Effects of silicon amendment on the occurrence of rice insect pests and diseases in a field test

Rice is one of the most important staple foods for the world population,but it is attacked by a number of destructive pests.While evidence from greenhouse and laboratory tests has shown that silicon（Si）amendment can confer enhanced resistance to pests in rice,few studies have directly demonstrated the Si-mediated protection from pests in a field situation.In this study,field plots with silicon amendments at 0,75,150 and 300 kg SiO2 ha-1 in early-and late-season rice were employed to evaluate the effects of silicon amendment on the occurrence of major insect pests and diseases and rice yield.Compared with the control plots without silicon amendment,plant damage by stem borer and leaf folder and population size of planthopper were significantly lower in three to five of the seven monitoring observations in each season in the plots amended with 300 kg SiO2 ha-1.The disease index of rice blast in the early-season rice was lower in the plots amended with Si at 300 kg SiO2 ha-1 than in the control plots,while Si protection from rice blast in the late-season rice and from rice sheath blight in the early-season rice were not apparent.An insignificant increase of rice yield by 16.4%（604 kg ha-1）was observed in the plots amended with 300 kg SiO2 ha-1 over the control plots.Our results indicate that Si amendment at 300kg SiO2 ha-1 can provide substantial protection from some of the rice pests under field conditions.These findings support the recommendation of silicon amendment as a key component of integrated management of rice pests.

The Predatory Function of Three Spiders to Two Insect Pests in Rice Within a Multi-species Co-existence System

The prey-seeking behavior of three spiders (X1-Pirata subpiraticus, X2-Clubiona japonicola and X3-Tetragnatha japonica) for brown plant hopper (X4-Nilaparvata lugens) and rice spittle bug (X5-Cal-litettix versicolor) was investigated, as well as how interference between and within species occurred, by using a quadratic regression rotational composite design. Six predation models derived from the analysis of interactions among and within predators and preys were developed. The total predatory capacity of spiders on rice insect pests after coexistence for one day can be expressed as follows: Y3 = 32.795 + 2.25X1 + 1.083X2 + 0.5X3 + 10.167X4 + 3.167X5 - 1.67X12 - 2.42X22 - 3.295X32 - 0.045X42 + 0.455X52 - 3.125X1X2 + 0.375X1X3 -0.625X1X4 - 0.375X1X5 + 0.375X2X3 - 0.875X2X4 + 0.125X2X5 + 0.375X3X4 - 0.375X3X5 + 0.125X4X5. The principal efficiency analysis using this model indicated that increases in insect pest density significantly increased predation by predators; this was much greater than the effect of any single predator. X4 had a greater effect than X5; however, X4 and X5 demonstrated little interspecific interference and even promoted each other and increased predation rates as the densities of the two pests increased. Among the three predators, an increase in the density of X, had the greatest effect on the increase in predation, X3 had the second, X2 the third greatest effect. As predator density increased inter- and intra-species interference occurred, which were largely related to the size, activity, niche breadth, niche overlap and searching efficiency of the predators. X2 produced the greatest interference between different individuals and between any other predator species. X3 had the second greatest, which reduced predation levels at high predator densities. Because of these factors, the highest predation rate was obtained at a prey density of 120 per 4 rice-hills. The optimal proportion of the three predators in the multi-predator prey system was X1: X2: X3 = 5.6:1.3:4.1.

Effect of Nitrogen Fertilizer on Herbivores and Its Stimulation to Major Insect Pests in Rice

Nitrogen is one of the most important factors in development of herbivore populations. The application of nitrogen fertilizer in plants can normally increase herbivore feeding preference, food consumption, survival, growth, reproduction, and population density, except few examples that nitrogen fertilizer reduces the herbivore performances. In most of the rice growing areas in Asia, the great increases in populations of major insect pests of rice, including planthoppers （Nilaparvata lugens and Sogatella furcifera）, leaffolder （ Cnaphalocrocis rnedinalis）, and stem borers （Scirpophaga incertulas, Chilo suppressalis, S. innotata, C. polychrysus and Sesarnia inferens） were closely related to the long-term excessive application of nitrogen fertilizers. The optimal regime of nitrogen fertilizer in irrigated paddy fields is proposed to improve the fertilizer-nitrogen use efficiency and reduce the environmental pollution.

Biological control of rice disease and insect by chitinase-producing bacterium X2-23

Enriched by the-medium containingchitin and cell wall of Phizoctoniasolani AG-1,a bacterium X2-23 withhigher chitinase activity was isolatedfrom 166 chitinase-producing bacteria.It could distinctly inhibit the fungi

抗虫转基因水稻及其杂交水稻对土壤微生物群落多样性与组成的影响

微生物是土壤物质循环与肥力演变的驱动者,其群落组成关系到土壤微生态系统的稳定与可持续性。对抗虫转基因水稻土壤微生物群落变化的研究是其环境安全性评价的重要内容。本研究基于细菌16S rRNA基因和真菌ITS基因的高通量测序,分析了田间试验中抗虫转基因水稻‘MFB’及其转基因杂交水稻‘闽丰A/MFB’‘天丰A/MFB’和‘谷丰A/MFB’与非转基因常规水稻‘闽恢3301’及杂交水稻‘天优华占’的土壤微生物群落多样性与组成的差异,并得出以下结果。首先,与两个非转基因水稻品种相比,抗虫转基因水稻及转基因杂交水稻均能显著增产(P<0.05)。同时,高通量测序结果表明,除水稻成熟期的土壤真菌群落外,与‘闽恢3301’相比‘MFB’的土壤细菌或真菌群落的α-多样性指数Chao1、Observed_species和Shannon均有所提高,且分别在水稻成熟期或分蘖期达到显著性水平(P<0.05);水稻齐穗期转基因杂交水稻‘闽丰A/MFB’‘天丰A/MFB’和‘谷丰A/MFB’的土壤细菌及真菌群落的多样性指数Shannon均介于‘MFB’与‘天优华占’之间;微生物群落β-多样性分析结果表明,本田间试验中不同品种水稻土壤细菌或真菌的群落组成均没有显著差异。但与‘闽恢3301’相比,稻田土壤细菌中丰度最高的变形菌门的相对丰度在‘MFB’土壤中明显增加,且在水稻分蘖期及成熟期达显著水平(P<0.05),而土壤真菌中丰度最高的子囊菌门的相对丰度在‘MFB’土壤中明显减少,且在水稻分蘖期及齐穗期差异显著(P<0.05);水稻齐穗期‘闽丰A/MFB’‘天丰A/MFB’和‘谷丰A/MFB’的土壤变形菌门或子囊菌门的相对丰度也均介于‘MFB’与‘天优华占’之间。此外,通过对微生物群落的功能组成预测可见,随水稻生长,‘MFB’与‘闽恢3301’的土壤细菌群落功能组成间差异存在增大的趋势。综上所述,本研究田间试验中,抗虫转基因水稻及其转基因杂交水稻在增产的同时提高了稻田土壤细菌或真菌群落的多样性,改变了主要细菌或真菌种类的相对丰度,但对细菌或真菌的群落及功能组成的影响不显著。

RNAi在水稻病虫害防控中的应用研究进展

近年来,来自病原微生物和各类害虫的威胁限制了水稻的生长发育和稳产,亟需一种绿色可控的技术进行有效的生物防治.RNAi技术能够使病虫害相关基因表达下调,具有特异性强、安全性高等优点,相较于化学农药防治,RNAi技术大大降低了非靶标生物(non-target organisms, NTOs)的危害.在农业领域,RNAi技术被寄予厚望,被誉为“农药史上的第三次革命”.通过查阅国内外相关文献,并分析、归纳后,综述了近年来RNAi在水稻抗病毒中的作用研究进展,重点阐述了水稻抗病虫害领域应用的最新研究成果,并针对RNAi沉默效率低、稳定性差等问题提出了不同RNAi的增强策略,为实现水稻病虫害精准高效的防治提供现实依据.

Evaluation and screening for resistance of some varieties(lines)to major diseases and insect pests of rice

During 1984-1988,2,231 varieties(lines)from International Rice Testing Program(IRTP)were evaluated and screened for resistance to riceblast(Bl),bacterial blight(BB),sheath blight

2013—2022年我国水稻病虫害发生特点与绿色防控技术集成

水稻是我国第一大粮食作物,水稻病虫害防治直接关系着粮食稳产增产。本文在对2013年至2022年全国植保专业统计资料的分析基础上,总结回顾了水稻病虫害发生种类和特点、发生面积和为害损失等情况,分类梳理了水稻病虫害防治面积、挽回损失以及主要措施应用等防控概况,尤其是针对近年来生态调控、天敌保护和利用等绿色防控技术应用面积和发展趋势进行了研判总结,同时分别从技术覆盖、内容集成等角度分析探讨了水稻病虫害绿色防控技术发展成效,并对下一步绿色防控工作提出了思考和建议,旨在为我国未来水稻安全生产提供相应参考。

水稻害虫管理专家系统(ESRICE)的设计与实现

水稻害虫管理专家系统(ESRICE)系用知识工程语言NEW、编译BASIC和dBASEⅢ等构筑。系统共由13个子系统组成。各子系统可对不同代次的褐飞虱、稻纵卷叶螟的种群动态进行监测,并提供决策方案。系统耦联了外部数学模型以帮助用户回答咨询过程中系统提出的问题,或进一步确认是否需要化防及其用药时间。应用表明,该系统在水稻害虫管理上已达到专家水平。

高通量测序分析褐飞虱circRNA表达谱及其潜在功能

【目的】探究褐飞虱Nilaparvata lugens如何适应抗性水稻品种YHY15,并为研究环状RNA(circular RNA, circRNA)在褐飞虱对抗性水稻适应机制中的作用奠定基础。【方法】利用高通量测序技术鉴定生物型1和生物型Y(能致害抗性水稻YHY15的生物型)褐飞虱的circRNA,并统计其类型和分布。分析生物型1和生物型Y褐飞虱间circRNA表达差异,并对circRNA来源基因进行GO功能注释和KEGG富集分析。【结果】生物型1和生物型Y褐飞虱共鉴定到19个circRNA,分布在9条染色体上,其中17个circRNA由剪接位点之间的外显子构成,2个circRNA由剪接位点之间的所有碱基构成,17个circRNA长度在200~800 bp。生物型Y褐飞虱的circRNA表达丰度与表达量比生物型1褐飞虱的更高。分析结果表明,在生物型1褐飞虱克服抗性水稻YHY15形成新的生物型Y的过程中,在自然选择压力下,circRNA的表达出现变化,推测这种变化影响了褐飞虱新生物型的形成。KEGG分析结果表明,鉴定到的生物型1和生物型Y褐飞虱circRNA来源基因主要富集到自噬相关通路上。【结论】褐飞虱长期取食抗性水稻,导致褐飞虱消化、解毒和代谢能力进化,能降解抗性水稻为抵御褐飞虱而产生的次生代谢物。鉴定到的生物型1和生物型Y褐飞虱的circRNA来源基因与细胞自噬相关,表明褐飞虱通过细胞自噬过程应答抗虫水稻,这种应答反应促进褐飞虱适应抗虫水稻,致害性增强和生物型形成。

褐飞虱唾液内生菌对抗虫水稻过氧化氢酶的影响

为了解褐飞虱唾液内生菌是否引起植物体内过氧化氢酶活性的改变,采用褐飞虱直接刺吸和人工模拟褐飞虱刺吸的方法处理感虫水稻和抗虫水稻,提取并测定了水稻过氧化氢酶的活性。结果表明,在最初的4 h,褐飞虱直接取食水稻,表现出降低抗虫水稻的CAT活性;而无菌唾液模拟刺吸则使得抗虫水稻B5叶片部位的CAT酶活升高。说明褐飞虱唾液中的某些内生菌能抑制水稻的CAT酶活。本研究结果将为进一步明确植物-昆虫-内生菌的互作提供实验依据。

感染隐蔽性害虫玉米象的稻谷、糙米和大米微环境中二氧化碳浓度变化

粮食中隐蔽性害虫早检早治可更好地避免粮食损失,明确粮堆中因害虫代谢产生的二氧化碳与稻米中隐蔽性害虫感染度的关系有助于隐蔽害虫快速检测。本研究分别以内含玉米象卵、1龄幼虫、2龄幼虫、3龄幼虫、蛹和粒内成虫的稻谷、糙米和大米按0、5、10头/kg和20头/kg密度混于无虫稻谷、糙米和大米中检测其中二氧化碳浓度。24 h时,无虫粮二氧化碳浓度仅为0.04%,含5、10头/kg和20头/kg卵和1龄幼虫的稻谷、糙米和大米中二氧化碳浓度为0.042%~0.055%;含2龄幼虫相应密度稻谷中二氧化碳浓度为0.127%、0.246%和0.425%,糙米中为0.145%、0.234%和0.483%,大米中为0.134%、0.246%和0.438%;含3龄幼虫相应密度稻谷中二氧化碳浓度为0.292%、0.425%和0.677%,糙米中为0.303%、0.482%和0.670%,大米中为0.292%、0.463%和0.668%;含蛹相应密度稻谷中二氧化碳浓度为0.095%、0.237%和0.381%,糙米中为0.082%、0.223%、0.430%,大米中为0.096%、0.235%和0.385%;含羽化成虫相应密度下稻谷中二氧化碳浓度为0.125%、0.215%、0.494%,糙米中为0.151%、0.235%、0.557%,大米中为0.131%、0.221%、0.503%。结果表明,稻谷、糙米和大米感染隐蔽虫态的玉米象24 h,环境二氧化碳浓度在0.15%以下为轻度感染(除蛹期外,此时玉米象多处于卵、1龄幼虫以及密度5头/kg及以下的2龄幼虫,为害虫发生初期或低密度感染状态),浓度为0.2%~0.4%时为中度感染(此时玉米象多处于2龄幼虫期,虫口密度10头/kg左右),浓度达0.55%以上时为严重感染(此时玉米象多处于3龄幼虫期,虫口密度20头/kg左右)。中度和严重感染时可在12 h检测到其显著变化。比较结果显示,糙米最容易被隐蔽的玉米象取食并产生较多气体,其次为大米和稻谷。

德夸菌素对水稻品种徐稻10与湘两优900抗褐飞虱的影响

【目的】德夸菌素(decoyinine,DCY)是一种新型植物生长调节剂。本研究旨在探究DCY浸种处理对商用水稻品种徐稻10与湘两优900抗褐飞虱Nilaparvata lugens的影响。【方法】利用年龄-龄期两性生命表测定和比较了褐飞虱初孵若虫取食不同浓度[0(清水对照),25,50和100 mg/L]DCY浸种处理的徐稻10和湘两优900植株后的生长发育、成虫繁殖力及种群生命表参数,并模拟其60 d内的种群增长情况。还调查了100 mg/L DCY浸种处理对褐飞虱雌成虫蜜露分泌量、体重及取食和产卵偏好的影响。【结果】与取食对照稻株相比,褐飞虱初孵若虫取食不同浓度DCY浸种处理的徐稻10植株后,若虫历期显著延长,成虫繁殖力(单雌产卵量)显著下降,种群参数净增殖率R_(0)、内禀增长率r_(m)和周限增长率λ显著降低,平均世代周期T和种群倍增时间DT显著升高;褐飞虱初孵若虫取食不同浓度DCY浸种处理的湘两优900植株后,若虫历期显著缩短,单雌产卵量显著下降,仅平均世代周期T显著升高,其他种群参数无显著差异。在两种水稻上,60 d种群模拟的结果表明3个处理组的种群大小都小于对照组的。取食100 mg/L DCY浸种处理的徐稻10与湘两优900稻株的褐飞虱雌成虫的蜜露分泌量和体重都显著低于取食对照组稻株的。取食和产卵选择试验表明,褐飞虱雌成虫更倾向于在对照稻株上取食和产卵。【结论】DCY浸种处理徐稻10与湘两优900后会提高其对褐飞虱的抗性。

利用改进MobileNet V2网络识别水稻叶片病虫害的方法

针对传统水稻叶片病虫害分类效率不高、精度低和模型占用空间过大等问题,改进MobileNet V2网络,并结合迁移学习策略对水稻叶片病虫害进行识别。实验以4种常见水稻叶片病虫害作为研究对象,利用注意力机制对MobileNet V2进行改进,通过修改模型残差结构引入通道注意力机制,并采用迁移学习策略对改进模型进行训练。实验表明,相比于原始模型,引入注意力机制并采用迁移学习的改进模型CAM_qianyi的准确率提升了0.82个百分点,达到了84.32%,其准确率也高于轻量化卷积神经网络ResNet18(82.54%)和未采用迁移学习的改进模型CAM(73.65%)。改进模型能准确提取水稻叶片病虫害特征,有效提高了识别效率和精度。

辽宁水稻种植技术与病虫害防治研究

水稻是辽宁省重要的粮食作物。以辽宁省为例,详细分析全省水稻种植现状、水稻种植技术与病虫害防治等内容,进一步阐述水稻种植要点,旨在为其他地区推动水稻生产提供一定的参考。

Effects of Transgenic Bt Rice on the Food Consumption, Growth and Survival of Cnaphalocrocis medinalis (Guenée) Larvae

The transgenic rice KMD1, expressing a synthetic CrylAb gene from Bacillus thuringiensis, showed effective resistance to the older （third-to fifth-instar） larvae of the rice leaf-folder （RLF）, Cnaphalocrocis medinalis （Guenee） in laboratory bioassay. Significant declines were revealed in food consumption and growth of the older RLF nymphs fed on the cut-leaves of transgenic KMD1 plants. The increase rate of food consumption by larvae fed on KMD1 was drastically lower than those on Xiushui 11. Food consumption was varied with different instars when the larvae fed on the Bt rice. Those of fourth- and fifth-instar larvae were different compared to the third-instar, lower than those on the non-transgenic rice but still increased a little when the feeding time prolonged. It is indicated that younger RLF larvae are more sensitive to Bt rice than older ones. Also, about 81%, 78% and 68% of the third-, fourth- and fifth-instar RLF larvae died within 72 hours bioassay period on KMD1 leaves, respectively. These results demonstrated that Bt-transgene in KMD1 rice confers substantial protection against infestations with older RLF larvae.

Automated Counting of Rice Planthoppers in Paddy Fields Based on Image Processing

A quantitative survey of rice planthoppers in paddy fields is important to assess the population density and make forecasting decisions. Manual rice planthopper survey methods in paddy fields are time-consuming, fatiguing and tedious. This paper describes a handheld device for easily capturing planthopper images on rice stems and an automatic method for counting rice planthoppers based on image processing. The handheld device consists of a digital camera with WiFi, a smartphone and an extrendable pole. The surveyor can use the smartphone to control the camera, which is fixed on the front of the pole by WiFi, and to photograph planthoppers on rice stems. For the counting of planthoppers on rice stems, we adopt three layers of detection that involve the following：（a） the first layer of detection is an AdaBoost classifier based on Haar features;（b） the second layer of detection is a support vector machine（SVM） classifier based on histogram of oriented gradient（HOG） features;（c） the third layer of detection is the threshold judgment of the three features. We use this method to detect and count whiteback planthoppers（Sogatella furcifera） on rice plant images and achieve an 85.2% detection rate and a 9.6% false detection rate. The method is easy, rapid and accurate for the assessment of the population density of rice planthoppers in paddy fields.

Mapping of a New Gene Wbph6(t) Resistant to the Whitebacked Planthopper, Sogatella furcifera, in Rice

A rice population consisting of 90 TN1/Guiyigu F3 lines was employed to analyze the linkage between DNA markers and a new gene Wbph6(t) conferring resistance to whitebacked planthopper, Sogatella furcifera By using the mapping approach of bulked extremes and recessive class, Wbph6(t) was mapped onto the short arm of chromosome 11 with a genetic distance of 21.2 cM to SSLP marker RM167.

Breeding and Characterization of a New Rice Restorer Line Containing Bt Gene

Bt5198, a new rice restorer line containing Bt gene, was developed from the cross and backcross of the elite restorer line Chenghui 177 with Bt Minghui 63, a transgenic Bt restorer line. The inbred lines were evaluated using PCR amplification, test paper evaluation, insect resistance evaluation in both the laboratory and paddy fields, nursery evaluation of rice blast resistance and pedigree selection of agronomic traits. Larval mortalities on Bt5198 and Bt Minghui 63 were 100% when rice culms were inoculated with the eggs of the striped stem borer （SSB） in the laboratory. Bt5198 was highly resistant against SSB and the yellow stem borer （YSB） under field conditions. The F1 hybrids derived from Bt5198 and four cytoplasmic male sterile （CMS） lines were also highly resistant to SSB and YSB and had a significant heterosis. Two-year evaluation of rice blast resistance confirmed that the resistance levels of Bt5198 to leaf blast and neck blast were similar to those of Chenghui 177 and significantly better than those of Bt Minghui 63. Seed germination ability and pollen yield of Bt5198 were similar with Chenghui 177, suggesting that the introduction of the Bt gene into the new restorer line had no significant effects on seed vitality or the yield of seed production. To identify the presence of the Bt gene, it was effective to combine test paper examination with the evaluation of insect-resistance, both in the laboratory and under field conditions.

Development of lepidopteran pest-resistant transgenic japonica rice harboring a synthetic cry2A* gene

A synthetic cry2A^＊ gene enco ding Bacillus thuringiensis（Bt） δ-endotoxi n that resi st ance to lepidopteran pest was transformed into japonica rice variety Jijing 88, which is the most widely cultivated variety in Jilin Province, Northeast China, by Agrobacterium-mediated transformation. A total of 106 independent transformants overexpressing cry2A^＊ gene driven by ubiquitin（Ubi） promoter was produced. Three single-copy homozygous transgenic lines were finally selected based on the results of PCR analysis, se gregation ratio of Bast a resistance, and Southern hybridiza tion analyse s. RT-PCR and enzyme linke dimmune sorbent assay（ELISA） revealed that cry2A^＊ transcripts and protein were highly expressed in these lines. The high level of Cry2A^＊ protein expression resulted in high resistance to rice striped stem borer as evidence d by insect feeding bioassays. Our results demonst rate that cry2A^＊ transgenic japonica rice confers resistance to the rice striped stem borer in the laboratory conditions.