Effect of seed size on seed yield and on nitrogen fixation related traits in bush bean crosses combining andean and middle american gene pools

Abstract

The literature documents that crosses made between races Mesoaxnerica and Nueva Granada have increased seed yield of large-seed-derived lines by 30%. However, no crosses between these gene pools have been made to improve nitrogen (N2) fixation of coraraon beans (Phaseolus vulgaris L.). In the present research Paragachi and Imbabello, two large seed commercial cultivars from Ecuador, were chosen as recipient parents. Puebla 152, a médium-seed-size landrace from México, and RIZ 21, a CIAT-bred line of small seed size, were chosen as donor parents for high N2 fixation. Following hybridization combining the donor parents and recipient parents, the four populations were advanced to the F3 generation and evaluated. The objectives were to investígate the effect of seed size on seed yield and on N2 fixation- related traits in F3 families, and, to research the potential for selecting large seed, high fixing, high yielding families.