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Ikeda T.M.,Japan National Agricultural Research Center | Cong H.,Xinjiang Academy of Agricultural Science | Suzuki T.,Hokkaido Central Agricultural Experiment Station | Takata K.,Japan National Agricultural Research Center
Journal of Cereal Science | Year: 2010

Wheat grain hardness is one of the most important phenotypes related to milling, baking and noodle making. Either a mutation of the Puroindoline-a (Pina) gene or Puroindoline-b (Pinb) gene results in hard grain texture. A deletion mutation of Pina (Pina-D1b) is widely distributed among common wheat cultivars. Although North/South American and Australian cultivars and their descendants have a 15-kbp deletion in common, two new types of deletion mutation were found among Asian wheat cultivars. A 4.4-kbp deletion was found in one Korean and two Chinese wheat cultivars beginning at position +371 within the Pina coding region. The other, a 10.4-kbp deletion, was found in three Chinese and nine Japanese wheat cultivars, including five Japanese landraces, beginning at position -5112. It caused the deletion of the full-length Pina gene. These findings suggest that Asian wheat cultivars are genetically distinct from those in other regions. The 4.4-kbp and 10.4-kbp deletion mutants were designated as Pina-D1r and Pina-D1s, respectively. © 2010 Elsevier Ltd. All rights reserved.

Oyoo M.E.,University of Tsukuba | Benitez E.R.,Japan National Agriculture and Food Research Organization | Kurosaki H.,Hokkaido Prefectural Kitami Agricultural Experiment Station | Ohnishi S.,Hokkaido Central Agricultural Experiment Station | And 6 more authors.
Crop Science | Year: 2011

In soybean [Glycine max (L.) Merr.], the dominant allele of the T locus for tawny pubescence is associated with chilling tolerance and is useful for breeding for chilling tolerance. Yellow hilum cultivars with the dominant I allele are preferred in Japan because of a better external appearance. However, the II TT allelic combination darkens the entire seed coat and degrades the external appearance. This study was conducted to investigate the genetic basis of seed coat discoloration using DNA markers. F2 populations derived from crosses between soybean breeding lines 0518BW-8 with slight discoloration and 0734BW-1 with severe discoloration were grown at Memuro in 2003 and Kunneppu in 2007. Seed coat discoloration was measured by the L* value with a two-dimensional colorimeter. A total of 104 simple sequence repeat markers were classified into 20 linkage groups (LGs) spanning 1025 cM in 2003 and 19 LGs spanning 789 cM in 2007. A quantitative trait locus (QTL), discol1, was identified by composite interval mapping in LG A2 (chromosome 8) across years and locations. It had an LOD score of 5.58 explaining 22.0% of phenotypic variance in 2003 and a LOD score of 5.62 explaining 20.2% of variance in 2007. The allele from 0518BW-8 increased the L* value at the QTL. Position of discol1 was close to the I locus corresponding to the chalcone synthase (CHS) multigene family cluster. No sequence differences were observed between the two lines in nucleotide sequences of CHS1 and CHS3 genes and the intergenic region between CHS1 and CHS3. © Crop Science Society of America.

Watanabe T.,Hokkaido University | Enomoto T.,Hokkaido University | Sakurai M.,Hokkaido Central Agricultural Experiment Station | Okamoto M.,Japan National Agricultural Research Center | And 2 more authors.
Journal of Plant Nutrition | Year: 2012

Seedlings of bok choy and tomato were grown in soils with different nitrogen (N) sources [no N (-N), ammonium sulfate (AS), and cattle farmyard manure (CM)]. Comparison between soils treated with -N and CM indicated that the growth and N accumulation in bok choy were significantly enhanced by CM treatment, whereas no difference was found in tomato. In the rhizosphere soils, the highest protease activity was detected in CM treatment irrespective of species. Correlation analysis between rhizospheric protease activity and total N accumulation of plant treated with -N and CM showed a significant positive correlation only for bok choy. The determination of amino acid absorption rate in excised roots indicated that glycine was taken up at a significantly higher rate in bok choy than tomato. This study suggested that at least two possible factors affected the acquisition of organic N: rhizospheric protease activity and ability to absorb amino acids in roots. © 2012 Copyright Taylor and Francis Group, LLC.

Inukai T.,Hokkaido University | Hirayama Y.,Hokkaido Central Agricultural Experiment Station
Journal of Agronomy and Crop Science | Year: 2010

One problem caused by high temperature during ripening in Japonica rice cultivars is a reduction in the amount of starch in the endosperm. To better understand this deleterious effect, we compared the accumulation of the two components of starch, amylose and amylopectin in grains ripened at high (32/28 °C) and low (22/18 °C) day/night temperatures in a set of lines of Japonica cultivar Taichung 65 (T65Wx b) that are near-isogenic for the Wx locus, which encodes granule-bound starch synthase I. In T65Wx b ripened at high temperature, the amount of starch per grain decreased. However, amylose per grain significantly decreased while amylopectin per grain significantly increased. On the other hand, the amount of amylopectin in T65wx, the amylose-free line, did not differ significantly at the high and low temperatures. These data indicated that high temperatures during ripening did not directly affect amylopectin accumulation in T65Wx b and that the reduction in starch in T65Wx b from the high temperatures was caused by a decrease only of amylose. The results for T65Wx a and T65Wx op were also consistent with this conclusion. As a result of the decrease in amylose, the outer region of starch granules from T65Wx b ripened at the high temperatures also had less I 2KI staining. Because this fact might suggest that a portion of amylose was synthesized inside the developing granules after amylopectin synthesis in rice, the effect of amylose deposition in increasing of the density of starch granules is also discussed. ©2010 Blackwell Verlag GmbH.

Matsuo Y.,Bio oriented Technology Research Advancement Institution | Yukumoto O.,Bio oriented Technology Research Advancement Institution | Yamamoto S.,Bio oriented Technology Research Advancement Institution | Noguchi N.,Hokkaido University | Hara Y.,Hokkaido Central Agricultural Experiment Station
Japan Agricultural Research Quarterly | Year: 2013

A tilling robot capable of unmanned rotary tilling with the XNAV navigation system was examined to improve and expand the adaptability of the robot operation. Firstly, as an effective and safe method of using the robot, we proposed a method whereby one operator manually operated a conventional tractor while engaged in the unmanned operation of a robot tractor. As a result of the rotary tilling test, to which the use method was applied, the robot operation was performed without trouble, and one operator could perform the operation with efficiency about 1.8 times superiorto manned operation. Secondly, as an application to farm work other than rotary tilling, operation software for seeding and soil paddling was created based on operation software for rotary tilling. From the results of robot wheat seeding field tests, it was proved that the operation could be successfully performed without trouble and that the conventional two-person work could be done by one operator. The robot soil paddling was also successfully performed with efficient operation paths compared to manned operation.

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