Final version of Tropical Legumes II Project Report for Phase 1 - icrisat

Number of degree training students (MSc, PhD) completed or ongoing
Our original milestone called for two PhD candidates to advance in their studies and two MSc candidates
to complete their degrees. In addition to this, it was possible to give partial operational support to two
other students, only one of whom finished his degree. At one time we saw the opportunity to stretch
funding to include another PhD candidate in place of one of the MSc candidates, but that person
withdrew his candidacy when an opportunity arose to study in New Zealand, and the funding was
used for an MSc as originally planned. Degree training proved to be an excellent bridge between the
TL I and TL II projects, as several theses were derived from topics directly from TL I , or closely akin to
themes developed there.
Degree training: scholarships
Berhanu Amsalu of EIAR, Melkassa Research Center in Nazareth, Ethiopia is in his last year of PhD
study at the University of Pretoria, Republic of South Africa, with expectations to finish in late 2011.
Berhanu is studying aspects of nitrogen fixation in common bean under drought, looking at the activity
of protease inhibitors as indicators of nodule health. It is known that as legumes come under stress,
nodules degrade under the influence of proteases that break down proteins including nitrogenase. Lower
protease activity (or conversely, more activity of protease inhibitors) could be an indicator of nodule
health, especially under stress when fixation tends to decline. Berhanu initiated with a greenhouse
study of soybean (thus, his thesis and his results could eventually be relevant for BNF of soybean under
stress as well). Subsequently Berhanu continued greenhouse studies on common bean with the high
nitrogen fixing line BAT 477, the poor fixer DOR 364, and their progenies. He also carried out a field
trial with the same genotypes. Finally he executed a trial looking at the interaction of drought x P levels,
under the hypothesis that the protease degradation of nodules is a generalized mechanism in response
to stress, and that BAT 477 will show low activity of proteases under both moisture stress and low P
stress. He currently is assaying protease activity to test this hypothesis.
Godwill Makunde of Zimbabwe is completing one more cycle of field work in his home country, and
then will return to Free State University, RSA, to analyze his data and to write his thesis. He should be
finishing toward the end of 2011. His university expenses have been financed by TL-II, and his research
has been supported mostly by TL-I. His research involves a physiological analysis of the TL I reference
collection, which is a sub-set of 202 accessions from the CIAT core collection, re-selected based on
detailed molecular analysis and employing a more focused attention on race Durango from Mexico,
and on Andean types. These two groups were emphasized with the philosophy that race Durango
might yield new sources of drought resistance, and the Andean types were those that were most in
need of improvement, and that it would be useful to take advantage of whatever variability that exists
among the Andeans. Godwill will have two seasons’ data from Zimbabwe, and three seasons’ data
from Colombia under varying degrees of moisture stress. Godwill himself executed the physiological
sampling and analysis of the reference collection in CIAT-Colombia under intense terminal stress. He
also conducted root phenotyping studies at CIAT-Colombia on selected genotypes from the reference
collection. With data from several sites and seasons, Godwill will perform an analysis of association
mapping using SNP data generated at UC-Davis in the group of Doug Cook. This will be the first such
attempt in common bean.
Felix Waweru graduated from the University of Nairobi, Kenya with an MSc degree in a study shared
with TL I. Felix carried out a field phenotyping of recombinant inbred lines (RILs) of a cross of BAT 881
x G21212. BAT 881 is sensitive to abiotic stress, and G21212 is relatively resistant. G21212 was first
recognized as tolerant to low soil P, and subsequently it also proved to have a good response to drought
and aluminum toxicity. It presents excellent remobilization of photosynthate to grain under stress, and
this appears to be its mechanism of multiple stress resistance. A genetic map exists for this population,
and the data of Felix could help elucidate the inheritance of this trait. Felix also analyzed a regional
collection of landraces and lines, compiled under TL I.
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