小麦抗穗发芽基因挖掘及分子育种进展

穗发芽是影响小麦品质和产量的重要自然灾害之一。了解小麦穗发芽抗性遗传和分子基础,有助于穗发芽抗性改良。本文从穗发芽抗性QTL发掘、功能标记开发、穗发芽主要抗源以及抗穗发芽分子育种几方面对小麦穗发芽研究进展进行综述,并对今后小麦穗发芽抗性研究重点及育种思路进行讨论,以期为小麦穗发芽遗传研究和抗性育种提供参考。     

小麦赤霉病的抗性遗传分析

为给小麦抗赤霉病遗传改良提供参考,利用苏麦3号及5个当地推广小麦品种为亲本,按Griffing双列杂交法Ⅱ配制15个杂交组合,以赤霉病病小穗率为抗性指标,研究了小麦赤霉病抗性的遗传。结果表明,在6个小麦品种中,苏麦3号和扬麦9号赤霉病抗性的一般配合力最好,能极显著地提高杂种后代的赤霉病抗性。小麦赤霉病抗性的遗传符合加性显性模型,同时受加性和显性效应的作用,且加性效应更重要,显性程度为部分显性。控制赤霉病遗传的增效等位基因为显性,增减效等位基因频率在亲本中的分配存在显著差异。苏麦3号具有最多的控制赤霉病抗性遗传的显性基因,而宁麦8号则具有控制赤霉病抗性遗传最多的隐性基因。小麦赤霉病抗性可能受2~3对主效基因的控制,狭义遗传力较高,早代选择有效。论文最后还就小麦抗赤霉病育种进行了探讨。     

对冬小麦品种穗发芽抗性的初步研究

１９９２－１９９５年用室内保湿法对１５００份小麦材料进行穗发芽抗性鉴定，从小麦穗长发芽与收获后的种子发芽的比较把小麦收获前穗发芽分为低，中，高３种敏感型，白粒品种穗发芽抗性低于红粒品种；数量遗传分析表明，小麦穗发芽率的广义遗传力高于６０％。     

水稻抗病优质品种主要性状的配合力分析

 选用10个优质的或抗稻瘟病的品种,通过双列分析研究了稻瘟病抗性、有效穗、直链淀粉含量和胶稠度的遗传和配合力进行了分析。结果表明,稻瘟病抗性、直链淀粉含量和胶稠度主要受加性基因效应控制。每株分蘖数、穗数、穗长和株高既受加性效应也受非加性效应控制。外选35是具有抗稻瘟病、粒形美观和高配合力和抗性遗传力强的品种,但在胶稠度和直链淀粉上不佳。试验还发现,二八占抗性和米质性状结合较好,其抗性和米质的一般配合力效应均较显著,可以作为新的抗性材料。     

母体对小麦胚的ABA敏感性和种子休眠性的影响

种子休眠是品种穗发芽抗性的主导因素,休眠特性与母体效应和胚对ABA的敏感性均有密切关系。为了了解母体对小麦胚的ABA敏感性和种子休眠的影响,为抗穗发芽育种提供科学依据,对穗发芽抗性不同的小麦品种及它们正反交F1后代授粉后不同发育阶段的胚进行了ABA敏感性鉴定,并对收获前的籽粒发芽能力进行了测定。结果表明,在种子发育过程中,不同基因型的离体胚萌发能力存在差异,抗穗发芽品种的胚对ABA敏感性明显高于易穗发芽品种,胚对ABA的敏感性与其萌发能力关系密切,随着萌发能力的升高,胚对ABA的敏感性降低。在成熟种子中,F1的休眠性偏向于抗性亲本。尽管成熟种子和胚的休眠表现出一定的母体效应,但母体对发育至成熟过程中胚的ABA敏感性并没有影响。因而,母体对种子休眠的影响可能与胚的ABA敏感性无关。     

白皮小麦抗穗发芽资源评价及抗性候选位点关联分析

白皮小麦皮薄且胚乳相对含量及出粉率高,较红皮小麦更受农户和企业青睐,但也更易发生穗发芽。为了给抗穗发芽机理研究及抗性育种提供参考,本研究首先在7个不同环境条件下对来自世界主要小麦产区的502个白皮小麦材料进行穗发芽抗性鉴定和评价,然后对白皮小麦穗发芽抗性进行位点关联分析。穗发芽抗性鉴定结果表明,502个白皮小麦材料中,仅1.39%的材料平均发芽率小于40%,其中Osiris（埃及）、Vilmorin 29（法国）、Miana（法国）、Kanto 107（日本）、Darwin（德国）、Magnif MG（阿根廷）和Benefactress（英国）具有在多个环境下稳定的穗发芽抗性。利用与小麦穗发芽抗性紧密连锁的236对标记筛选到202个多样性位点,依据遗传结构将白皮小麦群体分为3类（K=3）时,分别有40.92%、30.03%和29.04%的材料分在三个亚群中,当K=6时群体结构趋于稳定,同时发现,非洲的材料群体结构单一,而来自其他地区的材料遗传结构更复杂。结合穗发芽表型与K=3~6时的遗传结构数据对具有代表性的303个白皮小麦材料进行关联分析,通过平均值与各环境值分别关联到4个与15个在白皮小麦群体中与穗发芽抗性相关的等位变异位点。其中, Xwmc24.2-1A、 Xcfd44.1-2D、 Xbarc321.2-3A、 Xgwm397.1-4A和 Xwmc75.1-5B能够在不同环境中关联到,为较稳定的白皮小麦抗穗发芽位点。     

杂交水稻种子穗萌遗传效应的研究

 以穗萌抗性水平不一的6个不育系和7个恢复系为亲本材料，采用不完全双列杂交的试验设计，并运用包括胚乳、细胞质和母体植株三套遗传体系的种子遗传模型及估算遗传方差分量和预测遗传效应值的统计分析方法，对杂交水稻种子穗萌特性的遗传效应进行了研究。结果表明，杂交水稻种子的穗发芽率同时受种子直接加性、种子直接显性和母体加性效应的影响，且以种子直接效应为主，不受细胞质和母体显性效应的影响。在选择育种中，田间穗上发芽率以单粒选为好。而穗萌指数同时受制于种子直接遗传效应、母体效应和细胞质效应，但母体植株中只测到显著的母体加性效应。     

山西省冬小麦品种资源对穗发芽的抗性鉴定研究

对２３５个品种（系）进行了小麦成熟期的穗发芽抗性鉴定研究，结果表明，红粒品种普遍抗穗发芽，但不少白粒品种抗性亦较强，颖壳颜色与抗性无关，山西省育成品种（系）的抗性比国外品种较差。从山西省的１５２份白粒品种中鉴定出８份较抗穗发芽的品种，以供育种及专题研究利用。     

不同麦区小麦品种穗发芽抗性及其与穗部性状的相关性

为探究不同麦区小麦品种的穗发芽抗性及其与穗部性状的相关性,以黄淮冬麦区(南片和北片)、北部冬麦区及长江中下游麦区的235份小麦品种为试验材料,选用2个能够有效用于穗发芽抗性筛选的分子标记Vp1B3和WMC104,结合整穗发芽试验,对各麦区小麦品种穗发芽抗性进行鉴定,并分析穗发芽抗性与穗部及籽粒性状间的相关性。结果表明,长江中下游麦区小麦穗发芽抗性显著高于其他三个麦区,其供试小麦品种60%以上达到抗性等级,其余三个麦区中达到抗性等级的品种均不超过30%;供试品种中,扬麦10号、荆麦103、川农16等15个品种为高抗穗发芽品种,发芽率均值为4.85%,是穗发芽抗性育种中的重要抗性资源。整穗发芽率与穗部及籽粒性状相关性分析表明,穗发芽率与籽粒颜色极显著正相关,与小穗密度、千粒重、籽粒宽度等显著正相关。在育种过程中,可将籽粒颜色、小穗密度、千粒重及籽粒宽度等作为抗穗发芽小麦品种的重要参考指标。     

节节麦大穗大粒相关农艺性状的遗传分析

节节麦(Aegilops tauschii,DD)是六倍体普通小麦D基因组的祖先,其自然类群中含有丰富的抗逆、高产基因,利用其与四倍体硬粒小麦合成的六倍体小麦在现代小麦育种中得到了愈来愈多的应用。本课题在野生节节麦类群中发现了大穗、大粒材料AT462,利用其作母本与节节麦材料AT18(强分蘖)杂交;构建了F2、F3群体,通过调查亲本和群体单株的穗长、小穗数、粒长、粒宽和粒重等表型,对这些穗部性状进行了相关性分析和遗传分析。结果表明:(1)在F2和F3群体中,粒重、粒长与穗长之间不存在显著相关性,而且穗长与粒宽之间在两个群体中的平均相关系数绝对值小于0.1,粒重与小穗数之间的相关系数绝对值小于0.2,表明节节麦大粒相关性状不受穗长的影响,受小穗数影响也较小;(2)采用F2单世代分离分析的方法对节节麦AT462×AT18的F2群体大穗、大粒相关性状进行遗传分析,其中穗长受2对具有加性效应的主效基因控制;粒重和小穗数均同时受2对基因的加性效应、显性效应以及互作效应控制,其中加性效应占主导地位;粒长、粒宽均受2对基因的加性效应、显性效应以及互作效应控制,且三种效应较为均衡。这说明控制节节麦粒重、穗长、小穗数等产量性状相关基因的加性效应在遗传中占主导地位,在育种中较易利用,且其主效基因的遗传力达0.9。     

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.     

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.     

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.     

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.     

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.