|CHEN, CHEN - Chinese Academy Of Sciences|
|JIANG, QIAN - Chinese Academy Of Sciences|
|ZHU, CHUNWU - Chinese Academy Of Sciences|
|ZHANG, JISHUANG - Chinese Academy Of Sciences|
|ZHU, JIANGUO - Chinese Academy Of Sciences|
|LIU, GANG - Chinese Academy Of Sciences|
|NI, KANG - Chinese Academy Of Sciences|
|SENEWEERA, SAMAN - University Of Southern Queensland|
Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2015
Publication Date: 5/1/2015
Citation: Chen, C., Jiang, Q., Ziska, L.H., Zhu, C., Zhang, J., Zhu, J., Liu, G., Ni, K., Seneweera, S. 2015. Seed vigor of contrasting rice cutivars in response to rising CO2. Field Crops Research. 178:63-68.
Interpretive Summary: Carbon dioxide, CO2, in addition to begin a greenhouse gas, can also stimulate the growth of numerous plant species, including rice, an important cereal crop globally. Previous studies have shown that some rice varieties respond more to the increase in CO2 than others, but the basis for the different responses is not known. In this study we investigated whether rising CO2, by altering seed vigor and germination rates, was the basis for the different responses to CO2 observed among rice varieties. We measured seed quality in six rice lines that differed in the growth and reproductive response to rising CO2. Although increasing CO2 did reduce seed nitrogen and protein concentration, it did not affect seed germination or seed biology in a way that could explain the differential response to CO2 among different rice varieties. Although additional data from more rice varieties is needed to confirm these results, this study suggests that the differential response of rice varieties to rising CO2 is not attributable to the direct effect of CO2 on seed vigor and germination rates. This information will be of interest to agronomists, breeders, and climate change scientists.
Technical Abstract: Although a number of studies have shown that rising atmospheric carbon dioxide concentration, [CO2], can differentially affect the growth and yield potential of rice (Oryza sativa L.) cultivars, there has been no attempt to determine if the response is associated with changes in seed vigor, an essential aspect of crop establishment. Because previous investigations have shown that [CO2] can change the grain structure and quality of rice seed, we hypothesized that [CO2] would decrease vigor via decreased germination rates. To test this hypothesis, we used an in situ, Free-Air CO2 Enrichment (FACE) system to assess seed quality in six rice cultivars that differed in their growth and reproductive response to rising [CO2]. Elevated [CO2] had no effect on seed hull thickness or seed specific gravity, but did significantly reduce total nitrogen and protein concentration for all cultivars. Despite the changes in grain physical and chemical traits associated with germination, no clear indication of quantitative effects of elevated [CO2] on rice germination was found.