Most cotton in the U.S. has already been genetically modified to resist caterpillar pests. But as new problems emerge, new solutions will be needed that may require complicated changes to the cotton genome. Getting regulatory approval for a genetically modified crop is a long and expensive process.

However, ordinary genetic modification is not the only possibility. Modern genetic sequencing technology can allow researchers to examine various wild cotton varieties and identify the genetic markers for desirable traits. Once valuable genes in wild species have been identified, traditional plant breeding techniques could be used to produce cultivated cotton varieties that are more resistant to disease and drought.

Climate change is raising average global temperatures and some important cotton-producing regions such as the U.S. Southwest are becoming drier. Researchers are hoping to produce cultivated cotton that can tolerate drought at the seedling stage. The ultimate goal is to create more sustainable and genetically diverse cotton that can thrive in a changing world.

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Cotton Breeders Are Using Genetic Insights To Make This Global Crop More Sustainable

Photo, posted November 9, 2008, courtesy of BP Takoma via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Corals Saving Corals | Earth Wise

A new study by researchers at the University of California, Davis, has found that under the right circumstances, disease-resistant corals can rescue corals that are more vulnerable to disease.

Web Links

Making Cotton More Sustainable | Earth Wise

In the United States, cotton is a $7 billion annual crop grown in 17 states. Cotton plants in the largest producing countries in the world – India, China, and the U.S. – are genetically very similar and, like other crops that lack diversity, can be at risk.

Web Links