|Smith, Marianne - IOWA STATE UNIVERSITY|
|Horner, Harry - IOWA STATE UNIVERSITY|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 3, 2000
Publication Date: N/A
Interpretive Summary: Temperature and the number of hours of light and of dark that plants receive (called photoperiod) influences the vegetative growth and reproductive growth of many plants. Soybean is especially sensitive to photoperiod changes. In fact commercial soybean varieties are categorized by their photoperiod requirements from very early (Canada) to very late (tropical regions). We investigated the effect of temperature and photoperiod on the stability of male sterility of a cms soybean. cms refers to cytoplasmic male sterility and this sterility only occurs in the female not the male. Extremes of temperature and photoperiod had no effect on male sterility, i.e. all cms plants remained male sterile at all the tested temperature and photoperiod conditions. The plants did experience differences in vegetative growth as expected. The stability of the cms system indicates that its use in plant breeding to produce hybrid seed is justified. Commercialization of this cms soybean line with related technology could result in 10% or more yield increase.
Technical Abstract: The objective of this study was to subject cytoplasmic male-sterile (cms) BC5F1 plants, from a cross of a Chinese Glycine max wild-type soybean with a Chinese wild annual soybean G. soja, and controls, to a variety of different temperature and photoperiod treatments to test whether cms is stable under various environmental conditions. Plants were grown in growth hchambers under controlled temperature, photoperiod, and irradiance regimes until pod set, and then they were transferred to a glasshouse until they matured. Plants were evaluated for time of anthesis after photoperiod induction (h light/11 h dark) and fertility/sterility. Another squash and pod set data showed that sterility of the cms line was stable under all environmental conditions tested, whereas fertility-restored control plants remained fertile. Extreme environmental conditions led to delayed floral induction and/or stunted growth.