玻璃化冷冻体外成熟牛卵母细胞的尝试

通过两个试验对体外培养成熟的牛卵母细胞进行玻璃化冷冻。试验１用１０％丙二醇（ＰＧ）加上不同浓度（０％～２０％）的乙二醇（ＥＧ）作为细胞内玻璃化溶液（ＶＳ１），２５％ＰＧ＋２５％ＥＧ作为细胞外玻璃化溶液（ＶＳ２）对卵母细胞进行冷冻。结果卵母细胞的体外受精分裂率（０．９％～２３．４％）均显著低于对照组（７５．０％）。在处理组中，以１０％ＰＧ＋５％ＥＧ和１０％ＰＧ＋１０％ＥＧ作为ＶＳ１的效果较好，分裂率分别为２３．４％和２２．２％，均显著高于其他处理组。试验２以１０％ＰＧ＋５％ＥＧ作为ＶＳ１，２５％ＰＧ＋２５％ＥＧ作为ＶＳ２进行冷冻。解冻后在０．５ｍｏｌ／Ｌ或０．２５ｍｏｌ／Ｌ蔗糖溶液中１～２步或在含防冻剂的溶液中经２～３步稀释防冻剂。卵母细胞经体外受精后，分裂率在１８．２％～３０．６％之间。在０．２５ｍｏｌ／Ｌ蔗糖溶液中一步脱防冻剂的卵母细胞经体外受精、体外培养后，２５个早期胚胎中有３个发育成囊胚，其它组均未发现囊胚。这些结果表明玻璃化过程对卵母细胞造成了损伤。引起损伤的原因可能是玻璃化溶液的化学毒性作用及脱防冻剂过程中卵母细胞受到的渗透压损伤。     

不同发育阶段和质量的牛体外受精胚胎冷冻后的效果

胚胎的冷冻是用二步降温法，将胚胎降至－２５℃，并直接投入液氮。试验Ⅰ，将６～８日龄的牛胚胎置于显微镜下，按发育期把胚胎分成桑椹胚、早期囊胚、囊胚、扩展囊胚四个阶段，然后分别平衡在１．５ｍｏｌ／Ｌ甘油＋０．２５ｍｏｌ／Ｌ蔗糖ＰＢＳ液中，２０ｍｉｎ后进行冷冻。解冻后，各阶段的胚胎孵化率分别为：２９．０％，７３．２％，７４．６％，６１．２％。桑椹胚的孵化率极显著（Ｐ＜０．０１）地低于其它三个阶段的胚胎，其它三个阶段之间无显著差异（（Ｐ＞０．０５）。试验Ⅱ，将７日龄的囊胚，在显微镜下鉴定质量并分为１～５级，仅１，２级胚胎用于冷冻。试验结果表明：每管装２枚胚胎时，有１枚胚胎以上孵化的细管数，１级的有９３．８％（４５／４８），２级的有７７．４％（２４／３１），它们之间差异显著（Ｐ＜０．０５）。每管装３枚胚胎时，有２枚胚胎以上孵化的细管数，１级的有８７．５％（４２／４８），２级的有６８．０％（１７／２５），二者间差异显著（Ｐ＜０．０５）。本研究结果表明：不同阶段和质量的牛体外培养胚胎冷冻后对存活率有显著的影响。     

生长因子对卵母细胞体外成熟及早期胚胎体外发育的影响

为了探讨生长因子（ＥＧＦ，ＰＤＧＦ）对牛卵母细胞体外成熟与早期胚胎体外发育的影响，本研究进行了两个实验。实验１：在卵母细胞体外成熟（ＩＶＭ）中，将卵母细胞平均随机的放入表皮生长因子浓度为０，２．５，２５，５０μｇ／Ｌ的成熟培养液和对照组中。实验２：在早期胚胎体外培养（ＩＶＣ）过程中，将受精卵平均随机分配入５个不同培养液的处理组：（１）ＴＣＭ－１９９＋１０％阉公牛血清（ＳＳ）；（２）ＴＣＭ－１９９＋ＥＧＦ＋ＰＤＧＦ；（３）ＴＣＭ－１９９＋ＥＧＦ；（４）ＴＣＭ－１９９＋ＰＤＧＦ；（５）ＴＣＭ－１９９＋无生长因子、其中ＥＧＦ：５０μｇ／Ｌ，ＰＤＧＦ：０．１μｇ／Ｌ。２，３，４，５组有０．１％ＰＶＡ和０．３％ＢＳＡ，并与颗粒细胞单层协同培养。卵母细胞的体外成熟（ＩＶＭ）、体外受精（ＩＶＦ）和早期胚胎体外培养（ＩＶＣ）的方法与Ｌｕ等（１９８７）报道的相同。结果表明：浓度为５０μｇ／Ｌ的处理组分裂率与对照组无差异（８９．０％，９２．４％，Ｐ＞０．０５），而浓度为０，２．５，２５μｇ／Ｌ的处理组分裂率均显著低于对照组（７８．６％，８２．３％，８４．３％，Ｐ＜０．０５），在囊胚率和第７ｄ一级胚胎率上各组均无差异。ＥＧＦ在体     

红壤中铝的形态

以改进的连续分级提取方法,用１ｍｏｌ／Ｌ,ＫＣｌ,０．２ｍｏｌ／Ｌ,ＨＣｌ,０．１ｍｏｌ／Ｌ Ｎａ４Ｐ２Ｏ７（ｐＨ８．５）,ＤＣＢ溶液,０．３３ｍｏｌ／Ｌ,柠檬酸钠和０．５ｍｏｌ／Ｌ ＮａＯＨ为提取剂,把红壤中可提取的非晶态铝区分为交换态铝,肿附态无机羟基铝,有机配合态铝,氧化铁结合态铝,层间铝和非晶态铝硅酸盐。     

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。     

受精液中肝素和咖啡因的组合对牛卵母细胞体外受精的影响

采用２种肝素浓度（１０，３０ｍｇ／Ｌ）与３种咖啡因浓度（２．５，５，１０ｍｍｏｌ／Ｌ）的交叉组合，以３０ｍｇ／Ｌ肝素的受精液为对照，探讨肝素和咖啡因对牛卵母细胞体外受精的影响，并确定受精后将卵母细胞移至单层细胞的合适时间。结果表明，当卵母细胞在受精后５ｈ移至单层细胞时，１０ｍｇ／Ｌ肝素加５ｍｍｏｌ／Ｌ咖啡因或３０ｍｇ／Ｌ肝素加２．５ｍｍｏｌ／Ｌ咖啡因的体外受精效果最好，二者的囊胚率和囊胚孵化率分别为５６．９％±７．０，８１．１％±１２．７及５６．９％±７．０，７８．９％±９．８。     

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％。     

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。     

氯化胆碱对二种木本植物组培苗生长的影响

以哈斯油梨（ＰｅｒｓｅａａｍｅｒｉｃａｎａＭｉｌｃｖ．Ｈａｓｓ）胚和抗根腐病砧木托马斯（Ｐ．ａｍｅｒｉｃａｎａＭｉｌｒｏｏｔｓｔｏｃｋＴｈｏｍａｓ）茎段及大叶桉（ＥｕｃａｌｙｐｔｕｓｒｏｂｕｓｔａＳｍｉｔｈ）组培苗茎尖为试材，在１／２ＭＴ（１／２无机盐＋有机物＋２％蔗糖＋０．９％琼脂）附加不同浓度（０，５０，１００，３００，５００，７００，１０００ｍｇ·Ｌ－１）的氯化胆碱的培养基上培养，结果表明适宜浓度的氯化胆碱可显著提高两种木本植物组培苗的生长，刺激发根和根的伸长，可使砧木茎段上处于“休眠”状态的腋芽大量萌发；７种浓度中以５００ｍｇ·Ｌ－１的浓度处理效果最为显著     

无机盐离子对早期牛胚胎在体外发育的影响

本研究系统的探索了培养液中的主要无机盐离子对早期牛胚胎在体外发育的影响。结果表明：培养液中的Ｎａ＋／Ｋ＋比显著影响牛胚胎在体外的发育，提高Ｋ＋浓度有降低囊胚率的作用，最适的Ｎａ＋／Ｋ＋比为１１４／３．２；Ｃａ２＋和Ｍｇ２＋同样为胚胎发育所必需，其最适浓度分别为２ｍｍｏｌ／Ｌ和０．５ｍｍｏｌ／Ｌ；培养液中添加２．８８ｍｇ／Ｌ的Ｚｎ２＋，其囊胚发育率显著高于空白对照组；培养液中添加０．０２５ｍｇ／Ｌ或０．２５ｍｇ／Ｌ的Ｃｕ２＋完全抑制囊胚发育。这表明Ｚｎ２＋对早期牛胚胎在体外发育有显著的促进作用，Ｃｕ２＋对早期牛胚胎在体外发育有强烈的抑制作用。     

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.