The research team, led by Hernán Ceballos at the International Center for Tropical Agriculture, identified four different sources of tolerance to a phenomenon known as post-harvest physiological deterioration. This process renders the cassava roots inedible and unmarketable a mere two to four days after harvesting.
This study started with an accident. A few roots from a cassava clone (belonging to a new high-carotene generation) were left on a shelf for more than two months between. When inspected these roots did not show any symptoms of deterioration. This result prompted the planning and execution of a study whose results are presented in the July-August 2010 edition of Crop Science, published by the Crop Science Society of America.
One source of tolerance was found in the only species of cassava native to the United States. A second source was induced by mutagenic levels of gamma rays which silenced one of the genes that cause the deterioration symptoms.
A third source was a group of high-carotene clones. The authors suggest that the antioxidant properties of carotenoids protect the roots from deterioration, which is basically an oxidative process. Finally, tolerance was also observed in a waxy-starch mutant. The researchers believe that the waxy-starch gene is co-located next to a tolerance gene, and resistance to deterioration is not directly caused by the mutant gene.
“This kind of discovery includes sources from wild relatives of cassava, which supports the need for germplasm collections,” says lead researcher Hernán Ceballos. “It also has new sources of tolerance induced through mutagenesis or exposed through inbreeding, which is a rather new thing for cassava. Finally, some of the tolerance comes from the anti-oxidant properties of high carotene cassava. But mostly this is very important for women who sell cassava roots in markets throughout Africa or Latin America who will not necessarily lose their products if they fail to sell them within a day or two after harvest.”
The economic relevance of these discoveries is expected to be huge. Cassava is one of the most important staple crops worldwide, and is the most important in many arid regions, such as sub-Saharan Africa. It can produce reasonable root yields under adverse climatic and soil conditions, and offers the advantage of a flexible harvesting date, allowing farmers to keep the roots in the ground until needed. In addition to the important role cassava plays in food security, there is a growing demand for cassava roots by the starch, food, animal feed, and ethanol processing industries.
The results of this study suggest that tolerance to post-harvest physiological deterioration can be found in different sources, and they seem to be acting through different biochemical/genetic mechanisms. They also highlight the importance of germplasm collections and their screening, the usefulness of inbreeding cassava (in search of recessive traits) and the potential of induced mutations, particularly with the advent of molecular tools.
Future research will focus on finding additional sources of tolerance and identifying molecular markers linked to those traits. This will allow for early identification of tolerant varieties, overcoming the current limitations of cassava research, which involve growing large numbers of roots to obtain sufficient data.
This study will go a long way towards addressing bottlenecks that prevent cassava having a larger impact on the livelihoods of the communities that depend on it, as identified by the Food and Agriculture Organization of the United Nations (FAO) Global Cassava Initiative, which culminated in 2000. It concluded that cassava could become the raw material base for an array of processed products and contribute to agricultural transformation and economic growth in developing countries.
The full article is available for no charge for 30 days following the date of this summary. View the abstract at https://www.crops.org/publications/cs/abstracts/50/4/1333.
Crop Science is the flagship journal of the Crop Science Society of America. Original research is peer-reviewed and published in this highly cited journal. It also contains invited review and interpretation articles and perspectives that offer insight and commentary on recent advances in crop science. For more information, visit http://crop.scijournals.org
The Crop Science Society of America (CSSA), founded in 1955, is an international scientific society comprised of 6,000+ members with its headquarters in Madison, WI. Members advance the discipline of crop science by acquiring and disseminating information about crop breeding and genetics; crop physiology; crop ecology, management, and quality; seed physiology, production, and technology; turfgrass science; forage and grazinglands; genomics, molecular genetics, and biotechnology; and biomedical and enhanced plants.
CSSA fosters the transfer of knowledge through an array of programs and services, including publications, meetings, career services, and science policy initiatives.
Cascading use is also beneficial for wood
11.12.2017 | Technische Universität München
The future of crop engineering
08.12.2017 | Max-Planck-Institut für Biochemie
DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.
Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
15.12.2017 | Power and Electrical Engineering
15.12.2017 | Materials Sciences
15.12.2017 | Life Sciences