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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Adaptive Cropping Systems Laboratory » Research » Publications at this Location » Publication #315375
Title: Responses of flowering time to elevated carbon dioxide among soybean photoperiod isolines

Author
item Bunce, James
item CRUZ, WILBERT - INSTITUTO NACIONAL DE INNOVACION AGRARIA (INIA)

Submitted to: American Journal of Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2016
Publication Date: 4/19/2016
Citation: Bunce, J.A., Cruz, W. 2016. Responses of flowering time to elevated carbon dioxide among soybean photoperiod isolines. American Journal of Plant Sciences. 7:773-779.

Interpretive Summary: The increases in yield of soybeans caused by growth at elevated carbon dioxide concentrations vary depending on how much their flowering time is affected by carbon dioxide concentrations. This study identified three genes in soybean known to affect flowering time whose effects on flowering also vary with the carbon dioxide concentration. This research will aid researchers in adapting soybeans to the rising concentration of carbon dioxide in the atmosphere.

Technical Abstract: Previous work indicated that changes in the phenology of flowering in soybeans caused by long-term growth at elevated carbon dioxide may be important to the responses of seed yield to elevated carbon dioxide. In this study we utilized near-isogenic lines of soybeans differing in three genes influencing photoperiod sensitivity to determine which, if any, of these genes affected the response of flowering time to elevated carbon dioxide. Six isolines of Harosoy 63 were grown at ambient (380 ppm) and elevated (560 ppm) carbon dioxide concentrations in air-conditioned glasshouses with natural summer photoperiods, and in indoor chambers with day lengths of 11, 13, 15, and 17 hours. The effect of carbon dioxide concentration on flowering time varied with genotype, and there was also an interaction between carbon dioxide and photoperiod in all genotypes. Elevated carbon dioxide accelerated flowering in some cases, and delayed it in other cases. For all three of the isolines with single dominant genes, elevated carbon dioxide decreased the days to first open flower at the longest photoperiod. At the shortest photoperiod, elevated carbon dioxide delayed flowering in all isolines. The all-recessive isoline had slower flowering at elevated carbon dioxide at both the shortest and the longest photoperiods, and also in the glasshouse. Delayed flowering in the glasshouse was associated with an increased final number of main stem nodes. It is concluded that the E1, E3, and E4 genes each influenced how the time to first flowering was affected by carbon dioxide concentration at long photoperiods.