| 概要 |
Low temperatures are a primary limitation to soybean (Glycine max [L.] Merr.) production in cool temperate regions. This study examined the influence of a short cold period during different growth sta...ges on the vegetative and reproductive development of soybean under two changing (increasing and decreasing) daylength conditions. In the increasing daylength experiment, Hutcheson (MG V, determinate cultivar) soybean seedlings that emerged on 10 April in day-lit growth chambers (39°N lat.) were exposed to 8℃ for 48h at VC, V2, V6, or V9 stage. In the decreasing daylength experiment, 'Hutcheson' seedlings that emerged on 15 July were exposed to 8℃ for 48h at VE, VC, V6, or V11 stage. The magnitudes of the changes in daylength were the same for the two experiments, but the direction of the change was opposite. All plants were kept at a 14h thermoperiod of 28/23℃ except during cold treatments. The cold treatments in decreasing daylength conditions delayed R1 and R2 stages by 2 to 3d. The cold treatments imposed at VC, V2, and V9 stages in increasing daylength conditions, however, delayed the R1 stage by 11, 7, and 5d, respectively. The cold treatments delayed V stages, while final height and biomass in the coldtreated plants reached the same or exceeded that of the control plants due to prolonged duration of vegetative growth. Our results indicate that delays in developmental stages were greater when cold temperatures occurred during earlier vegetative stages than during later stages and in increasing than in decreasing daylengths. The reductions in vegetative growth were due in part to the decreases in leaf photosynthesis.続きを見る
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Mendeley出力
KJ00004506892