title: qEMF3, a novel QTL for the early-morning flowering trait from wild rice, Oryza officinalis, to mitigate heat stress damage at flowering in rice, O. sativa.
abstract: A decline in rice (Oryza sativa L.) production caused by heat stress is one of the biggest concerns resulting from future climate change. Rice spikelets are most susceptible to heat stress at flowering. The early-morning flowering (EMF) trait mitigates heat-induced spikelet sterility at the flowering stage by escaping heat stress during the daytime. We attempted to develop near-isogenic lines (NILs) for EMF in the indica-type genetic background by exploiting the EMF locus from wild rice, O. officinalis (CC genome). A stable quantitative trait locus (QTL) for flower opening time (FOT) was detected on chromosome 3. A QTL was designated as qEMF3 and it shifted FOT by 1.5-2.0 h earlier for cv. Nanjing 11 in temperate Japan and cv. IR64 in the Philippine tropics. NILs for EMF mitigated heat-induced spikelet sterility under elevated temperature conditions completing flower opening before reaching 35°C, a general threshold value leading to spikelet sterility. Quantification of FOT of cultivars popular in the tropics and subtropics did not reveal the EMF trait in any of the cultivars tested, suggesting that qEMF3 has the potential to advance FOT of currently popular cultivars to escape heat stress at flowering under future hotter climates. This is the first report to examine rice with the EMF trait through marker-assisted breeding using wild rice as a genetic resource.
authors.affiliation: NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Hirabayashi
authors.affiliation: Japan International Research Centre for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines The University of Tokyo, Graduate School of Agricultural and Life Sciences, Institute of Sustainable Agro-ecosystem Services (ISAS), 1-1-1 Midoricho, Nishitokyo, Tokyo 188-0002, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kambe
authors.affiliation: International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines.
authors.forename: Ritchel B
authors.initials: RB
authors.lastname: Gannaban
authors.affiliation: University of the Philippines, Los Baños, Laguna, The Philippines.
authors.forename: Monaliza A
authors.initials: MA
authors.lastname: Miras
authors.affiliation: University of the Philippines, Los Baños, Laguna, The Philippines.
authors.forename: Merlyn S
authors.initials: MS
authors.lastname: Mendioro
authors.affiliation: International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines.
authors.forename: Eliza V
authors.initials: EV
authors.lastname: Simon
authors.affiliation: International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Lumanglas
authors.affiliation: International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fujita
authors.affiliation: NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Takemoto-Kuno
authors.affiliation: NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Takeuchi
authors.affiliation: NARO Tohoku Agricultural Research Centre (TARC), NARO, Shimo Furumichi, Daisen, Akita 014-0102, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Kaji
authors.affiliation: NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Motohiko
authors.initials: M
authors.lastname: Kondo
authors.affiliation: NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan Japan International Research Centre for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines.
authors.forename: Nobuya
authors.initials: N
authors.lastname: Kobayashi
authors.affiliation: Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen kihanadai nishi, Miyazaki, Miyazaki 889-2192, Japan.
authors.forename: Tsugufumi
authors.initials: T
authors.lastname: Ogawa
authors.affiliation: NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Ando
authors.affiliation: International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines.
authors.forename: Krishna S V
authors.initials: KS
authors.lastname: Jagadish
authors.affiliation: NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan Japan International Research Centre for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines t.ishimaru@irri.org.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Ishimaru
mesh_terms: D001947:Breeding; D002980:Climate; D035264:Flowers / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D006358:Hot Temperature; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D040641:Quantitative Trait Loci; D013312:Stress, Physiological
keywords: Early-morning flowering (EMF); flower opening time (FOT); global warming; heat stress; quantitative trait locus (QTL); rice (Oryza sativa L.); spikelet sterility.