Managing Global Resources for a Secure Future

2017 Annual Meeting | Oct. 22-25 | Tampa, FL

106389 Impact of the Accumulation of QTLs for Heat Tolerance on Grain Appearance Quality of Rice and Differences Among Cultivars and Years Under Free-Air CO2 Enrichment (FACE).

Poster Number 1430

See more from this Division: ASA Section: Climatology and Modeling
See more from this Session: Global Climate Change and AgMIP: More Recent Observations and Adaptations Poster

Tuesday, October 24, 2017
Tampa Convention Center, East Exhibit Hall

Yasuhiro Usui1, Hidemitsu Sakai2, Takeshi Tokida2, Hirofumi Nakamura3, Hitomi Wakatsuki2, Asako Kobayashi4, Hiroshi Nakagawa5, Mayumi Yoshimoto2 and Toshihiro Hasegawa6, (1)Hokkaido Agricultural Research Center, NARO, Memuro, Kasai, Hokkaido, ., JAPAN
(2)Institute for Agro-Environmental Sciences, NARO, Tsukuba, Ibaraki, Japan
(3)Taiyo Keiki Co. Ltd, Kitaku, Tokyo, Japan
(4)Fukui Agricultural Experiment Station, Fukui, Japan
(5)Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, Tsukuba, Japan
(6)Agro-Environmental Research Division, Tohoku Agricultural Research Center, NARO, Morioka, Iwate, JAPAN
Abstract:
Elevated CO2 (E-[CO2]) significantly reduces appearance quality of rice (Yang et al., 2007; Usui et al., 2014, 2016), by increasing chalky grains, particularly in the back or close to the basal parts of the caryopsiss (WBSG-type chalks). The effects of E-[CO2] were smaller with cultivars that are tolerant to heat for better appearance quality (Usui et al., 2014), suggesting heat-tolerance can also be effective for reducing the negative effects of E-[CO2].

Kobayashi et al. (2007, 2013) have identified two Quantitative Trait Loci (QTLs) that could reduce % of WBSG-type chalky grains under high temperatures; qWB6 and qWB3 derived from Hanaechizen (HE) and developed near isogenic lines (NILs) incorporating one or two QTLs in the susceptible Niigatawase (NW); qWB6 (NIL-6) and the other qWB6 and qWB3 (NIL-6+3). We hypothesized that accumulation of these QTLs could be effective under E-[CO2], To examine their performance under E-[CO2], we conducted Free-Air CO2Enrichment (FACE) experiments at Tsukuba, Ibaraki, Japan for three years.

Percentage of undamaged grains (UDG) of the four genotypes ranged from 47 to 66 % under ambient-[CO2] averaged over three years. UDG of all genotypes was decreased by E-[CO2] by on average 16% point (P < 0.001), largely due to increase % of chalky grains. UDG differed among genotypes (P < 0.001) and years (P < 0.001), with the highest being observed in HE and the lowest in NW. When averaged over two [CO2] treatments for three years, UDG of NIL-6 increased by 9 % point, and NIL-6+3 increased by 15 % point, compared to NW. This suggests that accumulation of heat-tolerant QTLs is effective to reduce the negative effects of E-[CO2] on grain appearance quality of rice. However, year×[CO2] ×genotype interaction for WBSG was significant suggesting the effects can vary under different environments, which needs further study.

See more from this Division: ASA Section: Climatology and Modeling
See more from this Session: Global Climate Change and AgMIP: More Recent Observations and Adaptations Poster