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Tanamachi K.,Kyushu University | Miyazaki M.,Fukuoka Agriculture and Forestry Research Center | Matsuo K.,Kyushu University | Suriyasak C.,Kyushu University | And 4 more authors.
Plant Production Science | Year: 2016

High-temperature stress during the grain-filling stage reduces grain quality of rice, and this is a serious problem in Japan, especially in the Kyushu region. To solve this problem, various heat-tolerant cultivars have been bred, such as ‘Nikomaru’, ‘Kumasannochikara’, ‘Genkitsukushi’, ‘Sagabiyori’, and ‘Otentosodachi’. When cultivated under high temperature after flowering, these heat-tolerant cultivars had lower percentages of chalky grains than in the heat-sensitive cultivar ‘Hinohikari’. All the heat-tolerant cultivars markedly decreased the nonstructural carbohydrate content in the stem under the high temperature compared to control condition during early grain-filling stage, which is considered to be a common trait of heat tolerance. Notably, ‘Sagabiyori’, ‘Genkitsukushi’, and ‘Nikomaru’ maintained a nucellar epidermis at 17 days after flowering (DAF) under high temperature, whereas the nucellar epidermis disappeared in ‘Hinohikari’. In addition, the expression of AGPS2b, thought to be a rate-limiting enzyme in starch synthesis, in ‘Kumasannochikara’, ‘Otentosodachi’, and ‘Nikomaru’ did not decrease under high temperature, whereas ‘Hinohikari’, ‘Sagabiyori’, and ‘Genkitsukushi’ could not maintain expression of the gene at 17 DAF. Moreover, the expression of Amy3E, a starch-degradation-related gene considered to induce grain chalkiness, in ‘Kumasannochikara’ at 17 DAF was not increased by high temperature. These results suggest that the heat-stress-tolerant cultivars have various mechanisms for dealing with high-temperature stress. © 2016 The Author(s). Published by Taylor & Francis.

Mita T.,Japan National Agriculture and Food Research Organization | Nishimoto H.,Aichi Agricultural Research Center | Shimizu N.,Fukuoka Agriculture and Forestry Research Center | Mizutani N.,Japan National Agriculture and Food Research Organization
Applied Entomology and Zoology | Year: 2014

Trissolcus basalis (Wollaston), a cosmopolitan egg parasitoid of Nezara viridula (Linnaeus), was newly discovered in Central Honshu and Kyushu, Japan. The morphological characteristics useful to identify Tr. basalis from other species of Trissolcus occurring in Japan were indicated. Partial mitochondrial COI gene sequences of samples obtained from Aichi to Fukuoka Prefectures almost completely correspond to those obtained from overseas retrieved from the DDBJ/Genbank database. The sequence of Tr. basalis was different by 13–17 % from Trissolcus species compared and Telenomus turesis (Dalman). Further field research is needed to clarify the impact of Tr. basalis on local parasitoid guilds. © 2014, The Japanese Society of Applied Entomology and Zoology.

Wada T.,Fukuoka Agriculture and Forestry Research Center | Miyahara K.,Fukuoka Agriculture and Forestry Research Center | Sonoda J.-Y.,Kagoshima Prefectural Institute for Agricultural Development | Tsukaguchi T.,Ishikawa Prefectural University | And 12 more authors.
Breeding Science | Year: 2015

There is increasing evidence that global warming affects the development of rice. High temperatures during ripening increase the ratio of undesirable chalky grains followed by deteriorating grain appearance quality. In order to detect quantitative trait loci (QTLs) controlling the occurrence of white-back and basal-white chalky grains of brown rice, QTL analysis was performed using recombinant inbred lines derived from a cross between two strains, ‘Tsukushiroman’ (sensitive to heat stress) and ‘Chikushi 52’ (tolerant of heat stress). The F7 and F8 lines were exposed to heat stress during the ripening period in two locations, Fukuoka and Kagoshima, in Japan. QTLs for white-back grains and basal-white grains were detected on chromosomes 1, 3, and 8, and those for basal-white grains were detected on chromosomes 2, 3, and 12. QTLs on chromosome 8 for whiteback grains were shared in the plants grown in both locations. Near-isogenic lines (NILs), which harbored a segment from ‘Chikushi 52’ on chromosome 8 with the genetic background of ‘Tsukushiroman’, showed relatively lower ratios of white-back grains than ‘Tsukushiroman’. Therefore, insertion of the ‘Chikushi 52’ genomic region of the QTL on chromosome 8 can improve the quality of rice when it is grown under heat stress conditions. © 2015, Japanese Society of Breeding. All rights reserved.

Suyama T.,Fukuoka Agriculture and Forestry Research Center | Tanigawa T.,Fukuoka Agriculture and Forestry Research Center | Yamada A.,Fukuoka Agriculture and Forestry Research Center | Yamada A.,Fukuoka Prefecture Tagawa Agricultural Extension Center | And 5 more authors.
Horticulture Journal | Year: 2015

Species belonging to the Hydrangea genus, including Hydrangea macrophylla (Thunb.) Ser. and H. serrata (Thunb.) Ser., have inflorescences consisting of decorative and non-decorative flowers. The generation of double-flowered decorative flowers is an important objective for hydrangea breeders. This study aimed to elucidate the inheritance pattern of double flowers in H. macrophylla and H. serrata. Double-flowered progeny were obtained from three out of eleven crosses between double-flowered cultivars as the seed parent and single-flowered cultivars or lines as the pollen parent. When double-flowered progeny were produced using three cross combinations, the progenitor of both double-flowered cultivars and single-flowered lines was the double-flowered cultivar ‘Jogasaki’. In progeny obtained from these crosses, the segregation ratio of doubleand single-flowered types was 1:1. Conversely, all progeny obtained from a cross in which the double-flowered cultivar as the seed parent differed from the seed parent of the single-flowered line as the pollen parent bore single flowers, and double-flowered progeny were not produced. Double-flowered progeny were obtained in two out of four crosses among the single-flowered lines; the segregation ratio of double- and single-flowered types was 1:3. The single-flowered lines shared the same seed parents, ‘Jogasaki’ or ‘Sumidanohanabi’. These results indicate that the double-flowered phenotype of decorative hydrangea flowers may be a recessive characteristic controlled by a single major gene. In addition, these results indicate that double-flowered progeny can be obtained when a pair of recessive genes are identical. © 2015 The Japanese Society for Horticultural Science (JSHS), All rights reserved.

Mori M.,Fukuoka Agriculture and Forestry Research Center | Hayashi T.,Fukuoka Agriculture and Forestry Research Center | Isozaki Y.,Fukuoka Agriculture and Forestry Research Center | Takenouchi N.,Japan National Agriculture and Food Research Organization | Sakatani M.,Japan National Agriculture and Food Research Organization
Journal of Reproduction and Development | Year: 2015

In this study, the effect of heat shock on frozen-thawed blastocysts was evaluated using in vitro-produced (IVP) bovine embryos. In experiment 1, the effects of 6 h of heat shock at 41.0 C on fresh blastocysts were evaluated. HSPA1A expression as a reflection of stress was increased by heat shock (P < 0.05), but the expressions of the quality markers IFNT and POU5F1 were not affected. In experiment 2, frozen-thawed blastocysts were incubated at 38.5 C for 6 h (cryo-con) or exposed to heat shock at 41.0 C for 6 h (cryo-HS). Then, blastocysts were cultured at 38.5 C until 48 h after thawing (both conditions). Cryo-HS blastocysts exhibited a decreased recovery rate: HSPA1A expression was dramatically increased compared with that in fresh or cryo-con blastocysts at 6 h, and IFNT expression was decreased compared with that in cryo-con blastocysts at 6 h (both P < 0.05). Cryo-con blastocysts at 6 h also exhibited higher HSPA1A expression than fresh blastocysts (P < 0.05). At 48 h after thawing, the number of hatched blastocysts and blastocyst diameter were lower in cryo-HS blastocysts (P < 0.05). Cryo-con blastocysts showed lower POU5F1 levels at 48 h than fresh, cryo-con or cryo-HS blastocysts at 6 h (P < 0.05), but their POU5F1 levels were not different from those of cryo-HS blastocysts at 48 h. These results indicated that application of heat shock to frozen-thawed blastocysts was highly damaging. The increase in damage by the interaction of freezing-thawing and heat shock might be one reason for the low conception rate in frozen-thawed embryo transfer in summer. © 2015 by the Society for Reproduction and Development.

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