Panicle Formation Research Articles

In vitroImprovement in Regeneration Potentiality by Using Kinetin Primed Seeds of Rice (var. MTU-7029)

The present study deals with the somatic embryogenesis of rice (var. Swarna/MTU-7029), where a comparative characterization of the calli were made, using dehusked, sterilized whole seeds, obtained from kinetin primed and nonprimed one. For callus induction 30gL−1 sucrose + 1gL−1 casein hydrolysate and 30gL−1 maltose + 1gL−1 casein hydrolysate were added in MS medium separately which was supplemented with 2 mgL−1 2,4-D. In the regeneration medium (MSR1 to 6) different concentration of BAP, kinetin and NAA (2:0:1, 3:0:1, 4:0:1, 2:3:1, 3:2:1 and 4:1:1 mgL1) were used respectively. For regeneration of roots half strength MS basal medium was used supplemented with IBA 1mgL−1, sucrose 2% (w/v) and 0.8% (w/v) agar. Different concentrations (2.5 and 5 ppm) of the kinetin used for priming before using the seeds for inoculation in the culture medium, showed promising results regarding the total callus induction percentage, total embryogenic calli percentage, fresh and dry weights, proline content, nitrate reductase and superoxide dismutase activities in respect to non primed one. 2.5ppm (T2) kinetin primed seeds showed best result than 5ppm(T3) kinetin primed seeds. Among the entire regenerated medium, MSR6 showed highest regeneration (%), number of shoots regenerated per calli and recovery of plantlets from 50 tubes in all the treatments. The plantlets recovered from inoculated primed seeds calli have more number of roots in respect to non-primed one. Plantlets obtained from primed and non-primed control seeds were hardened in polyhouse and studied in detail upto the formation of panicle. On the basis of the above data T2 was found better than control.

Prediction Number of Spikelets by Growth Diagnosis on Panicle Formation Stage for Ear Manuring in Rice Cultivar 'Koshihikari'

Prediction Number of Spikelets by Growth Diagnosis on Panicle Formation Stage for Ear Manuring in Rice Cultivar 'Koshihikari'

Tillering Characteristics and Its Relationship with Population Productivity of Super-high Yield Rice Population of Yongyou 12

We comparatively studied tillering and panicle formation characteristics of super-high and high yield populations formed by the regulation of cultivation measures using indica-japonica super rice Yongyou 12 transplanted by seedlings with tillers at the age of four leaves with one leaf bud. The results showed that yield from tillers and its contribution rate to total yield were 11.53 t ha–1 and 87.77% for super-high yield population, and 10.59 t ha–1 and 87.40% for high yield population. Super-high yield population had higher yield from primary and secondary tillers which were the major part contributed to total yield, the contribution rate to total yield of primary tillers for super-high yield population was slightly lower than that for high yield group, while that of secondary tillers, the contribution rate to total yield was higher in super-high yield population than in high yield population. For super-high yield population, the primary tillers emerged from leaf 1 to leaf 9 on main stem, among them the tillers from leaf 4 to leaf 7 had higher emerging rate and more panicles, secondary tillers emerged and earbeared mainly in 1/3, 2/3, 3/3, 2/4, 1/5. High yield population had higher emerging rate of triple tillers but lower panicle rate than super-high yield population, its primary tillers emerged and earbeared mainly in 4/0 to 7/0 while in the secondary tillers 1/3, 2/3, 3/3. Super-high yield population had higher mean values in panicle length, panicle weight, total grain number and grain density than high yield population, but seed-setting rate was slightly lower.

Genetic analysis of an elite super-hybrid rice parent using high-density SNP markers.

BackgroundWith an increasing world population and a gradual decline in the amount of arable land, food security remains a global challenge. Continued increases in rice yield will be required to break through the barriers to grain output. In order to transition from hybrid rice to super-hybrid rice, breeding demands cannot be addressed through traditional heterosis. Therefore, it is necessary to incorporate high yield loci from other rice genetic groups and to scientifically utilize intersubspecific heterosis in breeding lines. In this study, 781 lines from a segregating F2 population constructed by crossing the indica variety, “Giant Spike Rice” R1128 as trait donor with the japonica cultivar ‘Nipponbare’, were re-sequenced using high-throughout multiplexed shotgun genotyping (MSG) technology. In combination with high-density single nucleotide polymorphisms, quantitative trait locus (QTL) mapping and genetic effect analysis were performed for five yield factors (spikelet number per panicle, primary branches per panicle, secondary branches per panicle, plant height, and panicle length) to explore the genetic mechanisms underlying the formation of the giant panicle of R1128. Also, they were preformed to locate new high-yielding rice genetic intervals, providing data for super-high-yielding rice breeding.ResultsQTL mapping and genetic effect analysis for five yield factors in the population gave the following results: 49 QTLs for the five yield factors were distributed on 11 of 12 chromosomes. The super-hybrid line R1128 carries multiple major genes for good traits, including Sd1 for plant height, Hd1 and Ehd1 for heading date, Gn1a for spikelet number and IPA1 for ideal plant shape. These genes accounted for 44.3%, 21.9%, 6.2%, 12.9% and 10.6% of the phenotypic variation in the individual traits. Six novel QTLs, qph1-2, qph9-1, qpl12-1, qgn3-1, qgn11-1 and qsbn11-1 are reported here for the first time.ConclusionsHigh-throughout sequencing technology makes it convenient to study rice genomics and makes the QTL/gene mapping direct, efficient, and more reliable. The genetic regions discovered in this study will be valuable for breeding in rice varieties because of the diverse genetic backgrounds of the rice.Electronic supplementary materialThe online version of this article (doi:10.1186/1939-8433-6-21) contains supplementary material, which is available to authorized users.

Studies on Floral Biology of Seven Litchi (Litchi chinensis Sonn.) Cultivars

Floral biology of seven litchi cultivars (China, Deshi, Elaichi, Kasba, McLean, Nafarpal and Piazi) was studied. Cultivar Deshi showed panicle formation on 2nd January, while panicle initiation was early (10th February) in cv. Piazi. Flowering duration varied between 13±4 days in 'China' and 30±3 days in 'Piazi'. Male:hermaphrodite flower ratio was maximum in 'Piazi' (5.8:1) and minimum in 'China' (2.74:1). In general, anthesis was maximum between 7 and 8 AM, while, anther dehiscence was maximum between 9 and 10 AM. Percentage of viable pollen varied between 82.14% in cv. Elaichi and 91.38% in cv. Piazi Pollen germination was higher in 15% sucrose solution.

A near isogenic line of rice carrying chromosome segments containing OsSPS1 of Kasalath in the genetic background of Koshihikari produces an increased spikelet number per panicle

The aim of this study was to analyze the yield characteristics of a near isogenic line (NIL) that carried chromosome segments containing OsSPS1, a gene encoding sucrose phosphate synthase (SPS), of the indica cultivar ‘Kasalath’ in the genetic background of the japonica cultivar ‘Koshihikari’ (designated as NIL-SPS1). To determine the growth and yield characteristics of NIL-SPS1, we compared NIL-SPS1 with the parental cultivar, Koshihikari, from field trials conducted over the course of a three-year period. The SPS activity in the source leaves of NIL-SPS1 was higher than that of Koshihikari at the transplanting and panicle formation stage. However, at the heading stage, no significant differences were observed in the leaf SPS activities. An analysis of the yield components revealed that the spikelet number per panicle in NIL-SPS1 was 38–47% higher than that in Koshihikari, mainly due to the larger number of secondary rachis branches. In the substituted chromosome region of NIL-SPS1, no quantitative trait loci (QTLs) for the number of secondary rachis branches have been reported, so far. Collectively, these results suggest that the chromosome segments of Kasalath in NIL-SPS1 contain a new putative QTL for the number of secondary rachis branches. Analysis of the distribution of dry matter revealed that a higher source-leaf SPS activity in NIL-SPS1 at the panicle formation stage might promote the distribution of dry matter to panicles and increase the number of secondary rachis branches.

비닐하우스 재배 수수의 그루터기 재생 및 양분흡수 특성

This study was conducted to get the basic information for absorb enhancement of accumulated soil nutrients in plastic film house. The grain sorghum (Sorghum bicolor L.) was sowing in plastic film house which soil nutrient accumulated moderately and was cutting at major growth period of sorghum. We were analyzed the regrowth pattern, biomass due to cutting time and amount of plant nutrient of grain sorghum. The obtained results were as follows. The heading date after cutting of sorghum in plastic film house was came to about 35 days. The accumulated of plant height were the longest as 379.4 cm in cutting at milk stage. The total biomass of sorghum in cutting at heading stage was 1.73 ton in cutting at heading stage. The high grain yields were produced with non-cutting and cutting at 10 leaves stage as 75~113 kg but the lowest grain yields were the cutting plots at booting stage as below 24 kg . The content of nutrient in sorghum plant was low as progress of growth. The concentrations in aboveground sorghum due to plant parts was in order to leaves > panicle > stalk. The nitrogen content of sorghum was 0.6~0.7% in stalk, 1.5~1.6% in panicle and 1.8~2.3% in leaves. The amount of nutrient absorbed in sorghum was 4.2 kg in nitrogen, 1.7 kg phosphorus and 7.7 kg in potassium and the absorbing different by cutting time in order to booting > non-cutting > panicle formation milk ripe > 10 leaves stage.

Diagnostic mapping of canopy nitrogen content in rice based on hyperspectral measurements

Timely assessment of canopy nitrogen content (CNC) in crops is critical for growth diagnosis and precision management of crops to generate higher yield and better quality while also minimizing adverse environmental impacts. The objective of this study was to determine the most suitable algorithm, using hyperspectral reflectance data, for the regional assessment of CNC at a critical growth stage in paddy rice. Ground-based hyperspectral datasets were obtained during the panicle formation stage under a wide range of plant and environmental conditions in Japan and China using spectroradiometers. A hyperspectral airborne dataset was obtained over a typical rice-growing region in Japan using the Compact Airborne Spectrographic Imager 3 (CASI-3). On the basis of a comprehensive analysis of the hyperspectral data, significant spectral indices (SIs) such as the normalized difference spectral index (NDSI) and ratio spectral index (RSI) were explored to provide an accurate and robust assessment of CNC. The capability of multivariable regression approaches, such as partial least-squares regression (PLSR) using the whole hyperspectral data or interval PLSR (IPLSR) using selected wavebands was also examined. Among various SIs, a simple index, RSI (D740, D522) using the first derivative (D) values at 740nm and 522nm, was found to be most accurate and robust for the assessment of CNC. The predictive ability of the index was comparable to those of PLSR and IPLSR. Independent validation using the airborne dataset supported the robust applicability of the new SI. The CNC was closely related to the conventional diagnostic indicators based on direct plant measurements. The results demonstrated the operational applicability of hyperspectral measurements for diagnostic mapping of CNC on a regional scale. The investigation based on the precise dataset for rice will be a good basis for remote sensing of canopy nitrogen content in a wide range of vegetation.

The contribution of entrapped gas bubbles to the soil methane pool and their role in methane emission from rice paddy soil in free-air [CO2] enrichment and soil warming experiments

We attempted to determine the contribution of entrapped gas bubbles to the soil methane (CH4) pool and their role in CH4 emissions in rice paddies open to the atmosphere. We buried pots with soil and rice in four treatments comprising two atmospheric CO2 concentrations (ambient and ambient +200 μmol mol−1) and two soil temperatures (ambient and ambient +2 °C). Pots were retrieved for destructive measurements of rice growth and the gaseous CH4 pool in the soil at three stages of crop development: panicle formation, heading, and grain filling. Methane flux was measured before pot retrieval. Bubbles that contained CH4 accounted for a substantial fraction of the total CH4 pool in the soil: 26–45 % at panicle formation and 60–68 % at the heading and grain filling stages. At panicle formation, a higher CH4 mixing ratio in the bubbles was accompanied by a greater volume of bubbles, but at heading and grain filling, the volume of bubbles plateaued and contained ~35 % CH4. The bubble-borne CH4 pool was closely related to the putative rice-mediated CH4 emissions measured at each stage across the CO2 concentration and temperature treatments. However, much unexplained variation remained between the different growth stages, presumably because the CH4 transport capacity of rice plants also affected the emission rate. The gas phase needs to be considered for accurate quantification of the soil CH4 pool. Not only ebullition but also plant-mediated emission depends on the gaseous-CH4 pool and the transport capacity of the rice plants.

Effects of different application timings of methane fermentation digested liquid to paddy plots on soil nitrogen and rice yield

Treatment of animal and food wastes using a methane fermentation technique is drawing considerable public attention as a suitable option for the utilization of biomass resources. The application of a fermentation byproduct (methane fermentation digested liquid) as an agricultural fertilizer has been investigated. Determining the appropriate timing required for applying digested liquid on a rice (Oryza sativa L.) paddy plot is important. The concentrations of soil nitrogen (N) components and rice yield should be considered because digested liquid contains both inorganic and organic N. This study compares the N transformation and the rice yield and growth at different application times over a period of 3 y. The effects of the timing of basal application on soil N were different and the timing that maximized the rice yield was different in each year. Days before ponding (DBP) affected soil N before mid-summer drainage, and rice growth rates at the panicle formation stage and the ear emergence stage. The effects of DBP disappeared before harvest. The results indicated that sufficient potentially mineralizable N existed regardless of DBP, and the effect of DBP lessened after the mid-summer drainage, which coincides with the period when N uptake is most active.

Hydraulic conductance as well as nitrogen accumulation plays a role in the higher rate of leaf photosynthesis of the most productive variety of rice in Japan

An indica variety Takanari is known as one of the most productive rice varieties in Japan and consistently produces 20–30% heavier dry matter during ripening than Japanese commercial varieties in the field. The higher rate of photosynthesis of individual leaves during ripening has been recognized in Takanari. By using pot-grown plants under conditions of minimal mutual shading, it was confirmed that the higher rate of leaf photosynthesis is responsible for the higher dry matter production after heading in Takanari as compared with a japonica variety, Koshihikari. The rate of leaf photosynthesis and shoot dry weight became larger in Takanari after the panicle formation and heading stages, respectively, than in Koshihikari. Roots grew rapidly in the panicle formation stage until heading in Takanari compared with Koshihikari. The higher rate of leaf photosynthesis in Takanari resulted not only from the higher content of leaf nitrogen, which was caused by its elevated capacity for nitrogen accumulation, but also from higher stomatal conductance. When measured under light-saturated conditions, stomatal conductance was already decreased due to the reduction in leaf water potential in Koshihikari even under conditions of a relatively small difference in leaf–air vapour pressure difference. In contrast, the higher stomatal conductance was supported by the maintenance of higher leaf water potential through the higher hydraulic conductance in Takanari with the larger area of root surface. However, no increase in root hydraulic conductivity was expected in Takanari. The larger root surface area of Takanari might be a target trait in future rice breeding for increasing dry matter production.

Tillering Characteristics and Its Relationships with Population Productivity of Super Rice under Different Cultivation Methods in Rice-Wheat Cropping Areas

To explore tillering characteristics and its relationships with population productivity of rice under different cultivation methods in the rice-wheat cropping system in the lower Yangtze River,we compared the characteristics of rice tillering and panicle formation and its productivity and contribution to yield with two super rice cultivars Huaidao 9 and Xudao 3 by using three cultivation methods,precision artificial transplanting with dry nursery middle and strong seedlings,mechanical transplanting with small seedlings and direct seeding.Results showed that rice yields by using different cultivation methods were significantly different,artificial transplanting rice was the highest,while direct seeding rice was the lowest.The great contribution to yields of mechanical transplanting rice and direct seeding rice were mainly from main stem and primary tillers group,in particular for the direct seeding rice,the proportion of stem yield was up to 27.5%,that of secondary tillers group only about 5%.However,for artificial transplanting rice the stem yield proportion was small(16.7%),yield of secondary tillers group accounted for nearly 20%.The proportion of primary tillers group yield was relatively stable among the different cultivation methods and it ranged from 65.84% to 67.09%.The number of tiller leaf position of artificial transplanting rice was more,earbearing tiller percentage was higher and panicle number per plant was more.The primary tillers group emerged from leaf 1 to leaf 10 on main stem,among them the tillers from leaf 5 to leaf 8 had higher emerging rate and more panicles,secondary tillers group emerged and earbeared mainly in 1/5,1/6,and 1/7.Tillers of mechanical transplanting rice had a more concentrated emergence,the primary tillers group emerged from leaf 3 to leaf 7 on main stem,among them leaves 4 to 7 were the superior positions for tiller emerging and panicle formation,secondary tillers group emerged mainly in 1/4,2/4,1/5,but earbeared mainly in 1/4.The primary tillers group of direct seeding rice emerged from leaf 1 to leaf 5 on main stem,among them the leaf positions of 1 to 4 had higher rate of tiller emerging and panicle formation,secondary tillers emerged more,but earbeared only in 1/1,2/1,1/2,with a very low earbearing percentage.These three cultivation methods did not give tillering three times and more than three times.The tillers group of main stem and superior leaf positions in each cultivation method had higher population productivity and better panicle traits,made great contributions to the yield,and more than 85% of the yield came from these stems and tillers.The results suggested that the tillering and panicle formation law by different cultivation methods is different.It is indicated that increasing percentage of earbearing tiller and panicle number per plant and playing regulation fully of tillers group will improve the yield.In rice production,we should enhance the superior leaf position tillers' emergence and flowering frequency,inhibit invalid tillers,improve the population quali-ty,explore the way to increase yield potential of the superior leaf position by using the consequentially supporting management measures and through the precise regulation of density,fertilizer application and irrigation based on the actual various cultivation methods,consequently,achieve the target of high yield and efficient production under different cultivation methods.

Effects of Topdressing at the Panicle Formation Stage on the Moisture Content of Rough Rice and Cracked Rice Kernel

Effects of Topdressing at the Panicle Formation Stage on the Moisture Content of Rough Rice and Cracked Rice Kernel

Assessment of N topdressing rate at panicle initiation stage with chlorophyll meter-based diagnosis in rice

This study was conducted to determine N topdressing rate at panicle initiation stage by using chlorophyll meter (SPAD-502)-based N nutritional diagnosis in rice plant for high quality production of the Chucheongbyeo variety. Field experiments were carried for 3 years from 2003 to 2005 in Gyeonggi, Hwaseong. To confirm the method of measuring the leaf color with SPAD-502, leaf position of rice plant and measuring point on the leaf were studied. And the proper period to examine the leaf color and growth characteristics of rice plants was suggested at panicle initiation stage, from the results of the correlation between SPAD value and both content of chlorophyll and nitrogen in rice leaves. The multiply value of plant height, number of tillers per m2 and SPAD value could explain well the effect of nitrogen fertilization on the growth of rice plants, and was used to determine an equation for on-site determination of nitrogen fertilization rate for Chucheongbyeo variety at the panicle initiation stage. Nitrogen fertilization increased number of tillers and rice yields, and affected the increase in protein content in rice grain resulting in loss of quality, such as taste value, and decreased the percentages of both ripened and whole rice grains. Based on the response surface statistical methodology using the SAS program, the relationship equation among protein content of brown rice (PROT), plant growth value (plant height × number of tillers × SPAD value, PGV), and nitrogen fertilization rate at the panicle formation stage (NF) was developed. That is, PROT (%) = 7.379403 − (5.27E-7) a − 0.013291 b + (3.025355E-13) a2 + (3.222997E-8) ab + (6.781E-05) b2, where a means PGV and b is NF (%), and the equation’s coefficient of determination (R2) was 0.967. From this equation, to recommend the optimum N fertilization rate at panicle initiation stage easily to produce high quality rice of Chucheongbyeo variety, which contains the target protein content of brown rice.

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Continuous Monitoring of Visible and Near-Infrared Band Reflectance from a Rice Paddy for Determining Nitrogen Uptake Using Digital Cameras

A two-band digital imaging system —one band for the visible red band (RED, 630−670 nm) and the other for the near infrared band (NIR, 820−900 nm)— was devised and positioned at a height of 12 m above a rice field of 300 m2 in area during the 2007 growing season. The imaging system automatically logged bird’seye view images at 10-min intervals from 0800−1600 every day. Radiometric corrections for the pairs of two-band images were done using solar irradiance sensors and preceding calibrations to calculate daily band-reflectance and the normalized difference vegetation index (NDVI) values for 9 plots of rice plants, with 3 levels of planting density and basal fertilization. The daily- averaged reflectance values in the RED and the NIR bands showed different but smooth seasonal changing patterns according to the growth of plants. At the maximum tiller number and the panicle formation stages, the RED and NIR reflectance values had correlation coefficients (r) of 0.79 and 0.81 with above-ground nitrogen absorption per unit land area (NA, g m-2), respectively, whereas the NDVI using the two band reflectance values showed r-value of -0.13. An empirically derived equation for the NA using two band reflectance values showed r-value of 0.96 and a root mean square of error (RMSE) 0.5 g m–2 (10% of the mean observed NA) in the estimation for the original (not validated) data set acquired at the maximum tiller number and the panicle formation stages. The results indicated that reflectance observation in the RED and NIR bands using the digital imaging system was potentially effective for assessing rice growth.

Top-dressing of silicate at the panicle formation stage of rice alleviates yield suppression induced by seawater adhered on the panicles at ripening stage

Top-dressing of silicate at the panicle formation stage of rice alleviates yield suppression induced by seawater adhered on the panicles at ripening stage

Effectiveness of silica application at the panicle formation stage on the rice production

Effectiveness of silica application at the panicle formation stage on the rice production