SATrends Issue 75 February 2007
  • At the root of the solution!
  • Action speaks louder than words
  • Suc-SEED-ing in seed distribution

  • 1. At the root of the solution!
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    In SATrends issue 62 (January 2006), we reported that DREB1A transcription factor from Arabidopsis thaliana, when introduced transgenically into groundnut and expressed under the control of a stress-responsive promoter from A. thaliana rd29A gene, appears to confer water-economizing capacity compared to its wild type parent variety JL 24 (WT). We now have some exciting observations on roots of DREB1A transgenics.

    Using a lysimetric system, these transgenic groundnuts were grown in 1.2 m long and 16 cm diameter PVC tubes, closely mimicking field conditions. Five transgenic events were assessed along with their WT by growing them for 30 days. At 30 DAS, following cylinder saturation with water, 6 plants were maintained under well-watered conditions (WW) by compensating their water loss, while the other 6 were water stressed (WS). The weight of cylinders was recorded every 3 days to measure the plant water uptake. The total plant water uptake under WS was higher in the transgenics than in the WT, whereas under WW the total plant water uptake was similar in all genotypes.

    Remarkably, the root dry weight of all genotypes was very similar under WW conditions (1.48 - 1.63 g. WT was 1.61 g). By contrast, the root dry weight of WT remained unchanged under WS (1.73g), whereas that of all the transgenics dramatically increased (2.27 - 2.65 g range) by 30% overall (Figure 1A). Under WW, the root/shoot ratio was similar and slightly larger in WT than in the transgenics. By contrast, under WS the root/shoot ratio dramatically increased in all transgenics and became higher than in WT (Figure 1B).


    Figure 1A,B: Distribution of root dry weight over different depth in 5 transgenic DREB1A::rd29 events and wild type JL 24, at 35 days after imposing water stress (A) and under well-watered conditions (B).

    Although, under WW conditions, no rooting differences were observed between the genotypes (Figure 2), under WS all the tested transgenics had more profuse deep rooting than the WT. In fact, there was an excellent relation between the root dry weight within the 40 -120 cm depth and the total plant water uptake (r2 = 0.91). As a consequence, shoot dry weight was 20 - 40% higher than WT under WS only. Moreover, the transpiration efficiency (TE) under WS was found to be 20% higher in events RD2, RD11, and RD20 than in WT.


    Figure 2A,B: Root DW (A) and root/shoot ratio (B) in 5 transgenic DREB1A::rd29 events and wild type JL 24, at 35 days after imposing water stress and under well-watered conditions.

    Hence, it appears that DREB1A clearly induced a positive root response under water deficit conditions. Now we hope to look at a holistic approach to compare how this transcription factor might regulate the water relations in transgenic plants under natural water-limiting conditions.

    For more information contact v.vadez@cgiar.org or k.sharma@cgiar.org

    2. Action speaks louder than words
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    Video is a powerful communication, marketing and educational medium. It engages the senses and communicates ideas, emotions and a sense of the surroundings. It makes dry text come alive and helps the viewer feel more connected to the subject.

    New developments in video and web technology have recently made web-based video clips a practical reality, as evidenced by the emergence of popular web video sites such as YouTube. ICRISAT is becoming one of the first CGIAR Centers to exploit this potential to support resource mobilization, public awareness and e-learning.

    The great advantage of a web clip is that the web link can be sent to anyone, anywhere in the world for viewing, instead of having to mail them a physical CD or DVD (which takes time to reach them, and which they may not take the trouble to watch, or they may misplace). The link will move through the institutional channels along with your email or document - unlike a physical disk.

    ICRISAT's project development/marketing, communications and information technology teams have developed a protocol to rapidly assemble video clips for these purposes. Just in the last two weeks, three clips have been put together. For example, to view the chickpea clip featuring PM Gaur, click on the picture below or click on the link www.icrisat.org/Investors/Video.htm to see other listed video clips.

    (Tip for the bandwidth-challenged: so it will play smoothly, first click the 'play' arrow, and once it starts to play, click 'pause'… then do some other work or go have a cup of tea to give it time to fully download… then click 'play' again and it will play through without stopping.)

    The intent is to keep the clips short and documentary style, not to compete with Bollywood or Hollywood. We want to convey credible science that makes a difference for the dryland poor. By being short (3 minutes or less) and to the point, these video clips will be accessible to people even with low bandwith connections - leaving a lasting impression without taking up too much of the viewer's valuable time.

    For more information contact r.Navarro@cgiar.org or b.Shapiro@cgiar.org or m.winslow@cgiar.org

    3. Suc-SEED-ing in seed distribution
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    Farmers in many countries in Africa are unable to obtain high quality seed of improved publicly developed varieties due to a lack of effective seed distribution networks. It is time to stop free seed handouts and alternative seed production schemes in preference to delivery through commercial entities. Where poverty limits access to seed through commercial channels, cash or vouchers can be provided to those farmers.

    Implementation of regional variety releases, seed certification, and the development of science-based quarantine pest lists in all three regions of sub-Saharan Africa will encourage investment by the larger seed companies in the development of sustainable seed distribution networks. Typically, these companies concentrate on a few well-established seed crops with broad adaptation that they know farmers will buy (eg, hybrid maize and vegetables). The cost of seed is high because of the companies' high overheads, which include the costs of maintaining crop breeding programs.

    The performance of broadly adapted varieties is limited by the variability in growing conditions. Also, they often do not cater to local tastes. These market niches will best be served by smaller seed companies with lower overheads. These companies would be in a better position to determine local performance and farmer preferences.

    A dealer in Babati, Tanzania
    A dealer in Babati, Tanzania who markets seed of several crops including pigeonpeas.

    The African Seed Trade Association (AFSTA) and the program for the Sustainable Commercialization of Seeds in Africa (SCOSA) support the development of technical agreements for seed trade harmonization, and are committed to supporting their implementation once political approvals have been obtained. At the same time both organizations have embarked on an initiative with 21 countries across sub-Saharan Africa with national seed trade associations to support the development of small and medium-sized seed companies. This is being done through the establishment of Seed Enterprise Enhancement and Development Services (SEEDS) that will include independently run and financially sustainable foundation seed enterprises (FSEs). FSEs will market seed of publicly developed varieties for use by seed companies without their own breeding programs. They will also provide access to seed storage and processing facilities to existing and emerging seed entrepreneurs. SEEDS will provide technical and business development support to seed entrepreneurs who will become the customers of the FSEs, ensuring their sustainability.

    The dual approach of supporting seed trade harmonization and the development of small/medium-sized seed companies will provide farmers with greater choice of improved crops and varieties. This will complement existing farmer managed seed systems that are expected to benefit from being able to access new varieties developed by research.

    For more information contact r.jones@cgiar.org or Justin Rakotoarisaona - Secretary General AFSTA (afsta@afsta.org)

    (SCOSA is implemented by ICRISAT with a grant from USAID. Richard Jones is the Program Manager.)