我国双季稻生产机械化制约因子与发展对策

20世纪70年代中期以来,我国双季稻种植面积占水稻总面积比例持续下降,从当时的71%下降到近年的40%左右。按单位土地面积计算,双季稻早晚两季产量比单季稻高57%左右,改单季稻为双季稻种植,在保持稻田面积不变情况下,可大幅提高种植面积和总产。双季稻种植面积下降的主要原因是机械化程度较低,生产效益不高。制约双季稻全程机械化的关键是机插秧比例不高,特别是双季稻机插秧季节紧张,适宜机插搭配品种少,机插质量较差,及主要作业环节机械化不配套等。发展双季稻生产全程机械化的关键途径是:选育和筛选一批适宜双季稻机械化生产的品种,优化双季稻机械化生产的品种搭配布局;创新一批双季稻机械化生产模式,完善关键环节技术模式;创制一批双季稻机械化生产的机械装备,实现机具装备配套;研发一批双季稻全程机械化栽培技术,推进农机农艺技术配套与应用。     

双季稻塑料盘旱育秧抛植高产高效栽培技术

早、晚季水稻采用塑料盘旱育秧抛植配套栽培技术，可以达到高产高效的目的，同时减轻了劳动强度。文中介绍了早晚两季盘育旱秧的方法和抛秧技术及大田栽培管理措施。该技术是双季稻高产高效栽培的新途径。     

华南双季优质稻在张家界中稻区的气候生态适应性初步研究

2004年选用广东省水稻研究所提供的华南双季稻品种，通过比较广州早稻栽培与湘西北张家界中稻试种的产量与米质变化，以探索华南双季优质稻与广适性超级稻对不同气候生态条件的适应性。结果表明，各品种在两地生育期表现相近；张家界水稻生育前期和中期气温较高，因而有效穗数比广州增加，但每穗总粒数显著减少；由于张家界8月上旬水稻抽穗开花期常出现过高温时段，因而结实率下降，但水稻灌浆结实期气温比广州低，故千粒重比广州高；两地各品种产量水平相当，大多在7．50～8．25t／hm^2；在稻米品质方面，张家界稻区的糙米率和精米率下降而垩白粒率和垩白度增加，稻米直链淀粉含量大多高于广州。张家界低海拔地区引进华南双季稻品种作中熟中稻栽培。表现出良好的气候生态适应性。     

华南籼稻稻米品质性状早晚季间变化规律探讨

目前 ,华南双季稻作区种植的常规稻品种大多数都是早晚兼用型品种 ,不少生产上应用的杂交组合也属早晚兼用型。早晚兼用型品种 (组合 )在早晚季种植时稻米品质会有所不同 ,普遍的经验认为晚季稻米的食味品质优于早季 ,但对于稻米蒸煮、外观、碾米、食味等具体品质指标在早晚季的变化尚缺乏深入的量化研究。本文采用国家优质稻谷标准ＧＢ／Ｔ１７８９１-１９９９,测定并分析了９个华南籼稻品种 (组合 )在６个试点早晚两季种植的稻谷样品的品质指标 ,试图揭示华南籼稻品种 (组合 )早晚季品质变化的规律 ,讨论了新国标的可操作性。一、材料与方…     

高温对湖南省一季稻及再生稻结实的影响及应对策略

为了解2022年罕见持续高温天气下湖南省一季稻及再生稻灌浆结实情况,对湖南省一季稻种植区域内常规稻和杂交稻结实率和籽粒充实度进行调研。结果表明,高温显著地降低了一季稻结实率,且对常规稻的影响大于杂交稻。同时,高温对一季稻结实率的影响存在明显的地域性差异,湖南省北部区域的结实率受高温影响较大,28°N以北区域的常规稻和杂交稻结实率分别比28°N以南区域降低了6.7和3.1个百分点。此外,高温对再生稻头季和再生季籽粒灌浆结实和产量的影响存在明显差异,头季和再生季分别于7月15日之前和9月1—17日齐穗的再生稻品种,能一定程度上缓解高温对再生稻两季结实率和产量的影响。针对高温对湖南省一季稻和再生稻结实的影响以及再生稻生产现状,提出了应对全球变暖环境下高温胁迫对一季稻结实影响的策略：选育耐高温水稻品种;在经济效益相当的条件下,湖南省28°N以北地区选种杂交稻;由一季稻种植模式转变成再生稻种植模式,并搭配适宜播期。     

播期和种植密度对玉米子粒灌浆的影响

通过设计不同的播种时期和种植密度,研究不同处理造成的温光生态条件和群体结构差异对玉米不同部位子粒灌浆的影响。结果表明,播期和种植密度对玉米中部子粒灌浆速率影响主要表现在灌浆后期,密度影响较大;播期和种植密度对玉米顶部子粒灌浆速率主要是阶段性影响。播期对玉米中部子粒含水率影响较大,种植密度对玉米中部子粒含水率没有影响。     

灌浆结实期不同时段温度对水稻结实与稻米品质的影响

 利用人工气候箱在水稻灌浆结实期不同时段进行温度试验，研究温度对水稻结实与稻米品质的影响。结果表明，灌浆结实期40℃高温处理后籽粒结实率显著降低，粒重下降，外观品质和食味品质变差。不同水稻品种对灌浆结实期温度的响应表现不一致。在试验条件下，华粳1号开花受精的敏感温度为35℃，而特优559开花、灌浆结实的最适温度为30℃，该温度处理结实率、粒重较高，外观品质以及食味品质较优。此外，灌浆结实期不同时段的高温对水稻结实与稻米品质的影响也存在显著差异：结实率对高温最敏感的时期是开花后1~5 d，粒重对高温最敏感的时期是开花后11~20 d；而温度对稻米品质影响最大的时期主要在花后16~20 d，25 d后温度处理影响较小。因此，灌浆前期适宜的温度条件对水稻优质栽培意义重大。     

机械种植方式对双季稻生育期、产量及经济效益的影响

以中早39、陆两优996分别作早季和晚季供试品种,两季均设置机插、机抛、机直播3种机械种植方式,共组成9种试验搭配组合,研究机械种植方式对双季稻生育期、产量及经济效益的影响。两季全生育期均表现为机插>机抛>机直播,两季大田生育期均表现为机直播>机插>机抛;两季分蘖发生速度与高峰苗数均表现为机抛>机直播>机插;干物质积累量在早季抽穗期表现为机抛显著高于机插和机直播,成熟期机插和机抛显著高于机直播,晚季抽穗期无差异,成熟期机插和机抛显著高于机直播;两季产量均表现为机抛>机插>机直播,周年产量以机抛—机抛方式最高;两季成本和产值均表现为机抛>机插>机直播,周年利润以机抛—机抛方式最高,机插—机直播方式最低。综上,机抛—机抛方式在双季稻生产中表现最优,可加大推广应用力度。     

超级稻丰两优香1号再生栽培示范技术

对超级稻品种丰两优香1号进行再生栽培示范和系统观察,丰两优香1号再生苗节数均为5个节,再生苗的节间长度均比头季短;再生季植株上部3片功能叶面积均比头季小;再生栽培两季稻谷产量可达到15 274.5 kg/hm2,比"早稻-晚稻"连作种植产量低733.5 kg/hm2,但是再生稻米质优、价格高,总产值与双季稻相当,同时因再生稻省种、省工、省投入,纯收入比双季稻连作高3 736元/hm2。     

双季玉米栽培技术

玉米在湖南春夏秋三季都可播种,除高寒山区外,夏播玉米常因病虫严重和夏秋长期干旱导致减产。春玉米 秋玉米 冬作,可以充分利用地力,提高产量。双季玉米对光热要求比双季水稻低,凡能种双季稻的地区都可种双季玉米,种水稻光热两季不足一季有余的地区,也可通过品种搭配和育苗移栽种好双季玉米。其种植方法如下。     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

La pourriture fongique des tubercules de pomme de terre en atmosphère contrôlée

Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.

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Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

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Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.

     

Marine Pharmacology in 2016–2017: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems,and Other Miscellaneous Mechanisms of Action

The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.     

Effects of Micronutrient Deficiencies on Human Health: Its Status in South Asia

SUMMARY

Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia.     

Management of Soil Micronutrient Deficiencies in the Rice-Wheat Cropping System

Summary

Within the last three decades, the rice-wheat cropping system has triggered, and with time, aggravated soil micronutrient deficiencies in the Indo-Gangetic Plains (IGP). This has largely been due to the shift from an earlier rice and wheat monoculture with low yielding, long duration indigenous varieties, to an intensive rice-wheat rotation cropping system with short duration modern high yielding varieties on the same piece of land. The problems related to micronutrient deficiency in the IGP are more due to the size of its available pools in the soil rather than its total contents and are greatly influenced by crop management, or rather its mismanagement. Deficiency of zinc is widespread in the IGP, but with the extensive use of zinc sulfate, zinc deficiency has reduced in some areas of the region. Meanwhile, the deficiency of Fe, Mn and B has increased in the IGP. Deficiency of Cu and Mo is location specific and can limit rice and wheat yields. The adoption and spread of the rice-wheat system in permeable coarse textured soils, particularly in the western IGP, not only caused iron deficiency in rice but also resulted in the emergence of manganese deficiency in wheat. In highly calcareous and acidic soils, boron is the next limiting micronutrient in crop production after zinc. Bumper rice and wheat harvests in the past decade, the declining use of organic manures in the region and except for the widespread use of zinc sulfate, a general lack of awareness amongst farmers on micronutrient deficiency problems has contributed to micronutrients limiting rice and wheat yields in the IGP. Approaches to alleviating micronutrient deficiencies include matching the crop removals of the micronutrients with its replenishments through their respective external carriers, supplementation through organic sources and mobilization/utilization through cultivation of micronutrient efficient crop cultivars. Identification of efficient micronutrient carriers and finding the optimum rate, mode and time of its application is important in ameliorating the micronutrient deficiencies. This article reviews the extent of micronutrient deficiency and discusses various management options available to reduce micronutrient deficiency induced crop yield reduction for rice and wheat in the Indo-Gangetic Plains.     

Irrigation but not N fertilization enhances seedhead density in plains rough fescue ( F estuca hallii)

Plains rough fescue ( F estuca hallii) is an important forage grass species in western Canada. Seed for use in pastures and ecological restoration is in high demand but supply is limited because F. hallii is an erratic seed producer. Seed producers require an understanding of the factors that influence flowering and seed set in this species. The aim of this study was to assess the effect of irrigation and nitrogen fertilization on the flowering and growth of F. hallii in a native rough fescue prairie in Alberta, Canada. Irrigation had a strong positive effect on seedhead density, whereas fertilization had limited effects on growth and reproduction of F. hallii. These results demonstrate that under field conditions, available moisture is likely to be a key factor driving flowering and seed production in F. hallii.     

Marine Drugs Regulating Apoptosis Induced by Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)

Marine biomass diversity is a tremendous source of potential anticancer compounds. Several natural marine products have been described to restore tumor cell sensitivity to TNF-related apoptosis inducing ligand (TRAIL)-induced cell death. TRAIL is involved during tumor immune surveillance. Its selectivity for cancer cells has attracted much attention in oncology. This review aims at discussing the main mechanisms by which TRAIL signaling is regulated and presenting how marine bioactive compounds have been found, so far, to overcome TRAIL resistance in tumor cells.     

In vitro reproduction in the annual pasture legumes subterranean clover (Trifolium subterraneum L.) and French serradella (Ornithopus sativus Brot.)

Pasture legumes are important components of both mixed farming rotations and permanent pastures in temperate climates. Breeding of two widely sown pasture legumes, subterranean clover (Trifolium subterraneum L.) and French serradella (Ornithopus sativus Brot.), is constrained by the long generation cycle, typically enabling only one generation per year. We hypothesized manipulation of culture medium and conditions would enable the development of a laboratory‐based protocol for in vitro reproduction in subterranean clover and French serradella. In vitro flowering and viable seed set was induced from both species. For subterranean clover, the most effective treatment was culturing on modified MS medium with 1 μm kinetin and 0·1 m sucrose under a 100 μmol m^?2 s^?1 light intensity and continuous photoperiod. For French serradella, culture on a hormone‐free B5 medium with 5 mm NH₄Cl and 0·1 m sucrose under a 100 μmol m^?2 s^?1 light intensity and 20 h photoperiod was optimum. It is expected this technique will have application in accelerating generation turnover within breeding programs, for the study of factors influencing flowering in pasture legumes, and for the propagation of valuable yet enfeebled plants such as embryo‐rescued hybrids.     

Biochemical and morphological characterization of potato clones differing in their resistance to late blight

Summary Morphological and biochemical parameters that could be involved in resistance to late blight were studied in non-infected and in infected potato hybrids resulting from a cross betweenSolanum phureja, resistant toPhytophthora infestans, and a susceptibleSolanum tuberosum. Some morphological differences between resistant and susceptible hybrids, indicating a positive correlation between stem diameter and phloem thickness in the stem and resistance toP. infestans, were observed. The lignin content in the leaves of the resistant hybrid rose upon infection byP. infestans. In the leaves of the susceptible hybrid, a diminution of the lignin content could be observed upon infection byP. infestans. In the same context, peroxidasic activity raised upon infection byP. infestans in both resistant and susceptible hybrids. Further characterization of the hybrid clones based on the polymorphism of peroxidases was attempted using isoelectric focusing.     

Estimation of lucerne yield stability for enabling effective cultivar selection under rainfed conditions

Evaluation of crop and forage yield stability is of increasing relevance in the context of current and recent environmental changes but, in contrast to other field crops, there are no published systematic analyses among forage crops in Europe. A study of stability performance was conducted with 13 Czech cultivars of lucerne at four locations over a 2‐year period with the following aims: (a) to evaluate yield stability of varieties across different environments and (b) to calculate measurable benefits of variety selection in relation to the specific environment. The cultivar Vlasta was identified as the highest yielding cultivar (annual yield 16.0 t DM/ha), whereas the lowest yielding cv. Magda, Tereza and Oslava averaged around 14.9 t DM/ha. Effect of genotype × environment interaction (G × E) was two times higher than for genotype alone. Additive main effects and the multiplicative interaction (AMMI) model showed that the highest yielding cultivars may not be stable across environments. This study demonstrated further that significant yield improvement could be detected, even among a relatively homogenous group of domestic cultivars, and this was driven mainly by site productivity: the improvement was +10% in low‐yielding sites, compared with +3% in high‐yielding sites. Results highlight that advanced agronomy should also consider stability parameters such as AMMI stability value or superiority measures for forage crops in response to the challenges associated with climate change.