ANNOUNCEMENT OF 10 HERBICIDE-RESISTANT CIMMYT MAIZE INBRED LINES SUITABLE TO COMBAT STRIGA

November 25, 2006

Dear Cooperator:

CIMMYT has periodically announced CIMMYT Maize Lines (CMLs). CMLs are carefully selected inbred lines with good general combining ability and a significant number of value-adding traits such as drought tolerance, N use efficiency, acid soil tolerance, resistance to disease and insect pests. In many instances, they are parental lines of hybrids which have proven successful in one or several maize mega-environments.

Since 1991, 511 CMLs have been announced and made available to assist partners in the development of hybrids, vigorous and productive inbred progenitors, and high performance synthetics, particularly targeted at developing countries.

The announcement of these 10 new CMLs has a very specific focus. The 10 CML lines are BC3-conversions of existing CML lines, adapted to eastern and southern Africa, and contain a natural form of herbicide resistance against Imidazolinone, originally found in a mutant. Important attributes of these CMLs are detailed in Table 1.

The seed of Imidazolinone-resistant (IR) maize can be treated (seed-coated) with Imidazolinone to provide an effective protection against Striga species (S. hermontica and S. asiatica), a parasitic weed which attaches to maize roots and results in severe maize yield reduction in some parts of Africa. IR maize seed coated with Imidazolinone restores maize production under Striga-infested conditions and also contributes to reducing the Striga seed bank in the soil. IR maize can also be grown in non-Striga affected areas, like any other maize cultivar, with or without Imidazolinone seed coating.

Deployment of the Imidazolinone resistance trait and seed dressing needs to be done in a responsible manner to assure the effectiveness and durability of the technology, to the benefit of seed producers, farmers and the environment. Unless such measures are taken, seed may be improperly treated and the crop fail, Striga may more quickly develop resistance against the herbicide, the seed company may contaminate other seed stocks with the herbicide, or farmers may improperly use the technology and incur crop losses.

To ensure responsible deployment, CIMMYT entered into an agreement with “BASF – The Chemical Company” for deployment of IR maize hybrid and open-pollinated varieties under the trade name “StrigAway®”. This partnership will provide the necessary know-how to deploy the technology as “StrigaAway®” seed and in an appropriate manner. The partnership will also continue to raise awareness about the technology in Sub-Saharan Africa, so that seed labeled as StrigAway® will be recognized as seed that provides effective control against Striga .

Seed of these CMLs will therefore be dispatched under a specific Material Transfer Agreement (attached) which requires the recipient to use StrigAway® technology when deploying these inbred lines, crosses or descendants carrying the Imidazolinone-resistant trait. Also, the recipient agrees to only commercialize varieties which are homozygous for the IR trait (a single dominant gene).

Breeders are free to use these lines for research purposes and develop their own IR maize lines, hybrids and synthetics. Seed requests however must indicate that as a recipient you agree to the conditions of the enclosed Material Transfer Agreement for Imidazolinone Resistant (IR) Maize.

Given that Striga is a problem exclusive to Africa, no seed shipments to cooperators outside Africa will be made. To our partners outside of Africa, we recommend use of the original, non-IR versions of these CMLs (see Table 1).

Yours sincerely,

Marianne Bänziger
Director Global Maize Program

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