Soybean Fibrous Root Heritability and Genotypic Correlations with Agronomic and Seed Quality Traits
- Vincent R. Pantalone ,
- Joseph W. Burton and
- Thomas E. Carter
A major obstacle in selecting for increased soybean [Glycine max (L.) Merr.l seed protein concentration lies in the negative genetic correlation between seed yield and protein. The plant introduction PI 416937 has extensive fibrous root surface area that contributes to increased nitrogen fixation. PI 416937 also exhibits drought tolerance. It may be an important breeding line in the Southeast region of the USA, which is vulnerable to drought stress during soybean development. The development of breeding lines with superior root systems may be an effective way of stabilizing soybean production in drought-prone regions. The objectives of this study were to estimate the heritability of phenotypic root score and genotypic correlations between root score and seed yield, seed protein concentration, seed oil concentration, and seed weight. A peanut inverter was used to excavate F2 plants of a population from the cross ‘Lee 74’ × PI 416937. The root systems were scored visually, based on the percentage of fibrous root area. F2:3 and F2:4 rows were grown at two locations, Clayton and Kinston, NC, in 1992 and 1993. Ten plants per plot were evaluated for root score at the R7 stage of development. Heritability estimates for root score were 0.39 on an entry-mean basis from testing in 2 yr and two locations, and 0.24 from a realized heritability estimate. The genotypic correlation between root score and seed protein concentration was positive (rG = 0.42). This is encouraging and suggests that PI 416937 is a valuable germplasm resource for developing high protein, high yielding breeding lines.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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