Association of Seed Yield with Partitioned Lengths of the Reproductive Period in Soybean Genotypes1
- W. D. Hanson2
The total reproductive period (TRP) of the soybean [Glycine max (L.) Merr.] was partitioned into a period for pod initiation and establishment (PEP) and a period for pod-filling and maturation (PFP). The objective was to determine the effects increasing PEP vs. PFP upon seed yield. The study utilized a broad-base population of 140 soybean genotypes selected for determinant growth habit and for full-season maturity within a 2-week period. The selected lines were field tested for 3 years at one location. The lengths for the three reproductive periods and the PFP/PEP ratio had heritabilities between 62 and 86% and would therefore respond to selection. The genotypic correlation between PEP and TRP was +0.77 while the genotypic correlations involving PEP and TRP with PFP were −0.21 and +0.45, respectively. No association was found between PEP and seed yield. Non significant increase in seed yield was associated with genotypes having larger PFP/PEP ratios or longer TRP. Genotypes with larger node numbers or with longer PFP had significantly greater seed yields. Selecting genotypes with both longer TRP and larger proportion of TRP devoted to pod filling relative to pod establishment led to the identification of a unique set of genotypes with high seed yields. The length of PEP in this study was apparently sufficient to establish sink load (number of seeds), but longer PFP was needed to insure photosynthetic availability to the sinks over an extended period of time.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .