Improvement of nutritional quality must go hand in hand with improvement of agronomic characters. Data from 2005 in Mesoamerican bush beans demonstrate an ample advantage over checks in drought tolerance (200% or more yield under very difficult conditions!) while increasing iron concentration by about 20% in several lines. Black beans with higher minerals and drought tolerance were also resistant to angular leaf spot and BGYMV. While increases attained in minerals were real, this was still a relatively modest gain. Thus, in the next cycle of crosses, more care was taken to obtain mineral data on F_1.3 families across sites before making individual plant selections.

Compared to the first cycle selections, this group expressed much better gain in iron and zinc (as much as 50 and 30% respectively), suggesting that the modifications in the selection procedure were effective for recovery of higher minerals. In small seeded heat tolerant climbers, derived from popular African cultivars G2333 and G685 and tested across sites, the range in seed iron content was from 36 ppm to 104 ppm for iron content with averages of 62.6 ppm for Palmira and 55.90 for Darien. These materials will undoubtedly be very popular in mid-to-low altitude production areas in Africa.

Contact: Stephen Beebe and Matthew Blair