磷肥对土壤中镉的植物有效性影响及其机理

为寻求保障镉污染农田稻米质量安全的有效措施,采用盆栽方法研究了低镉磷肥(Cd＜0.2 mg·kg^-1)及不同施磷量(0.10、0.20 g P₂O₅·kg^-1)对污染稻田土壤中(潮泥田)镉的植物有效性影响,并探讨了相关机理.结果表明： 在0.10 g·kg^-1磷剂量水平下,与对照(无磷肥)相比,钙镁磷和磷酸二氢钾处理显著提高了土壤pH和降低了土壤镉活性,钙镁磷和过磷酸钙处理显著降低了水稻对镉的吸收累积;当施磷量增至0.20 g·kg^-1时,磷酸氢钙处理显著提高了土壤pH和降低了土壤镉活性,钙镁磷、磷酸二氢钾和磷酸氢钙处理下DTPA提取态镉含量降低11.8%、9.8%和11.8%,NH₄OAc提取态镉含量降低9.5%、7.1%和7.1%;5种磷肥处理均显著降低了水稻茎叶中镉含量(降幅24.9%～50.8%),除磷酸氢钙处理外,糙米镉含量的降幅均达到显著水平,钙镁磷和过磷酸钙处理下糙米镉含量接近国家粮食卫生标准(GB 2715-2005).5种供试磷肥中,能提高土壤pH的磷肥(钙镁磷、磷酸二氢钾和磷酸氢钙)降低土壤镉有效性的效果显著,含钙磷肥(钙镁磷和过磷酸钙)降低水稻镉积累的效果较好.磷肥化学性质的差异可能是影响其效果的主要原因,选择碱性含钙磷肥对控制污染农田中作物吸收累积镉更有效.     

长期不施磷对稻田温室气体排放的影响

稻田磷肥的“旱重水轻”施肥策略是有效提高磷素利用率、减少磷素流失的有效技术途径,但稻季不施磷对温室气体排放的影响尚不明确。本研究监测了苏州和宜兴两块长期定位试验田中正常施磷与不施磷处理水稻生育期内CH₄和N₂O的排放通量。结果表明: 与正常施磷处理相比,长期不施磷处理均显著促进了稻田CH₄和N₂O排放,其中,苏州试验田CH₄和N₂O排放量分别增加57%和25%,宜兴试验田CH₄和N₂O排放量分别增加221%和70%。长期不施磷使土壤的速效磷、有机酸和可溶性有机碳含量下降,与CH₄排放密切相关,特别是土壤速效磷含量与CH₄排放量呈显著负相关,相关系数r=-0.987。两处试验田不施磷处理的全球增温潜势均大于施磷处理。因此,稻田长期缺磷会对土壤有机酸、可溶性有机碳和速效磷含量产生影响,进而增加稻田CH₄和N₂O的排放。     

干旱绿洲灌区大白菜施磷效应与磷肥投入阈值

针对磷肥施用量大且利用率不高的问题,通过2011—2013年在甘肃省农业科学院张掖绿洲灌区农业生态环境重点野外台站进行定位试验,研究了不同施磷量对露地大白菜产量、磷肥利用率以及磷素平衡的影响.结果表明:大白菜产量随施磷量的增加先增加后呈下降的趋势.在施磷量为112.52 kg·hm^-2时产量达到最高(5489.1 kg·hm^-2),且显著高于其他处理,与不施磷处理相比,增产13.3%~23.8%,此时磷肥利用率为14.2%.土壤中土壤有效磷(Olsen-P)和可溶性总磷(CaCl-P)呈现较好的正相关性,土壤Olsen-P含量为24.22 mg·kg-12时对应的施磷量为111.1 kg·hm^-2,表明当土壤中Olsen-P含量小于24.22 mg·kg-1时,土壤中的磷素不发生盈余,对环境不造成污染.当施磷量为60.17 kg·hm^-2时,磷输入与输出达到平衡,即此施磷量水平能满足作物的需求.结合研究区的土壤肥力状况,综合产量、磷肥利用率及土壤有效磷含量,干旱绿洲灌区磷肥投入阈值在60.17~112.52 kg·hm^-2时,能保证露地大白菜高产,并且不会造成环境污染.     

不同播期和抽穗期弱光胁迫对杂交稻生理性状及产量的影响

以耐阴性中等的杂交稻川香9838为材料,研究不同播期和抽穗期弱光胁迫对杂交稻抽穗期光合特征、渗透调节物质、保护性酶活性和产量的影响.结果表明:不同播期和抽穗期弱光胁迫对水稻抽穗期干物质积累、剑叶光合速率、抗氧化酶活性和产量均有显著影响.随播期的推迟,全生育期明显缩短,稻谷产量呈不同程度的下降趋势.与对照相比,抽穗期轻度弱光胁迫(遮光20％)能缓解水稻生育过程中面临的高温及强光照危害,进而能缓解剑叶光合速率和抽穗期干物质累积的降低,调节抗氧化酶活性,适度提高结实率;而抽穗期中度(遮光40％)、重度(遮光60％)弱光胁迫均不利于水稻生长.剑叶光合速率、丙二醛含量和超氧化物歧化酶活性对播期和抽穗期弱光胁迫较为敏感.水稻始穗1 ～5d剑叶光合速率与稻谷产量和抽穗后干物质积累量显著相关.     

缺磷条件下不同水稻品种磷素吸收特性的研究

缺磷条件下,供试粳稻品种植株的单株鲜重、干重、全磷含量和单株磷累积量等具有较大差异,从中筛选出磷高效品种TP309和优质8号,其中TP309较磷低效品种早88-1的全磷含量和单株磷累积量分别增加37.50%~40.00%和82.76%~102.00%。单株根数、平均根长和根系体积与单株磷素吸收量的相关程度较小,光合速率(Pn)、叶片可溶蛋白含量和叶片可溶性糖含量均表现为随着吸磷量的增加而不断增大。     

施磷对土壤速效磷含量及径流磷组成的影响

在水稻生长季节设置不同施磷水平 (0、30、70、15 0、30 0 kg P/hm2 )田间小区试验 ,研究施磷对环境及水稻产量的影响。结果表明 ,施磷量与土壤速效磷含量、土表径流磷含量均呈极显著正相关 ,随施磷量提高 ,表层土壤速效磷含量明显增加 ,径流磷含量也随之增加。早期径流液中的磷以颗粒磷为主 ,而后期可溶性磷的比例加大。一般施磷水平下径流液的可溶性磷中有机磷占的比例较大 ,而大施磷量时无机磷占的比例较大。虽然通过径流损失的磷占总施磷量的 0 .2 %以下 ,但径流液中可溶性磷的浓度和总磷浓度均已超过水体富营养化磷浓度的临界值 ,意味着长期的田间排水存在诱发附近水体富营养化的可能     

长期施磷对玉米-小麦轮作系统作物产量和磷素吸收及土壤磷积累的影响

本研究利用位于河北省保定市的7年田间定位试验,探讨了4个磷水平(不施磷、70%优化施磷、优化施磷、130%优化施磷)对玉米-小麦轮作系统作物产量的影响,分析了作物磷素吸收和磷肥利用效率以及土壤磷盈亏的变化。结果表明: 长期(7年)施磷能够显著提高玉米和小麦产量及磷素吸收量,且玉米和小麦产量与磷素吸收量随着施磷量的增加均呈现先上升后下降的抛物线变化趋势。各施磷水平下玉米季磷肥利用率高于小麦季,小麦季磷肥累积利用率呈现下降趋势,下降速率表现为优化施磷>70%优化施磷>130%优化施磷;玉米季磷肥累积利用率均呈现上升趋势,上升速率表现为优化施磷>70%优化施磷>130%优化施磷。长期不施磷条件下土壤表观磷盈亏量和累积磷盈亏量都表现为亏缺状态,施磷条件下土壤磷表现为盈余,且施磷量越高,累积年限越长,土壤磷盈余量越高。河北潮土在秸秆还田条件下小麦施磷量在105～150 kg·hm^-2,玉米施磷量在63～90 kg·hm^-2时,既能保证作物高产,又能使磷肥利用率保持在较高水平,减少磷素在土壤中的累积,降低环境风险。     

施磷对鲜食甘薯产量、品质及磷利用效率的影响——以徐薯32为例

为了探索适宜的磷肥用量,提高鲜食型甘薯的经济产量和磷肥利用率,以徐薯32为例,于2018—2019年进行两年的田间试验(土壤有效磷含量为31.70 mg·kg^-1),比较了不同施磷量对鲜食甘薯产量、品质、磷积累和磷利用效率的影响。试验设置5个施磷水平(P₂O₅),分别为0(P₀)、25(P₂₅)、50(P₅₀)、75(P₇₅)和100 kg·hm^-2 (P₁₀₀)。结果表明: 1)与P₀相比,施磷显著提高了鲜薯产量和商品薯产量,以P₇₅处理最高,其次为P₅₀处理,两处理间差异不显著。2)施磷显著提高了薯块中淀粉和还原糖含量,在P₅₀处理下可溶性糖和蛋白质含量显著增加。3)在生育期90～120 d,施磷显著提高了甘薯的磷积累量和干物质积累量。4)磷表观利用率随着施磷量的增加而下降,磷农学效率则随着施磷量的增加先升后降,在P₅₀处理下显著高于其他处理。综合考虑鲜薯产量、品质、经济产量和磷肥利用率,本试验条件下P₂O₅的适宜用量为50 kg·hm^-2。     

磷肥对土壤中镉的植物有效性影响及其机理

为寻求保障镉污染农田稻米质量安全的有效措施,采用盆栽方法研究了低镉磷肥(Cd＜0.2 mg·kg-1)及不同施磷量(0.10、0.20 g P2O5·kg-1)对污染稻田土壤中(潮泥田)镉的植物有效性影响,并探讨了相关机理.结果表明:在0.10 g·kg-1磷剂量水平下,与对照(无磷肥)相比,钙镁磷和磷酸二氢钾处理显著提高了土壤pH和降低了土壤镉活性,钙镁磷和过磷酸钙处理显著降低了水稻对镉的吸收累积;当施磷量增至0.20 g·kg-1时,磷酸氢钙处理显著提高了土壤pH和降低了土壤镉活性,钙镁磷、磷酸二氢钾和磷酸氢钙处理下DTPA提取态镉含量降低11.8％、9.8％和11.8％,NH4OAc提取态镉含量降低9.5％、7.1％和7.1％;5种磷肥处理均显著降低了水稻茎叶中镉含量(降幅24.9％ ～ 50.8％),除磷酸氢钙处理外,糙米镉含量的降幅均达到显著水平,钙镁磷和过磷酸钙处理下糙米镉含量接近国家粮食卫生标准(GB 2715-2005).5种供试磷肥中,能提高土壤pH的磷肥(钙镁磷、磷酸二氢钾和磷酸氢钙)降低土壤镉有效性的效果显著,含钙磷肥(钙镁磷和过磷酸钙)降低水稻镉积累的效果较好.磷肥化学性质的差异可能是影响其效果的主要原因,选择碱性含钙磷肥对控制污染农田中作物吸收累积镉更有效.     

氮磷肥配施对苦荞根系生理生态及产量的影响

以苦荞品种‘迪庆’为材料,在盆栽试验条件下,研究了氮(纯氮用量分别为0g/kg、0.1g/kg、0.2g/kg)、磷(P2O5用量分别为0.1g/kg和0.2g/kg)配施对苦荞根系生长、生理指标及其产量的影响,旨在为黄土高原苦荞高产优质栽培提供理论依据。结果表明:(1)在相同施磷量条件下,苦荞幼苗的株高、茎粗、茎叶干重、主根长、根表面积、根系体积、根系直径、根系干重以及壮苗指数等均随施氮量的增加而呈先升后降的趋势,但根冠比随施氮量的增加而呈先降后升的趋势;叶片叶绿素含量以及根系活力、酸性磷酸酶(Apase)活性、可溶性蛋白含量和植株氮积累量随施氮量的增加呈抛物线变化趋势,根系硝酸还原酶(NR)活性和植株氮含量随施氮量的增加而增加;而根系可溶性糖含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、丙二醛(MDA)含量和游离脯氨酸含量等指标均随施氮量的增加而呈先降后升的趋势,0.1g/kg施氮处理各指标均显著低于其他处理;成熟期单株粒重、百粒重随施氮量的增加呈先升后降的趋势,0.1g/kg施氮处理各指标均显著高于其他处理。(2)在相同施氮量条件下,随着施磷量的增加,苦荞根系酸性磷酸酶(Apase)活性、SOD活性、POD活性、MDA含量、可溶性糖含量、可溶性蛋白以及游离脯氨酸含量等指标均降低,其余各指标则呈增加趋势。(3)无论施磷量条件如何,0.1g/kg的施氮处理下苦荞产量最高,与其他施氮处理相比,在低磷和高磷处理下的增产幅度分别为7.04%~37.40%和14.73%~68.26%;在施氮量一定的情况下,高磷处理比低磷处理增产15.96%~42.00%。(4)在该试验条件下,适当的氮磷肥配施表现出了明显的正加和效应,但过量施肥也有可能导致增产幅度下降,中氮高磷(施纯N量0.1g/kg,施P2O5量0.2g/kg)配施效果最优。     

超高产杂交稻不同生育期的光合色素含量、净光合速率和水分利用效率

 较为系统地研究了两个超高产杂交稻‘两优培九’、‘华安3号’和多年来大面积推广的常规杂交稻‘汕优63’不同生育期的光合色素含量、净光合速率和水分利用效率。结果表明,在苗期,3个杂交稻的单位叶面积的叶绿素（Chl）含量差别不大,类胡萝卜素（Car）的含量以‘汕优63’为最高。然而,随着发育阶段的推进,到分蘖期,尤其是抽穗期剑叶的单位叶面积Chl和Car含量,两个超高产杂交稻高于‘汕优63’。从苗期到抽穗期,超高产杂交稻‘两优培九’和‘华安3号’的净光合速率（Pn）都比‘汕优63’高,而在苗期的午间强光条件下和分蘖期的早晨以及抽穗期的早晚相对弱光条件下其Pn的差别尤为显著。在苗期,‘汕优63’的水分利用效率（WUE）略高于‘两优培九’和‘华安3号’;到分蘖期和抽穗期,在上午10时之前和下午14时以后的时间段,则是两个超高产杂交稻明显高于‘汕优63’。这些结果说明,超高产杂交稻‘两优培九’和‘华安3号’不仅有较高的Pn和较强的抗光抑制能力,而且还能充分利用早晨和傍晚较弱的光强进行光合作用,这些是它们之所以高产的重要生理基础。此外,超高产杂交稻在生长发育的中后期（分蘖期和抽穗期）具有较高的WUE,有利于节约农业用水。     

Olfactory response of Stenotus rubrovittatus to rice and paddy weed,Scirpus juncoides

The olfactory response of the sorghum plant bug, Stenotus rubrovittatus (Matsumura) (Het., Miridae), to rice, Oryza sativa L., and paddy weed, Scirpus juncoides Roxb. var. ohwianus T. Koyama, was investigated with an olfactometer to clarify the mechanism of the invasion of the bugs in paddy fields. Both adult females and males were significantly attracted to panicles of rice in the flowering and full‐ripe stages. Whole plants (aboveground parts) of rice in the panicle‐formation stage, and stems and leaves of rice in the flowering stage significantly attracted only adult females. Other rice structures tested did not attract males or females. Both males and females were attracted to the flowering spikelets of S. juncoides. Although females showed no olfactory response to stems of S. juncoides in the flowering stage, males were repelled by them. Only females were attracted to whole plants of flowering S. juncoides. Whole plants of S. juncoides in the spikelet‐formation stage significantly attracted only females. The findings suggest that the invasions of S. rubrovittatus into paddy fields are caused by their olfactory responses to the volatiles emitted from rice and some paddy weeds such as S. juncoides.     

外源海藻糖对高温胁迫下穗分化期水稻叶片生理特性及产量的影响

该研究以耐热型水稻品种Nagina22和热敏型水稻品种YR343为供试材料,采用盆栽试验,设置喷施清水+常温处理(NT0)、喷施清水+穗分化期高温胁迫(HT0),以及分别喷施5、10、15、20 mmol·L^-1外源海藻糖+高温胁迫(分别记为HT1、HT2、HT3、HT4)共6个处理,分析外源海藻糖对高温胁迫下穗分化期水稻叶片叶绿素含量、光合气体交换参数、抗氧化酶活性、渗透调节物质含量、活性氧含量等生理特性,以及籽粒产量及其构成因素的影响,为水稻抗热栽培和耐热品种的选育提供理论依据。结果表明:(1)在高温胁迫下水稻穗分化期,2个水稻品种叶片的叶绿素含量、光合气体交换参数及渗透调节物质含量均降低,叶片MDA和H₂O₂含量以及■的产生速率均上升,叶片抗氧化酶活性呈先增后降的趋势,最终显示水稻籽粒产量及其构成因素显著下降。(2)喷施外源海藻糖能显著增加高温胁迫下穗分化期水稻的每穗粒数、千粒重和结实率,从而提高籽粒产量,其中弱势粒千粒重和结实率的增幅高于强势粒,外源海藻糖最适喷施浓度为15 mmol·L^-1...     

Enhancement of Yield,Grain Quality Characters, 2-Acetyl-1-Pyrroline Content,and Photosynthesis of Fragrant Rice Cultivars by Foliar Application of Paclobutrazol

Paclobutrazol is a well-known plant growth regulator. However, the application of paclobutrazol in fragrant rice production has not been reported. The present study conducted a field experiment with two cropping seasons and three fragrant rice cultivars to investigate the effects of paclobutrazol application on yield formation, grain quality, 2-acetyl-1-pyrroline (2-AP, key component of fragrant rice aroma) biosynthesis, and photosynthesis of fragrant rice. At the initial heading stage, paclobutrazol solutions at 0 (control), 30, 60, 100, and 120 mg L^?1 were foliar applied to fragrant rice plants, respectively. Compared with control, paclobutrazol treatments significantly (P?<?0.05) increased grain yield and seed-setting rate of fragrant rice cultivars by 6.77–22.82% and 5.09–25.66%, respectively. Increased contents of photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoid) and the improved net photosynthetic rate at the grain-filling stage were observed due to paclobutrazol treatments. The paclobutrazol application increased head rice rate and grain 2-AP content by 3.94–8.94% and 6.47–18.80%, respectively. Lower chalky rice rate and chalkiness were recorded in paclobutrazol treatment than in control. Moreover, foliar application of paclobutrazol increased proline and Δ1-pyrroline contents in fragrant rice by 7.90–32.12% and 13.21–34.90%. Overall, foliar application of paclobutrazol could enhance productivity, improve grain quality, and increase the 2-AP content of fragrant rice, and 100–120 mg L^?1 was considered the suggested concentration of paclobutrazol application in fragrant rice production.

     

秸秆还田配施不同比例化肥对晚稻产量及土壤养分的影响

在不同秸秆还田方式对早稻的效应研究确定的最佳还田方式和还田量(粉碎还田3000 kg/hm2)基础上,以单施秸秆为对照,研究了秸秆还田配施不同比例化肥对晚稻产量、干物质积累与分配及土壤养分的影响。结果表明:(1)与对照相比,秸秆3000 kg/hm2+N 150 kg/hm2+P2O575 kg/hm2+K2O 37.5 kg/hm2增产效果最为显著,在水稻的每穗粒数、千粒重、结实率、充实度和产量等方面增加幅度最大,分别为9.32%、4.28%、13.70%、2.74%和26.38%。(2)各处理的干物质茎鞘比例随着生育进程不断降低,从孕穗期的66.68%—77.00%降低至成熟期的25.97%—34.79%,除SNPK1外,叶片比例从孕穗期的23.00%—33.32%降低至成熟期的7.41%—21.03%;秸秆还田配施不同比例化肥处理的茎鞘比例在孕穗期、抽穗期和成熟期高于对照,而叶片比例与茎鞘比例呈相反趋势。(3)与对照相比,秸秆还田配施不同比例化肥处理提高了土壤pH值、有机碳、全氮、碱解氮、全磷、有效磷、全钾、速效钾,降低了土壤C/N比。研究结果说明,秸秆还田配施不同比例化肥可以提高植株干物质积累速率、群体生物量,合理改善土壤养分,保证较高的水稻增产潜力,其中秸秆3000 kg/hm2+N 150 kg/hm2+P2O575 kg/hm2+K2O 37.5 kg/hm2效果最为显著。     

Relationship between leaf photosynthetic function at grain filling stage and yield in super high-yielding hybrid rice (<Emphasis Type="Italic">Oryza sativa</Emphasis>. L)

The characteristics of dry matter production before and after heading and the relationships between photosynthesis of flag leaves and dry matter accumulation in panicles were investigated on super high-yielding rice cv. Xieyou 9308 (the yield of up to 12 t/ha) with rice cv. Xieyou 63 as a control. The results showed that (i) the capacity of dry matter production before and after heading in Xieyou 9308, i.e. biomass and daily dry matter production, was remarkably higher than that in Xieyou 63, especially after heading; (ii) CO₂ assimilation capacity in flag leaves in Xieyou 9308, namely Leaf Source Capacity (LSC), was also significantly higher than that in Xieyou 63, and the supply of photosynthate in leaves and the demand of grain filling were completely synchronous in Xieyou 9308, but photosynthetic function in flag leaves in Xieyou 63 declined sharply 20 days after heading and it was not enough to meet the demand of grain filling. These results confirmed that high efficient photosynthetic function in leaves after heading and its complete synchronization with grain filling are the key approaches to super high yield of rice.     

稻田土壤氧化态有机碳组分变化及其与甲烷排放的关联性

稻田土壤有机碳是甲烷排放的关键底物之一,不同研究者由于采取的有机碳研究方法不同而得出稻田甲烷排放与土壤有机碳关系的结论不一.为明确影响稻田甲烷排放的土壤有机碳组分,设计了稻田施用不同外源有机碳(稻草还田、鸡粪和猪粪)的田间试验,对稻田甲烷排放和土壤有机碳组分的动态变化及其关联性进行监测和分析.结果表明,猪粪处理的甲烷排放与化肥处理无显著差异,而鸡粪和稻草2个处理的甲烷排放分别比化肥增加1.67倍(P＜0.05),2.69倍(P＜0.05);甲烷排放量与土壤易氧化有机碳含量显示相同顺序:稻草＞鸡粪＞猪粪＞化肥;通径分析表明,土壤易氧化有机碳组分1(被33 mmol/L KMnO4氧化的有机碳)与甲烷排放直接相关,其他有机碳组分仅通过组分1间接作用于水稻生育后期甲烷排放,且排放量较低.由此推断,易氧化有机碳组分1是甲烷排放的主要底物,通过有效措施降低肥源中易氧化态有机碳组分1是减排甲烷的关键技术之一.     

Relationship between leaf photosynthetic function at grain filling stage and yield in super high-yielding hybrid rice ( Oryza sativa . L)

The characteristics of dry matter production before and after heading and the relationships between photosynthesis of flag leaves and dry matter accumulation in panicles were investigated on super high-yielding rice cv. Xieyou 9308 (the yield of up to 12 t/ha) with rice cv. Xieyou 63 as a control. The results showed that (i) the capacity of dry matter production before and after heading in Xieyou 9308, i.e. biomass and daily dry matter production, was remarkably higher than that in Xieyou 63, especially after heading; (ii) CO₂ assimilation capacity in flag leaves in Xieyou 9308, namely Leaf Source Capacity (LSC), was also significantly higher than that in Xieyou 63, and the supply of photosynthate in leaves and the demand of grain filling were completely synchronous in Xieyou 9308, but photosynthetic function in flag leaves in Xieyou 63 declined sharply 20 days after heading and it was not enough to meet the demand of grain filling. These results confirmed that high efficient photosynthetic function in leaves after heading and its complete synchronization with grain filling are the key approaches to super high yield of rice.     

Olfactory response of Trigonotylus caelestialium (Het.: Miridae) to rice plant and gramineous weeds

Abstract:  The olfactory response of Trigonotylus caelestialium , to rice, Oryza sativa L., and two species of gramineous weeds, Poa annua and Digitaria ciliaris , was investigated with an olfactometer to clarify the role of host-plant odours as olfactory cues in their host-finding behaviour. Third-instar nymphs and adult males were significantly attracted to whole plants (above ground parts) of P. annua . However, adult females were not significantly attracted to whole plants of P. annua . Attractancy of rice to T. caelestialium differed with the growth stage and part of the plant. Adult females were significantly attracted to stems and leaves in the panicle-formation stage, and panicles in the flowering stage. They were not attracted to stems and leaves in the fourth-leaf stage and flowering stage, or to panicles in the milk-and full-ripe stages. Although adult males were significantly attracted to stems and leaves in the panicle-formation stage, they were not attracted to the other rice structures tested. Both females and males were significantly attracted to stems and leaves, as well as panicles of D. ciliaris in the flowering stage. The findings suggest that T. caelestialium use host-plant volatiles as olfactory cues to find their host plants and their invasion to paddy fields were caused by olfactory responses to rice plant.     

不同生育阶段夜温升高对双季水稻产量的影响

利用两间玻璃温室内夜间不同的温度条件,研究了水稻不同生育阶段的夜温升高对双季早、晚稻产量的影响.结果表明：播种-幼穗分化（一次枝梗分化期）期间夜温升高,有利于双季水稻的分蘖,植株有效穗数显著增加,平均夜间最低温度每升高1 ℃,双季早、晚稻的产量分别提高10.02%～13.18%和6.52%～7.78%（P＜0.01）;幼穗分化-抽穗（10%稻穗抽出剑叶鞘）期间夜温升高,导致颖花退化,使每穗发育颖花数减少,平均夜间最低温度每升高1 ℃,双季早、晚稻的产量分别下降3.76%～6.67%和3.66%～6.94%（P＜0.01）;灌浆结实期（抽穗-成熟）夜温升高,双季早稻的结实率和产量显著下降,而双季晚稻的结实率和产量显著提高,平均夜间最低温度每升高1 ℃,双季早稻的产量下降2.07%～5.61%（P＜0.05）,双季晚稻的产量提高1.63%～2.28%（P＜0.05）.表明不同生育阶段的夜温升高对双季水稻产量的影响存在明显差异.