水域浮床水稻的干物质生产特性

 利用浮床无土栽培技术在自然水域种植杂交水稻,水上稻的产量比同期种植的水田稻增产12%左右。其本田生育前期总干物质积累量与水田稻基本接近,中、后期则明显高于水田稻,抽穗以后的总干物质积累量占总干物质积累量百分比较水田稻提高了3.4个百分点。水上稻绿叶干物质积累量在前期与水田稻基本接近,中、后期则一直保持比水田高30%左右的优势。茎鞘的干物质积累则呈现前、中期比水田稻低,但后期却反而高于水田稻的变化趋势,茎鞘的干物质输出率比水田稻低,对产量的贡献不如水田稻。     

适宜于水面种植的水上稻品种的评价

对适宜于自然水域水面上种植的水上稻品种进行了筛选和评价。结果表明，水上稻品种应根系发达，吸收低浓度养分的能力强，抗倒，生育期适中，不早衰，优质，产量高。筛选出中８７－１５６，泸红早１号，汕优１０号，秀水４８，秀水１１等５个适宜在杭州地区水上种植的品种。探讨了水上稻和水田灌溉稻在农艺性状和品质特性上的异同。     

不同供氮形态下水稻苗期磷吸收累积与根系形态的关系

【目的】植物根系形态对于适应低磷胁迫具有一定的可塑性,对提高磷的吸收利用具有重要意义。因此,本研究以长江中下游地区主推的102个水稻品种为供试材料,研究根系形态与水稻幼苗磷吸收利用的相关性。【方法】采用国际水稻所营养液培养方法,研究在NH_4^+-N和NO_3^--N供应条件下苗期植株生物量、磷含量和磷素累积量及其与根系形态指标的相关性。【结果】研究结果表明,在相同供氮水平(40 mg/L)下,供应NH_4^+-N时,水稻苗期平均生物量为67.87 mg/株,比供应NO_3^--N时高4.27 mg/株;水稻苗期平均磷含量为0.49%,比供应NO_3^--N时高0.10%;水稻苗期平均磷累积量为0.37 mg/株,比供应NO_3^--N时高0.10 mg/株。在NH_4^+-N条件下,水稻根系形态指标变异系数呈现根尖数>总根长>分支数>总根面积>交叉数>总根体积>平均根系直径的规律;在NO_3^--N条件下,水稻根系形态指标变异系数呈现根尖数>分枝数>总根长>总根面积>交叉数>总根体积>平均根系直径的趋势。在NH_4^+-N条件下,总根长、总根面积、分枝数、交叉数四个形态指标与植株生物量、磷含量、磷累积相关最为显著(P<0.01),而在NO_3^--N培养下,总根长、总根面积、根尖数、交叉数与植株生物量及磷素吸收累积指标相关性最为显著(P<0.01)。【结论】供应氨态氮,水稻营养指标与根系形态指标的相关性更高。水稻苗期根系总根长、总根面积、交叉数可作为水稻磷高效评价的重要指标。     

自然水域无土栽培水稻的生态适应性研究

 为探明自然水域浮床无土栽培水稻（简称水上种稻，下同）技术应用于大型水库等水域的可行性，1991～1993年，在浙江省境内的5种水域类型上进行了生态适应性试验。累计试种双季和单季稻4.33 hm2，均经受住了不同生态环境和不同年份气候条件的考验。其中，除连作早稻单产低于水田水稻对照外，其他两季的单产均超过了水田水稻对照。最高的双季连作稻和单季晚稻单产分别达14 985和10 065　kg/hm2。 从而证明，在各类型水域上进行水上种稻不但可行，且能取得与水田水稻相仿甚至更高的产量。     

水稻膜下滴灌栽培技术在我国发展的优势及前景分析

水稻膜下滴灌栽培技术通过滴灌、机械直播、覆膜等技术与水稻种植相结合,很大程度上改变了水稻"水田水作"的方式。与水稻传统种植相比,其优势在于全生育期无水层,只是局部灌溉,比水稻传统种植节水60%以上,肥料利用率提高10%以上,有利于降低化肥、农药污染以及稻田温室气体的排放量。     

水改旱不同种植模式效益比较分析

在干旱条件下，将水田改为旱地，分别种植大豆、玉米与大豆间套种和玉米，并与种植水稻产生的经济效益进行比较分析。结果表明，效益最好的种植模式是玉米与大豆间套种，亩产值为1152元，其次是净种玉米，其产值为1037元，分别比种植水稻亩产值高351元和236元，净种大豆效益最差，亩产值仅为740元。     

水稻生产存在的主要问题及解决途径

通过调查研究,总结出黑龙江省泰来县水稻生产中存在种植品种混杂、各乡镇栽培技术水平参差不齐、水田机械化程度低、水利设施不配套、推广体系不健全等问题。提出了壮大本地品牌,解决水稻品种杂乱现象;大力发展机改电项目,减少水稻生产投入;加强政策扶持和资金投入,提高水田机械化程度;完善水田水利设施及排灌渠系建设,解决水田排水难题;加强推广体系建设,提高技术到位率等针对上述问题的解决途径。     

间歇灌溉对水稻生长发育及产量性状的影响

针对黑龙江省水田面积日益扩大、水资源日益短缺这一现象,设计研究了间歇灌溉对水稻生长发育、产量性状的影响变化。试验在旱育稀植、培育壮秧的基础上,研究间歇灌溉条件下水稻分蘖动态、产量构成因子等方面的变化,为节水灌溉的研究与推广提供科学依据。     

膜下滴灌水稻高产栽培技术要点

水稻膜下滴灌栽培方法与传统水田水稻生产方式的根本不同之点在于前者是好氧条件下全程机械化水稻栽培,后者是在厌氧条件下栽培,故水稻膜下滴灌高产栽培有其独有的特点。新疆土壤都为盐碱地,含盐量大,对水稻的生长发育有极大的影响。通过多年研究,总结出了本膜下滴灌水稻高产栽培技术要点。     

水杨酸通过一氧化氮途径调控水稻缓解低磷胁迫

【目的】深入剖析水杨酸调控水稻低磷胁迫响应的生理与分子机制具有重要意义。【方法】选取常规水稻品种日本晴,外源添加水杨酸后测定水稻体内总磷含量、酸性磷酸酶活性、木质部汁液磷含量、水稻根系特征参数、磷转运子基因表达水平和一氧化氮含量等指标解析水杨酸缓解水稻缺磷胁迫的生理和分子机制。【结果】1）水杨酸对水稻磷吸收的调控存在剂量效应,1 μmol/L水杨酸显著提高低磷条件下水稻体内总磷含量,5 μmol/L水杨酸则降低水稻体内总磷含量。2）低磷条件下,1 μmol/L水杨酸使酸性磷酸酶活性提高了11.35%,根系总长增加了20.90%,根系表面积增加11.86%,根系体积增加了15.38%,总根数增加了23.55%,木质部汁液中的磷含量提高了22.67%。同时,1 μmol/L水杨酸提高了水稻根系磷转运子基因的表达,从而提高水稻对外界磷的吸收和体内磷的转运。3）水杨酸通过提高硝酸还原酶的活性增加水稻根系的一氧化氮含量,从而通过调控磷转运子基因的表达提高低磷条件下水稻对外界磷的吸收。【结论】水杨酸与信号分子一氧化氮互作缓解低磷胁迫。     

Convenient Estimation of Unfertilized Grains in Rice

Abstract

Failure of fertilization in rice is a critical yield-determining factor in plants subjected to temperature or water stress at the early-reproductive stage and in high-yield cultivars bearing heavy spikelets. Although it is important to identify quickly the unfertilized spikelets for research and selection of stress-resistant or high-ripening cultivars from bulksamples, the identification takes time because unfertilized spikelets are usually determined by visual and manual procedures. Our objective was to develop a convenient method to identify unfertilized spikelets in rice. Takanari spikelets at maturity grown in the paddy field were separated into floating and sinking spikelets by different specific gravity solutions of ethanol/water mixture. The unfertilized spikelets were identified by checking the grains inside the spikelets by light penetration and examining the spikelets manually. The percentage of floating spikelets decreased with the increase in ethanol concentration, and that of floating spikelets approximately coincided with the percentage of unfertilized spikelets when the specific gravity was below 0.90×10>³ kg m-³, corresponding to over 70% -ethanol. In a practical range of temperature the specific gravity scarcely changed. In an 80%-ethanol solution, the percentages of floating spikelets in Takanari grown under different nitrogen applications and in rice cultivars having different spikelet size approximately coincided with percentages of unfertilized spikelets, though the percentages of floating spikelets was 5 to 7% higher than the unfertilized spikelets. The use of 70%-ethanol solution increased the difference in some rice cultivars. We concluded that the gravitation method would be convenient for identification of unfertilized spikelets in bulk samples of rice.     

Effect of Field Drainage on Root Lodging Tolerance in Direct-Sown Rice in Flooded Paddy Field

Abstract

To elucidate the effect of drainage of paddy fields on root lodging tolerance in direct-sown rice, we measured the pushing resistance (R), diameter of hill at the base (Dm), shoot dry weight (Ws) and root dry weight (Wr), in rice varieties grown using several irrigation management schemes that differed in the frequency and length of field drainage during the growing season. Soil hardness was also monitored to investigate the relationship between the variance of soil physical properties caused by different irrigation treatments and root lodging tolerance. Pushing resistance moment (Rh), i.e., product of pushing resistance (R) and height of pushed part of hill (h), showed higher values in rice grown in fields drained more frequently or for longer periods. A similar pattern was found in rice grown in field plots where root penetration to the subsoil layers was prevented by laying an unwoven cloth between the topsoil and subsoil layers. Higher values for pushing resistance efficiency based on root dry weight (Kr : Rh/Wr/Dm) were also found in plots subjected to more frequent or prolonged drainage, irrespective of rice variety. Soil hardness was progressively increased by each field drainage during the growing season, and showed a highly significant relationship with Kr. The above results suggest that field drainage increases the root lodging tolerance in direct-sown rice through improvement of anchoring ability caused by increased soil hardness.     

香米品质与微量元素含量特征关系的研究

采用“江永香稻”与、香稻80－66”两个香稻品种，在香稻产地与非产地同时进行大田试验，对其稻米、灌溉水与土壤中的11种微量元素含量与稻米品质各项指标进行了分析。结果表明：不同产地同一品种稻米品质与不同品种稻米品质存在明显差异；江永香米的Zn,Mn,Cr含量均比普通稻米及香稻80－66的含量高，香稻80－66香米中Zn含量也较普通稻米高。香米产地香米香味长期不退化，可能与灌溉水中Zn元素含量较高有关。     

播种量对机插水卷苗秧苗素质及产量形成的影响

【目的】本研究旨在探明水卷苗机插高产适宜的播种量。【方法】以长江中下游地区代表性品种武运粳24号(常规粳稻)和6两优9368(杂交籼稻)为供试材料,研究不同播种量对水卷苗秧苗素质、机插质量、大田生长特性及产量的影响。【结果】移栽前秧苗地上部和根系干物质量、发根力、根系活性、成苗率、苗基宽、重高比及光合速率均随着播种量的降低而显著增强,叶面积指数显著下降。小播量处理秧苗返青活棵快、分蘖发生力强、每穗粒数多,但播量过小导致基本苗和穗数不足,当武运粳24号播种量从180g/盘降低到120g/盘(738.9g/m²)、6两优9368播种量从110g/盘降低到70g/盘(431.0g/m²)时,产量没有显著变化;但播种量继续降低,产量均显著下降。【结论】水卷苗育秧方法适宜播种量,常规粳稻为2.03粒/cm²,杂交籼稻为1.14粒/cm²。     

Variation of Germination Response to Temperature in Formosan Lily (Lilium formosanum Wall.) Collected from Different Latitudes and Elevations in Taiwan

Abstract

Deep penetration of an axile root is one of the important factors that allow crops to form deep root systems. In this study, the nodes from which the deepest penetrated roots had emerged were examined at the heading stage in upland rice and maize grown in large root boxes and in the field. Both experiments were designed to measure the direction, length, and rooting nodes of each root. In maize, the growth angles of axile roots increased with vertical elongation as rooting nodes acropetally advanced. The roots that emerged from the lower nodes, namely from coleoptilar to the second node, exhibited conspicuously horizontal elongation in the field, reaching 2.3 m in width at the maximum. The roots that emerged from higher than the fifth node were too short to penetrate deeply. Thus, these roots became the deepest root in less or no probability under field conditions. On the other hand, the fourth nodal root, which had an intermediate growth angle and length, had the highest probability. In upland rice, the deepest roots emerged from the nodes lower than the forth node on the main stem in the root boxes. In the field, however, the deepest roots emerged at later stages, that is, the roots from the middle nodes on the main stem and from the low nodes on the primary and secondary tillers were the deepest roots. Five out of nine of the deepest roots were from the prophyll nodes in three field-grown upland rice. The deepest roots from the same plant were estimated to have emerged and grown at approximately the same stage.     

苗期快速分选水稻人工无融合生殖克隆种子

【目的】人工无融合生殖系统的建立为水稻杂种优势固定提供了途径。当前人工无融合生殖系统在产生克隆种子的同时会伴随大量的四倍体种子,有必要开发简易高效的分选克隆种子方法。【方法】通过不同温度、盐浓度处理春优84和MiMe（同时突变PAIR1、REC8和OSD1获得的可将减数分裂转化成有丝分裂的材料）种子萌发的幼苗,观察它们形态学上的差异,确定最佳筛选条件。在最佳条件下,处理Fix材料（通过基因编辑技术同时突变PAIR1、REC8、OSD1和MTL基因获得的可固定杂种优势的材料）种子萌发的幼苗,根据形态差异分选克隆种子。利用流式细胞术确定分选的效率。【结果】无融合生殖材料Fix产生4.4%的克隆种子和95.6%的四倍体材料;而MiMe材料的后代全是四倍体。利用滤网在23℃、28℃和32℃水温条件下萌发春优84和MiMe种子48 h,MiMe材料的初生根直径在3种温度处理下均显著大于春优84,以28 ℃处理最优。在28 ℃水温条件下,利用0%、0.05%、0.1%、0.2%和0.5% NaCl溶液培养春优84和MiMe种子7 d,MiMe材料的根长、苗长与春优84无显著性差异,但春优84材料第1片完全叶在0.1%盐浓度下严重萎缩坏死,而MiMe材料受盐害影响较小。以28 ℃水温条件下先处理Fix种子48 h,先通过初生根根直径差异进行初次筛选,再利用0.1% NaCl溶液培养7 d,观察第1片完全叶形态差异再次分选,最后挑选出来的单株利用流式细胞术验证,分选效率达61.1%。将获得的克隆植株和四倍体对照种植田间,至成熟期表现明显的植株形态差异。【结论】在水稻苗期,对无融合生殖材料Fix进行温度及盐处理后,通过初生根、叶片等形态上差异可达到初步分选克隆植株的目标。     

蓝光对水稻幼苗生长效应的研究

蓝光对水稻幼苗生长效应的研究李韶山，潘瑞炽（华南师范大学，广州５１０６３１）ＥｆｆｅｃｔｓｏｆＢｌｕｅＬｉｇｈｔｏｎｔｈｅＧｒｏｗｔｈｏｆＲｉｃｅＳｅｅｄｌｉｎｇｓ￥ＬｉＳｈａｏｓｈａｎ；ＰＡＮＲｕｉｃｈｉ（ＳｏｕｔｈＣｈｉｎａＮｏｒｍａｌＵｎｉｖｅ...     

Field level damage of deepwater rice by the 2011 Southeast Asian Flood in a flood plain of Tonle Sap Lake,Northwest Cambodia

The 2011 flood damaged about 11 % of planting area in Cambodia, but the damaged proportion reached 30 % in Sangke district, Battambang province, located in the flood plains of Tonle Sap Lake. The aim of this study was to characterize completely damaged deepwater rice production due to the flood along the transect from the town-side shallower fields to the lake-side deeper fields. The flooding water from Tonle Sap Lake rose with 7 cm/day in September and October in the deeper fields where floating rice was grown and 8–10 cm/day in October in the shallower fields where lowland rice was grown. The maximum water was recorded on 16 October with 3.2 and 2.0 m at the deepest and shallowest edge fields. The area was characterized as flatness with only 1.2 m elevation differences in 4.3 km distance along the transect. The flooding water took 13.7 h for approaching 100 m distance. Complete recession of flood water was end of November at the shallow edge and at late December in the deep edge in 2011. The flooding duration deeper than 50 cm was 2.5 month and nearly 3 months in the middle zone and deeper floating rice area, respectively. The complete submergence started first in some fields in the middle zone on 12 September, followed by the shallower lowland rice area, and finally in the deep floating rice area by 1 October. Countermeasures to improve rice production in deepwater rice area in the floodplain of Tonle Sap Lake were proposed.     

水稻种质对稗草和莴苣的化感效应研究

用改进的叶浸提法和田间共生鉴定法,比较分析了从124份不同来源水稻种质中初步筛选的27份化感种质对稗草和莴苣的化感抑制效果。结果表明,叶浸提液对莴苣的抑制效果明显大于稗草;对稗草和莴苣根长的抑制效果大于苗高和发芽势;叶浸提液法与田间共生法对稗草的抑制效果呈显著的正相关,两种方法的鉴定结果有较高的一致性。叶浸提液对稗草发芽势的抑制指数与田间共生对稗草苗干重的抑制指数及其综合抑制指数呈极显著的正相关,认为稗草种子发芽势可作为测试水稻种质化感效应的重要指标。田间水稻苗高与叶浸提液对稗草根长的抑制指数及其综合抑制指数和田间共生对稗草苗高和苗干重的抑制指数及其综合抑制指数呈极显著的正相关,水稻苗高较高的种质较苗矮的种质表现出较强的化感效应。珍珠42、沙粘1、六月早、青团2号、红脚粘2和地谷的化感效应突出,对稗草的平均综合抑制指数分别为0.56、0.47、0.45、0.45、0.41和0.39,可作为强化感种质提供应用。