DTMA genotyping call

Posted on general, September 13, 2010

The DTMA project would like to open the call for partner genotyping for 2010.

Genotyping services offered are detailed below. Any requests for genotyping need to reflect the aims of the DTMA project; materials must be DT or must be parents with high value characteristics that will be/are being used in DT breeding work.

Proposals submitted for consideration need to detail:

  • the objective of the genotyping (examples could include. using genotyping for seed quality control for drought tolerant germplasm or using genotyping for genetic distance analysis in order to select parents for drought tolerant hybrid crosses, but others will be considered).
  • the germplasm to be tested and characteristics (i.e. indicate the name of the line and pedigree and define known characteristics; drought tolerant, disease resistant (MSV, GLS)
  • timeline for sample submission

The services provided are:

Service Uses Notes
SNP genotyping of up to 100 inbred lines with 50 SNP#. For each inbred line four bulk samples of eight plants per bulk will be required. Quality control of lines. Assesses level of  uniformity and serves as a reference point for future seed generation DT germplasm or parents used in generation of DT
hybrids/OPVs. CIMMYT /
IITA materials may be listed but will not be included if data are already available
SNP genotyping of up to 40 inbred lines with 200 SNP#. One bulk of eight plants will be required per inbred line. Diversity assessment of own materials and comparison with CIMMYT/IITA materials DT germplasm or parents used in generation of DT
hybrids/OPVs. CIMMYT /
IITA materials may be listed but will not be included if
data is already available.
Bulk SSR genotyping of 20 samples of OPV or hybrid (these can be different materials or the same materials from different sources. 20 individual plants per sample will be required) with up to 40
SSRs (actual number will be defined by variability observed) ‡
Identify OPV and hybrid seed in market. Evaluate efficiency of OPV and hybrid production by out growers. Registered DT materials
# Partners will receive kits to harvest and send leaf samples to the laboratory providing the genotyping service. Partner will receive back a table detailing the SNP data calls of the materials submitted.
‡ Partners will submit seed or leaf to labs in Kenya (partners in E and S Africa) or Nigeria (partners in W and C Africa) for genotyping. Partners will receive a spreadsheet detailing the SSR data calls of the materials submitted

In addition to the services provided, we will also consider proposals from DTMA partners to conduct genotyping in their own facilities, though these proposals must be competitive with existing services. The total budget should not exceed $4000 and funds should cover laboratory and technical staff requirements, not field activities. Such proposals need to detail;

  • the objective of the genotyping e.g. using genotyping for seed quality control for drought tolerant germplasm or using genotyping for genetic distance analysis in order to select parents for drought tolerant hybrid crosses
  • the germplasm to be tested and characteristics (i.e. indicate the name of the line and pedigree and define known characteristics; drought tolerant, disease resistant (MSV, GLS)
  • the marker system suggested (SSR, SNP)
  • workplan with timeline
  • budget
  • the proposed location of the genotyping.

DNA extraction and genotyping facilities are available for use by DTMA partners at hubs in Kenya and Nigeria. SSR genotyping can be done at the hubs either by DTMA staff as needed or by PIs/co PIs of funded projects (lab experience required). For further information on costs please contact Sarah Hearne (shearne@cgiar.org) for information on Nigeria operations and Kassa Semagn (k.semagn@cgiar.org) for information on Kenyan operations. Only operational costs can be covered, costs for accommodation, travel and living expenses must be funded by applicants.

Responses to the call are to be submitted in electronic format to Sarah Hearne (shearne@cgiar.org). There is no closing date for the call. Projects will be funded continuously as budget allows. Proposals will be assessed by a panel of experts and judged according to their relevance to DTMA objectives. Up to 16 projects will be funded for E and S Africa and 8 projects for W and C Africa.

Definitions of common terms used in the DTMA Project

Posted on general, August 17, 2009

PDF version:

DTMA Definitions 2009


These definitions are:



Adoption is the uptake of a technology by a farmer; the uptake and continuous use of a technology.

Drought tolerant (DT)

Among maize varieties that have similar maturity and similar grain yield under good conditions, a drought tolerant maize variety has a relative higher yield than others when drought occurs. To generate and disseminate such varieties is the focus of the DTMA project.

An early maturing maize variety may escape drought and has therefore a higher yield under drought. It however yields less when conditions are good.

Mega environments vs agroecologies/agroecological zones

Maize mega environment describes the geographic area within which maize varieties show similar ranking for grain yield due to similar growing conditions (rainfall, temperature, soil type). Mega environment cover more extensive areas than agroecologies/agroecological zones.

A maize agroecology/agroecological zone refers to a specific geographic region, usually covering a few countries in which the interactions of maize varieties with the environment (rainfall, temperature, soil type, altitude) are studied. Agroecology (as a study) provides an interdisciplinary framework with which to study the activity of agriculture.

Seed business vs seed merchant

A maize seed business is an organization that produces and markets maize seed.

A maize seed merchant is an organization that markets seed, without producing the seed: i.e., a buyer and seller of seed, like a retailer.

Seed demand vs production

Seed demand means wanting/needing seed and being able to pay for it. Demand is market driven; it is what the consumer (in this case the farmer) is requesting and is willing to pay for.

Production of seed involves area and yield. Production is what a supplier to that market is responsible for, he/she produces seed in order to address demand at a price he/she is willing to sell for.

Seed distribution

Seed distribution is the dissemination of seed from a producer to a farmer via formal or informal markets; the system of delivering seed from the production point to farmers.

Unmet market demand vs excess capacity

Unmet market demand means that demand is greater than supply while excess capacity means supply is greater than demand.

Unmet market demand: a situation whereby a consumer is unable to source material at a price they are willing to pay for a commodity or service.

Excess capacity: the ability to generate more produce than is currently being demanded.

General FAQ

Posted on general, May 19, 2008

What is drought tolerant maize?

Drought tolerant maize varieties are higher yielding when drought strikes. They have in-built tolerance mechanisms to water shortage and continue producing more than other maize varieties.

Is drought tolerant maize a Genetically Modified Organism?

The drought tolerance in the maize varieties developed by CIMMYT, IITA and collaborating national agricultural research institutes is developed through conventional breeding methods, so they are not genetically modified organisms (GMOs).

What about if there is ample rain, will the drought tolerant variety yield less than other varieties?

Many of the drought tolerant maize varieties are similar or even higher yielding than normal maize varieties under good conditions. Because we know that farmers do not want to lose out on yield in good years, we designed our breeding approach to combine drought tolerance with high yield potential and other farmer-demanded traits such as disease resistance.

Where is drought tolerant maize seed available now?

Through collaboration with National Agricultural Research Programs and the private seed sector, several drought tolerant maize varieties become available (DT maize varieties and hybrids) on the market. In sub-Saharan Africa, they include both open-pollinated varieties and hybrid varieties. Pleases ask your local Ministry of Agriculture for advice.

Is the seed more expensive than normal commercial varieties?

There is no reason for seed of a drought tolerant maize variety to be any more expensive than seed of other varieties.

Can drought tolerant maize be grown anywhere?

A good drought tolerant maize variety has the same maturity and often similar other variety characteristics as non-drought tolerant varieties. It can be grown like any other maize variety but it will show its benefit when drought hits.

With drought tolerant maize varieties becoming available, will farmers in sub-Saharan Africa simply grow maize and no other crops?

We expect rather the opposite to happen and the maize area to reduce. Due to the uncertainty of drought, many farmers in sub-Saharan Africa grow maize in a larger area than needed for home consumption in an average year. They want to be food secure even when drought strikes. As a result, they have little land and labor left to grow other crops such as legumes or cash crops. With a drought tolerant maize variety, farmers are more likely to be food secure, can allocate less land to maize and invest in other crops to the benefit of a more balanced diet, higher incomes and improved soil fertility.

How much more drought tolerant can you make maize?

Maize is an amazingly diverse crop and this natural genetic variation is at the heart of our breeding strategy. Most of our efforts focus on making maize more tolerant to drought during its productive stage, flowering and grain filling. So far, we have seen no limits to further improving the drought tolerance during those stages. Essentially, with every year of investment in drought tolerance breeding, we add another 100 kg ha-1 to a drought affected maize crop.

How do you achieve this?

The underlying concept is quite simple. We cross-fertilize different varieties – something that farmers and breeders have done for centuries – and generate thousands of new varieties. We then use rain-free periods to grow them under carefully managed drought conditions. The new varieties still receive some water, but not much. Using a portfolio of tools, including physiological and molecular markers and advanced statistical analysis tools, we select the best.

Can breeders from collaborating institutions submit new varieties for these trials?

Yes. Collaborating breeders are encouraged to submit their new varieties to be included in regional trials and we have developed a Procedures Manual showing details of how to submit the new varieties.

Are farmers involved in the selection of new drought tolerant maize varieties?

Yes. National agricultural research institutes, often in collaboration with extension and NGOs, test new drought tolerant maize varieties with smallholder farmers under farmers’ own conditions. Farmer-preferred varieties go forward into seed production and become available on the market.

What is the greatest obstacle for getting drought tolerant maize seed to farmers?

Few seed companies in Africa increase and distribute seed. In many instances improved maize seed is only sold in major towns and with little information made available to the wider farming community. So, the dissemination of new varieties is quite slow. Fortunately, there is an increasing number of stakeholders – including national governments, donors, international and sub-regional organizations – who are aware about the complex set of constraints affecting seed sector development. Through combined efforts of all stakeholders, we expect significant progress over the next decade in SSA.

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