We examined the cultivar difference in the relationship between rice grain yield per solar radiation (Y/R) and air temperature (T) during 40 days after heading using high-yielding cultivars Bekoaoba, Momiroman, Takanari and Hokuriku 193, and control cultivars Akihikari and Nipponbare. The relationship was regressed to a quadratic equation in all cultivars. The maximum Y/R in the equation was higher in Bekoaoba, Takanari and Hokuriku 193 than in the control cultivars. The T value at which the maximum Y/R was obtained was 21.1 in Bekoaoba, a japonica cultivar with a large grain size, and was similar to that in the control cultivars (21.2). In contrast, the T values in the indica cultivars Takanari and Hokuriku 193, and the indica-japonica cross Momiroman was 23.9–24.7, which was higher than in the control cultivars. We concluded that there is a cultivar difference in the response of Y/R to T, and that the optimum temperature during the grain filling period could be 3 degrees higher in Momiroman, Takanari and Hokuriku 193 than in Bekoaoba.
In order to develop a high-yielding culture method for wheat we examined the effects of a higher top to basal nitrogen dressing ratio (HTBD) on the growth and yield of the new lodging tolerant variety “Satonosora” for two years. The reduced basal dressing accompanied with increased top dressing, increased the leaf area index (LAI) after jointing stage, and maintained a high net assimilation rate (NAR) during the late ripening period resulting in increased dry matter production. On the other hand, smaller stem number due to reduced basal dressing and plentiful nitrogen top dressing at the jointing stage were considered to alleviate competition of assimilate and nitrogen among stems and improved stem survival rate, resulting in both larger panicle number and panicle size. High NAR during the late ripening period might also increase the 1000 grain weight. As a result of the increased dry matter production and yield components, a HTBD increased the yield of wheat by 15 - 50%. On the other hand, some problems hindering practical use were clarified; delay of maturation, decline in the apparent quality, excess grain protein content, and acceleration of soil acidification.
An effective fertilizer system is required to achieve high and stable grain protein levels in the wheat cultivar “ChikushiW2” for Chinese noodles. In this study, we examined the fertilizer nitrogen utilization rate (FNU), grain nitrogen content, nitrogen contribution ratio (NCR) of nitrogen fertilizer, and nitrogen fertility using 15N-labeled ammonium sulfate in “ChikushiW2” to determine the nitrogen kinetics in wheat plants. At the early-ripening stage, nitrogen was distributed within the range 78-83% in foliage and 17-22% in grain. Nitrogen translocated from foliage to grain during the middle-ripening stage, with a final grain accumulation of 87-89% of the nitrogen at the late-ripening stage. FNU of the basal dressing was the lowest at 15-20%, increasing to 37-56% for the topdressing at tillering stage with annual variation, and highest at 67-74% for the topdressing at the panicle formation stage and the topdressing at full heading. NCR in the grain nitrogen content was lowest at 4-7% for basal dressing, 10-14% for the topdressing at the tillering stage and topdressing at the panicle formation stage, 24-30% for the topdressing at full heading, and highest at 41-49% for nitrogen fertility. These results indicate that reducing the quantity of low FNU basal dressing, reducing the variable FNU on the topdressing at the tillering stage, and adjusting the timing and quantity of fertilizer application on the high-FNU topdressing at the panicle formation stage, may be effective in enhancing and stabilizing the grain protein content.
In Japan, approximately 80% of soybean is cultivated in upland converted paddy fields. A major problem in soybean production in such fields is the damage due to inadequate water content of soil which depresses the growth and yield of soybean. Recently, a water table control system, called the Farm-Oriented Enhancement for Aquatic System (FOEAS), was developed, and it is important to understand the combined effect of FOEAS and non-tillage cultivation on the growth and yield of soybean plants in farming scale fields. The objective of this study was to clarify the effects of three different cultivation methods (non-tillage narrow cultivation (NN), conventional rotary tillage narrow cultivation (CN), and conventional rotary tillage cultivation (CC)) on soybean growth, yield, and work efficiency in fields with FOEAS. In NN, the yield and nitrogen fixation of soybeans in FOEAS fields were increased by 25% and 24%, respectively, than those in the control field. In NN with FOEAS, due to increased emergence, shoot dry weight at maturity, ripened pod number, seed number, and hundred-seed-weight, the yield was increased by 12% and 69%, compared with that in CN and CC, respectively. The combined yield of NN was increased by 15% and 40%, compared with that in CN and CC, respectively. The combination of NN and FOEAS has some advantages, which include rapid seeding after rainfall, rapid sowing speed, low lodge-index at harvesting period, low weed biomass at harvesting period, and to skip intertillage-ridging. As a result, the seed yield in NN was greater than in either CN or CC, which suggests that the combination of FOEAS and non-tillage cultivation contributes to stable soybean production in Kanto District.
Four kinds of near-isogenic lines (NILs) of Japanese soft wheat with different compositions of high-molecular-weight glutenin subunits, which are controlled by Glu-A1 and Glu-D1 genes were cultivated with different amounts of nitrogen fertilizer applied at flowering time. Using their flour, the proportions of extractable polymeric protein (EPP), extractable monomeric protein (EMP) and unextractable polymeric protein (UPP) to total protein (EPP (%), EMP (%) and UPP (%)) were analyzed by size-exclusion high performance liquid chromatography. In a set of the lines carrying subunits 2+12 at Glu-D1 locus, UPP (%) was not significantly influenced by the presence or absence of the subunit at Glu-A1 locus. On the other hand, in a set of the lines carrying subunits 2.2+12 at Glu-D1 locus, EPP (%) and EMP (%) were increased and UPP (%) was reduced by the absence of the subunit at Glu-A1 locus. The increase in EPP, EMP, and UPP contents against the increase in flour protein content did not vary among the NILs, but in a set of the lines carrying subunits 2.2+12 at Glu-D1 locus, EPP content was greatly increased by the absence of the subunit at Glu-A1 locus, but the UPP content was not increased so much. In a set of the lines carrying subunits 2.2+12 at Glu-D1 locus, the increase in SDS sedimentation volume against the increase in flour protein content was significantly reduced by the absence of the subunit at Glu-A1 locus. This result may be explained by the differences between the increases in EPP and UPP content against the increase in flour protein contents. Thus, in the wheat carrying subunits 2.2+12 at Glu-D1 locus, introduction of a subunit at Glu-A1 locus is expected to improve the dough strength.
We investigated the change in O2 evolution rate and proteins property in the leaf blade of wild species Oryza officinalis, in response to salinity (NaCl) and compared the response with those in salt-sensitive wild O. rufiopgon, salt-tolerant wild O. latifolia, and salt-tolerant variety O. sativa L. cv. Pokkali. Chlorophyll (Chl) content and Chl-based O2 evolution rate in the upper leaves of O. officinalis subjected to salinity stress tended to be higher than those of the control plant. Wild Oryza species had a higher leaf Na+ content than Pokkali, and the Na+ accumulation pattern in O. officinalis and O. latifolia was different from that in O. rufipogon and Pokkali. O. officinalis and O. latifolia accumulated more Na+ in the lower leaves. In all tested plants, there was no correlation between the Chl based O2 evolution rate and Na+ content of upper leaves. We analyzed the leaf blade protein by two-dimensional electrophoresis, and found 53 spots that were over-expressed by salinity stress in O. officinalis compared to that in the control, in which 24 spots were estimated to be localized in the chloroplast, and related to Chl synthesis, photosystem and water-water cycle. These results showed that the O2 evolution rate in the upper leaves of O. officinalis was increased by salinity stress, regardless of the accumulation of Na+. It is suggested that the increased O2 evolution rate per leaf area in the upper leaves is related to over-expression of proteins related to Chl synthesis, photosystem and scavengers of reactive oxygen species.
Growing linseed in winter is an alternative strategy that allows increased diversification of cropping systems in temperate regions. A field experiment was conducted in Kyoto, Japan, during the 2013/2014 and 2014/2015 seasons to study the growth and yield potential of linseed variety Lirina sown in autumn (mid-October, late-October, and early-November) as well as in spring (mid-March and late-March). Autumn-sown linseed plants came into flowering in April and into ripening in the middle of June. Although the seed yield, 310–420 g m–2 in the 2013/2014 season and 270–350 g m–2 in the 2014/2015 season, did not vary with sowing date, late sowing resulted in a decreased number of capsules per inflorescence branch and increased one seed weight. Seed yield of autumn-sown linseed was the same as or slightly higher than that of spring-sown linseed. Autumn-sown linseed had a larger aboveground biomass and, consequently, lower harvest index (24–32%) than spring-sown linseed (31–40%). Autumn-sown linseed plants had more basal branches and produced larger seeds (5.9–6.5 mg per seed) than spring-sown plants (5.3–6.0 mg per seed). Linseed is considered to be a promising autumn-sown crop to diversify cropping systems in warm regions in Japan.
In recent years, cv. “Akimiyabi” which has superior lodging resistance has been released as a medium maturing variety in the Tohoku Region. This study was conducted in Akita and Iwate Prefecture in the Tohoku Region. Akimiyabi was grown singly at a fixed planting density of 26.9 plants/m2 with interrow spaces of 24, 36, and 48, and interhill spaces of 15.6, 10.4, and 7.8 cm, respectively. The relative solar radiation on the ground surface was higher in the 48-cm interrow spacing plot than in the other interrow spacing plots. Shading was severer in the interhill space than in the interrow space. The 48-cm row spacing tended to decrease the number of branches during the flowering period, decreasing LAI. In contrast, the 24-cm row spacing increased the number of nodes on the main stem. Furthermore, the 24-cm and 36-cm row spacing plot showed a larger dry matter production and a larger number of ripening pods; accompanied with significantly higher yield. The seed protein content, inspection grade and seed size were not influenced by planting pattern, and the yield was closely correlated with the ripening pod number, 100-grain weight, and dry matter production. Our results suggest that when Akimiyabi is subjected to late-sowing narrow-row dense cultivation, adjusting the interhall space keeping the row space in the range of 24 cm to 36 cm is preferable to obtain a large growth volume, large pod number, and stable high yield.
Water absorption of flour is one of the most important characteristics for bread making. The farinograph is the most common instrument used for measuring water absorption, but it consumes a large amount of sample. This paper describes the availability of the micro-doughLAB, which is able to measure water absorption with 4 g of flour. In order to compare the water absorption measured using the farinograph with those of the micro-doughLAB, we used flour milled using a Buehler laboratory mill. The water absorption measured using the two instruments showed good agreement indicating that the micro-doughLAB can be used in place of the farinograph. Furthermore, measurement using the micro-doughLAB with an auto-drip system, which allows the addition of water to a sample during the test, reduced the measurement time and amount of sample required for a test. In addition to water absorption, ‘stability’ and ‘softening’ values measured using the micro-doughLAB also well correlated with those measured using the farinograph. The water absorption of flour milled with a Brabender Quadrumat Junior was also measured using the micro-doughLAB. There was a high correlation in water absorption between the flour obtained with the Buehler laboratory mill and that obtained with the Brabender laboratory mill, suggesting that the flour from a Brabender laboratory mill is useful for measurement of water absorption. The results from this survey indicate that, like the farinograph, the micro-doughLAB could provide dough property data for small-scale analysis.