Clair Hershey Cassava at CIAT Annual Program Review 2011 Nairobi, Kenya 10 May 2011

Starches

Hidrolisis Waxy cassava starch granules (AM206-5) Small granule cassava starch (5 G160-13) Small granule cassava starch (5 G160-13)

Glucose content during Simultaneous Saccharification & Fermentation (SSF) of Very High Gravity (VHG) cassava starch for ethanol production Enzyme: Stargen 2; Genencor

Development of double mutants to generate new starch phenotypes Waxy starch (wxwxSGSG) Small Granule WxWx sgsg X F1 (Wxwx SGsg) Self-pollinated or crossed Wx -- SG-- (Normal starch) wx wx SG-- (Waxy starch) Wx -- sgsg (Small granule) wx wx sg sg (Double mutant) 784 S 1 and 188 “F 2 ”, transplanted at the end of 2010, will be harvested and tested by the end of 2011

Progress increasing carotenoids content

Progress in total carotenoids content in cassava roots during the last six years of breeding TCC (µg/ g) Minimum Average Maximum Year y = 2.346x R 2 =

Relevant results from the evaluations made in 2010 Nutritional goal of 15 ug established in 2005 achieved through a rapid cycling scheme Nutritional goal of 15 ug established in 2005 achieved through a rapid cycling scheme

New tools

y = x R 2 = All trans β-carotene Selection index The use of colorimeter (based on 478 observations) for quantifying β-carotene: combining the two relevant parameters in a selection index: (a – (h2*10)

Tolerance to PPD and/or training

First evaluation of post-harvest physiological deterioration in Thailand (Huey Bong) 1. Training on the procedure 2. Introduction of potential sources of tolerance

Gender issues

Most women in Africa are involved in weeding cassava fields (typically for the first two months of the crop) Tolerance to herbicides could have a positive impact on the lives of these women. We are focusing on this trait Women in Africa and LAC are involved in peeling cassava for small processing facilities (i.e. gari,farinha, etc.) Thick peels facilitate peeling, but is undesirable for starch extraction The article “Genetic variability of root peel thickness and its influence in extractable starch from cassava (Manihot esculenta Crantz) roots” to be published in Plant Breeding adress this issue

Better understanding of cassava reproductive biology

New research on reproductive biology of cassava is required for the doubled haploids project Germination of pollen and definition of time required by the pollen tube to reach the micropyle of the ovule Stages of “normal” embryo sac development through the first four weeks after pollination Definition of timing of stigma viability (before or after optimum timing) Pollination of female cassava flowers with castor pollen for the production of (doubled) haploid seeds

Methodology to analyze the growth of pollen tube in un-pollinated female flowers (a-b); one hour after pollination (c-d) and three hours after pollination (e-f) P: pollen grain; PT: pollen tube

Illustrations of the kind of preparations made to understand the development of the embryo sac in cassava

Training Lisette Natalia Ramos (Ph.D. student, wide crosses)

Colored root segregation pattern in an advance breeding family 17 μg 0 μg Plant Resources

Advance breeding family CM8996 for WF R MEcu72 MCol2246 Susceptible MEcu 72 Resistant Plant Resources

Genetic and Genomics - MAS IPP Geranylgeranyl diphosphate Phytoene Lycopene  -carotene (vitamin A precursor)  -carotene (vitamin A precursor) Phytoene synthase Phytoene desaturase Lycopene-beta-cyclase ξ-carotene desaturase  -Carotene Pathway in Plants

Genetic and Genomics - MAS

Cassava SSRs were Silver stained These SSRs are expensive & time consuming to perform Genetic and Genomics - MAS

Electronic data capturing and analysis 96 or 384 well-plates A B B B B B A A A Previously developed genetic maps Genetic and Genomics - MAS

SNP discovery by genome RESCANing RRG NNN N N N Non-Illumina Adapter Barcode Illumina Adapter NNN N N N Barcode Combine at least 48 genotypes per sequencing lane ~2-3X coverage BREAD: Extending Unisexuality and Heterosis to Cosexual Cereal Crops Processes and time-frame for developing breeder ready tools