CHARACTERIZATION OF AGRONOMIC TRAITS AND MARKERS OF RECOMBINANT INBRED LINES FROM INTRARACIAL AND INTERRACIAL POPULATIONS OF PHASEOLUS-VULGARIS L

The value of intra- and interracial populations in common bean (Phaseo lus vulgar is L.) needs to be determined in order to create useful gen etic variation for maximizing gains from selection, broadening the gen etic base of commercial cultivars, and making efficient use of availab le resources. Five large-seeded parents of race Nueva Granada (N), two small-seeded race Mesoamerica (M), and one medium-seeded race Durango (D) were hybridized to produce one intraracial (N x N) and three inte rracial(two N x M and one N x D) populations. Seventy-nine F-2-derived F-6 lines randomly taken from each population along with their parent s were evaluated for agronomic traits and markers at Palmira and Popay an, Colombia, in 1990 and 1991. Variation for agronomic traits and for morphological, protein, and isozyme markers was larger in interracial populations than in the intraracial population. Mean seed yield of al l lines as well as yield of the highest yielding line from two interra cial populations were significantly higher than that of the intraracia l population. The highest( greater than or equal to 0.80 +/- 0.15) her itability was recorded for 100-seed weight. Values for seed yield vari ed from 0.19 +/- 0.17 to 0.50 +/- 0.16. Gains from selection (at 20% s election pressure) for seed yield ranged from 3.9% to 11.4%. Seed yiel d was positively associated with biomass yield, pods/m(2), and days to maturity, but harvest index showed negative correlations with these t raits and a positive value with 100-seed weight. Polymorphism was reco rded for phaseolin, lectins, protein Group-1 and protein Group-2 fract ions, and six isozyme loci. Lines with indeterminate growth habit had significantly (P < 0.01) higher seed yield than lines with determinate growth habit in a Redkloud x MAM 4 population. Also, 23 other associa tions of markers with agronomic traits other than seed yield were reco rded. Of these associations, lines with T phaseolin, the Diapl(2) alle le, and lilac flower color tended to possess greater seed weight.