应用缩节安(DPC)调控棉花株型的定位定量效应研究

缩节安(1,1-dimeyl piperidinium cloride, DPC)是棉花生产中广泛应用的植物生长延缓剂,其调控棉花茎枝生长的定位定量效应尚缺乏系统的量化研究。本研究 2013-2014 年在田间条件下分别于棉花现蕾期、盛蕾期后、盛花期前、盛花期后和打顶后单次应用不同剂量的 DPC,测量了 DPC 作用有效期内的棉花株高和主茎生长速率,探究了所有主茎节间及所有果节对 DPC 的响应。结果表明, DPC 处理对棉花主茎节间的影响范围为 N 节(应用 DPC 时的主茎节)以下 1~4 个和 N 节以上 0~6 个(打顶条件下),对果枝的影响范围为 N 节以下 1~11 个和 N 节以上 0~5 个,其中 N 节以下果枝受影响的果节多于 N 节以上果枝。将盛蕾期后和盛花期前 2 次应用 DPC 的效应叠加,其影响范围几乎可以覆盖全部主茎节间(果枝始节以上)和全部果节。DPC 应用剂量与其作用强度并不总存在较好的线性关系。DPC 的定位定量效应除了与应用时间和剂量有关,还受到温度、降水等环境条件和棉株生物量、源库关系的影响。     

In-field development of a conceptual crop functioning and management model: A case study on cotton in southern Mali

West African cotton production has increased rapidly in recent years. Cotton is being cropped under new ecological conditions by new cotton-producing farmers, but the cropping techniques recommended by developers have essentially remained the same. Methodologies are needed to generate a broad scope of recommendations on cropping techniques to deal with the increasing diversity concerning farmers and cropping conditions.

A conceptual model of a cotton field was developed that approaches a crop field as a biophysical system under the influence of a “technical system” (i.e. the combination of farmers’ practices implemented in the field). The system outputs were restricted to yield and the main yield components. A theoretical model was first designed on the basis of published data and expert knowledge on cotton physiology, local soil–climate conditions and farmers’ practices. It was based on five specific hypotheses on links between technical and biophysical systems. The hypotheses were tested in a local farmers’ network. Thirty “cropping situations” (soil–crop–technique combinations) were selected in farmers’ fields around Katogo village (Mali), a village that had been previously selected for a cotton crop management prototyping program. Homogeneous groups of situations were drawn up on the basis of the dynamics of crop aerial biomass accumulation. They were compared for their management and environment features. The initial conceptual model was then simplified, while taking the measured variability in its components and the sensitivity of the outputs to these components into account. This conceptual model is being evaluated in other villages, where we have partnerships with farmers, in order to develop a version adapted to a broad range of situations.     

长江流域麦(油)后直播棉增效缩节胺化学封顶技术研究

【目的】明确长江流域麦(油)后直播棉应用增效缩节胺(25%DPC水剂,简称DPC+)进行化学封顶的可行性。【方法】于2015―2017年在江苏大丰、安徽宿松和湖北武汉开展田间试验,采用随机区组设计,以人工打顶为对照,研究化学封顶时期(人工打顶同期、人工打顶后5 d)和封顶剂DPC+剂量(750,1 125,1 500 m L·hm^-2)对麦(油)后直播棉农艺性状及经济性状的影响。【结果】与人工打顶相比,DPC+化学封顶处理的株高和果枝数增加(最多分别增加21.6 cm和4.8个),中部和上部果枝(尤其是上部果枝)缩短,除个别点次外果节数不受影响。在不同环境条件下,化学封顶处理的产量多与人工打顶相当,低剂量DPC+处理的产量在降水量大的年份有一定程度下降,化学封顶时期对产量影响较小。【结论】应用DPC+对长江流域麦(油)后直播棉进行化学封顶有较好的可行性,未来需进一步优化技术参数、建立稳发稳长的配套栽培技术体系。     

Choosing the most representative technical management routes within diverse management practices: Application to vineyards in the Loire Valley for environmental and quality assessment

Diversity of agricultural systems can be described at different scales in terms of three main types of variables: technical management of cropping systems, farming systems and food supply chains. We focus on the diversity of technical management routes (TMRs), defined as logical successions of technical options (TOs) designed by the farmers. The study, comparison and assessment of this great diversity of complex routes are impossible with classical agronomic experiments or exhaustive assessments such as life cycle assessment (LCA). Hence, the selection of representative cases is necessary. Multidimensional data analysis methods permit the characterization of a diversity of TMRs and the construction of typologies but do not allow the consideration of the specific associations of TOs constituting the various TMRs.The aim of this paper is threefold: (i) to propose a new combined method, “Typ-iti”, to classify the field TMRs of farmers, to identify key TO associations and to select the most relevant cases for study; (ii) to test this method on vineyard management diversity using a panel of vineyard fields of Loire Valley producers; and (iii) to discuss the capability of the proposed Typ-iti method for use in the characterization and selection of cases of other agricultural systems at diverse scales.The example developed in this paper is the selection of vineyard management cases for grape LCA combined with grape quality evaluation. The cases were selected to represent the regional diversity of management practices. A detailed on-farm survey of management methods was performed on a diverse range of wine production estates in the Middle Loire Valley. The Typ-iti method was constructed and implemented on the survey database. It combines a multidimensional analysis of qualitative survey data and typology and partitioning (clustering) associated with data mining methods (frequent pattern mining search and association rules).The surveyed sample was partitioned into 5 types of management practices, 2 of which were organic and 3 conventional. The partitioning was driven primarily by choices involving pest management and floor management. Each type was characterized by specific TOs, specific associations of TOs and remarkable TMRs. The cases were chosen on the basis of these 3 parameters.The Typ-iti method can be applied to other crops and at different scales; the only limitation is the availability of precise information on the practices used by farmers in their fields.     

Evaluation of chlorophyll fluorescence as a tool for the identification of drought tolerance in upland cotton

Chlorophyll fluorescence (CF) is one tool used by researchers to quantify plant water status during periods of limited water availability. The research reported herein was designed to evaluate a CF-based protocol as a tool for use in cotton, Gossypium spp. breeding programs for the identification of drought tolerant genotypes. Twenty genotypes were selected to represent diverse and distinct US germplasm pools. Replicated tests were performed in Lubbock and College Station, TX in 2006 and 2007. Dryland and irrigated treatments, as main plots, were applied in a randomized complete block design, split to genotypes. CF measurements were taken at mid-bloom and late bloom growth stages. Source leaf tissue was harvested at predawn and subjected to high temperature incubation with CF measurements subsequently taken hourly for 5 h. Drought stressed plants had not mobilized their carbohydrate reserves from their source leaves overnight and thus maintained cell viability and therefore higher CF values throughout the incubation and measurement period with the opposite being true for non-stressed plants. Fiber lint yield and fiber properties were measured for comparison with the CF data. Genotype × treatment effects complicated the classification of genotypic response to drought. Few and inconsistent correlations were found among CF values and lint yield or fiber properties. Data suggested that this procedure provides little potential in selecting plants for drought tolerance when plants are grown under field culture.     

不同株型棉种产量结构模式的研究和应用

传统的棉种产量结构模式与直播棉和棉种的粗加工(毛子剥绒子)相适应,我们概括这一模式为:单位面积种子产量=单位面积铃数×霜前铃%×铃种子数×粒重。新扩展的棉花良种产量结构模式与育苗移栽和棉种的深加工(硫酸脱绒子、包衣子)相适应,我们概括这一模式为:单位面积良种产量=单位面积铃数×霜前铃%×铃成熟种子数×粒重。铃成熟种子数既是数量构成因素,又有质量的内涵,是实际而有效用于生产的种子,作者建议将扩展模式中诸因素形成的产量定名为良种,以便与传统模式种子产量相区别。本文采用灰色关联度的分析方法从两种模式不同株型产量结构诸因子中作出比较和判断,找出影响较大的主要因素,从筛选最佳株型入手,明确产质量结构的主攻目标,对促进棉种专业化生产水平的发展,社会化效益的提高,具有一定的参考价值。     

AM真菌Glomus versiforme对连作土壤上黄瓜生长及养分吸收的影响

为明确AM真菌Glomus versiforme在缓解连作障碍中的潜力,以黄瓜为试验材料,于黄瓜播种同时接种G.versiforme,并设立相应对照,苗龄40天时,将幼苗分别移栽至自然连作土与灭菌连作土上,研究2种土壤条件下G.versiforme对黄瓜幼苗的生长,氮磷养分吸收及根际微生物群落组成的影响。结果表明:G.versiforme对幼苗地上部与根系生长的影响因土壤条件而异。出苗第55天时,连作土上接种G.versiforme的幼苗地上部生物量是其相应对照的1.81倍,且该处理与灭菌土上菌根化处理间差异不显著。同时,灭菌土上接种G.versiforme的幼苗根系生物量是连作土上菌根化处理的1.22倍,是连作土上非菌根化处理的2.11倍。连作土上菌根化幼苗地上部生物量的显著积累与G.versiforme对幼苗叶片中氮营养的改善有关,与此同时,灭菌土上G.versiforme可促进根系对磷的吸收。此外,接种G.versiforme可在一定程度上改善土壤环境,使连作土中的细菌数量增加,真菌数量降低。土壤灭菌处理或将菌根化幼苗移栽于连作土壤上均可有效缓解设施黄瓜连作障碍。     

Effect of 1-Naphthaleneacetic Acid Concentrations and the Number of its Applications on the Yield Components, Yield and Fibre Properties of Egyptian Cotton (Gossypium barbadense L.)

Field experiments were performed in two successive seasons at the Experimental Station, Faculty of Agriculture, Cairo University, Giza, Egypt, on the Egyptian cotton cultivar Giza 75 ( Gossypium barbadense L.). Cotton plants were sprayed with the growth regulator 1-naphthaleneace acid (NAA) once (at 90 days), or twice (at 90 and 105 days) or thrice (90, 105 and 120 days) after sowing, during the square initiation and boiling stage at the concentrations of 5, 10, 15, 20 or 25 p.p.m. The volume of solution was the same for all treatments. 9601 ha⁻¹. The control plants were sprayed with water only. The effect of the previous treatments on yield components, cotton yield and fibre properties was studied.
The application of NAA increased the number of opened bolls plant⁻¹, boll weight, seed index, seed cotton yield plant⁻¹ and seed cotton and lint yields ha⁻¹. The most significant effects were obtained with the 15 and 20 p.p.m. concentrations. Lint percentage, fibre length parameters and micronaire value were not significantly affected by NAA. Flat bundle strength was significantly affected by NAA but with no definite trend. The application of NAA twice or thrice tended to give the best results on yield components and cotton yield compared with one application. The results of this study suggested that 20 p.p.m. of NAA gave the best figures when applied twice on the Egyptian cotton plants.     

植物生长调节物质对设施杏果实生长发育的影响

以凯特杏为试材,在设施栽培条件下研究了3种植物生长调节物质(GA3、6-BA、NAA)对其果实生长发育的影响。结果表明:GA3、6-BA处理显著促进果实生长,果实纵横径、单果重、果实体积均明显高于对照,GA3处理效果最为显著,细胞学研究表明其对果实增大的原因在于增加了果实细胞数目,NAA处理对果实生长促进效果不明显,与对照相比差异不大;3种处理均提高了果实可溶性总糖含量,以6-BA处理效果最为明显,各处理对果实可滴定酸含量影响不显著。     

气候变化对北京地区小麦玉米两熟种植制度的影响

研究了北京地区小麦和玉米生产与气象条件的关系，并根据未来气候变化 的研究设计了气候情景，在此基础上讨论了未来气候化对小麦玉米一年二熟种植制度的影响。结果表明，温度升高对小麦和玉米生产有利，玉米产量的提高大于小麦；降水减少首先对小麦生产不利，当降水进一步减少时，对玉米生产也不利。     

Effects of irrigation and nitrogen fertilization on the greenhouse gas emissions of a cropping system on a sandy soil in northeast Germany

Irrigation induces processes that may either decrease or increase greenhouse gas emissions from cropping systems. To estimate the net effect of irrigation on the greenhouse gas emissions, it is necessary to consider changes in the crop yields, the content of soil organic carbon and nitrous oxide emissions, as well as in emissions from the use and production of machinery and auxiliary materials. In this study the net greenhouse gas emissions of a cropping system on a sandy soil in northeast Germany were calculated based on a long-term field experiment coupled with two-year N₂O flux measurements on selected plots. The cropping system comprised a rotation of potato, winter wheat, winter oil seed rape, winter rye and cocksfoot each under three nitrogen (N) fertilization intensities with and without irrigation. Total greenhouse gas emissions ranged from 452 to 3503 kg CO_2-eq ha⁻¹ and 0.09 to 1.81 kg CO_2-eq kg⁻¹ yield. Application of an adequate amount of N fertilizer led to a decrease in greenhouse gas emissions compared to zero N fertilization whereas excessive N fertilization did not result in a further decrease. Under N fertilization there were no significant differences between irrigation and non-irrigation. Increases in greenhouse gas emissions from the operation, production and maintenance of irrigation equipment were mainly offset by increases in crop yield and soil organic carbon contents. Thus, on a sandy soil under climatic conditions of north-east Germany it is possible to produce higher yields under irrigation without an increase in the yield-related greenhouse gas emissions.     

Using a multicriteria assessment model to evaluate the sustainability of conservation agriculture at the cropping system level in France

Several international research and development organizations are promoting conservation agriculture in a wide range of contexts. Conservation agriculture is based on a combination of three main principles: (i) minimal or no mechanical soil disturbance; (ii) diversified crop rotations and (iii) permanent soil cover (consisting of a growing crop or a dead mulch of crop residues). However, in the face of the diversity of practices that can be associated with conservation agriculture, of goals assigned to agricultural systems, and pedoclimatic contexts, there is still no empirical evidence about the overall performance of conservation agriculture in France. Global assessments of conservation agriculture, with the full or partial application of its principles and in different contexts, are required to provide a more comprehensive picture of the performance of such systems. We tackled these objectives simultaneously, by evaluating 31 cropping systems with the MASC^® model (for Multicriteria Assessment of the Sustainability of Cropping Systems). These systems were selected to represent a wide diversity of practices, from ploughed conventional systems to crop sequences based on the full application of conservation agriculture principles. Positive interactions were observed between the key elements of conservation agriculture, resulting in better sustainability performances (particularly in terms of environmental criteria). Nevertheless, the systems most closely respecting the principles of conservation agriculture displayed several weaknesses, principally of a social or technical nature, in this study. Careful attention should be paid to attenuating these weaknesses. A more detailed analysis of the results also suggested that decreasing soil tillage tends to decrease the overall performance of the system unless associated with a diversification of the crop rotation.     

Perennial wild plant mixtures for biomass production: Impact of species composition dynamics on yield performance over a five-year cultivation period in southwest Germany

Wild plant mixtures (WPMs) are a promising perennial cultivation system for biogas production with numerous ecological benefits. However, to date, there is little information on their long-term development. To investigate this, two different WPMs (S1, Rieger-Hofmann GmbH, 2016; S2, Saaten-Zeller GmbH, 2016) of up to 27 native, mainly wild species with a combination of annual, biennial and perennial life cycles were established at three sites in southwest Germany in 2011. At Hohenheim (HOH), fertilization was varied (0, 50, 100 kg ha⁻¹ nitrogen) and a split plot design with three replications was used. At Renningen (REN) and Sankt Johann (SJO) single plots were used and fertilized with 50 kg ha⁻¹. Harvest and sample analysis were conducted each year over a five-year cultivation period. The development of dry matter yield (DMY), dry matter content (DMC) and species composition dynamics of the WPMs were investigated.The DMYs varied strongly between the mixtures, sites and years, ranging from 2.9–22.5 Mg ha⁻¹ yr⁻¹. Significant effects of mixture (P < 0.001) and site x age interactions (P < 0.05) were found. On average, S2 had about 55% higher yield than S1 over the five years (S2 accumulated DMY: 50.2–74.2 Mg ha⁻¹ s). For both mixtures, a high number (up to 19) of WPM species were recorded, but this declined over the cultivation period at all sites. The DMYs at REN and SJO increased with time, whereas at HOH the high weed pressure from the grassland pre-crop resulted in decreasing yields. Here, the nitrogen mineralization of the grassland residues was high enough to mask fertilization effects. A good substrate quality for ensilaging (DMC >28%) was achieved at all sites every year except 2011. From these findings, we can recommend the WPM concept based on the S2 mixture as a feasible cultivation system with potentially high ecological benefits, in particular for marginal sites.     

Diversity of methodologies to experiment Integrated Pest Management in arable cropping systems: Analysis and reflections based on a European network

Integrated Pest Management (IPM) aims to promote physical and biological regulation strategies that help farmers contain populations of pests (pathogens, animal pests and weeds) and to finally reduce the reliance on pesticides. It is based on the holistic combination of multiple management measures rather than on the sum of single methods, each of them having only small effects on pests reduction. Thus, to analyse the interactions between IPM measures and to evaluate the sustainability of their implementation, we require an approach considering the whole cropping system (CS), i.e. a functional entity whose complexity is more than the sum of its parts. A network of European experiments at the CS level was set up recently, and aimed at sharing data and expertise to enhance knowledge of IPM. Comparison of existing methodologies highlighted a diversity of CS designs and experimental layouts. We deduced that the concept of CS itself was viewed differently among scientists, and this affected experimental protocols. Other differences were related to the research context and objectives. Some experiments aimed to explore very innovative strategies and generated knowledge on both their effects on the agroecosystem and their ability to satisfy a set of performance targets, while others aimed to provide quickly adoptable solutions for local farmers in line with the current socio-economic constraints. In some research programmes, the experiment was part of the CS design process — and tested CS were regularly revised based on an continuous improvement loop — while in other cases CS were kept stable across years so as to enable the evaluation of their long-term cumulative effects. A critical aspect contributing to the diversity among CS experiments was the distinction between a factorial design of experimental CS and systemic approaches: factorial experiments allowed quantification of the effects of each IPM component regardless of the consistency between components defining the CS. In contrast, systemic approaches focused on the overall evaluation of CS designed with consideration of their consistency, hence maximising their ability to meet the objectives. Because CS experiments represent a huge investment in terms of economics and time, preliminary reflections of the relevance of the experimental strategy is of critical importance.     

Application of the CSM-CERES-Maize model for planting date evaluation and yield forecasting for maize grown off-season in a subtropical environment

In recent years, maize has become one of the main alternative crops for the Autumn–Winter growing season (off-season) in several regions of Brazil. Water deficits, sub-optimum temperatures and low solar radiation levels are some of the more common problems that are experienced during this growing season. However, the impact of variable weather conditions on crop production can be analyzed with crop simulation models. The objectives of this study were to evaluate the Cropping System Model (CSM)-CERES-Maize for its ability to simulate growth, development, grain yield for four different maturity maize hybrids grown off-season in a subtropical region of Brazil, to study the impact of different planting dates on maize performance under rainfed and irrigated conditions, and for yield forecasting for the most common off-season production system. The CSM-CERES-Maize model was evaluated with experimental data collected during three field experiments conducted in Piracicaba, SP, Brazil. The experiments were completely randomized with three replications for the 2001 experiment and four replications for the 2002 experiments. For the yield forecasting application, daily weather data for 2002 were used until the forecast date, complemented with 25 years of historical daily weather data for the remainder of the growing season. Six planting dates were simulated, starting on February 1 and repeated every 15 days until April 15. The evaluation of the CSM-CERES-Maize showed that the model was able to simulate phenology and grain yield for the four hybrids accurately, with normalized RMSE (expressed in percentage) less than 15%. The planting date analysis showed that a delayed planting date from February 1 to April 15 caused a decrease in average yield of 55% for the rainfed and 21% for the irrigated conditions for all hybrids. The yield forecasting analysis demonstrated that an accurate yield forecast could be provided at approximately 45 days prior to the harvest date for all four maize hybrids. These results are promising for farmers and decision makers, as they could have access to accurate yield forecasts prior to final harvest. However, to be able to make practical decisions for stock management of maize grains, it is necessary to develop this methodology for different locations. Future model evaluations might also be needed due to the release of new cultivars by breeders.     

Long-term evaluation of productivity,stability and sustainability for cropping systems in Mediterranean rainfed conditions

Mediterranean cropping systems in rainfed conditions are generally based on rotations with a very high frequency of winter wheat and, therefore, they are at risk of declining trends for yield and soil health in the long-term. In order to quantify this risk, a long-term experiment was set-up in 1971 in central Italy, which is still running at present (2016). This experiment is based on 13 rotations, i.e. three continuous winter wheat systems with different N fertilization rates (W150, W200 and W250), five maize/winter wheat rotations with increasing wheat frequency (maize preceded by 1–5 years of wheat: i.e., WM, 2WM, 3WM, 4WM and 5WM) and five two-year rotations of winter wheat with either pea (WP), faba bean (WFB), grain sorghum (WGS), sugar beet (WSB) or sunflower (WSU). All these rotations are managed either with the removal of crop residues after harvest (REM), or with their burial into the soil at ploughing (BUR). For each rotation, all phases are simultaneously grown in each year, according to a split-plot design (with REM and BUR randomised to main plots), with three replicates in complete blocks and plots of 24.5 m² each. The following data are considered: (1) total and marketable biomass yields from 1983 to 2012; (2) content of Organic carbon (OC) and total nitrogen (N) in soil, as determined in 2014. Considering the 30-year period, BUR resulted in an average positive effect on yield (+3.7%), increased OC (+13.8%) and total N content (+9.4%) in soil, while the C/N ratio was not significantly affected. Wheat in two-year rotations showed a significantly higher (+19.4%) average yield level than in continuous cropping or in 2WM, 3WM, 4WM and 5WM, mainly due to a drop in yield occurring in the first (−13%) and second (−19%) year of recropping. Increasing N fertilisation level from 150 to 250 kg N ha⁻¹ with continuous cropping resulted in an increase (+3.7%) in long-term average yield and in a decrease in yield stability. All rotations heavily based on wheat (continuous cropping and 5WM) produced the highest amount of buried biomass (>175 t ha⁻¹ in 30 years), with the highest increase in soil OC content (>16 t ha⁻¹). All the other rotations produced a lower amount of residues and were less efficient in terms of carbon sequestration in soil, apart from WFB, which gave a high increase in soil organic carbon content (+18.9 t ha⁻¹ in 30 years), in spite of a low amount of buried residues (158 t ha⁻¹).     

Control of alternaria black spot in persimmon fruit by a mixture of gibberellin and benzyl adenine,and its mode of action

In Israel, alternaria black spot (ABS) disease, caused by Alternaria alternata, is the main postharvest factor that reduces quality and impairs storability of persimmon fruit Diospyros kaki cv. Triumph. The fungus infects the fruit in the orchard and remains quiescent until harvest, or renews its development just before harvest, following rain or high humidity; it then preferentially colonizes the stem-end of the fruit. Recent findings suggest the importance of ethylene and respiration during early fruit growth as factors influencing maturity, crack development, and occurrence of ABS in the stem end of the fruit. We tested the effects of the growth regulator Superlon, a mixture of gibberellin (GA₄₊₇) and benzyl adenine (BA), applied at 40 μg mL⁻¹ once a month during three consecutive months, on fruit physiological responses during growth and on ABS occurrence during storage at 0 °C. Superlon treatments during the early stages of fruit growth, i.e., starting 40 days after fruit set (daf), applied once monthly during three consecutive months, inhibited ethylene and CO₂ production in the stem end. Treatments applied starting 100 daf enhanced cell proliferation under the fruit cuticle. Regardless of application timing, Superlon delayed chlorophyll degradation, and reduced fruit cuticle cracking and ABS susceptibility during the late stages of fruit growth and during storage. Present results suggest that the phytohormone, acting as a modulator of host physiological responses that result in delayed fruit maturation, is a main factor in enhanced resistance to ABS at harvest and during storage.     

不同植物生长调节剂对烤烟生长发育的影响

为深入了解植物生长调节剂对烤烟生长发育的影响,以云烟87为试验材料,采用大田试验的方法,研究微生物菌剂、生根粉和表油菜素内酯对烤烟农艺性状、抗氧化酶、多酚氧化酶、根系活力以及烤后烟叶化学成分的影响。结果表明,施用植物生长调节剂对烟株农艺性状、根系活力、过氧化指标相关酶类和烟叶化学成分均有影响。随着烟株的生长,各处理过氧化物酶（POD）活性逐渐升高,多酚氧化酶（PPO）活性呈现降-升-降的趋势。与对照和施用表油菜素内酯相比,施用微生物菌剂灌根和生根粉浸根提高了烤烟的株高、茎围、最大叶长、最大叶宽和有效叶片数;在移栽后45d提高了POD和PPO活性,增强了根系活力,使烤后烟叶化学成分更加协调。综合来看,施用微生物菌剂灌根和生根粉浸根能够改善烤烟的生长发育情况,提高烟叶品质。     

QTL mapping for economic traits based on a dense genetic map of cotton with PCR-based markers using the interspecific cross of Gossypium hirsutum × Gossypium barbadense

A high-density molecular marker linkage map of cotton based entirely on polymerase chain reaction-based markers is useful for a marker-assisted breeding program. Four kinds of markers—simple sequence repeats (SSRs), sequence-related amplified polymorphism (SRAP), random amplified polymorphic DNA (RAPD), and retrotransposon-microsatellite amplified polymorphism (REMAP)—were used to assay an F₂ population from a cross between “Handan208” (Gossypium hirsutum) and “Pima90” (Gossypium barbadense). Sixty-nine F₂ plants were used for map construction using 834 SSRs, 437 SRAPs, 107 RAPDs, and 16 REMAPs. Linkage analysis revealed that 1,029 loci could be mapped to 26 linkage groups that extended for 5,472.3 cM, with an average distance between 2 loci of 5.32 cM. The corresponding 69 F_2:3 families were grown, arranged in two replicates, and scored for eight phenotypes. Quantitative trait loci (QTL) analysis was performed by means of composite interval mapping using WinQtlCart ver 2.0. A total of 52 distinct QTLs were detected: 4 QTLs for lint index, 8 for seed index, 11 for lint yield, 4 for seed cotton yield, 9 for number of seed per boll, 3 for fiber strength, 5 for fiber length, and 8 for micronaire value. The present map and QTL analysis may provide a useful tool for breeders to transfer desirable traits from G. barbadense to the mainly cultivated species, G. hirsutum.     

多功能高分子植物生长调节剂在干旱区玉米生产上的试验效果初报

报道了以观测记录和拍照方式研究多功能高分子植物生长调节剂对玉米生长和繁殖的影响结果，分别用玉米生长、结实和产量指标、玉米品质指标以及经济效益指标与对照比较以评定试验效果。结果显示，施用试剂有利于玉米的营养和结实生长，使玉米产量增加11.06%、品质有所改善（试验组玉米粗蛋白和粗脂肪含量有所提升），经济效益有所提高，仅仅考虑增产就净增产值607.95元/hm2。