赤泥对水稻植株各部位镉含量及水稻生物量的影响

随着稻田镉污染日益严重,镉在稻田中的不断富集,直接影响水稻生长和稻米品质。本实验主要通过测定水稻各部位镉的含量以及成熟期水稻株高、穗长、千粒重等指标,分析施用赤泥对水稻植株各部位镉富集以及水稻生物量的影响。结果表明,镉在水稻植株各部位的分布为根>茎>>叶>籽实。施用赤泥可减少镉在水稻各部位的累积,并能起到促进水稻生长的作用。在本实验中按7500kg赤泥/hm2土施用赤泥可以较好地减少水稻植株对镉的吸收。

纳米氧化物和溶磷真菌对盆栽水稻生物量和土壤有效磷含量的影响

采用室内培养基培养和盆栽试验方法研究了不同粒径、不同浓度纳米ZnO和纳米TiO_(2)对烟曲霉菌(Aspergillus fumigatus L.)和黄曲霉菌(Aspergillus flavus L.)溶磷能力、土壤有效磷含量、土壤磷酸酶活性和水稻生物量的影响。结果表明:添加100 mg/kg剂量的纳米TiO_(2)+接种A.flavus处理能够显著提高难溶性磷酸盐培养基滤液中的有效磷含量;添加30 nm粒径纳米ZnO 10 mg/kg+接种A.fumigatus处理的培养基中有效磷含量、盆栽水稻土壤磷酸酶活性以及水稻地下生物量均显著增加;添加500 mg/kg剂量的纳米ZnO抑制了真菌对磷酸盐的溶解能力。

外源铅对水稻土微生物量、微生物活性及水稻生长的影响

盆栽试验研究了土壤-水稻-铅-微生物相互作用的体系中，外源铅不同处理水平（CK、100、300、500、700、900mg·kg^-1）对两种水稻土壤微生物生物量碳、氮，微生物活性，水稻生理指标及生物量的影响。结果表明：水稻土壤中微生物量碳、氮，微生物活性及水稻叶绿素与生物量都随铅处理水平的增大而增加。多数指标在300～500mg·kg^-1铅处理时出现峰值。然后随铅水平的增加而降低，它们的转折点受土壤性质（如颗粒组成，有机质含量等）影响。试验范围内，水稻脯氨酸含量和过氧化物酶活性都随铅处理水平的增大而缓慢增加。体系中土壤微生物指标和水稻生理指标的变化存在一定的相关性，其大小也受土壤类型的制约。试验还表明，土壤微生物量氮、脱氢酶活性及水稻过氧化物酶活性是铅处理后更为敏感的生物学指标。

基于最佳植被指数组合的水稻鲜生物量估测

目前已经开展了大量基于单一植被指数的水稻生物量遥感监测研究。但由于生物量随着水稻生长是一个动态变化的过程,单一植被指数只能反映某一时期水稻冠层和背景信息而不能精确地用于整个生育期生物量的监测。为此,采用40个植被指数,利用具有正交特性的逐步回归法,建立了一个彼此间包含较少冗余信息的植被指数组合,该组合中不同的植被指数适应于水稻不同生育期生物量的估算。运用具有非线性预测能力的支持向量机对植被指数组合估测效果进行验证,R^2达到0.81,RMSE达到0.51 kg/m^2。结果表明此植被指数组合相较于单一植被指数更能反应水稻生物量的动态变化过程,具有较好的生物量估算能力,为水稻全生期育生物量估算提供了一个有效工具。

结合数据融合算法的光能利用率模型反演水稻地上部生物量

水稻作为世界范围内的重要粮食作物,其生长状况与产量信息的快速、精确获取,对保障耕地资源安全与粮食安全具有重要意义。本研究探索结合数据融合算法的光能利用率模型反演水稻地上部生物量,将增强型空间和时间自适应反射融合模型(ESTARFM)预测的水稻关键生长期数据,驱动EC-LUE(Eddy covariance-light use efficiency)模型反演水稻地上部生物量,分别验证2个模型的精度。结果显示,ESTARFM算法预测值与真实值的Pearson相关系数为0.668(P<0.001),对于中型耕地(11~50个Landsat像元),ESTARFM算法预测精度最为理想。EC-LUE模型反演的水稻地上部生物量预测值与地面实测值Pearson相关系数为0.630(P<0.001)。EC-LUE模型驱动数据的空间分辨率与时间分辨率是制约反演结果精度的关键因素。

大气CO_(2)浓度增加和升温对不同品种水稻根系形态的影响

[目的]本文旨在研究大气CO_(2)浓度增加和升温对不同品种水稻根系形态的影响。[方法]在田间开放条件下模拟大气CO_(2)浓度增加和升温,设置CT(对照,CO_(2)浓度和温度与正常大气环境保持一致)、C+T(大气CO_(2)浓度增加200μmol·mol-1)、CT+(冠层温度升高2℃)和C+T+(大气CO_(2)浓度和温度同时升高)4个处理。每个处理种植‘扬稻6号’和‘常优5号’2个品种,连续开展2年(2020、2021年)田间试验。在水稻分蘖期、灌浆期和成熟期采集地上部和根系样品,分析大气CO_(2)浓度增加、升温及其交互作用对地上部干重、根干重、根冠比和根系形态(根长、根直径、根表面积、根体积和根尖数)的影响。[结果]大气CO_(2)浓度增加显著提高不同生育期‘扬稻6号’和‘常优5号’地上部干重、根干重和根冠比,其中‘常优5号’的增加幅度大于‘扬稻6号’。大气CO_(2)浓度增加显著提高不同生育期‘扬稻6号’根长、根直径、根体积、根表面积和根尖数,分别提高了20.5%~25.8%、9.0%~12.3%、20.1%~47.3%、47.1%和23.0%~40.2%。‘常优5号’根长、根体积、根表面积和根尖数分别提高18.1%~22.7%、19.2%~68.1%、12.6%~65.2%和13.5%~44.3%。升温抑制了不同生育期‘扬稻6号’和‘常优5号’地上部干重、根干重和根冠比。升温显著降低不同生育期‘扬稻6号’根长、根体积、根表面积和根尖数,分别降低了9.7%~20.1%、15.8%~28.2%、22.0%~27.3%和13.8%~28.7%。‘常优5号’根长、根直径、根表面积和根尖数分别下降了31.4%~32.0%、8.6%、19.6%、18.0%~19.7%。大气CO_(2)浓度增加和升温对‘扬稻6号’和‘常优5号’不同生育期的根系形态和水稻生长存在显著的交互作用。[结论]大气CO_(2)浓度增加促进水稻生长和根系形态发育,升温抑制水稻生长和根系形态发育。大气CO_(2)浓度增加和升温交互作用抑制水稻生长和根系形态。

江西进贤水田长期施肥模式对水稻养分吸收利用的影响

利用江西进贤26年的长期定位试验,研究了不同施肥模式下水稻不同器官养分分配及其与土壤养分的关系。结果表明：长期施用化肥对土壤有机C含量没有显著影响,但显著提高了土壤中有效养分含量;有机无机肥配施显著提高土壤有机C和有效养分含量。水稻各器官对N、P、K的吸收存在明显差异,籽实中N、P的吸收量占总吸收量的比例分别为56%～73%和65%～85%,K的吸收则主要集中在秸秆（49%～60%）。籽实产量与N、P施肥量显著相关,施肥对根茬生物量的影响比对籽实、秸秆的影响更明显;土壤养分状况显著影响水稻籽实、秸秆与根茬的生物量。N、P、K化肥的均衡施用及有机-无机配施提高了水稻籽实产量,其中NPK＋OM处理籽实产量最高,较对照增产73.4%,2NPK与NPK处理分别增产59.5%和35.2%;配合施肥可以提高肥料表观利用率。水稻籽实、秸秆与根茬产量受土壤性质的影响显著,全P、速效P及碱解N与水稻总生物量极显著相关（相关系数分别为0.89,0.98和0.95）。

温度和CO_2浓度升高对稻田CH_4排放的影响:T-FACE平台观测研究

以同步模拟自由大气二氧化碳浓度和温度升高的太湖地区稻田T-FACE平台为依托,采用静态暗箱-气相色谱法原位观测研究了温度(T)和CO2浓度(C)升高以及温度和CO2浓度同步升高(CT)对稻田CH4排放的影响。结果表明:温度和CO2浓度升高并未改变稻田CH4排放的季节动态模式,但显著增加水稻生长季CH4的排放量,且促进效应依次为C>CT>T。在本底自由大气处理(CK)条件下,有、无水稻植株参与的稻田生态系统和土壤CH4季节平均排放通量分别为1.88、1.08 mg·m-2·h-1。有、无水稻植株参与下C、CT和T处理CH4季节排放量都较CK处理显著提高,分别增加了273%、106%、59%和317%、142%、79%。温度和CO2浓度升高显著增加了水稻生物量,相对于CK而言,C、T和CT处理导致水稻的生物量分别增加了24%、7%和16%。无论有、无水稻植株参与,稻田甲烷排放量与水稻生物量和产量均呈极显著正相关关系。

接种丛枝菌根真菌对麦秆分解和旱稻生长的影响

为探究丛枝菌根真菌对还田秸秆分解和作物生长的作用,以旱稻和麦秆为试验材料,利用盆栽试验研究接种AM真菌对麦秆分解率、氮素释放率、土壤酶活性以及旱稻叶绿素含量、根系活力、生物量的影响。结果显示:AM真菌的菌根定殖率为27.17%~28.53%。与秸秆还田不接菌处理相比,还田同时接种AM真菌处理显著促进了麦秆的分解率和氮素释放率,而且土壤蛋白酶、脲酶和纤维素酶的活性显著增加;秸秆还田同时接种AM真菌显著提高了旱稻第60天的根系活力和第90天叶片的总叶绿素含量,显著促进了地上部分和根系生物量的累积。在旱稻田接种AM真菌能有效促进麦秆的分解和土壤酶的分泌、增加旱稻的根系活力,有利于旱稻生物量的积累。

Genetic Analysis of a Biomass Mutant in Oryza sativa

[ Objective ] The study aimed to reveal the genetic model of a biomass mutant in Oryza sativa. [ Method ] In the process of screening and identification of Bar-transgenic rice, a biomass mutant was found in 10 lines of T1 progenies. The mutant was investigated for genetic analysis and agronomic traits by herbicide spraying and PCR amplification. [ Result] The segregation ratio is consistent with mendelian law（3：1）. The mutant assumed not only higher plant height, wider straw and earlier florescence, but also more tillers, bigger spikes and resultantly higher biomass. PCR detections indicated that no co-segregation was observed between mutant traits and target gene（Bar） in the T-DNA inserted, proving that the mutant is not caused by the insertion of T-DNA containing target gene （Bar）. [ Conclusion] Our study may avail to understand the cloning of mutant gene and the mechanism of the mutant gene on biomass.

The Effects of Cropping Methods on Growth, Crop Index and Yield Response to Water of Rice （Oryza sativa L.） in Rainfed Agriculture

In this study, four combinations of crops： rice （C）, rice-maize （MCSI）, rice-cassava （MCS2） and rice-maize-cassava （MCS3） with 3 m × 3 m each plots at two field areas--Saptosari and Tanjungsari were observed. Both field areas are located in Gunungkidul district, South-Central of Java Island, with that 93% at those areas are 185 m to 500 m above sea level and high proportion of multiple cropping systems （MCS）. The aim of this study was to investigate the effect of different cropping method on growth, crop index and yield response to water of rice in rainfed agriculture. Mathematical models were developed to describe rice growth. The rice height was followed monomolecular function and the number of tillers followed exponential polynomial function. Crop index was calculated from climate data during plant growth phase. And yield response to water was calculated from actual evapotranspiration （ETa） and the maximum evapotranspiration （ETm）. The results showed that the height of rice was not significantly different between each combination （P 〉 0.05）. Number of tillers was also not significant （P 〉 0.05）. However, monoculture treatment had more number of tillers than rice in MCS. Crop index of rice at Saptosari was higher than at Tanjungsari. Based on the calculation of evapotranspiration （ET）, water deficit at initial was less than at mid-season （ETa 〈 ETm） and affected water stress. Statistical analysis showed that cropping methods did not significantly affect rice growth and yield （P 〉 0.05）.

Modeling of Organ Morphology and Biomass Dynamics in Rice

Physiological processes governing rice plant light capture and subsequent crop growth and development are intimately tied to canopy architecture. Conversely, the production and spatial orientation of organs are dependent on the underlying physiological processes. An integrated functional-architectural modeling system would allow greater refinement of intra- and inter-plant interactions, facilitate the incorporation of additional mechanistic processes, allow greater integration of processes across multiple structural scales, and improve the accuracy of predictions. The objective of this study is to quantify the physiological bases for organ morphological development of 3 rice cultivars （Banks, IR68886B, and their hybrid Banks × IR68886A）. Detailed organ morphological data were obtained through repeated field observations and destructive samplings over the growing season, including leaf length, width, area, mass, and leaf phyllochron; sheath length, diameter and mass; internode length, diameter and mass; panicle length; stem and tiller number. The result showed that the plant age （GDD, 〉 10 ℃ d） at the first full leaf initiation （node = 2） was 147.92, 154.35, 166.23 for Banks, IR68886B, and Banks × IR68886A respectively. Banks × IR68886A produced 18 nodes, while IR68886B produced 17 nodes, and Banks 16 nodes. The Specific Leaf Weight （SLW, mg cm2） was fairly constant （about 6 mg cm2） during the growing season for the 3 cultivars, and appears to slowly increase for the latter nodes. The leaf length and SLW of Banks × IR68886A was more than Banks and IR68886B. Specific internodes weight of Banks x IR68886A was higher than IR68886B ×and Banks. Growing duration for Banks × IR68886A is longer than Banks and IR68886B. Banks × IR68886A shows positive heterosis,, and the mid-parent heterosis （MPH） for panicle length was 26.74% and that for stem and tiller number was 135.00%. Results from the experiments were used to parameterize a rice functional-architectural model that simulates organ dynamics and renders organ growth in a 3-dimensional space over the rice growing season.

An Attempt to Quantify Cu-Resistant Microorganisms in a Paddy Soil from Jiaxing, China

Understanding the mechanisms of Cu pollution-induced community tolerance (PICT) in soil requires the characterization of Cu-resistant microorganisms at a community level using modern molecular tools. A primer pair (copAF2010 (5 -TGCAC CTGAC VGGSC AYAT-3 )/copAR2333 (5 -GVACT TCRCG GAACA TRCC-3 )) tentatively targeting Pseudomonas-like Cu-resistant microorganisms was designed in this study. The specification of the primers was tested through conventional polymerase chain reaction (PCR) and the construction of a Pseudomonas-like copA gene fragment library, and then the primers were used to quantify the Cu-resistant microorganisms using quantitative PCR technique. A significant increase of Cu-resistant microorganisms targeted by the primers was observed in a paddy soil from Jiaxing, China which has been exposed to one-year Cu contamination. The results provided direct evidence for Cu PICT in the soil, and the quantification method developed in this study has the potential to be used as a molecular assay for soil Cu pollution.

Effcts of Irrigation Patterns and Nitrogen Fertilization on Rice Yield and Microbial Community Structure in Paddy Soil

Water and nitrogen （N） are considered the most important factors affecting rice production and play vital roles in regulating soil microbial biomass, activity, and community. The effects of irrigation patterns and N fertilizer levels on the soil microbial community structure and yield of paddy rice were investigated in a pot experiment. The experiment was designed with four N levels of 0 （NO）, 126 （N1）, 157.5 （N2）, and 210 kg N ha^（-1） （N3） under two irrigation patterns of continuous water-logging irrigation （WLI） and water- controlled irrigation （WCI）. Phospholipid fatty acid （PLFA） analysis was conducted to track the dynamics of soil microbial communities at tillering, grain-filling, and maturity stages. The results showed that the maximums of grain yield, above-ground biomass, and total N uptake were all obtained in the N2 treatment under WCI. Similar variations in total PLFAs, as well as bacterial and fungM PLFAs, were found, with an increase from the tillering to the grain-filling stage and a decrease at the maturity stage except for actinomycetic PLFAs, which decreased continuously from the tillering to the maturity stage. A shift in composition of the microbial community at different stages of the plant growth was indicated by principal component analysis （PCA）, in which the samples at the vegetative stage （tillering stage） were separated from those at the reproductive stage （grain-filling and maturity stages）. Soil microbial biomass, measured as total PLFAs, was significantly higher under WCI than that under WLI mainly at the grain-filling stage, whereas the fungal PLFAs detected under WCI were significantly higher than those under WLI at the tillering, grain-filling, and maturity stages. The application of N fertilizer also significantly increased soil microbial biomass and the main microbial groups both under WLI and WCI conditions. The proper combination of irrigation management and N fertilizer level in this study was the N2 （157.5 kg N ha^（-1）） treatment under the water-controlled irrigation pattern.

Responses of Soil Micro-Food Web to Land Use Change from Upland to Paddy Fields with Different Years of Rice Cultivation

Land use changes affect belowground ecosystems.During the past few decades,land use in Northeast China has changed considerably,and the area of paddy fields has increased rapidly from upland.In this study,soil characteristics and soil biotic community in paddy fields with different years of rice cultivation were measured to examine the effects of land use change from upland to paddy fields on soil micro-food web.The upland maize fields were selected as control and the microbial community composition was characterized using phospholipid fatty acids(PLFAs) analysis.The microbial biomass(total PLFA),bacteria biomass,and fungi biomass were higher in the 20-40-year(late-stage) than 1-10-year(early-stage) paddy fields.The abundances of total nematodes and bacterivores were lower in the early-stage than late-stage paddy fields.The abundance of herbivores was the highest in the early-stage paddy fields but that of omnivore-predators was the highest in the late-stage paddy fields.Structural equation model indicated that soil food web was developed and structured after 20 years of paddy cultivation.Our results suggested that soil micro-food web may be a good indicator for soil development and stabilization of paddy fields following land use change.