柠檬桉组织培养的初步研究

本文初步研究了柠檬桉（ＥｕｃａｌｙｐｔｕｓｃｉｔｒｉｏｄｏｒａＨｏｏｋ．）茎段培养中腋芽伸长生长、继代增殖及试管苗生根的主要影响因素。在含有６－ＢＡ０．１～２．５ｍｇ／Ｌ、ＮＡＡ０．１～０．５ｍｇ／Ｌ的激素组合的改良ＭＳ培养基上都能诱导柠檬桉茎段腋芽伸长生长，最高诱导率可达７３％。继代增殖以６－ＢＡ０．５～１．０ｍｇ／Ｌ为宜，约２０～３０ｄ，丛生芽可增殖４左右，以每年７代计，年增殖率约１．６×１０４。继代培养基的６－ＢＡ浓度过高会导致丛生芽在形态上产生变异，并对生根产生不利的影响。继代增殖在７代内生活力未见有明显衰退。ＩＢＡ对柠檬桉试管苗生根有良好的促进作用，浓度以０．５～２．０ｍｇ／ｔ较为适宜。生根效果不仅与ＩＢＡ浓度有关，还与继代丛生芽的状态有关。生根的小苗已成功移栽到室内的盆中。本研究结果表明，可以用组织培养技术，快速繁殖经过选优的柠檬桉优良无性系。     

黄脉爵床微体繁殖技术研究

对黄脉爵床（Ｓａｎｃｈｅｚｉａ ｎｏｂｉｌｉｓ Ｈｏｏｋ．ｆ．）微繁技术进行了研究并获成功。研究结果表明,外源植物生长调节剂及营养物质对试管芽苗增殖生长及其不定根诱导均有显著影响。试管芽苗在ＭＳ＋ＢＡ０．５ｍｇ／Ｌ＋ＺＴ０．５ｍｇ／Ｌ＋ＮＡＡ０．０３ｍｇ／Ｌ＋ＩＡＡ０．０３ｍｇ／Ｌ培养基上,可获得最大的单位芽苗数。ＭＳ（大量元素减半,肌醇１／４量）＋ＩＢＡ１．０ｍｇ／Ｌ（或ＮＡＡ０．２ｍｇ／Ｌ）＋     

珠美海棠组培苗繁殖技术的研究

以珠美涨棠为材料,研究了培养基配比、苗龄、琼脂等组培苗工厂化生产关键技术,光照条件和培养容器对组培苗生长发育的影响。结果表明,采用改良型培养基ＭＳ＋６－ＢＡ０．５ｍｇ／Ｌ＋ＩＡＡ０．２ｍｇ／Ｌ用于分化培养、１／２ＭＳ＋ＩＡＡ０．５ｍｇ／Ｌ或１／２ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ用于生根培养,苗龄３０－４０ｄ,使用接近国际标准的琼脂、光照强度１５００－２０００ｌｘ条例上生产的组培苗繁殖系数最大、有效苗最多     

苄嘧黄隆及甲黄隆的气相色谱分析方法研究

本文研究了苄嘧黄隆和甲黄隆的气相色谱分析方法。采用（１）５％ＯＶ－１０１／Ｃｈｒｏ－ｍｏｓｏｒｂＧＡＷＤＭＣＳ（０．２５～０．１８ｍｍ）；（２）５％新戊二醇己二酸聚酯／ＣｈｒｏｍｏｓｏｒｂＧＡＷＤＭ－ＣＳ（０．２５～０．１８ｍｍ）的两条色谱柱，邻苯二甲酸二戊酯为内标，氢火焰离子化检测器，标准偏差（ＳＤ）≤０．０６４％，变异系数（ＣＶ）≤２．１％，平均回收率为９６．７％～９８．８％。     

草莓主栽品种Tudla遗传转化体系的建立

本研究建立起农杆菌介导的草莓主栽品种Ｔｕｄｌａ的转化体系,获得了转化植株,试管苗叶片与携双元载体ｐＭＯＧ４１０的农杆菌菌株ＥＨＡ１０５共培养３天,共培养后叶片在附加止那霉素４０ｍｇ．Ｌ＾－１的再生培养基（ＭＳ＋ＴＤＺ２．０ｍｇ．Ｌ＾－１＋ＩＢＡ０．１ｍｇ．Ｌ＾－１）上选择培养４周后,外植株再生出明显可见的转化芽,转化芽再生频率达４．５％,转化芽在附加卡那霉素２５ｍｇ．Ｌ＾－１草莓继代培养基上分化成     

树胡椒的组织培养

树胡椒种子作为外殖体进行微繁殖,不同培养阶段适宜的培养基分别为：（１）愈伤组织诱导：ＭＳ＋ＢＡ１ｍｇ／Ｌ＋ＮＡＡ０．１ｍｇ／Ｌ＋活性碳０．０３％;（２）分化和继代：Ｂ５＋ＫＴ０．５ｍｇ／Ｌ＋ＬＡＡ０．０５ｍｇ／Ｌ和Ｂ５＋ＫＴ２ｍｇ／Ｌ＋ＩＡＡｍｇ／Ｌ;（３）生根：Ｂ５＋ＩＡＡ０．５～２ｍｇ／Ｌ。     

GnRH－A诱导泰和鸡母鸡排卵的生殖内分泌机制

本试验研究了促性腺激素释放激素类似物───［Ｄ－Ｌｅｕ￣６，Ｐｒｏ￣９］－ＧｎＲＨＮ－乙酰胺（ＧｎＲＨ－Ａ）诱导泰和鸡母鸡排卵的生理效应，藉此探讨其生殖内分泌机制。结果表明：（１）ＧｎＲＨ－Ａ具有显著刺激母鸡生殖器官发育的效应，导致母鸡卵巢、输卵管以及肝重增加（Ｐ＜０．０１），但对鸡体重没有显著的影响（Ｐ＜０．０５）；产蛋停止前１周施用ＧｎＲＨ－Ａ可维持母鸡正常产蛋的生殖生理状态。（２）ＧｎＲＨ－Ａ给药后最初２０ｄ诱发出两个鸡血浆促黄体生成素（ＬＨ）释放峰，处理组（ＧｎＲＨ－Ａ组）血浆ＬＨ浓度在此期间显著高于对照组（Ｐ＜０．０１）；然而与对照组相比较，处理组鸡血浆促卵泡素（ＦＳＨ）却没有明显变化（Ｐ＜０．０５）。（３）鸡血浆孕酮（Ｐ４）浓庆在施用ＧｎＲＨ－Ａ后明显上升，显著高于尚处休产期的对照组（Ｐ＜０．０１）。与此相反，给药后的囊初８ｄ内，鸡血浆雌二醇（Ｅ２）浓度明显降低，虽然随后略有回升，但仍低于对照组（Ｐ＜０．０１）。据此可以认为，ＧｎＲＨ－Ａ诱导卵巢和输卵管发育与鸡血浆ＬＨ、Ｐ４以及Ｅ２浓度变化密切相关，ＧｎＲＨ－Ａ是一种有效的制剂，可应用于诱导卵巢和输卵管发育及换羽前产蛋力的改善     

药用植物甜茶的快速繁殖

将甜茶（ＲｕｂｕｓｓｕａｖｉｓｉｍｕｓＳ．Ｌｅｅ）茎段接种在以ＭＳ和Ｗｈｉｔｅ为基本培养基分别附加不同浓度ＢＡ的培养基上。研究表明,以ＭＳ为基本培养基附加２ｍｇ／Ｌ的ＢＡ和０．５ｍｇ／Ｌ的ＮＡＡ,对芽的增殖和生长效果较显著,增殖率比对照高９１％。将试管苗转入以ＭＳ为基本培养基附加１ｍｇ／Ｌ的ＮＡＡ和２ｍｇ／Ｌ多效唑的培养基中,出根率最高达４３％,根茎粗壮。     

无病毒苹果苗试管微繁技术研究

对经脱毒的优良苹果品种北海道９号、皇家嘎拉和长富２号进行了试管微繁技术的研究。结果表明：适合于３个品种试管苗增殖的培养基为ＭＳ＋６—ＢＡ０．５ｍｇ／Ｌ＋ＮＡＡ０．０５ｍｇ／Ｌ＋蔗糖３０ｇ／Ｌ,增殖率为２５～３,≥３ｃｍ的试管苗率约为５０％。通用的生根培养基为１／２ＭＳ＋ＩＡＡ０．５ｍｇ／Ｌ＋ＩＢＡ０．５ｍｇ／Ｌ＋ＮＡＡ０．１５ｍｇ／Ｌ＋蔗糖２５ｇ／Ｌ－肌醇,平均生根率保持在７５％左右。生根试管苗采用“一步法移栽”,平均成活率在７８％以上。     

苜蓿细胞悬浮培养与耐受高浓度PEG变异体的筛选

本文对紫花苜蓿的细胞悬浮培养、悬浮细胞系的建立、离体辐射效应和高浓度ＰＥＧ耐受性变异体的筛透进行了研究。结果表明：１．高浓度的２，４．Ｄ（５～１０ｍｇ／Ｌ），低浓度的ＡＢＡ（０．１～２ｍｇ／Ｌ），高浓度的蔗糖（６％～９％），较高的离子强度，以及逐步缩短继代时间，均有利于胚性悬浮细胞系的快速建立。相反，细胞分裂素，高浓度的ＮＨ和ＧＡａ的存在，不利于悬浮系的建立。细胞分裂素（４ＰＵ３０，ＫＴ或ＢＡ）可促进细胞的团聚，不利于细胞的分散。此外，低浓度的２，４－Ｄ，４ＰＵ３０（或ＢＡ，ＫＴ）和ＡＢＡ的配合使用，在悬浮培养基中可形成大量的体细胞胚。２．辐射处理悬浮细胞的最适剂量为２０～６０Ｇｙ。３．未经改造的初期悬浮培养物远较悬浮细胞系对高水势敏感。４．胚性悬浮细胞系经２０Ｇｙ的γ射线处理，筛选出了对１５％ＰＥＧ水势（约－１１巴）耐受性的克隆６个，并获得了一批再生植株，从２０％ＰＥＧ（约－１５巴）筛选出１个抗性克隆。抗性细胞系对高浓度ＰＥＧ和ＮａＣｌ产生的水势在细胞水平表现出很强的抗性。     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

“绿色革命”以来大气CO2浓度升高对C3作物营养品质的影响

自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。     

Potential of wild species for genetic enhancement of some semi-arid food crops

Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.     

Einfluss der düngungsmethoden auf die entwicklung von zuckerrübenkrankheiten

Während neunjähriger (1994-2002) Untersuchungen in der Versuchsanstalt Ba?cyny (Fahlerde, Fall-Gleyboden, ausgebildet aus leichtem Lehmboden) wurde der Befall mit Krankheiten an der Zuckerrübe in Abhängigkeit von der Düngungsmethode bewertet. Folgende Methoden wurden angewendet: A - Mineraldünger, B - Stalldung und Mineraldünger, C - Stroh-, Gründung und Mineraldünger, D - Kompostdünger und Biopräparate (ökologische Düngung). Auf den Objekten A, B, C wurden bei konstanter Phosphor-Kalium-Düngung die Stickstoffgaben von 0 bis 180 kg.ha^?1 differenziert. Auf dem ökologischen Objekt D ohne Mineraldünger wurden statt Stickstoff die Biopräparate P₅₀₀ und P₅₀₁ verabreicht. Der geringste Befall von Krankheiten wurde an der Zuckerrübe auf jenem Objekt festgestellt, das mit Kompost und den Biopräparaten gedüngt worden war. Im Rahmen der konventionellen Düngungsmethoden wurde allgemein die höchste Intensität der Krankheiten an der mit Stroh, Gründung und Mineraldünger gedüngten Zuckerrübe beobachtet. Ausnahmen von dieser Regel bildete das Vorkommen von echtem Mehltau und Keimlingsfäule. Auf den Objekten A, B, C nahm die Intensität der Krankheiten mit der Steigerung der Stickstoffgabe zu. Auch die auf Objekt D verabreichten Biopräparate stimulierten die Entwicklung der Krankheiten. The effect of various fertilization methods on the diseases of sugar beet was estimated on the basis of nine-year studies (1994-2002) conducted in the Experimental Production Farm in Ba?cyny on loess-based, sedimentary-gley, light-clay soil. The following fertilization methods were applied: A - mineral fertilization, B - mineral and manure fertilization, C - straw, green manure and mineral fertilization, D - ecological compost and biodynamic preparations fertilization. In the objects A, B and C fertilized with phosphorus and potassium, various doses of nitrogen ranging from 0 to 180 kg/ha^?1 were used. In the ecological object D, where mineral fertilization was not used, biodynamic preparations P₅₀₀ and P₅₀₁ were applied instead of nitrogen. The lowest ratio of the diseases of sugar beet was observed in the object fertilized with the compost and biodynamic preparations. In view of the conventional fertilization methods, generally the highest incidence of diseases was noted in the sugar beet fertilized with straw, green manure and mineral fertilizers. The exception was the occurrence of powdery mildew and the black leg. In objects A, B and C the incidence of the diseases increased with the increase in nitrogen doses. The applied biodynamical preparations in the object D stimulated the development of diseases too.     

Prospects for control of Pythium damping-off of lettuce with Trichoderma,Gliocladium and Enterobacter spp.

Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g^-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×10⁵ viable propagules g^-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.