Functions of Nitrogen,Phosphorus and Potassium in Energy Status and Their Influences on Rice Growth and Development

Nitrogen(N),phosphorus(P)and potassium(K)are important essential nutrients for plant growth and development,but their functions in energy status remains unclear.Here,we grew Nipponbare rice seedlings in a growth chamber for 20 d at 30℃/24℃day/night)under natural sunlight conditions with different nutrient regimes.The results showed that N had the strongest influence on the plant growth and development,followed by P and K.The highest nonstructural carbohydrate content,dry matter weight,net photosynthetic rate(Pn),ATP content,as well as NADH dehydrogenase,cytochrome oxidase and ATPase activities were found in the plants that received sufficient N,P and K.The lowest values of these parameters were detected in the N-deficient plants.Higher dry matter accumulation was observed in the K-deficient than in the P-deficient treatments,but there was no significant difference in the ratio of respiration rate to Pn between these two treatments,suggesting that differences in energy production efficiency may have accounted for this result.This hypothesis was confirmed by higher ATP contents and activities of NADH dehydrogenase,cytochrome oxidase and ATPase in the K-deficient plants than in the P-deficient plants.We therefore inferred different abilities in energy production efficiency among N,P and K in rice seedlings,which determined rice plant growth and development.

Functions of Phytochrome in Rice Growth and Development

Phytochrome family mainly senses red and far-red light to regulate a range of developmental processes throughout the life cycle of plants. Rice phytochrome gene family is composed of three members known as PHYA, PHYB and PHYC. It has been elucidated that individual phytochromes display both unique and overlapping roles in rice photomorphogenesis by characterization of all rice phytochrome mutants including single mutants, all combinations of double mutants as well as triple mutants. Based on the published data and authors’ ongoing studies, current knowledge of rice phytochrome functions in regulating seedling de-etiolation, root gravitropic response and elongation, plant architecture, flowering time and fertility is summarized. Additionally, the important issues in the field of rice phytochromes are proposed.

Dynamic changes of rumen microbiota and serum metabolome revealed increases in meat quality and growth performances of sheep fed bio‑fermented rice straw

Background Providing high-quality roughage is crucial for improvement of ruminant production because it is an essential component of their feed.Our previous study showed that feeding bio-fermented rice straw(BF)improved the feed intake and weight gain of sheep.However,it remains unclear why feeding BF to sheep increased their feed intake and weight gain.Therefore,the purposes of this research were to investigate how the rumen micro-biota and serum metabolome are dynamically changing after feeding BF,as well as how their changes influence the feed intake,digestibility,nutrient transport,meat quality and growth performances of sheep.Twelve growing Hu sheep were allocated into 3 groups:alfalfa hay fed group(AH:positive control),rice straw fed group(RS:negative control)and BF fed group(BF:treatment).Samples of rumen content,blood,rumen epithelium,muscle,feed offered and refusals were collected for the subsequent analysis.Results Feeding BF changed the microbial community and rumen fermentation,particularly increasing(P<0.05)relative abundance of Prevotella and propionate production,and decreasing(P<0.05)enteric methane yield.The histomorphology(height,width,area and thickness)of rumen papillae and gene expression for carbohydrate trans-port(MCT1),tight junction(claudin-1,claudin-4),and cell proliferation(CDK4,Cyclin A2,Cyclin E1)were improved(P<0.05)in sheep fed BF.Additionally,serum metabolome was also dynamically changed,which led to up-regulating(P<0.05)the primary bile acid biosynthesis and biosynthesis of unsaturated fatty acid in sheep fed BF.As a result,the higher(P<0.05)feed intake,digestibility,growth rate,feed efficiency,meat quality and mono-unsaturated fatty acid concentration in muscle,and the lower(P<0.05)feed cost per kg of live weight were achieved by feeding BF.Conclusions Feeding BF improved the growth performances and meat quality of sheep and reduced their feed cost.Therefore,bio-fermentation of rice straw could be an innovative way for improving ruminant production with mini-mizing production costs.

OsPPG encodes a pseudouridine-5'-phosphate glycosidase and regulates rice spikelet development

Florets are the basic structural units of spikelets,and their morphogenesis determines the yield and quality of rice grains.However,whether and how pseudouridine-5’-phosphate glycosidase participates in rice spikelet development remains an open question.In this study,we identified a novel gene,OsPPG,which encodes a peroxisome-localized pseudouridine-5’-phosphate glycosidase and regulates the development of rice spikelets.osppg mutants exhibited abnormal sterile lemma,lemma,palea,lodicule,stamens,and pistils;male sterility;shorter panicles;and reduced plant height.OsPPG was found to regulate several OsMADS genes,thereby affecting the morphogenesis of rice spikelets.Furthermore,metabolomics revealed that the OsPPG gene was involved in the decomposition of pseudouridine via the pyrimidine metabolism pathway and may affect the jasmonic acid signaling pathway.These results suggest that OsPPG is a key regulator of rice spikelet development.

Effects of Biostimulant NEAU10 on Growth of Rice Seedlings and Soil Physicochemical Parameters

The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and ecological development of agriculture.In this study,1.0 and 2.0 g•m^(-2) of the biostimulant were applied to soil in rice seedbeds.Growth indicators of rice,antioxidant enzyme activities and soil physicochemical characteristics were assessed at the 2.5-leaf and 4-leaf stages of rice.The results indicated that applying 2.0 g•m^(-2) of the biostimulant at both the 2.5-leaf and 4-leaf stages had the most significant promoting effect on rice growth.At the 2.5-leaf and 4-leaf stages,the number of fibrous roots increased by 23.43%and 22.25%,stem base width increased by 19.05%and 19.58%,above ground dry weight increased by 18.09%and 16.47%,root dry weight increased by 19.67%and 18.28%,leaf peroxidase(POD)activity increased by 34.44%and 42.94%,superoxide dismutase(SOD)activity increased by 37.24%and 56.79%,malondialdehyde(MDA)content decreased by 18.60%and 27.67%,and chlorophyll content increased significantly by 28.31%and 34.24%,respectively.At the 4-leaf stage of rice,urease,phosphatase and cellulase activities in the seedbed soil increased by 42.13%,25.96%and 33.59%,respectively,while soil alkaline nitrogen,available phosphorus and available potassium content decreased by 19.76%,19.02%and 17.88%,respectively.The application of biostimulants played a crucial role in promoting the growth of rice seedlings and enhancing soil nutrient absorption.

Effects of Soil Copper Concentration on Growth, Development and Yield Formation of Rice (Oryza sativa)

Pot experiments were conducted in 2002 and 2003 to investigate the effects of soil copper（Cu） concentration on growth, development and yield formation of rice by using the japonica cultivar Wuxiangjing 14 and hybrid rice combination Shanyou 63. The plant height, leaf number, elongated internode number and heading date of rice plants were not affected at soil Cu levels below 200 mg/kg, but affected significantly at above 400 mg/kg. The inhibitory effects on rice growth and development were increased with the increment of soil Cu levels. The grain yields decreased significantly with raising soil Cu levels. The main reasons for the grain yield reductions under lower soil Cu levels （100, 200 mg/kg） were mainly due to the decrease of number of spikelets per panicle, however, under higher soil Cu levels （more than 400 mg/kg）, both panicle number and number of spikelets per panicle contributed to the yield loss. The decreases of panicle number by Cu stress were mainly attributed to slow recovery from transplanting, delayed tillering and reduced maximum tiller numbers. The reduction of number of spikelets per panicle under soil Cu stress resulted from the decreases of both shoot dry weight （SDW） at the heading date and the ratio of spikelets to SDW. Total biomass at maturity decreased significantly with the increase of soil Cu levels, while economic coefficient showed non-significant decrease except under soil Cu levels above 800 mg/kg.

A Pleiotropic Drug Resistance Family Protein Gene Is Required for Rice Growth, Seed Development and Zinc Homeostasis

Zinc(Zn) is an essential mineral element for plant growth and development. Zn deficiency in crops frequently occurs in many types of soils. It is therefore crucial to identify genetic resources linking Zn acquisition traits and development of crops with improved Zn-use efficiency for sustainable crop production. In this study, we functionally identified a rice uncharacterized ABCG(ATP-binding cassette G-subfamily) gene encoding a PDR20(pleiotropic drug resistance 20) metal transporter for mediation of rice growth, seed development and Zn accumulation. OsPDR20 was localized to the plasma membrane, but it was not transcriptionally induced under Zn deficiency, rather was sufficiently up-regulated under high level of Zn stress. Yeast(Saccharomyces cerevisiae) transformed with OsPDR20 displayed a relatively lower Zn accumulation with attenuated cellular growth, suggesting that OsPDR20 had an activity for Zn transport. Knocking-down OsPDR20 by RNA interference(RNAi) compromised rice growth with shorter plant height and decreased biomass in rice plantlets grown under hydroponic media. Zn concentration in the roots of OsPDR20 knocked-down rice lines declined under Zn deficiency, while they remained unchanged compared with the wild type under normal Zn supply. A rice lifelong field trial demonstrated that OsPDR20 mutation impaired the capacity of seed development, with shortened panicle and seed length, compromised spikelet fertility, and reduced grain number per plant or grain weight per unit area. Interestingly, OsPDR20 mutation elevated the accumulation of Zn in husk and brown rice over the wild type. Overall, this study pointed out that OsPDR20 is fundamentally required for rice growth and seed development through Zn transport and homeostasis.

Effects of Nitrate on the Growth of Lateral Root and Nitrogen Absorption in Rice

Lateral root is primary organ for plant to explore and utilize soil nutrient efficiently. The development of lateral roots (LR) is controlled by both genetic factors and nutrient status in environment. To investigate the effects of nitrate (NO3-) on rice lateral root growth and nitrogen (N) uptake efficiency under upland condition, three treatments, including root-split culture and whole plant culture in N sufficient and deficient conditions, were used in a vermiculite culture experiment. Root-split treatment showed that the growth of lateral roots was stimulated by localized nitrate supply. However, in whole plant culture, elongation of lateral roots was induced by NO3- deficiency. The effects of NO3- on rice lateral root growth were genotype-dependent. Similar N concentration, soluble sugar concentration and N content in shoot were observed in both root-split treatment and whole plant culture under NO3- sufficient condition, suggesting that the nitrogen requirement for rice normal growth could be satisfied with only half of roots supplied with NO3-. In the root-split treatment, N uptake was positively correlated with the average of lateral root length (ALRL) in NO3--supplied side, suggesting that the ALRL is important for rice root N uptake in the environment where the nitrogen nutrient is limiting factor. No significant correlation was observed between N uptake and ALRL in whole plant culture under N sufficient condition, which implies that the length of lateral roots may not be the main factor to determine tire rice root N uptake in nutrient-rich zone. Morphological and metabolic evidence in this study provided some prospects for genetic improvement of root system characters to improve the efficiency of nutrient absorption in rice.

Effect of Fulvic Acid on Growth and Yield Components of Direct Seeding Rice

ObjectiveThis study aimed to investigate the effect of fulvic acid on the growth and yield components of direct seeding rice （Nanjing 44）. MethodThe rice seeds were soaked in 0 （water as a control）, 1, 2, 4 and 6 g/L fulvic acid （FA） before sowed. Then, the rice morphological indices, leaf chlorophyll content, photosynthesis parameters, root activity and chlorophyll fluorescence parameters were measured in the following field studies. ResultCompared with the control, the leaf area index, chlorophyll content, net photosynthetic rate, stomatal conductance and dry matter weight and some fluorescence parameters such as the maximum photochemical efficiency of photosystem II （PSII） （Fv/Fm）, excitation energy capture efficiency of opened PSII reaction center （Fv’/Fm’） and efficiency of the open reaction centre （ΦPS II） increased by different levels at both jointing stage and heading stage of direct seeding rice, whose seeds were soaked by FA with different concentrations. High FA concentration （4-6 g/L） significantly increased the cultivated rice leaf area index, chlorophyll content, net photosynthetic rate, stomatal conductance, transpiration rate and dry matter weight by 10.32% -22.88% , 5.88% -13.11% , 12.16% -26.84% , 11.43% -88.46% , 10.63% -21.63% , 18.49% -19.68% , respectively, thereby improving the physiological function and light energy transform efficiency of rice at the growth stage. With FA concentration increasing, the yield, effective panicles, grain number per panicle and seed setting rate were increased significantly compared with the control by 17.52%-18.71%, 3.46%-3.85%, 6.30%- 6.51% and 7.82%-8.69% respectively. ConclusionSoaking rice seed with FA could be considered as an effective way to improve the rice competitiveness at early growth stage.

Effects of Tiller-inhibitor on Growth and Yield Formation of Super Early Hybrid Rice Jinyou458

[Objective]The paper was to study the effect of tiller-inhibitor on the growth and yield formation of super early rice Jinyou 458.[Method] Two treatments including spraying tiller-inhibitor（TI） and spraying water（CK） at the SN-n stage were set in the test,the effect of tiller-inhibitor on yield and its components,leaf and plant morphology,field microclimate at booting stage and quality characteristics of rice population were studied.[Result] Spraying tiller-inhibitor could effectively reduce the occurrence of invalid and inefficient tillers,increase the proportion of high effective tillers（tiller with 4 or more leaves） in tiller composition at the maximal tiller stage.The panicle length,spikelets per panicle,spikelets density,number of secondary branches and the secondary spikelets,seed setting rate of rice plant sprayed with tiller-inhibitor were significantly higher than CK.Meanwhile,spraying tiller-inhibitor could increase plant height,biomass weight and leaf area index of rice population during middle and late stages of rice growing,improve the leaf temperature of top three leaves and the light transmittance of rice population at the booting stage,increase the leaf SPAD value,thus enhance photosynthetic capacity of rice plants.It also showed the characteristics of elongating the internode of rice plant and decreasing the stem thickness,etc.[Conclusion] The panicle-bearing rate of stems and tillers,effective panicles,spikelets per panicle,seed setting rate and 1 000-grain weight had coordinately increased after spraying tiller-inhibitor,thus increased the yield.

Current Status of Rice Production in Burundi and Its Development Strategies

Burundi, a landlocked country locked near the equator, is one of the least developed countries confirmed by the United Nations and the 60% financial revenue needs aid. Rice is the most important and extravagant food in Burundian consumption for no more than 5 kg on average per people by year. It＇s especially suitable to plant rice in Burundi because of the sufficient sunlight and rain. But the lack of new varieties, practical technology and modern service make it very difficult for rice production. According to this significant roll, the rice production has to be increased in order to satisfy the consumption needs which are now becoming higher and keep the food safe. This article mainly shows the rice ecological types, production facts and the major constraints of rice production in Burundi, and then look into the distance on how to solve the problems.

Effects of FCMP Compound Fertilizer on Development and Yield of Early Rice

[Objective] The aim was to explore effects of FCMP compound fertilizer on growth, development and yield of early rice. [Method] Based on lower-graded phos- phate resource, effects of FCMP compound fertilizers on yield and growth of early rice in a field were researched. [Result] FCMP compound fertilizers 0, 1 and 2 en- hanced rice yield, increasing by 21.86%, 20.25% and 13.46%, compared with the rice applied with conventional fertilizer; number of productive ears and grain number per ear in unit area were improved by FCMP compound fertilizer, for example, the two factors achieved the highest with FCMP compound fertilizer 1, increasing by 11.70% and 19.63%. Furthermore, FCMP compound fertilizer promoted plant height and tiller number, maintained high photosynthetic efficiency, enhanced lodging-resis- tance and guaranteed stable and high yield. [Conclusion] The research is of theoret- ical and practical significance for further exploration of production techniques and application of FCMP compound fertilizer.

Effect of Microbial Inoculum Fertilizer on the Growth and Yield of Super Hybrid Rice

The research designed four application quantities of 0, 2 250, 4 500 and 6 750 g/hm2 based on Liangyou No. 959 to explore the effects of microbial inocu- lure fertilizer on growth and yield of super hybrid rice. The results indicate that the treatment with traditional fertilizers and 4 500 g/hm2 HYT microbial inoculum fertilizer performed the best, where average number of tiller was 2.4 more than that of the control; the number of effective ear was 11.05% higher; yield increased by 10.3%. These have demonstrated that microbial inoculum fertilizer is of great value in pro- motion on super hybrid rice production.

Characteristics of Growth and Yield Formation of Rice in Rice-Fish Farming System

By using single rice cultivation as a control, the effect of rice-fish culture on growth dynamic, plant type and yield formation of rice was studied. The results showed as follows： rice-fish culture improved the physical-chemical properties of arable layer soil of paddy field, extended growth period of rice, increased dry matter and LAI of different growth stages, improved three top leaves area, deterred the degeneration of leaves function, increased the diameter of stem, promoted the growth of roots and the formation of roots in the extended stem. At the same time, rice-fish culture extended the length of basal internodes, increased the number of internodes, uplifted the gravity of plant, and depressed the root vigor. For the grain yield and yield structure office, rice-fish culture decreased ear/tillering ratio, spikelet/panicle and seed set percentage, increased grain weight. If variety choice and cultivation technology were controlled appropriately, rice-fish culture could increase the effective panicles and improve grain yield of rice.

Analysis of Natural Condition,Present Situation and Potential of Rice Production Development in Angola

[Objective] The aim was to make analysis on natural condition,present situation,and potential of rice production development in Angola.[Method] Conclusion and analysis of rice development in Angola were conducted from natural condition,production status,present problem and development potential.[Result] In Angola,about 30 million hectares agricultural lands enjoy fresh water,temperature,and light resources which are requirement for rice development.Presently,however,some disadvantages have harassed the nation,such as outdated production mode and technology,small cultivated area and low level of per unit yield.In addition,about 98% of consumed rice was imported from other countries.The government has attached high importance to food production,and rice production was a priority of national investment.Per unit rice yield would achieve 7 500 kg/hm2 if Angola introduces hybrid rice species and high-yield cultivation techniques from China.[Conclusion] The research provided technical reference for enterprises or individuals ready to invest in rice development in Angola.

Effects of Silicon Fertilizer on Rice Blast (Magnaporthe oryzae) Green Control, Rice Growth and Yield

Three doses of silicon fertilizer and seven dominant rice varieties were selected to study the effects of silicon fertilizer on rice blast(Magnaporthe oryzae)green control,rice growth and yield.The results showed application of silicon fertilizer had certain control effect on panicle blast,and was beneficial for rice growth and yield.However,application effect varied among different varieties,and application of silicon fertilizer at the dose of 225 kg/hm2 received the best effect.Applying silicon fertilizer to control rice blast is safe and environmental-friendly,which is beneficial to the production of green food production.

Study on Cadmium Tolerance of Seed Germination and Seedlings Growth of Different Rice Varieties

The research used bioassay method to explore seed tolerance of Cd in terms of seed germination and seedling growth. Specifically, 12 rice varieties of three types were investigated under Cd stress, covering germination rate, shooting index, vigor index, seedling and shoot lengths, and fresh weights. The results showed that as Cd concentration grew, seed germination and seedling growth kept increasingly inhibited; germination index, vigor index, root length, shoot length and fresh weights went down; inhibition effects on seed germination and seedling growth were conventional rice〉two-line hybrid rice〉three-line hybrid ,rice. Shanyou 9588, Tianyou 998, Chuanxiang 8, and Y Liangyou 1 performed ~rongly in Cd tolerance; C Liangyou 651, Nei 5 You 263, Xiangwanxian 16, Huanghuazhan, Xiangwanxian 13, and Zhunliangyou 527 performed poorly in Cd tolerance, and Cd tolerance of rest treatments were moderate.

Effects of Farming and Seedling-raising Methods on Population Growth and Grain Yield of Mechanized Transplanting Rice

The effects of farming method, rice variety and seedling-raising method were studied on the population growth quality and grain yield of the mechanized transplanting rice by way of three-factor split plot design. The results showed that the no-tillage mechanical transplanting treatment was poorer than the conventional mechanical transplanting treatment in transplanting quality in general, but the former was similar to the latter in population growth quality. In regard to grain yield, the no-tillage mechanical transplanting treatment was lower than the conventional me- chanical transplanting treatment. Raising both pot-mat seedling and plastic-tray seedling did not make much difference in population growth and grain yield of mechanized transplanting rice, so both of the seedling-raising methods can be adopted according to practical conditions.

Rice plant growth and yield: foliar application of plasma activated water

Plasma activated water(PAW)was prepared for 10 min to be applied one tofive times as a foliar spray to rice plants,to investigate plant growth,yield and the concentrations of total soluble protein and sugar in the rice grains produced.The results reveal that(1)the plant height,stem diameter,dry weight,chlorophyll and total carotene concentrations were improved by∼15%,∼25%,∼24%,∼47%and∼45%,respectively,with respect to control,(2)defense mechanisms of the plants treated with PAW were improved,(3)concentrations of total soluble protein and sugar were enhanced in the rice grains of PAW treated plants and(4)yield was increased by∼14%.

Effects of Different Application Times of Tillering Fertilizer on Grain Yield and Population Development of Double-cropping Rice Transplanted by Machine

The application of tillering fertilizer plays an important role in promoting rice tillering and improving rice yield. However, under the condition of mechanical transplanting, the optimal application time of tillering fertilizer is still unclear. In this study, the early rice cultivar Zhongjiazao 17 and late rice cultivar H You 518 were used as materials, and the effects of different application times of tillering fertilizer on yield and population development of double-cropping rice transplanted by machine were investigated. The tillering fertilizer was applied 7（D07）, 10（D10） and 13（D13） d after the transplanting, respectively. The results showed that compared with those in the D07 treatment groups, the yield of early rice in the D10 and D13 treatment groups were reduced by 9.4% and 3.8%, respectively, and the yield of late rice in the D10 and D13 treatment groups were reduced by 4.5% and 12.6%,respectively. However, there were no significant differences in rice yield among the treatment groups. The application time of tillering fertilizer showed significant effects on grain number per panicle and seed setting rate of early rice. The grain number per panicle in the D10 treatment group was significantly lower than that in the D07 treatment group, and the seed setting rate of the D13 treatment group was significantly lower than that in the D07 treatment group（P〈0.05）. For the late rice, the effect of application time of tillering fertilizer on effective tiller number was most obvious, and the effective tiller number in the D13 treatment group was significantly lower than that in the D07 treatment group（P〈0.05）. Compared with those in the D07 treatment group, the effective tiller numbers, leaf area indexes and biomasses in the D10 and D13 treatment groups were all trended to be decreased. Therefore,to improve the quality of population and fulfill the high-yielding potential of double-cropping rice transplanted by machine, the tillering fertilizer should be applied as early as possible after rice seedlings turn green.