Gas Exchange and Transpiration Ratio in Sorghum

Autor: Maria Balota, William L. Rooney, D. T. Rosenow, William A. Payne
Rok vydání: 2008
Předmět:
Zdroj: Crop Science. 48:2361-2371
ISSN: 1435-0653
0011-183X
DOI: 10.2135/cropsci2008.01.0051
Popis: Decreased water availability and increased food demand worldwide require development of more water-effi cient crops. This study was conducted to examine prefl ower transpiration ratio (CO 2 assimilation rate [A]/transpiration rate [E], A:E) in four inbred sorghum [Sorghum bicolor (L.) Moench] lines and 12 of their F 1 hybrids in terms of phenotypic and genetic variation, inheritance (i.e., additive and nonadditive genetic effects), and its relationship to water use effi ciency (WUE) (i.e., the ratio of whole-plant biomass to cumulative transpiration). Lines were selected with contrasting A and A:E in a fi eld trial and then crossed in a full diallel pattern. All hybrids and lines were further analyzed for A, E, A:E, biomass, and WUE in a greenhouse. Variation among hybrids and lines was signifi cant for all traits evaluated. In both environments, the most contrasting lines for A:E were Tx430 and Tx7078. Average A:E was 3.10 mmol CO 2 mol −1 H 2 O for Tx430 and 2.91 for Tx7078. Both Tx430 and Tx7078 had highest A. Genetic effects resulting from general (GCA) and specifi c combining ability (SCA) for A, E, and A:E were signifi cant for all traits. Tx430 had positive and Tx7078 negative GCA effects on A:E. Tx430 hybrids had the highest A:E values, and Tx7078 hybrids the lowest. The A:E ratio was correlated with total biomass and WUE for all crosses. Data suggest that concomitant selection for high A:E and A at prefl owering could result in improved WUE and biomass of mature sorghum.
Databáze: OpenAIRE
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