首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
吕晓丽 《玉米科学》2006,14(1):079-080
自90年代后,玉米主要以单交育种为主,但双交、三交也有一定的应用。以88-307、88-9040、9030-130这3个自交系组配的优良三交种“边三1号”,具有植株整齐度高、穗较长、偏硬粒型、产量相对较高、能够适应高纬寒地等特点。同时阐述了玉米三交种的杂交方式在高纬寒地的应用,探讨了三交种育种中的几个问题及其优劣势。  相似文献   

2.
本研究共配制了185个杂交组合,包括单交组合133个、三交组合17个、四交组合35个,在主要分离世代对选择效果进行了分析,结果表明:F2代和F4代的三交组合的优良组合入选率明显高于单交组合和四交组合,四交组合优良单株入选率高于单交组合和三交组合。  相似文献   

3.
关于高赖氨酸玉米选育方法的探讨   总被引:4,自引:0,他引:4  
利用3个普通玉米自交系和6个高赖氨酸玉米自交系进行双列杂交,分析了不同类型杂交组合的产量、赖氨酸含量和其它几个子粒性状的表现,并且通过灰色关联度法综合评价了各组合的优劣,以探讨用普通玉米和高赖氨酸玉米自交系组配单交种选育高赖氨酸玉米的可行性。从平均值看,普×高组合在产量、粒重、容重和收获时子粒含水量方面均优于高×高组合,普×高组合的子粒赖氨酸含量低于高×高组合,但两者的单位面积赖氨酸产量相近。灰色关联度法评价出的前10个组合中有7个是普×高组合,3个是高×高组合,并且第1、2、4、5、6位组合都是普×高组合。因此,用普通玉米自交系作母本与高赖氨酸玉米自交系组配杂交种是值得深入探讨的一种选育高赖氨酸玉米杂交种的有效途径。  相似文献   

4.
利用国内外10个优良玉米自交系与华玉11双亲Q736和Q1,分别组配成单交组合和三交组合,来评价这些自交系对华玉11产量和穗位高的改良潜力。结果表明,基于单交测试的鉴定方法难以充分发掘外来种质的利用价值,当外来种质与本地优良种质组配成半外来种质后,适应性显著增加,通过进一步组配三交测试种能更充分地挖掘出育种潜力。经鉴定,自交系HZ127IM、PHVA9、LH38、郑58、M54、Recovered B73、M5972和PHG29对改良华玉11的产量及穗位高有利用价值,同时对拓宽西南山区种质基础也有一定帮助。  相似文献   

5.
杂交粳稻同质恢复系选育方法研究   总被引:2,自引:0,他引:2  
借鉴杂交玉米二环系选育的理论与方法进行杂交粳稻同质恢复系选育方法研究,以4个不育系泗稻8号A、57A、67A、69A和3个恢复系LH422、C418、R89为材料,比较了单交(不育系/恢复系)、双交(不育系1/恢复系1∥不育系2/恢复系2)、三交(不育系/恢复系1∥恢复系2)、对照(CK,恢复系1/恢复系2)4种组配方式选育恢复系的效率,分析了基础群体与育成的同质恢复系的配合力的关系,结果表明,单交方式选育同质恢复系的效率较高,容易育成优良恢复系;选用高产的单交组合作为同质恢复系选育的基础群体,容易育成配合力优良的同质恢复系;基础群体中恢复系的一般配合力对育成的同质恢复系的产量及其测交F1产量的贡献较大。  相似文献   

6.
玉米二环系测交优势与其亲本杂种优势群的关系研究   总被引:2,自引:0,他引:2  
李玉玲  谈朗玉 《玉米科学》1998,6(2):018-021
本研究以来自不同杂种优势群自交系间7个单交基础材料的31个S3代选系与13个不同类群自交系组配而成的223个测交组合为材料,研究了不同单交及同一单交不同S3代选系的测交优势及其与单交亲本杂种优势群的关系。结果表明:(1)不同单交及同一单交不同S3代选系的对照优势存在明显差异;(2)除G外,各单交后代与其亲本的强优势群基本一致;(3)不同类群自交系间S3代选系穗粒重的对照优势表现为弱优势群间>R×L优势群间>其它优势群间>群内。因此,杂种优势群及其模式并不是绝对的,应灵活运用,同时注重优异新种质的发掘、研究和利用。  相似文献   

7.
本文通过对6年间关于甜菜O-型系保持通用性及Q-型系在甜菜优势育种中利用可行性等方面问题的试验研究,得出了:甜菜O-型系具有一定的保持通用性;(A_i×B_i)组合的雄不育率和配合力是O-型系在优势育种中利用的关键因素;单交、双交和三交的杂种优势均有突出表现。这些杂交方式间虽无显著差异,但有三交>双交>单交之趋势;充分利用O-型系类种质资源,可提高甜菜优势育种的成功机率。  相似文献   

8.
玉米植株形态和穗部性状的遗传特性及育种的选择方式   总被引:2,自引:1,他引:2  
本研究选用6个不同来源、各具特点的玉米自交系及其组成的双列杂交组合为供试材料,选择了17个农艺性状进行了配合力和广义遗传力分析。提出了在选育优良玉米自交系、组配高产杂交组合时各性状的选择方式。  相似文献   

9.
十个玉米自交系主要农艺性状的配合力分析   总被引:7,自引:2,他引:7  
用10个玉米自交系按不完全双列杂交组配成25个杂交组合。对玉米籽粒产量等7个农艺性状的配合力进行了分析。结果表明:4340、同系、82-2A等3个玉米自交系综合性状较优,为组配强优势杂交组合的优良玉米自交系。  相似文献   

10.
几个玉米骨干自交系杂交优势利用研究   总被引:2,自引:0,他引:2  
利用15份玉米自交系组配试验,对其主要数量性状的GCA、SCA、TCA以及各自交系的SCA方差进行估算和分析。结果表明,各自交系的GCA、SCA方差均达极显著水平。P6C1-2-1、Y65-941-1、6166、中黄6441等4个自交系综合性状较优,是组配强优势杂交组合的优良自交系。  相似文献   

11.
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.  相似文献   

12.
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.
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.

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.
  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
Potato is an important crop, grown worldwide. It suffers from many pests and diseases among which late blight, caused by the oomycete Phytophthora infestans, is the worst. The disease is still causing major damage in many potato production areas and control is only possible by applying fungicides frequently. The knowledge on the molecular biology and genetics of the interaction between the plant and the oomycete is developing rapidly. These are relevant fields of study, currently dominated by the discovery of many resistance genes and numerous effector proteins and the analysis of their specific mode of action. These studies may yield essential information needed for the development of durable resistance. The long-term and worldwide effort to breed for resistance so far has had little effect. A novel breeding approach may change this. It is based on cisgenic modification (CM) consisting of marker-free pyramiding of several resistance genes and their spatial and temporal deployment yielding dynamic varieties that contain potato genes only. It is envisioned that this CM approach with potato’s own genes will not only prove societally acceptable but may also result in simplifications in the legislation on use of the CM approach. Various parties in the potato research arena intend to cooperate in this novel approach in a number of developing countries where potato substantially contributes to food security. The use of resources such as land, water and energy improves when the effect of late blight is markedly reduced.  相似文献   

20.
In an experimental breeding scheme to improve late blight (Phytophthora infestans) and white potato cyst nematode (Globodera pallida) resistance of tetraploid potato over three generations of crossing and selection, 15 clones survived the final selection, and these were derived from 15 great-grandparents. There was no direct selection for resistance to Potato virus Y (PVY), but 14 out of the 15 great-grandparents were resistant to PVY and three had extreme resistance. Thirteen of the 15 descendants had PVY resistance and one extreme resistance. This was within the range expected for a random (unselected) sample from the genotypes of the great-grandparents. Hence, we found no evidence for any positive or negative association between PVY resistance and the attributes selected. The conclusion is that laborious selection is not required in every generation when many parents have PVY resistance, including some with more than one copy of a PVY resistance gene or resistance at more than one locus. However, in the future, determining the major virus resistance genes present in potential parents in each generation using diagnostic molecular markers would prevent susceptible × susceptible crosses being made and maximise the number of resistant × resistant ones.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号