Effects of Morphological Characteristics Upon Seed Yield in Soybeans¹

Abstract

We measured the effect of several morphological characters upon seed yield in soybeans (Glycine max (L.) Merrill) by transferring each of the characters into a common background by a backcrossing program. Morphological characters studied were small seed, large seed, low number of seeds per pod, high number of seeds per pod, indeterminate growth, glabrousness, curly pubescence, dense pubescence, and narrow leaves. The effects of flower color and pubescence color were also studied. The only characters that influenced yield were indeterminate growth and glabrousness. We considered the lower yield for the indeterminate growth type to be the result of increased lodging and the lower yield of the glabrous line to be the result of early season injury by the potato leaf hopper (Empoasca fabae (Harris)).

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“…Results indicate that selection for increased seed number per area should result in genotypes with greater yield potential and that negative yield component interactions did not occur in our study, as have been reported by others (Hartwig and Edwards, 1970). …”

Effects of Soybean Leaflet Type on Net Carbon Dioxide Exchange, Water Use, and Water-Use Efficiency

“…They attributed reported that higher populations had larger the increased NCE to "better distribution of LAI's, but that yield was not significantly light throughout the canopy" or to the different. supposition that the actively photosyn-Hicks et al (1969), growing Clark and thesizing leaf area could be the same for the Harosoy normal-and narrow-leaflet types two types but represented a higher propor-over a 2-yr peiod, and Hartwig and can.J.prmtsci.56:455-458(Juty1e76) Edwards (1970) …”

“…They attributed reported that higher populations had larger the increased NCE to "better distribution of LAI's, but that yield was not significantly light throughout the canopy" or to the different. supposition that the actively photosyn- Hicks et al (1969), growing Clark and thesizing leaf area could be the same for the Harosoy normal-and narrow-leaflet types two types but represented a higher propor-over a 2-yr peiod, and Hartwig and can.J.prmtsci.56:455-458(Juty1e76) Edwards (1970), growing the cultivar Lee and a near-isogenic line, D49-2491, with narrow leaflets, reported no significant increase in yield with the narrow-leaflet type; however, NCE differences may exist between the leaflet types (Curtis et al 1969) or at different populations and interrow spacings.…”

Use of principal factor analysis in the study of three stem termination types of soybean

“…In all these studies, the indeterminate stem termination type was used because it is the most prevalent type in the northern USA soybean production area . In studies using the indeterminate habit, it was postulated that the increased lodging was one of the main barriers to greater yield increases (WILCOX, 1974;CAMPER & SMITH, 1958 ;HARTWIG, 1957 ;MORAGHAN, 1970 ;COOPER, 1971 ;HARTWIG & EDWARDS, 1970) . BERNARD (1972)suggested the use of the Dt z allele (semideterminate stem termination type) to reduce lodging.…”

“…(1977) postulated that the reduced vegetative-reproductive competition for photosynthate in the more determinate types may also contribute to greater seed yields . A few studies have been conducted using a few semideterminate-indeterminate isoline pairs (HICKS et al ., 1969 ;WILSON & COLE, 1968 ;HARTWIG & EDWARDS, 1970) to determine the influence of certain plant characters on yield .…”