DNA technique measures suitability of soil for onion crops

November 11, 2005

Nematodes, such as the stem nematode, and fungi, such as white rot, are particularly harmful for onion crops in the Netherlands: they cause rot. Soil samples are investigated to detect this; a labour-intensive and expensive operation. Together with the Laboratory for Nematology (University of Wageningen) the company Blgg has developed a molecular technique to detect the stem nematode and white rot in soil samples.

Agricultural laboratory Blgg will start using the new system in November 2005. The system quickly and accurately measures soil samples at the molecular level. In a series of comparative trials, the molecular test had a higher detection rate than the traditional microscopic investigation for both the stem nematode and onion white rot.

Each year thousands of soil samples are investigated for their suitability for onion crops. They are examined for the presence of the nematode Ditylenchus dipsaci (the stem nematode) and the fungus Sclerotium cepivorum (onion white rot). For years this has been done visually under the microscope; a specialised and labour-intensive process.

Blgg director Henri Hekman had been looking for a more accurate, faster and cheaper method for some time. He came into contact with Wageningen researcher Hans Helder who, with funding from Technology Foundation STW, was compiling a DNA database of all nematode species in the Netherlands. This database, together with a method for the easy extraction of DNA from nematodes, forms the basis for the technique developed to detect harmful nematodes. The Technology Foundation STW filed a patent for this technology, and this patent was recently transferred to Blgg.

In close cooperation with the Laboratory for Nematology, Blgg managed to successfully combine the fundamental knowledge from the patent with state-of-the-art laboratory practice. The result is a practical test that conclusively demonstrates the presence of both the stem nematode and onion white rot.

Both parties are continuing to work on the development of molecular tests to detect other plant pathogenic nematode species in the soil. With this new method, the analysis of soil samples under the microscope will be made superfluous. It will soon be possible to detect nematodes extracted from the soil samples according to their individual DNA 'barcode'. The grower can then decide whether or not he wants to grow onions on the plot of land tested.
-end-


Netherlands Organization for Scientific Research

Related DNA Articles from Brightsurf:

A new twist on DNA origami
A team* of scientists from ASU and Shanghai Jiao Tong University (SJTU) led by Hao Yan, ASU's Milton Glick Professor in the School of Molecular Sciences, and director of the ASU Biodesign Institute's Center for Molecular Design and Biomimetics, has just announced the creation of a new type of meta-DNA structures that will open up the fields of optoelectronics (including information storage and encryption) as well as synthetic biology.

Solving a DNA mystery
''A watched pot never boils,'' as the saying goes, but that was not the case for UC Santa Barbara researchers watching a ''pot'' of liquids formed from DNA.

Junk DNA might be really, really useful for biocomputing
When you don't understand how things work, it's not unusual to think of them as just plain old junk.

Designing DNA from scratch: Engineering the functions of micrometer-sized DNA droplets
Scientists at Tokyo Institute of Technology (Tokyo Tech) have constructed ''DNA droplets'' comprising designed DNA nanostructures.

Does DNA in the water tell us how many fish are there?
Researchers have developed a new non-invasive method to count individual fish by measuring the concentration of environmental DNA in the water, which could be applied for quantitative monitoring of aquatic ecosystems.

Zigzag DNA
How the cell organizes DNA into tightly packed chromosomes. Nature publication by Delft University of Technology and EMBL Heidelberg.

Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.

DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.

A new spin on DNA
For decades, researchers have chased ways to study biological machines.

From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.

Read More: DNA News and DNA Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.