Effect of day and night temperature on the expression of male sterility of nuclear male-sterile (ms8ms8) soybean

Abstract

In soybean [Glycine max (L.) Merr.], an environmentally stable male-sterility system is one of the requirements to produce large quantities of hybrid seed. Observations of the nuclear male-sterile, female-fertile mutant ms8ms8 in different environments suggested that environmental conditions affected expressivity of the ms8 allele with respect to male sterility. The objective of this study was to determine the effect of day and night temperatures on the expression of male sterility of the ms8 ms8 genotype. Eighteen male-sterile, female-fertile ms8ms8 plants and ten fertile siblings Ms8_ were grown in growth chambers with the following day/night temperatures regimes: 20/20, 24/18, 25/19, 25/20, 27/21, 28/25, 29/17, 29/24, 30/25, 30/30, 32/25, and 35/25°C. Stability of the ms8 allele was affected by the different temperature regimes. Increased sterility of the ms8ms8 genotype was observed when night temperature was 25°C and day temperature varied between 30 and 35°C. We found optimal temperature regimes for sterility expression of the ms8 mutant. These regimes could be used for hybrid seed production when using insect-mediated cross pollination.