Genetic effects and plant architecture influences on outcrossing rate in soybean

Abstract

Outcrossing rate is an important determinant of cytoplasmic male sterile (CMS) breeding and hybrid seed production for heterosis in soybean. Parental lines with a high outcrossing rate were screened for backcross breeding to obtain the high outcrossing rate maintenance B-lines and sterile A-lines. Application in production practices will help to increase hybrid soybean production. In this study, JLCMS82B and JLCMS89B were selected as parents for the construction of outcrossing rate segregation populations, and the progeny-array approach (PAA) and glyphosate resistant gene markers were used to determine outcrossing rates. We found that: (1) The outcrossing rate between JLCMS82B and JLCMS89B was significantly different; (2) the outcrossing rate of the F2 segregating populations was a quantitative trait, though whether an additive or epistatic effect exists required analysis with a triple test intersection analysis; (3) agronomic traits correlated with outcrossing rate; outcrossing rate was the highest with plant height of about 84 cm, lower number of plant branches, earlier flowering time, larger angle between the branches and the main stem, and with more divergent plant morphology. Correlation analysis between agronomic traits and outcrossing rate can effectively guide the screening of parents with a high outcrossing rate.

Keywords

• soybean
• outcrossing rate
• stem height
• branch number
• initial bloom date