不同施氮量对水稻氮素吸收与分配的影响

运用15N示踪法研究了不同施氮量对两个品种水稻（4007和武运粳15）干物质积累量与其对15N吸收及分配的影响。结果表明,当施氮量超过N 150 kg/hm2时, 两个品种水稻子粒产量均不再显著增加。4007在4个施氮量下(N 100,150,200和 250 kg/hm2)分别比无氮区增产22.3%,36.9%,43.2%和38.1%;武运粳15分别增产10.6%,18.8%,27.1%和21.5%。同一施氮量下,4007子粒中15N累积量显著高于武运粳15,但茎叶和根中没有差异。增加施氮量降低了15N在水稻子粒中的分配比例,但提高了茎叶中15N的分配比例。15N在根中的分配比例不受施氮量和品种的影响。研究结果还表明,同一施氮量下,4007对肥料氮的总体利用率要比武运粳15高3～6个百分点。     

实时实地氮素管理对水稻产量和氮素吸收利用的影响

以扬两优6号和培两优3076水稻为材料,通过田间试验比较研究了基于SPAD值的氮素管理对水稻氮素吸收、产量和氮肥利用率的影响。结果表明,随着SPAD预设阈值的增加,氮肥用量增加,籽粒产量和氮素吸收也随之增加。实时氮素管理条件下,水稻扬两优6号和培两优3076均以SPAD值为41处理获得较高的籽粒产量和氮素利用率,该处理在籽粒产量不降低的同时节约了氮肥用量12. 8% ～33.3%;而实地氮素管理条件下,水稻扬两优6号和培两优3076均以SPAD值为39～41处理获得较高的籽粒产量和氮素利用率,该处理在籽粒产量不降低的同时节约了23.1%的氮肥用量。鉴于实地氮素管理在田间易于操作,因此建议采用39～41作为水稻关键生育期指导氮肥施用的SPAD阈值。     

环境因子变化对水稻氮素吸收及接种效益的影响

联合固氮菌在不同土壤环境中受水、肥、气、热等土壤因素的影响较大，其适宜参数是：（１）浅水或湿润灌溉稻田水层在５￣１６ｃｍ左右；（２）氮素总施肥量在７￣９ｋｇ／ｍｕ为宜，≥１１ｋｇ／ｍｕ增效显著性极低；（３）稻田氧化还原电位在１５０ｍＶ￣２００ｍＶ既有利于菌又有利于水稻的生长；（４）稻田水层昼夜温差在２．４℃左右。试验研究表明，必须选育出新的更加耐氨（即土壤碱解氮在１６８ｐｐｍ以上）的水稻联合工程固     

川东北麦秆还田对水稻氮素吸收转运的影响

为合理利用秸秆,于2014和2015年两个水稻生长季,在大田条件下,以当地平均施肥量为标准,设置不同量的化肥配施秸秆处理,研究秸秆还田下水稻氮素吸收转运特征。结果表明:较纯化肥处理,秸秆替代一部分氮肥处理对水稻产量、地上部氮素积累量、氮素收获指数及氮肥生产效率无显著影响(P0.05);在不同程度上降低氮素在穗部的分配比例、营养器官吸收氮素向穗部转运量、转运率、转运氮对籽粒氮素贡献率;在不同程度上提高成熟期营养器官氮素积累量,显著提升抽穗后氮素吸收量及其对籽粒氮素贡献率(P0.05)。综合氮素吸收转运及利用效率,川东北稻麦轮作区水稻季在化肥减施30%基础上,麦秆还田量以6 000 kg/hm~2为宜。     

不同施氮水平对水稻土氮素供应和烤烟氮素吸收积累的影响

采用大田试验研究分析了凉山州植烟水稻土在不同施氮水平下的无机氮供应动态、烟株干物质积累、烟株对氮素的吸收分配规律以及烤后烟叶品质的差异。结果表明:施氮对土壤无机氮的影响持续到移栽后13周,随施氮量的增加土壤无机氮浓度升高,各处理无机氮供应高峰出现在移栽后7周和13周;各施氮处理烟株干物质积累均显著高于不施氮处理,说明施氮可以促进前期烟株根系的发育;施氮显著提高了各时期烟株中氮素的含量,尤其表现在移栽后9~11周,施氮75 kg/hm~2处理烟株氮积累量显著高于施氮45 kg/hm~2处理,但施氮105 kg/hm~2处理积累量与施氮75 kg/hm~2处理差异不大。综合感官评吸结果,本研究认为供试水稻土施氮量以75 kg/hm~2较为适宜。     

稻草和尿素配施时水稻对肥料氮和土壤氮的吸收利用

利用＾１５Ｎ同位素示踪技术,研究了稻草和尿素配施时水稻对肥料和土壤氮的吸收。结果表明,稻草单施导致土壤速效氮的生物固定,氮素供应不足是影响水稻分蘖成穗的限制因子,稻草配合尿素施用,明显改善肥料氮和土壤氮的供应,既有利于当季水稻增产,也有利于培养土壤肥力,还有利于后茬物作产量的提高 。     

水稻基肥尿素干施与湿施对氮素损失及水稻氮素吸收的影响

运用大型原状土柱在田间条件下比较了水稻基肥干耕施(干施)与湿耙施(湿施)对氮素损失与水稻氮素吸收的影响,试验设尿素干施、湿施与对照3个处理,同步测定了施肥后小区的氨挥发、淋洗以及水稻的吸氮量。结果表明:(1)干施法氨挥发显著低于湿施法,模拟试验分别为40.1与68.8 kg hm-2,占施氮量的13.4%与22.9%,2004年的大田试验分别为19.2与26.2 kg hm-2,占施氮量的7.7%与10.4%;(2)而干施法的总氮(TN)淋洗量显著大于湿施法,分别为14.3与4.6 kg hm-2,占施氮量的4.8%与1.5%,氮的淋洗以NO3--N为主,占总量的73.7%～97.3%,两者的NH4+-N淋洗量差别很小;(3)与湿施法相比,干施法净减少氮肥损失19.0 kg hm-2,水稻吸氮量增加15.1 kg hm-2,氮肥利用率提高了5个百分点,产量略有提高,而土壤含氮量没有显著变化。因此,水稻基肥尿素干深施法是一项值得推广的施肥方法。     

不同施氮处理对水稻氮素吸收及产量的影响

从水稻高效施肥的角度,通过田间小区试验,分析不同施氮肥处理对水稻氮素吸收及产量的影响。结果表明,在一定氮肥施用量范围内,水稻氮素吸收量及产量随氮肥施用量增加而提高,氮肥施用过量时,水稻氮素吸收量及产量降低;等量的氮肥(210 kg.hm-2)处理下,随着追肥次数的增加,其水稻氮素吸收量及产量也随之提高;在基肥∶分蘖肥∶穗肥∶粒肥=3∶3∶3∶1的情况下,水稻氮素吸收量及产量均达到最高水平。     

水稻簇生穗控制基因ts的定位及育种利用研究

从水稻(Oryza sativa L.)育种材料广恢128、粳稻Kitaake、蜀恢955和蜀恢881的复合杂交F2群体中发现了一个簇生穗突变体,该突变体命名为TS(top-spikelet-two-grain mutant)。TS最显著的变异为穗部一、二次枝梗顶端表现为2~3个小穗簇生在一起。为了明确TS中所含簇生基因ts的遗传机理及其在水稻育种中的利用价值,本研究利用TS与G2480B(indica)杂交的F1、F2群体进行簇生性状的形态观察和遗传分析;利用3个携带有ts基因的转育纯系分析ts基因的应用前景。结果表明,F1群体表现为全部显性,F2群体出现3∶1显隐性状分离,突变性状受1对隐性单基因控制,能够稳定遗传。采用简单序列重复(simple sequence repeat,SSR)标记技术,将突变基因ts定位于第6染色体上的长臂端,位于RM20323和RM6298之间,遗传距离分别为5.1和5.6 cM。3个转育纯系中,L332在保持簇生性状的同时,与亲本G2480B相比,其产量性状无显著差异,蒸煮食味品质较优。ts基因的表达与水稻的单株穗数、每穗粒数、结实率、千粒重和单株产量无显著相关性。以上结果为ts基因在水稻育种上的利用提供了一定的理论基础。     

三种类型阻控剂对不同品种水稻富集镉的影响

如何降低水稻中镉(Cd)的含量已经成为一个研究热点。在湖南省衡阳县某地受轻度镉污染的农田上种植两季水稻(早稻、晚稻),随机采购市场上销售的阻控剂(石灰、硅肥和叶面锌肥),研究这3种类型阻控剂对水稻富集镉及稻谷中镉含量的影响,这3种类型的阻控剂的施用方式是石灰和硅肥作为基肥施于土壤,叶面锌肥通过叶面喷施。结果表明:与没有施加阻控剂相比,除石灰和晚稻锌处理之外,其他处理增产效果显著。在3种类型的阻控剂中,叶面锌肥对籽实富集镉的阻控效果最佳,分别使早稻Y俩优792和晚稻农香130降低了51.28%和50.92%,基施硅肥阻镉效果次之。田间试验结果进一步表明施硅肥和喷施叶面锌肥可作为当地的水稻镉污染阻控剂,但叶面锌肥与稻谷中镉的交互作用需要更深入的探讨。     

Effects of Perchlorate Stress on Growth and Physiological Characteristics of Rice (Oryza sativa L.) Seedlings

The main objective of the present study is to measure the levels of heavy metals in important fruit species such as apple, apricot, and nectarine and their nine, five, and six cultivars, respectively. This work investigates the accumulation of Fe, Cu, Zn, Ni, Cd, Pb, and Cr in flowers of above species, to measure the levels of heavy metal contamination. The obtained results revealed that amounts of heavy metals significantly varied among cultivars at the same species and were within the permissible amounts in general. The Cd was not detected in apricot, nectarine, and the most of apple cultivars. Results for floral Fe, and also for Cu and Zn, which are the most important micronutrients for fruit production, suggest that levels of these elements might be used for assessing the storage of these elements during the previous season. We assume that the production of apple, apricot, and nectarine is safe, and there is no risk of contamination with heavy metals.     

Direct and Residual Effects of Fly Ash-Based Integrated Fertilization on Rice (Oryza sativa L.) and Rapeseed (Brassica camprestris L.)

Integrated effects of fly ash (FA), farmyard manure (FYM), and chemical fertilizers recommended dose of fertilizer (RDF) on the performance of rice (Oryza sativa L.) and their residual effect on rapeseed (Brassica camprestris L. vartoria) were studied for two years in loamy acidic inceptisol of Assam, India.

The FA was generated from a bituminous and lignite coal-based captive thermal power plant of Hindustan Paper Corporation Ltd (HPCL), Assam. Rice yields were higher when FA, FYM, and RDF were used collectively vis-à-vis sole application of RDF reflected also in rapeseed under residual effect . FA effect on mean rice equivalent yield of the rice–rapeseed system was the highest (24.4%) under integrated application. Nickel (Ni) and cadmium (Cd) contents in rice decreased with increasing FA, while arsenic (As) was just the opposite. Integration of FA, FYM, and RDF was effective in lowering Ni, Cd, and As in rice compared to 100% RDF alone or together with FA. The residual effect on rapeseed was similar for Ni and As while the Cd content increased. Blending of FA, FYM, and RDF also positively altered the residual soil pH, organic carbon (C), and nitrogen, phosphorus, and potassium (NPK). Thus, FA can be an integral component of integrated plant nutrition system (IPNS) in augmenting crop yield and residual benefits in loamy acid inceptisol.     

Policosanol Content and Composition of Korean Rice (Oryza sativa L.) Cultivars

Policosanols (PCs) are a group of long‐chain alcohols that have been reported to have many beneficial physiological activities. In this study, the total content and composition of PCs in 15 rice (Oryza sativa L.) cultivars from Korea were characterized by gas chromatography–time‐of‐flight mass spectrometry. This method proved to be sufficiently precise and accurate with respect to the degree of endogenous biological variability found in the rice samples. Octacosanol (C28) and triacontanol (C30) were the major components of PCs in all cultivars. In addition, there were positive correlations among the determined PC contents. Given its high PC content, the Heughyangbyeo cultivar may appear to be a good candidate for future breeding programs.     

基因枪介导转化水稻花粉获得转基因植株

植物花粉是一种理想的植物遗传转化材料,利用转化后的花粉授粉,借助于植物胚胎的自然发育获得转基因种子,从而简化转化过程.大量研究表明基因枪是花粉转化的较理想工具,目前基因枪介导的花粉转化只在烟草、油菜等少数作物中获得成功.水稻是世界主要粮食作物,建立一个高效的水稻遗传转化体系对于水稻的遗传改良具有十分重要的意义.     

Crop growth and nitrogen transformations in wheat (Triticum aestivum L.) planted after wetland rice (Oryza sativa L.)

Summary A field study was undertaken to examine the effects of various management strategies on wheat (Triticum aestivum L.) performance and N cycling in an intensively cropped soil. Microplots receiving 100 kg N ha^–1 as¹⁵NH₄ ^{+ 15}NO₃ ^– at sowing, tillering or stem elongation were compared with unfertilized microplots. Stubble from the previous rice crop was either incorporated, burnt without tillage, burnt then tilled or retained on the surface of untilled soil. Wheat grain yield ranged from 1.5 to 5.1 t ha^– and was closely related to N uptake. Plant accumulation of soil N averaged 36 kg N ha^–1 (LSD 5% = 10) on stubble-incorporation plots and 54 kg N ha^–1 on stubble-retention plots. Fertilizer N accumulation averaged 18 kg N ha^–1 (LSD 51% = 6) on stubble-incorporation plots and 50 kg N ha^–1 on stubble-retention plots. Tillage had little effect on burnt plots. Delaying N application from sowing until stem elongation increased average fertilizer N uptake from 26 to 39 kg N ha^–1 (LSD 5% = 6), but reduced soil N uptake from 50 to 37 kg N ha^– (LSD 5% = 10).Immobilization and leaching did not vary greatly between treatments and approximately one-third of the fertilizer was immobilized. Less than 1% of the fertilizer was found below a depth of 300 mm. Incorporating 9 t ha^–1 of rice stubble 13 days before wheat sowing reduced net apparent mineralization of native soil N from 37 to 3 kg ha^–1 between tillering and maturity. It also increased apparent denitrification of fertilizer N from an average 34 to 53 kg N ha^–1 (LSD 5% = 6). N loss occurred over several months, suggesting that denitrification was maintained by continued release of metabolizable carbohydrate from the decaying rice stubble. The results demonstrate that no-till systems increase crop yield and use of both fertilizer and soil N in intensive rice-based rotations.     

Influence of Mn and Fe Counteraction on Rice (Oryza sativa L.)Oranging Physiological Disease

Mn and Fe are two important micronutrients of paddy soils derived from red earths.Rice(Oryza sativa L.)oranging physiological diease in newly reclaimed red rarths is related to Fe toxicity.There have been considerable studies on Mn and Fe counteraction,but influence of Mn and Fe counteration on rice oranging physiological disease still remains unknown.This paper is to study,using two soils from USA and China respectively,the relationship between Nn and Fe counteraction and the physiological disease.Analysis for water soluble and extractable Fe and Mn showed that Mn/Fe ratios of the red earths were lower than those of the paddy soils.Fertilizing with Mn raised Mn/Fe and reduced oranging leaves,improved growth and increased yields.Analysis with electron probe showed that Mn treatment had less Fe deposit in root epidermis and more Ca and Si in roots.The results indicated that fertilizing with Mn could correct Fe toxicity.How to apply Mn and Fe counteraction in practice is worth further studying.     

直接产生抗除草剂转基因水稻纯系的新方法

提出了一种提高转基因杂交后代育种选择效率的新途径，即在花药培养过程中添加抗性筛选物质，直接筛选含有目的基因的纯合体。以转bar基因水稻植株和非转基因植株杂交F1为试格进行花药培养，并对分化的绿苗进行PCR检测和田间抗性检测。结果表明，在愈伤组织诱导培养基和分化培养基中分别添加PPT0.05mg/L与未添加PPT的对照，均产生较多的愈伤组织和绿苗，并有较高比例不抗除草剂的假阳性株。当PPT浓度增至0.1mg/L时，所得花培苗全部抗除草剂，显示很好的筛选作用。PPT浓度继续增加，愈伤组织诱导率和绿苗分化率急剧下降。当PPT的浓度增至5mg/L时，愈伤组织的诱导和幼苗分化完全被抑制。对30个加倍单倍体系作连续两代农艺性状考察，约73％以上的株系在遗传率较高的性状中，变异系数很小（＜10％），说明这些株系的基因型已经纯合，证实了该方法的有效性。     

NPK Accumulation and Use Efficiencies of Manawthukha Rice (Oryza sativa L.) Affected By Pretransplant Basal and Split Applications of Nitrogen

We investigated the effects of split applications of nitrogen (N) on N, phosphorus, and potassium (NPK) uptake and use efficiency of rice under basal surface-application and incorporation methods. Different amounts of N were applied at the basal, tillering, and panicle initiation stages in five N split treatments. Basal incorporation provided greater NPK uptake than basal surface application until initiation of the panicle. In basal surface application, N2 (25:50:25) resulted in the greatest total NPK uptake, use efficiency, and N recovery efficiency. In basal incorporation, N1 (50:25:25) resulted in greater values for all parameters. The N5 (50:0:50), which included omitting N at tillering, resulted in low N recovery efficiency and uptake, both under basal incorporation and basal surface application. These results emphasize that split applications of N influence N recovery efficiency and total NPK uptake and use efficiency of rice.