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

Fast-Tracking and Technology Generation
Elite materials shared with the NARS programs
At the outset of the TL II project, a nursery was compiled of more than 1700 entries, with contributions
from PABRA (eastern Africa – ECABREN; and southern Africa - SABRN), as well as from CIAT headquarters
in Colombia. Some materials had been selected under drought stress previously, especially those
from CIAT-Colombia, while others were derived from regional nurseries, for example, the BILFA (Bean
Improvement for Low Soil Fertility in Africa) nursery composed of selections made under various low
fertility regimes. Others were elite lines from general breeding nurseries.
Given limitations of seed in early stages, a first nursery was planted in KARI, Katumani, Kenya in two
repetitions and short rows. The nursery developed well vegetatively and suffered a moderate level of
terminal drought stress with some late rains. It was, however, a useful nursery as a first evaluation of
drought response of lines, many of which had not been exposed to moisture stress previously. From this
nursery a sub-set of 500 entries were identified for subsequent distribution to other research sites in the
ECABREN region.
The nursery in Katumani served a training purpose as well. Since it was the first nursery planted under
the TL II project, which was the most significant effort in drought resistance to date, the nursery was also
the first significant opportunity to expose regional scientists to physiological sampling techniques for
the evaluation of drought resistance traits. Moreover, it was the first opportunity to test the physiological
parameters that had been identified in CIAT-Colombia as potential indicators of drought resistance. A
description of the training exercise per se is presented in the section on capacity building. With regards
to the results of the physiological analysis, both pod harvest index (seed biomass/pod biomass x 100)
and pod partitioning index (pod biomass at harvest/total shoot biomass at mid-pod fill x 100) proved to
be closely associated with seed yield (Figure 5; Table 9), validating results from Colombia.
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Seed yield (g plant -1 )
25
20
15
10
5
H Mean = 66
KG31-17
KG31-16
KG17-3
KG82-3
KG31-14
KG31-1
KG70-7
KG32-17 KG67-4
KG103-38
KG62-7
KG62-14 KG15-32
KG82-41 KG82-42KG103-22
KG111-9
KG15-37
KG71-43
Mean = 6.5
KG15-7
KG15-31
KG24-31
H
0
40 50 60 70 80 90 100
Pod harvest index (%)
Figure 6-5: The relationship between pod harvest index and seed yield in lines planted under drought stress in
Katumani Station, Kenya.
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Engaging Smallholder Farmers | Tropical Legumes II Project