遮荫对作物产量和品质的影响及其生理响应研究进展

植物为适应荫蔽的环境,其形态特征、解剖结构、光合器官、抗氧化酶、内源激素以及矿质营养元素的吸收和积累等都会发生一系列变化,从而保证植株自身能在荫蔽条件下充分利用光能进行正常的生命活动.通过遮荫处理对作物生长发育、产量和品质及其生理响应机制等方面的阐述,旨在指导我国南方地区间套作和设施栽培的实施,并最终实现作物高产稳产.     

不同时期弱光胁迫对晚稻不同耐弱光品种源库特征及叶片保护酶活性的影响

目的 本研究旨在明确弱光胁迫下不同弱光耐性品种在源库特征及叶片保护酶活性变化方面的差异,揭示其耐弱光胁迫的机制,为双季稻高产稳产新品种的选育及抗逆栽培提供理论指导。方法 以2个对弱光胁迫耐性存在显著差异的晚稻品种为材料,通过设置不同时期的遮光处理,研究弱光胁迫时期对晚稻不同耐性品种的源库特征及叶片保护酶活性的影响。结果 结果表明,不同时期弱光胁迫对晚稻生长有重要影响,分蘖期弱光胁迫下晚稻分蘖数、每穗粒数及总颖花量减少,叶面积下降,产量降低;幼穗分化期弱光胁迫下晚稻分蘖数和每穗粒数减少,总颖花量、叶面积、结实率均下降,产量降低;灌浆期弱光胁迫下水稻叶片净同化率降低,结实率和千粒重下降,产量降低。不同时期弱光胁迫对晚稻产量的影响表现为灌浆期>幼穗分化期>分蘖期。结论 耐弱光胁迫型品种能通过增加叶片的长宽度减少叶面积的下降,叶片含氮量保持相对稳定,叶片中SOD、CAT等保护酶活性保持在较高水平,POD活性保持相对稳定,叶片净同化率下降幅度小,在弱光胁迫下实现“强源”,减产率相对较低。弱光胁迫下具有较强的叶面积补偿能力和适宜氮含量以及较高的保护酶活性是水稻耐弱光胁迫的重要机制。     

水分亏缺对水稻生长发育、产量和稻米品质影响的相关研究

水资源短缺问题已制约着当今社会和经济的可持续发展，因水分亏缺引起植物生长和作物产量下降的影响超过了所有其它非生物胁迫所造成影响的总和。不同水分亏缺对作物的影响不一样，作物对不同水分亏缺的响应机制也不一样。本文在概括分析研究水分亏缺理论与实践意义的基础上，重点就水分亏缺对水稻生长发育、形态、生理生化、产量、品质及产量源库特性的影响作了详细阐述。     

弱光胁迫对花生生长发育和生理特性的影响

概述了弱光胁迫对花生形态特征、荚果产量、光合速率、水分利用效率、矿质营养吸收的影响,弱光胁迫解除后花生生长发育、光合作用等恢复特点,分析了弱光胁迫条件下花生生理、生态和生化因子之间的相互关系以及对弱光胁迫的适应机制,讨论了该领域研究中存在的问题及今后的研究方向.     

玉米产量形成与源库关系

研究表明,源库均影响玉米的产量。在不同基因型间源库特性存在差异,而基因型的源库性状表达又受到环境条件的限制和栽培措施的调控。基因型与环境条件之间原有的平衡关系,因新品种应用而打破,需要通过栽培措施调节环境条件,以满足品种遗传潜力发挥的要求,即通过栽培措施调节源库关系来协调个体与群体矛盾,从而在基因型与环境条件间建立新的平衡关系。产量形成过程中,产量的提高和潜力的发挥是作物与环境相互作用的调节过程,表现在源库平衡关系中,源是主导因素,库随源的变化进行调整,达到源库新的平衡。因此,源库不平衡是绝对的,平衡是相对的。     

产量与源库的关系及其在作物高产中的意义

作物生长发育过程中,源库关系在动态变化中相互协调取得平衡,是作物获得高产的基础。“源”的大小对“库”的建成及其潜力的发挥具有明显的作用,“库”原有的生产潜力能否转化为最终的籽粒产量,取决于同化“源”的供应量。因此,探讨“库”潜力,“源”的供应能力及“库”“源”的关系,对于充分发挥“库”的潜力,提高产量是十分必要的。本文简要的分析了源库关系对产量的影响。     

糖料作物抗氧化酶基因应答非生物胁迫的研究进展

糖料作物是重要的经济作物,和其他作物一样会受到各种环境胁迫,恶劣的环境会造成作物产量和品质的下降,利用分子生物学手段可有效地增强作物的抗逆性,因此研究糖料作物应答非生物胁迫的分子机制在理论和实际生产上具有重大意义.本文总结了国内外文献,对非生物胁迫对植物生长发育的影响、诱发活性氧(ROS)的积累和清除途径、非生物胁迫对...     

产量与源库的关系及其在作物高产中的意义

作物生长发育过程中，源库关系在动态变化中相互协调取得平衡，是作物获得高产的基础。“源”的大小对“库”的建成及其潜力的发挥具有明显的作用，“库”原有的生产潜力能否转化为最终的籽粒产量，取决于同化“源”的供应量、因此，探讨“库”潜力，“源”的供应能力及“库”“源”的关系，时于充分发挥“库”的潜力，提高产量是十分必要的。本文简要的分析了源库关系对产量的影响。     

玉米—大豆间套作模式研究现状及其展望

阐述了国内外有关玉米—大豆间套作种植方式的研究进展,分析了间套作对群体内光分布及光强度、CO_2含量和水分调节、病虫害防控、重金属固定和吸收的影响,阐明了间套作对玉米、大豆根系生长及养分吸收利用的影响,解释了间套作提高作物产量和品质的原因,并根据国内外玉米大豆间套作模式研究现状,提出我国间套作应注意的问题。     

源库关系研究现状及在橡胶树排胶机理研究中的展望

源库关系研究在作物产量和品质形成中具有重要的理论研究和技术应用价值。随着作物遗传育种、植物生理和分子生物学等多学科的交叉融合，源库关系研究近年来整合运用分子生物学技术、植物激素信号转导等众多新技术和新方法取得了重要进展。本文综述了源库关系理论和源库关系调控两方面研究进展，重点阐述了糖代谢、激素调控源库关系的机理，分析通过栽培措施协调源库关系提高产量的机理。同时结合热带重要经济作物橡胶树的排胶机理与调控研究进展，论述乙烯利刺激和割胶处理调节源库分配与橡胶树产量形成之间的关系，以期推动天然橡胶源库关系理论研究，为排胶调控技术创制提供技术指导。     

水稻源库关系评价体系研究进展与展望

 水稻产量的高低主要决定于源、库、流三者的强弱及其相互之间的协调程度。当前对于水稻源库关系的评价方法虽然很多，却缺乏完善且统一的标准。从水稻源库内容及其衡量标准，水稻源、库、流的互作效应及其对籽粒发育的影响以及我国水稻源库关系评价方法及品种源库类型划分等方面讨论了水稻源库关系评价的现状，在此基础上提出了完善水稻源库关系评价体系的主要研究方向。     

不同冠层结构下夏玉米产量形成的源库关系

试验对低、中、高3个种植密度下夏播玉米CF008、郑单958和金海5号产量形成的源库关系进行了研究,明确不同株穗型品种在较高的种植密度下限制产量的主要因素。结果表明,3个夏玉米品种均在低中密度下冠层透光率较高,源库性能较优。在低中密度下LAI发展动态合理,叶片Pn较高,并且在中密度下群体粒数、群体粒重和子粒品质较高。早衰型品种CF008成熟期粒叶比随密度增加而增加,高密度下源不足是限制产量的主要因素。保绿性较好的品种金海5号粒叶比随密度增加而降低,高密度下库容不足是限制产量的主要因素。郑单958中密度下成熟期LAI、粒叶比和子粒产量均较高,源库关系协调,但在低密度和高密度下均表现为库容不足。     

杂交稻新组合再生稻头季及再生季源库特征分析

 以6个两系杂交组合和2个三系杂交组合为材料，比较研究了杂交稻头季与再生季的源库特性和再生稻产量形成的源库关系。结果表明：(1)再生季LAI为头季的1/3左右，再生稻单茎叶面积约为头季稻的1/7~1/3，头季总库容约为再生季的1.5倍，再生稻粒叶比约为头季稻的1.5~2倍；(2)头季稻较大的粒叶比对高产有利；头季稻成熟期LAI较大、粒叶比较小、成熟期单茎鞘干质量较大、茎鞘物质输出率高，有利于再生稻的高产；(3)再生季齐穗期LAI与产量成显著正相关；对高节位再生稻而言，齐穗期单茎叶面积与单茎产量呈极显著正相关，粒叶比与结实率呈负相关、与产量呈极显著负相关。再生稻，特别是高节位再生稻，其源库关系属增源增产型；(4)陆18S/53159、康两优2054、培矮64S/E32和培两优500再生季产量较高，均在5200 kg/hm2以上。综合考虑再生季产量与两季总产，在2002年气候条件下，长沙地区最适于再生栽培的杂交稻是培矮64S/E32，其次是康两优2054和T98A/259。     

Genetic bases of source-,sink-,and yield-related traits revealed by genome-wide association study in Xian rice

The source-sink relationship determines the ultimate grain yield.We investigated the genetic basis of the relationship between source and sink and yield potential in rice.In two environments,we identified quantitative trait loci(QTL)associated with sink capacity(total spikelet number per panicle and thousand-grain weight),source leaf(flag leaf length,flag leaf width and flag leaf area),source-sink relationship(total spikelet number to flag leaf area ratio)and yield-related traits(filled grain number per panicle,panicle number per plant,grain yield per plant,biomass per plant,and harvest index)by genome-wide association analysis using 272 Xian(indica)accessions.The panel showed substantial variation for all traits in the two environments and revealed complex phenotypic correlations.A total of 70 QTL influencing the 11 traits were identified using 469,377 high-quality SNP markers.Five QTL were detected consistently in four chromosomal regions in both environments.Five QTL clusters simultaneously affected source,sink,source–sink relationship,and grain yield traits,probably explaining the genetic basis of significant correlations of grain yield with source and sink traits.We selected 24 candidate genes in the four consistent QTL regions by identifying linkage disequilibrium(LD)blocks associated with significant SNPs and performing haplotype analysis.The genes included one cloned gene(NOG1)and three newly identified QTL(qHI6,qTGW7,and qFLA8).These results provide a theoretical basis for high-yield rice breeding by increasing and balancing source–sink relationships using marker-assisted selection.     

穗重型小麦的源库特征研究

穗重型小麦新品种选育一直是超高产小麦育种的主攻方向之一。为了更好地选育和利用穗重型小麦,明确其大库容与源流的关系,对不同穗型小麦源、库特征进行了比较研究。结果表明,孕穗期穗重型小麦群体矫正光合势(APP)、群体生长率及叶绿素含量均显著地低于多穗型品种(对照);每穗粒数、群体平均单穗粒重、总库容量等显著高于多穗品种;籽粒充实指数、灌浆速率显著低于对照;粒叶比过大或过小。说明群体源不足,源、库关系不协调,是影响穗重型小麦实现高产潜力的根本原因。     

水稻源库关系研究进展

介绍了水稻源库基本概念、衡量指标、及源库类型的划分,从减源疏库、同位素、生物化学研究、疏导组织、作物模拟技术和群体调节、激素调节、肥料调节等方面对源库关系的主要研究手段和库源关系的优化调控进行了综述,同时阐述了源库关系对稻米品质的影响。     

旱地马铃薯间作玉米、玉米间作大豆效益分析

通过对马铃薯间作玉米、玉米间作大豆、净作玉米、净作马铃薯、净作大豆5种种植模式的比较分析认为：虽然间作时单一作物的产量、产值比净作时降低,但综合产量提高。通过调整搭配作物的种植密度可以达到作物间的相对平衡,从而获得各种作物的丰收。在作物搭配时应以其中一种作物为主,另一种作物为辅,不能同时并重。马铃薯间作玉米以马铃薯为主,玉米间作大豆时以玉米为主,能够获得较高的收益。     

Responses to shade and subsequent recovery of soya bean in maize-soya bean relay strip intercropping

In relay intercropping systems, late-planted crops often grow under the shade of the canopy of early-planted tall crops and then transfer to full sunlight after the harvest of the early-planted crops. In order to know the effects of recovery growth of the late-planted soya bean in maize–soya bean relay intercropping, a field experiment was carried out to observe architectural, morphological, physiological and anatomical traits of soya bean plants related to shade and subsequent removal in intercropping before and after maize harvest, respectively. During shade period, soya bean biomass was severely reduced, and stem elongation was stimulated. Typical features of shade grown leaves were found, such as lower LMA (leaf mass per unit area), thinner thickness, higher chlorophyll content, lower chlorophyll a:b ratio. Whole-plant leaf area analysis found that soya bean increased leaf area ratio by adjusting leaf morphology rather than by dry mass allocation. After maize harvest, leaf area and leaf mass increased rapidly, contributing to compensation growth in intercropped soya bean. Meanwhile, physiological and anatomical traits of leaf went back to similar levels as grown in sole cropping. However, stem morphological traits were irreversible after removal of shade. Finally, no difference on seed weight per plant of soya bean was observed between relay intercropping and sole cropping. Based on these findings, we speculated the recovery growth might be the direct determining factor on pod formation in soya bean, and improvement on the capacity of recovery growth could increase yield of relay intercropped soya bean.     

Land Equivalent Ratio of Groundnut-Fingermillet Intercrops as Affected by Plant Combination Ratio,and Nitrogen and Water Availability

Abstract

Field experiments were conducted to characterize intercropping advantages in groundnut-fingermillet intercrop in relation to crop combination ratios, soil moisture and nitrogen (N) availability. Three intercrops in 1 : 2, 1 : 1 and 2 : 1 alternating rows of groundnut and fingermillet were examined for their growth and yield in comparison with their respective sole crops in 1996. The effect of well watered (W) and water stressed (D) conditions on the intercropping advantage was also examined for 1 : 1 intercrops in 1995 and 1996. Fertilizer N was applied at the rate of 20 kg ha^?1 in 1995 and 50 kg ha^?1 in 1996. The total above-ground biomass (DM) and its land equivalent ratio (LER) were highest in the 1 : 1 combination ratio. The DM production of intercropped fingermillet was higher in 1996 with higher N than in 1995 with low N application, while those of groundnut were similar in both years. The intercropped groundnut exhibited significantly higher DM production after the fingermillet harvest. The LERs in grain yield were higher in 1996 (1.43 under W and 1.45 under D), than in 1995 (0.87 under W and 1.22 under D). Also, LERs were consistently higher under D than W conditions. Water stress severely reduced the leaf area index (LAI) of fingermillet at a low N, especially in the later stages, whereas higher N alleviated the water stress effect. A close linear relationship was observed between LAI and leaf area (LA) per unit leaf N both for groundnut and fingermillet, with intercrops producing larger LA per unit leaf N than sole crops. Intercropping maintained higher ability in leaf net photosynthesis and transpiration of groundnut up to later stages, and significantly reduced water evaporation from the soil surface under the canopy than sole cropping of fingermillet. These results suggest that three processes associated with the intercropping yield advantages in the groundnut-fingermillet intercrop; 1) higher leaf photosynthesis and vigorous growth of groundnut after the fingermillet harvest, 2) higher LA production per unit N and 3) efficient water use. In conclusion, interspecific shading was considered to be the key mechanism associated with these processes, leading to the intercropping advantages. The degree of the interspecific shade and its effect on growth and yield depended on the available soil N and water.