Adjusting the Phenology of Determinate Soybean Segregants Grown at High Latitude
- G. Saindon,
- H. D. Voldeng and
- W. D. Beversdorf
Breeding for determinate (dt1) cnltivars has been proposed as a way of reducing lodging in soybean [Glycine max (L.) Merr.]. However, determinate lines having maturity, acceptable for high latitude areas often exhibit insufficient plant height. The possibility of obtaining early-maturing, nondwarf determinate soybean ptaats by using a combination of alleles at loci controlling stem termination and maturity was explored. Progeny test data for the E1 maturity locus of six experimental lines indicated that the indeterminate Evans-e3, Harosoy-e3, X2403 (Evans-e3e4), and X2396 (Harosoy-e3e4) homozygous for e1, whereas the determinate PI 317334A and PI 445831 are homozygous for E1. PI 445831 and PI 317334A (both homozygous for e3 e4) wereach crossed to Evans-e3 real Harosoy-e3 (both homozygous for e3 E4) and to X2403 and X2396 (both homozygous for e3 e4). Days to RI and R7 stages, recorded in eight populations of F2 plants grown in the field at Ottawa (45° 25′ N, 75° 42′ W), revealed that phenotypes were generated across a large array of maturities in populations where the E1 and E4 loci jointly segregated. The El and E4 loci did not act ndditively on flowering and maturity in plants homozygous for e3. As a result of this nonadditive effect, early-maturing determinate phenotypes adapted to the short growing season of the latitude were isolated in populations derived from PI 317334A. These genotypes were not dwarf and their putative genotype is E1E1 e3e3 e4e4 dt1dt1.
Copyright © 1990.