Description of Aphelenchoides besseyi from Abnormal Rice with ‘Small Grains and Erect Panicles’ Symptom in China

The abnormal rice with small grains and erect panicles were found on a large scale in China, which showed shortend rice panicle and decreased number of grains in comparison with normal rice, and the grain was small and black-brown, and some of them were distorted, while the flag leaf was normal. A kind of nematode of Aphelenchoides was isolated from the grains of rice variety Wuyujing 3 which performed ＇small grains and erect panicles＇ symptom. There were 2014 nematodes in one hundred grains infected, and up to 74 in single grain, 92 percent of the grains tested had nematodes in the infested panicles. The diagnosis characters of nematode include lateral fields about one-fourth as wide as body, with 4 incisures. The terminus bears a mucro of diverse shape with 3-4 pointed processes. The female post-vulval uterine sac extends less than 50% of distance from vulva to anus, no sperm in it. Oocytes usually arrange in 2-4 rows. The male spicules have a moderately developed rostrum. Morphological measurements showed it to be conspecific with Aphelenchoides besseyi Christie, 1942.

Effect of ^(137)Cs Gamma Rays to Panicles on Rice Anther Culture

Panicles of an indica rice line TM7-5 were subjected to radiation with 137^Cs gamma rays at 0 （control）, 5, 10, 15 and 20 Gy respectively, and then its anthers were cultured. There were slight differences among the treatments in peak emerging time of callus initiation, from 38 to 44 days after inoculation （DAI） as well as the frequency of callus initiation （2.3-3.5%）. About two thirds calli were induced before 44 DAI, and calli derived beyond 60 DAI lost the regeneration ability. Green plant regeneration frequency was significantly stimulated from two- to three-fold by irradiation of the 1370S gamma rays compared with the control, and the maximum was 22,81% （15 Gy）. The culture ability based on callus initiation and green plantlet regeneration was 0.19% for the control while it was over 0.45% for all the irradiated treatments, and the maximum was 0,59% for 15 Gy treatment. The advantages of panicle irradiation before anther culture and the potential application in rice anther culture, especially for recalcitrant indica rice, were discussed.

Panicle-3D: A low-cost 3D-modeling method for rice panicles based on deep learning, shape from silhouette, and supervoxel clustering

Self-occlusions are common in rice canopy images and strongly influence the calculation accuracies of panicle traits. Such interference can be largely eliminated if panicles are phenotyped at the 3 D level.Research on 3 D panicle phenotyping has been limited. Given that existing 3 D modeling techniques do not focus on specified parts of a target object, an efficient method for panicle modeling of large numbers of rice plants is lacking. This paper presents an automatic and nondestructive method for 3 D panicle modeling. The proposed method integrates shoot rice reconstruction with shape from silhouette, 2 D panicle segmentation with a deep convolutional neural network, and 3 D panicle segmentation with ray tracing and supervoxel clustering. A multiview imaging system was built to acquire image sequences of rice canopies with an efficiency of approximately 4 min per rice plant. The execution time of panicle modeling per rice plant using 90 images was approximately 26 min. The outputs of the algorithm for a single rice plant are a shoot rice model, surface shoot rice model, panicle model, and surface panicle model, all represented by a list of spatial coordinates. The efficiency and performance were evaluated and compared with the classical structure-from-motion algorithm. The results demonstrated that the proposed method is well qualified to recover the 3 D shapes of rice panicles from multiview images and is readily adaptable to rice plants of diverse accessions and growth stages. The proposed algorithm is superior to the structure-from-motion method in terms of texture preservation and computational efficiency. The sample images and implementation of the algorithm are available online. This automatic, cost-efficient, and nondestructive method of 3 D panicle modeling may be applied to high-throughput 3 D phenotyping of large rice populations.

Comparisons of Protein Composition of Grains at Different Positions in Panicles between Erect and Curved Panicle Type Japonica Rice

Under field conditions, three erect panicle type japonica dee cultivars and three curved panicle type japonica rice cultivars were applied as experimental materials to investigate the differences of protein composition of grains at different positions in panicles between two different panicle types of japonica rice. Accord- ing to the results, the panicle type of japonica rice had no direct correlation with albumin content, globulin content, prolamin content and glutelin content in rice, variations of protein composition of grains at different positions in panicles. There were certain correlations between soluble protein contents at different grain posi- tions in the same panicle and the flowering order of glumous flowers in the panicle. Albumin content, prolamin content and glutelin content in grains on secondary rachis branches of two panicle types （erect and curved） of japonica rice cuhivars were higher than that on primary rachis branches, while globulin content exhibited an opposite trend. Globulin content, prolamin content and glutelin content in grains at different positions demonstrated a descending order of bottom 〉 middle 〉 top, while albumin content exhibited an opposite trend. The interactions between primary and secondary rachis branches and among top, middle and bottom rachis branches significantly affected soluble protein contents.

A novel Effective Panicle Number per Plant 4 haplotype enhances grain yield by coordinating panicle number and grain number in rice

Increasing effective panicle number per plant(EPN)is one approach to increase yield potential in rice.However,molecular mechanisms underlying EPN remain unclear.In this study,we integrated mapbased cloning and genome-wide association analysis to identify the EPN4 gene,which is allelic to NARROW LEAF1(NAL1).Overexpression lines containing the Teqing allele(TQ)of EPN4 had significantly increased EPN.NIL-EPN4^(TQ) in japonica(geng)cultivar Lemont(LT)exhibited significantly improved EPN but decreased grain number and flag leaf size relative to LT.Haplotype analysis indicated that accessions with EPN4-1 had medium EPN,medium grain number,and medium grain weight,but had the highest grain yield among seven haplotypes,indicating that EPN4-1 is an elite haplotype of EPN4 for positive coordination of the three components of grain yield.Furthermore,accessions carrying the combination of EPN4-1 and haplotype GNP1-6 of GNP1 for grain number per panicle showed higher grain yield than those with other allele combinations.Therefore,pyramiding of EPN4-1 and GNP1-6 could be a preferred approach to obtain high yield potential in breeding.

A 48-bp deletion upstream of LIGULELESS 1 alters rice panicle architecture

Panicle architecture is an agronomic determinant of crop yield and a target for cereal crop improvement.To investigate its molecular mechanisms in rice,we performed map-based cloning and characterization of OPEN PANICLE 1(OP1),a gain-of-function allele of LIGULELESS 1(LG1),controlling the spread-panicle phenotype.This allele results from a 48-bp deletion in the LG1 upstream region and promotes pulvinus development at the base of the primary branch.Increased OP1 expression and altered panicle phenotype in chimeric transgenic plants and upstream-region knockout mutants indicated that the deletion regulates spread-panicle architecture in the mutant spread panicle 1(sp1).Knocking out BRASSINOSTEROID UPREGULATED1(BU1)gene in the background of OP1 complementary plants resulted in compact panicles,suggesting OP1 may regulate inflorescence architecture via the brassinosteroid signaling pathway.We regard that manipulating the upstream regulatory region of OP1 or genes involved in BR signal pathway could be an efficient way to improve rice inflorescence architecture.

Identification of the BTA8 gene reveals the contribution of natural variation to tiller angle in rice

Plant architecture is a collection of major agronomic traits that determines rice grain production,and it is mainly influenced by tillering,tiller angle,plant height and panicle morphology(Wang and Li 2006).Tiller angle is one of the critical components that determines rice plant architecture,which in turn influences grain yield mainly due to its large impact on plant density(Wang et al.2022).

A hybrid CNN-LSTM model for diagnosing rice nutrient levels at the rice panicle initiation stage

Nitrogen(N)and potassium(K)are two key mineral nutrient elements involved in rice growth.Accurate diagnosis of N and K status is very important for the rational application of fertilizers at a specific rice growth stage.Therefore,we propose a hybrid model for diagnosing rice nutrient levels at the early panicle initiation stage(EPIS),which combines a convolutional neural network(CNN)with an attention mechanism and a long short-term memory network(LSTM).The model was validated on a large set of sequential images collected by an unmanned aerial vehicle(UAV)from rice canopies at different growth stages during a two-year experiment.Compared with VGG16,AlexNet,GoogleNet,DenseNet,and inceptionV3,ResNet101 combined with LSTM obtained the highest average accuracy of 83.81%on the dataset of Huanghuazhan(HHZ,an indica cultivar).When tested on the datasets of HHZ and Xiushui 134(XS134,a japonica rice variety)in 2021,the ResNet101-LSTM model enhanced with the squeeze-and-excitation(SE)block achieved the highest accuracies of 85.38 and 88.38%,respectively.Through the cross-dataset method,the average accuracies on the HHZ and XS134 datasets tested in 2022 were 81.25 and 82.50%,respectively,showing a good generalization.Our proposed model works with the dynamic information of different rice growth stages and can efficiently diagnose different rice nutrient status levels at EPIS,which are helpful for making practical decisions regarding rational fertilization treatments at the panicle initiation stage.

Fungal endophyte mediated occurrence of seminiferous and pseudoviviparous panicles in Festuca rubra

Fungal endophytes are suggested to manipulate host grass reproduction.Using different grass-endophyte combinations in a four year common garden experiment,we show that endophyte can retain control over the reproductive functions of the host.Plants were collected as seeds from two different environments,meadows and riverbanks.Natural endophyte infection(E+)increased reproductive effort of plants;13 and 15%higher proportion of E+plants produced panicles compared to naturally uninfected(E-)and manipulatively endophyte-infected(ME+)plants,respectively.Meadoworigin E+plants produced also higher number of panicles compared to E-in the last two years,and both meadow-and riverbank-origin ME+plants produced higher number of panicles compared to ME-plants in most of the years.Pseudovivipary was recorded in 5%of the plants each year.Pollen limitation appears not to induce pseudovivipary.Both E+and ME+plants produced higher number of seminiferous panicles compared to E-and ME-plants.The higher proportion of pseudoviviparism in ME+plants compared to E+,Eand ME-plants from meadows suggests specific genotypegenotype cross-talk between endophyte and grass.Pseudovivipary was affected by year and primarily explained by plant reproductive effort since most vigorous plants produced more pseudoviviparous panicles.We propose that endophytes can promote host grass reproduction in a habitatspecific manner and depending on genetic compatibility between partners.However,reproductive behavior depended on maternal habitat and the annual environmental conditions highlighting the importance of long-term experiments to estimate the effects of endophytes on host plant ecology.

Brassinosteroids Mediate Endogenous Phytohormone Metabolism to Alleviate High Temperature Injury at Panicle Initiation Stage in Rice

High temperatures cause physiological and biochemical changes and significantly affect young panicle development of rice(Oryza sativa L.).Brassinosteroids play important roles in enhancing crop stress resistance.In this study,we subjected rice cultivars Huanghuazhan(heat-resistant)and IR36(heat-sensitive)to high temperature(HT,40 oC)or normal temperature(NT,33 oC)for 7 d at the panicle initiation stage,in conjunction with application of 24-epibrassinolide[EBR,a synthetic brassinolide(BR)]or brassinazole(BRZ,a BR biosynthesis inhibitor)at the beginning of the treatments.HT exacerbated spikelet degeneration and inhibited young panicle growth,which were partially prevented by EBR application,while BRZ application aggravated the reduction in spikelet number.HT decreased the contents of BR,active cytokinins(aCTK),active gibberellins(aGA)and indole-3-acetic acid(IAA),but increased the content of abscisic acid(ABA)in young panicles.The activities of key enzymes involved in sucrose hydrolysis,glycolysis and the tricarboxylic acid cycle in young panicles were decreased with the change of endogenous hormone levels under HT.In addition,the contents of H2O2 and malondialdehyde(MDA)were increased and the activities of antioxidant enzymes were decreased in young panicles.Exogenous application of EBR induced the expression of phytohormone biosynthesis-related genes and down-regulated the expression of phytohormone catabolism-related genes to increase the contents of endogenous BR,aCTK,aGA and ABA,thus promoting the decomposition and utilization of sucrose in young panicles,enhancing the activities of superoxide dismutase,catalase and peroxidase,and reducing the accumulation of H2O2 and MDA in young panicles,whereas application of BRZ had the opposite physiological effects.These results showed that brassinosteroids mediate endogenous phytohormone metabolism to alleviate HT injury at the panicle initiation stage in rice.

Decreased panicle N application alleviates the negative effects of shading on rice grain yield and grain quality

Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)application strategies that can effectively alleviate the negative impacts of light deficiency on grain yield and quality in rice.A two-year field experiment was conducted to explore the effects of shading(non-shading and shading from heading to maturity)and panicle N application(NDP,decreased panicle N rate;NMP,medium panicle N rate;NIP,increased panicle N rate)treatments on rice yield-and quality-related characteristics.Compared with non-shading,shading resulted in a 9.5-14.8%yield loss(P<0.05),mainly due to lower filled-grain percentage and grain weight.NMP and NIP had higher(P<0.05)grain yield than NDP under non-shading,and no significant difference was observed in rice grain yield among NDP,NMP,and NIP under shading.Compared with NMP and NIP,NDP achieved less yield loss under shading because of the increased filled-grain percentage and grain weight.Shading reduced leaf photosynthetic rate after heading,as well as shoot biomass weight at maturity,shoot biomass accumulation from heading to maturity,and nonstructural carbohydrate(NSC)content in the stem at maturity(P<0.05).The harvest index and NSC remobilization reserve of NDP were increased under shading.Shading decreased(P<0.05)percentages of brown rice,milled rice,head rice,and amylose content while increasing(P<0.05)chalky rice percentage,chalky area,chalky degree,and grain protein.NMP demonstrated a better milling quality under non-shading,while NDP demonstrated under shading.NDP exhibited both lower chalky rice percentage,chalky area,and chalky degree under non-shading and shading,compared with NMP and NIP.NDP under shading decreased amylose content and breakdown but increased grain protein content and setback,contributing to similar overall palatability to non-shading.Our results suggested severe grain yield and quality penalty of rice when subjected to shading after heading.NDP improved NSC remobilization,harvest index,and sink-filling efficiency and alleviated yield loss under shading.Besides,NDP would maintain rice’s milling,appearance,and cooking and eating qualities under shading.Proper N management with a decreased panicle N rate could be adopted to mitigate the negative effects of shading on rice grain yield and quality.

Translocation and Distribution of Carbon-Nitrogen in Relation to Rice Yield and Grain Quality as Affected by High Temperature at Early Panicle Initiation Stage

Due to climate change, extreme heat stress events have become more frequent, adversely affecting rice yield and grain quality. The accumulation and translocation of dry matter and nitrogen substances are essential for rice yield and grain quality. To assess the impact of high temperature stress(HTS) at the early panicle initiation(EPI) stage on the accumulation, transportation, and distribution of dry matter and nitrogen substances in various organs of rice, as well as the resulting effects on rice yield and grain quality, pot experiments were conducted using an indica rice cultivar Yangdao 6(YD6) and a japonica rice cultivar Jinxiangyu 1(JXY1) under both normal temperature(32 ℃/26 ℃) and high temperature(38 ℃/29 ℃) conditions. The results indicated that exposure to HTS at the EPI stage significantly decreased rice yield by reducing spikelet number per panicle, grain-filling rate, and grain weight. However, it improved the nutritional quality of rice grains by increasing protein and amylose contents. The reduction in nitrogen and dry matter accumulation accounted for the changes in spikelet number per panicle, grain-filling rate, and grain size. Under HTS, the decrease in nitrogen accumulation accompanied by the reduction in dry matter may be due to the down-regulation of leaf net photosynthesis and senescence, as evidenced by the decrease in nitrogen content. Furthermore, the decrease in sink size limited the translocation of dry matter and nitrogen substances to grains, which was closely related to the reduction in grain weight and the deterioration of grain quality. These findings significantly contribute to our understanding of the mechanisms of HTS on grain yield and quality formation from the perspective of dry matter and nitrogen accumulation and translocation. Further efforts are needed to improve the adaptability of rice varieties to climate change in the near future.

Effect of GW8 Gene Editing on Appearance Quality of Erect-Panicle Type (dep1) Japonica Rice

Most high-yielding japonica rice varieties in China carry dep1,a multi-effective regulator of plant architecture and grain shape,resulting in erect panicle with short and round grain shape.However,its appearance quality needs to be improved since long-grain rice is favored by the market.GW8 is a dominant gene regulating grain shape,and its loss-of-function genotype leads to elongated grains with a better quality in appearance.

Effects of erect panicle genotype and environment interactions on rice yield and yield components

The dense and erect panicle (EP) genotype conferred by DEP1 has been widely used in the breeding of high-yield Chinese japonica rice varieties.However,the breeding value of the EP genotype has rarely been determined at the plant population level.Therefore,the effects of the interaction of EP genotype and the environment at different locations and times on rice yield and its various components were investigated in this study.Two sets of near-isogenic lines (NILs)of EP and non-EP (NEP) genotypes with Liaojing 5 (LG5) and Akitakomachi (AKI) backgrounds were grown in the field in 2016 and 2017 in Shenyang,China,and Kyoto,Japan.In 2018,these sets were grown only in Kyoto,Japan.The average yields of the EP and NEP genotypes were 6.67 and 6.13 t ha^(-1)for the AKI background,and 6.66 and 6.58 t ha^(-1)for the LG5 background,respectively.The EP genotype positively affected panicle number (PN) and grain number per square meter (GNPM),mostly resulting in a positive effect on harvest index (HI).In contrast,the EP genotype exerted a negative effect on thousand-grain weight (KGW).The ratio of the performance of the EP genotype relative to the NEP genotype in terms of yield and total biomass correlated positively with mean daily solar radiation during a 40-day period around heading.These results indicate that the effectiveness of the EP genotype depends on the availability of solar radiation,and the effect of this genotype is consistently positive for sink formation,conditional in terms of source capacity,and positive in a high-radiation environment.

TCD5 Enhances the Photosynthesis Capacity,Increases the Panicle Number and the Yield in Rice

Improvement of photosynthetic efficiency is a major approach to increase crop yield potential.Previously,we cloned a gene encoding the chloroplast-located putative monooxygenase TCD5,which is essential in plastid development under low temperature in rice(Oryza sativa L.).In this study,the effects of TCD5 on the photosynthesis and the yields were investigated in rice.Two sets of genetic materials with three levels of TCD5 expression,including tcd5 mutant or TCD5 RNAi transgenic lines and TCD5 over-expression transgenic lines in Jiahua1 and Nipponbare backgrounds,were used in the field trails of multi-locations and multi-years.TCD5 positively affected the panicle number and the yield at dosage.Compared with the wild-types,the panicle numbers were 12.4%-14.6%less in tcd5 mutant and 8.3%-38.6%less in TCD5 RNAi lines,but 26.2%-61.8%more in TCD5 over-expression lines.The grain yields per plant were 9.1%-18.4%less in tcd5 mutant and 14.3%-56.7%less in TCD5 RNAi lines,but 6.9%-56.5%more in TCD5 over-expression lines.The measurements of net photosynthetic rate indicated that mutation or knock down of TCD5 decreased the net photosynthetic rate by 10.4%and 15.6%,respectively,while increasing it by 8.9%and 8.7%in the TCD5 over-expression lines in Jiahua1 and Nipponbare backgrounds,respectively.Accordingly,the measurements of chlorophyll fluorescence parameters showed that the electron transport rate and quantum yield decreased in tcd5 mutant or TCD5 RNAi lines but increased in TCD5 overexpression lines,both in Jiahua1 and Nipponbare backgrounds.IP-MS screening revealed that TCD5 interacts with 29 chloroplast proteins involved in chlorophyll synthesis,photo-reactions of the photosynthesis,carbon assimilation and metabolism,energy metabolism,redox balance,protein synthesis and transportation.Two TCD5 interacted proteins,D1 and FBA were effective targets for improving photosynthesis.These results suggest a potentially new strategy for increasing rice yield by enhancing photosynthesis.

Ecofriendly Management of Wheat Panicle Blast Caused by Magnaporthe oryzae triticum

In this study, three wheat varieties were tested to determine seed germination and the incidence of Magnaporthe oryzae triticum (MoT). Among these varieties, BARI Gom 24 (Prodip) wheat seed exhibited the highest seed germination rate (93%) but also had the highest incidence (30%) of MoT. To manage blast disease in an ecofriendly manner, seven treatments were employed: T1 = Control, T2 = Garlic clove extracts, T3 = Aloe vera leaf extracts, T4 = Black cumin seed extracts, T5 = Neem leaf extracts, T6 = Nativo 75 WG, and T7 = Provax 200 WP. The experiment was conducted using a Randomized Complete Block Design (RCBD) layout with three replications using Prodip wheat variety that exhibited highest MoT infection severity based on laboratory analysis among collected varieties. Data were collected on blast disease incidence (%), disease severity, and various growth and yield parameters of wheat. The experiment’s results indicated that among all the treatments, T7 (Seed treatment with Provax 200 WP) and T5 (Foliar spraying with Neem leaf extract) performed better in controlling blast disease in wheat. The lowest blast disease incidence (%) was observed with T7 (Provax 200 WP), with values of 7.86, 9.86, and 10.19 recorded during the milking stage, soft dough stage, and hard dough stage of wheat, respectively. T5 (Neem leaf extract) also demonstrated a statistically equivalent reduction in blast disease incidence (%). In terms of disease severity, T7 (Seed treatment with Provax 200 WP) showed the lowest values of 1.03, 1.23, and 1.63 during the milking stage, soft dough stage, and hard dough stage of wheat, respectively. Foliar spraying with neem leaf extract also exhibited similar result as of Provax 200 WP regarding panicle blast severity. As a result of these findings, it can be concluded that T5 (Neem leaf extract) is recommended as an ecofriendly management approach for blast disease in wheat.

Dynamic Development of Aphelenchoides besseyi on Rice Plant by Artificial Inoculation in the Greenhouse

A study was done on the relationship between Aphelenchoides besseyi and the symptoms of small grains and erect panicles. This is an important rice disease in Jiangsu Province, China. A. besseyi was extracted from small grains and erect panicles and cultured artificially, and then inoculated into bud and leaf sheaths of seedlings of two Oryza sativa cultivars, namely Zhendao 2 and Wuyunjing 7 in a greenhouse. The effect on rice growth, in particular the small grains and erect panicles, was revealed by the extent of the disease, seed expansion stages, nematode load, and nematode mortality. In contrast to healthy seedlings, the height, length, and the numbers of spikelets of unhealthy panicles of Zhendao 2 were decreased by 6.7, 16.4, and 13.5%, respectively. Before anthesis, nematodes were attracted to the leaf sheath and apical meristem, nematode load increased by 40%; after anthesis, nematodes occurred in spikelets principally and the number increased by 90.8%. The percentages of infected seeds and nematode load were highest in plump seeds and lowest in empty seeds. Nematode mortality on grain with normal endosperm was lower than seeds with abnormal endosperm. Results indicated that A. besseyi was the pathogen in rice with the symptoms of small grains and erect panicles. Wuyunjing 7 manifests only the small grains and erect panicles symptoms and not the symptoms of leaf white-tip. These symptoms of small grains and erect panicles are new symptom records for the disease caused by A. besseyi on rice.

Discovery of and Preliminary studies on a Rapid-Leafing Rice Genotype at the Vegetative Growth Stage

The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont, and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar growth durations from sowing to heading. Furthermore, the difference of the leafing rate was significant at the vegetative growth stage, but not distinctive at the panicle initiation stage. Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character. Based on results of investigation for some plants with similar growth durations in the backcrossing populations, the rapid leafing genotypes exhibited earlier tillering and more tiller numbers per plant, and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes. Further research and application feasibility of the rapid leafing genotype in breeding were discussed.

PRESSURE DROP IN THE VERTICAL PNEUMATIC PIPE FOR POWDER CONVEYING

Based on the former research work of the authors,the resistance of differentsolid particle suspension flow in a vertical pipe is analysed,and investigatedexperimentally.The applicable formulas of pressure drop are presented.Two types of par-ticles,talcum powder and glass beads,are convcyed in the test which has been carried outat various air vclocities of 10 to 28 m/s and at the ratio of solids-air mass flow rateranged from 0 to 2.The experimental results show a good agreement with the calculatedones.

双季稻“三高一保”栽培技术模式应用研究(英文)

通过多年试验研究,形成了一套水稻高成穗率、高结实率、高籽粒充实度和保优质为核心的双季稻"三高一保"栽培技术模式。本文通过田间试验和多点应用示范,比较研究了双季"稻三高一保"栽培技术模式的效果。田间试验表明,"三高一保"栽培技术模式能促进前期早发、控制无效分蘖发生,促进有效分蘖生长和成穗,提高成穗率,增加总颖花数、提高结实率和籽粒充实度,极显著地增加水稻产量,增产幅度为12.22%～19.73%,并能改善米质。大田示范结果表明也验证了田间试验的结果。