著者

Shigeto Fujimura Kunio Yoshioka Takashi Saito Mutsuto Sato Makoto Sato Yuuki Sakuma Yasuyuki Muramatsu

出版者

日本作物学会

雑誌

Plant Production Science (ISSN:1343943X)

巻号頁・発行日

vol.16, no.2, pp.166-170, 2013 (Released:2013-03-19)

参考文献数

13

被引用文献数

45

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Radionuclides were released into the environment as a consequence of the Fukushima Daiichi Nuclear Power Plant accident that occurred on 11 March 2011. Radiocesium at an abnormal concentration was detected in brown rice produced in paddy fields located in northern part of Fukushima Prefecture. We examined several hypotheses that could potentially explain the excessive radiocesium level in brown rice in some of the paddy fields, including (i) low exchangeable potassium content of the soil, (ii) low sorption sites for cesium (Cs) in the soil, and (iii) radiocesium enrichment of water that is flowing into the paddy fields from surrounding forests. The results of experiments using pots with contaminated soil indicated that the concentration of radiocesium in rice plants was decreased by applying potassium or clay minerals such as zeolite and vermiculite. The obtained results indicated that high concentrations of radiocesium in rice are potentially a result of the low exchangeable potassium and sorption sites for Cs in the soils. Application of potassium fertilizer and clay minerals should provide an effective countermeasure for reducing radiocesium uptake by plants. Radiocesium-enriched water produced by leaching contaminated leaf litter was used to irrigate rice plants in the cultivation experiments. The results indicated that the radiocesium concentrations in rice plants increased when the radiocesium-enriched water was applied to the potted rice plants. This indicated the possibility that the radiocesium levels in brown rice will increase if the nuclide is transported with water into the rice paddy fields from surrounding forests.

著者

Tsutomu Matsui Kazuhiro Kobayasi Hisashi Kagata Takeshi Horie

出版者

CROP SCIENCE SOCIETY OF JAPAN

雑誌

Plant Production Science (ISSN:1343943X)

巻号頁・発行日

vol.8, no.2, pp.109-114, 2005 (Released:2005-09-02)

参考文献数

20

被引用文献数

60

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Anticipated global warming may increase the floret sterility of rice (Oryza sativa L.). For selection of genotypes tolerant to high temperatures during the flowering period, it is important to identify morphological traits associated with tolerance to temperature stress. This study investigated the relationship between the length of dehiscence at the basal part of thecae and the viability of pollination in 18 cultivars of rice subjected to a hot-and-humid condition (37/25°C, day/night, >90% relative humidity) for three days at flowering. Control plants were left under the ambient conditions in a semi-cylindrical house covered with cheesecloth (30% shading; temperature range: 24-35°C). The length of basal dehiscence of thecae and the number of pollen grains on the stigmata were examined with a light microscope after flowering. The length strongly correlated with the percentage of florets having more than 80 pollen grains on the stigmata under the ambient condition (r = 0.72, P r = 0.93, P japonica-type cultivars than in many of the japonica-type cultivars under both conditions. We concluded that the low pollination viability in the non-japonica-type cultivars is associated with their small basal dehiscence on the thecae, and the length of basal dehiscence can be used as a selection marker of high temperature tolerance.

著者

Izumi Oh-e Kuniyuki Saitoh Toshiro Kuroda

出版者

CROP SCIENCE SOCIETY OF JAPAN

雑誌

Plant Production Science (ISSN:1343943X)

巻号頁・発行日

vol.10, no.4, pp.412-422, 2007 (Released:2007-10-19)

参考文献数

33

被引用文献数

122

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The effect of high temperatures on growth, yield and dry-matter production of rice growing in the paddy field was examined during the whole growth period in a temperature gradient chamber (TGC) from 2002 to 2006. Experimental plots, TG1 (control), TG2, TG3 and TG4, were arranged along the temperature gradient (from low to high temperature) in TGC. The mean and maximum air-temperatures in TG4 were 2.0-3.6°C and 4.0-7.0°C higher, respectively, than those in TG1. The plant height was taller and the maximum tillering stage was earlier in TG2, TG3 and TG4 than in TG1. Plant dry weight at maturity in TG2 and TG3 was 12.8-16.4% heavier than that in TG1. In TG4, the increase in the panicle dry weight during the ripening period was smallest and plant dry weight at maturity was 11-16% heavier than that in TG1. The increase in plant dry-matter during the ripening period was smallest in TG4. The decrease in the dry weight of stem and leaf during the ripening period, which represents the amount of assimilate translocation to the panicle, was also larger in TG2-4 than in TG1. The increase in the dry weight of stem in TG2-4 at maturity was also larger than that in TG1. The photosynthetic rate in TG2-4 was up to 35.6% lower than that in TG1 because of the acceleration of leaf senescence. Brown rice yield in TG4 was 6.6-39.1% lower than that in TG1. This yield decline was due to the decrease in the percentage of ripened grains and increase in the percentage of sterile spikelets. The relation between brown rice yield and mean air-temperature during 20 days after heading showed that the brown rice yield declined when mean air-temperature exceeded 28°C.

著者

Mouritala Sikirou Kazuki Saito Enoch G. Achigan-Dako Khady Nani Dramé Adam Ahanchédé Ramaiah Venuprasad

出版者

日本作物学会

雑誌

Plant Production Science (ISSN:1343943X)

巻号頁・発行日

vol.18, no.4, pp.423-434, 2015 (Released:2015-09-19)

参考文献数

89

被引用文献数

37

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In sub-Saharan Africa, the demand for higher rice production continues to grow rapidly. Although there is a huge potential for increasing rice production through expansion of the rice cultivation area in wetlands, iron (Fe) toxicity tends to occur and consequently results in low rice yield. Development and deployment of varieties tolerant to Fe toxicity is one of the practical options to overcome this constraint. Several tolerant varieties have been developed through conventional breeding but progress in breeding has been generally slow mainly due to large genotype × environment interaction and field heterogeneity, which make rice selection ineffective. In addition, there are no valid managed-stress screening protocols which are highly efficient and that can predict rice performance in the diverse target environments of West Africa. Many O. glaberrima accessions have superior tolerance, but only a few of them have been utilized in breeding programs. The known quantitative trait loci (QTLs) related to Fe toxicity, have not been used for marker-assisted selection (MAS), as they gave small effects with a large confidence interval. Accelerating rice breeding efficiency for tolerance to Fe toxicity requires establishment of reliable screening protocols, use of O. glaberrima accessions as donors, identification of large-effect QTLs and MAS using such QTLs. This paper reviews the past and current efforts in West Africa to develop new varieties with superior tolerance to Fe toxicity.

著者

Agarie Sakae Hanaoka Naomi Ueno Osamu Miyazaki Akira Kubota Fumitake Agata Waichi Kaufman Peter B.

出版者

日本作物学会

雑誌

Plant production science (ISSN:1343943X)

巻号頁・発行日

vol.1, no.2, pp.96-103, 1998-06

参考文献数

54

被引用文献数

9

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To evaluate the positive effects of silicon on the stress tolerance of rice plants, we measured the electrolyte leakage (El) from leaf tissue caused by desiccation with polyethylene glycol (PEG) and by high temperature to estimate the integrity of cell membranes. The El caused by 30% and 40% solutions of PEG decreased with the increase in the level of Si in leaves. In leaves of plants grown with 100 ppm SiO_2, the level of polysaccharides in cell walls, which is one of the factors related to tolerance to desiccation, was 1.6-fold higher than that in leaves of plants grown without Si. Ultrastructural observations of leaves revealed that polymerized Si accumulated in the walls of epidermal cells but not in those of the mesophyll cells, which are probably the main sites of El. These findings suggested that silicon in rice leaves is involved in the water relations of cells, such as mechanical properties and water permeability and plays a role in preventing El through the synthesis and functions of cell walls. The El caused by high temperature (42.5℃) was also lower in the leaves grown with Si than in the leaves grown without Si, suggesting the involvement of silicon in the thermal stability of lipids in cell membranes. These results suggested that silicon prevents the structural and functional deterioration of cell membranes when rice plants are exposed to environmental stress.

著者

Koichi Futakuchi Moussa Sié Kazuki Saito

出版者

日本作物学会

雑誌

Plant Production Science (ISSN:1343943X)

巻号頁・発行日

vol.15, no.3, pp.151-163, 2012 (Released:2012-06-29)

参考文献数

80

被引用文献数

23 3

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Oryza glaberrima has mostly been used as a source to improve stress resistance of Oryza sativa. Improvement of this species could be an approach to use its adaptability to local environments in Africa such as multiple resistance to several indigenous constraints. The yield of O. glaberrima was inferior to that of O. sativa under favorable growth conditions but not under unfavorable conditions. Moreover, spikelet number before grain shattering was no less in O. glaberrima than in O. sativa at any fertilizer input levels, suggesting that the yield potential of O. glaberrima is as high as that of O. sativa. Inferior yield of O. glaberrima reported in favorable environments could result from grain shattering enhanced by such growth environments where higher incidence of lodging, which is another undesirable character of O. glaberrima, can occur. Regarding characteristics associated to yield generation, O. glaberrima seemed to possess: higher dry matter production and greater leaf area than O. sativa at least until heading; a lower photosynthetic rate per leaf area but a higher rate against the same leaf nitrogen content in a low content range; higher responsiveness of dry matter, leaf area and leaf photosynthesis to increases in nitrogen inputs; lower water-use efficiency on dry matter accumulation and gas exchange bases; faster progress of leaf senescence during maturity; and faster completion of grain filling during maturity than O. sativa.

著者

Satoko Yasumoto Yasuhiro Yamaguchi Hoshiko Yoshida Morio Matsuzaki Kensuke Okada

出版者

CROP SCIENCE SOCIETY OF JAPAN

雑誌

Plant Production Science (ISSN:1343943X)

巻号頁・発行日

vol.15, no.1, pp.23-31, 2012 (Released:2012-01-17)

参考文献数

24

被引用文献数

3

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We examined 50 cultivars of sunflower (Helianthus annuus L.) for their resistance to birds in a field experiment to find parental plants for breeding. Two cultivars, Armarvirskij3497 (from Russia) and Line-41 (from Myanmar), had bird-resistant characteristics. The laboratory bird feeding test indicated that the factors associated with bird resistance were globular seed shape and heavy seed coat, because the main bird feeding on sunflower, oriental greenfinch Carduelis sinica, is relatively small and have difficulty pecking large and globular seeds. Although the two cultivars had unfavorable characters such as low tolerance to lodging and late maturity, the oil contents of their seeds was not significantly lower than that in the susceptible cultivar (63M80). The present findings suggest that Armarvirskij3497 and Line-41 are candidate parental materials for breeding bird-resistant sunflower cultivars without losing seed oil productivity.

著者

Takuhito Nozoe Takuro Shinano Masaaki Tachibana Akira Uchino

出版者

CROP SCIENCE SOCIETY OF JAPAN

雑誌

Plant Production Science (ISSN:1343943X)

巻号頁・発行日

vol.13, no.3, pp.314-318, 2010 (Released:2010-06-14)

参考文献数

23

被引用文献数

9

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The effects of addition of rice straw to submerged soil on the emergence and growth of rice (Oryza sativa L.) and two paddy weeds (Echinochloa oryzicola Vasing. and Echinochloa crus-galli (L.) Beauv. var. crus-galli) were investigated. Rice straw suppressed both the emergence and growth of transplanted plants depending on the amount of rice straw added (0%, 0.3%, 0.6% and 0.9% (w/w)) in the order of E. crus-galli > E. oryzicola > rice. The severe suppression of emergence and growth of E. crus-galli in the presence of 0.9% rice straw in hydroponic culture was thought to be due to high Fe content of the shoots. Since the difference in tolerance for the toxicity of rice straw is an important factor, the addition of organic materials into soil may help to suppress Echinochloa weeds selectively.

著者

Agarie Sakae Kawaguchi Akiko Kodera Akiko Sunagawa Haruki Kojima Hide Nose Akihiro Nakahara Teruhisa

出版者

日本作物学会

雑誌

Plant production science (ISSN:1343943X)

巻号頁・発行日

vol.12, no.1, pp.37-46, 2009-01

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We measured the concentration of polyols (pinitol, ononitol, and myo-inositol), which are known to have health-promoting and/or disease-preventing functions, in the common ice plant (Mesembryanlhemum crystallinum L.) cultured under salt- and drought-stressed treatments. In NaCl-treated plant the concentration of pinitol/ononitol increased with increasing NaCl concentration in culture solution. The maximal concentration was 3.6mg g^<-1> FW, which was found in the shoot top, followed by small side shoots (2.1mg g_<-1> FW) of mature plants grown with 400mM NaCl for 35 ds. The drought stress also accelerated the accumulation of pinitol/ononitol. The maximal concentration was 1.2mg g^<-1> FW, which was found in the shoot top of plants under the stress for 25 ds. The myo-inositol increased in salt-stressed plants at 3 ds after the start of the treatment and then decreased with the lapse of time during stress. The concentration of polyols in the ice plant was comparable to that in the other species reported to accumulate polyols at high levels. Radical scavenging activity evaluated by DPPH assay was increased two-fold by 400mM NaCl treatment, which was twice as high as that in the leaves of lettuce (Lactuca sativa L.). These results indicated the high potential of the ice plant as a polyol-rich high-functional food.