辐照小麦花粉的诱变效应

应用５Ｇｙ、１０Ｇｙ、２０Ｇｙ和３０Ｇｙ６０ＣｏΥ射线辐照４个小麦品种（品系）的成熟花粉,研究其杂交当代籽粒的发育,Ｍ１的生理损伤及Ｍ２的诱变效应。结果表明,１０Ｇｙ辐照小麦成熟花粉的诱变效果好;在Ｍ１中,１０Ｇｙ处理的出苗率为１７．１％￣７０．２％,成株率一船达４０％左右;在Ｍ２中,突变性状有株高、穗长、熟期、颖壳颜色、芒性和育性等。用１０Ｇｙ辐照５４３６８小麦的花粉后自交,早熟突变高达５８．７     

花药辐射技术在小麦单倍体育种中的应用

对５个小麦品种（系）进行１２次花药辐照离体培养试验。结果表明，小麦花药培养前用０．５￣１Ｇｙ＾６０Ｃｏ γ射线预处理，有利于提高出愈率和绿苗分化率。用于诱变的辐照剂量以２Ｇｙ较为合适。     

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。     

唐菖蒲辐射诱变效应

唐菖浦Ｇｌａｄｉｏｌｕｓ ｈｙｂｒｉｄｕｓ Ｈｏｒｔ。辐射诱变效应研究表明，其球茎的适宜辐照剂量为４０－８０Ｇｙ。不同品种的唐菖蒲为＾６０Ｃｏγ射线的辐射敏感性不同，所引起的不同，所引起的花色、株型突变频率亦有不同，其幅度在２．０％－１４．９％。已选育出花色艳丽，观赏价值高的突变体。     

辐照埃及棉选育陆地棉性状的长绒棉突变体的研究

１９８５年用６０Ｃｏγ射线２７９Ｇｙ辐照埃及棉“Ａｓｈｒｎｏｕｎｉ”，于１９９１年选出了４个表现陆地棉性状、绒长达３３～３５ｍｍ以上的长绒棉突变体。如突变体９０１９７－１。绒长３５ｍｍ，生育期１３５天，株高９１．９ｃｍ左右，株型紧凑，结铃性强（４３．４个／株）．衣分４０％左右，其纤维品质：２．５％跨越长度为３４．９～３５．６ｍｍ，整齐度４８．５％～５０．２％，断裂比强度１９．２～２０．４ｇ／特克斯，麦克隆值３．９～４．０。这些突变体有待进一步过育和产量鉴定。经初步分析，诱变后代的染色体仍为四倍体，过氧化物酶和酯酶同工酶酶谱与亲本有显著差异。     

137Csγ射线对陆地棉花粉及其M1的辐射效应

本以浙棉９号和浙１０２花粉为材料,研究了＾１３７Ｃｓγ射线对陆地棉花粉及其Ｍ１,Ｆ１Ｍ１的辐射诱变效应。研究结果表明：１．辐射剂量与芬分活力呈高度负相关,浙棉９号和浙１０２花粉的半致死剂量分别为５．１７和４．６９Ｇｙ;２．７．５１Ｇｙ以上剂量辐射花粉后,对其ＡＭ１,Ｆ１Ｍ１的出苗,幼苗生长均有明显的抑制作用,辐射的致畸作用因品种而不同;     

苎麻核诱变育种技术及效果分析

用＾６０Ｃｏγ射线５００－１００Ｇｙ辐照,成功选育出高产,优质,抗性强和区域适应性广等优良特性为一体的苎麻新品种圆叶青和７４６９。苎麻不同器官的辐射敏感性不同,辐照苎麻种子的适宜剂量为５０－３００Ｇｙ,辐照地下茎的适宜剂量为２０－９０Ｇｙ。辐照苎麻种子Ｍ１能发生明显的变异分离,其诱变率可提高１２．７０％－５２．８３％。因此,在Ｍ１即可进行严格的选择,并采用无性系繁殖技术,固定其优良性状,扩大其群体     

60Coγ射线辐照大蒜离体培养苗诱变研究初报

用４个大蒜品种的离体培养芽进行＾６０Ｃｏγ射线诱变试验。以明确其敏感性和诱变率。供试材料的致死计量为７－９Ｇｙ,诱变率为５％。通过农艺性状观察和过氧化物同功酶分析,表明出现的两个突变体－Ｔａｉ Ｒ１和Ｃａｎｇ Ｒ２,其属遗传型变异。     

蒸发脱湿过程中盐胁迫对苜蓿生长及矿质元素吸收运输的影响

用土壤溶液浓度ＮａＣｌ７５　～３２５　ｍｍｏｌ／Ｌ的中性盐对苜蓿　进行胁迫处理，研究苜蓿在土壤脱湿过程中，盐胁迫对其生长及矿质元素吸收运输的影响．　结果表明，ＮａＣｌ胁迫浓度的增加和胁迫时间的延长均使苜蓿的相对生长速率、含水量、累积　蒸散量、水分利用效率、Ｋ含量和Ｋ／Ｎａ值下降，但土体中的剩余水量却呈上升趋势．苜蓿生长　受到水分与盐分胁迫双重胁迫的影响．随ＮａＣｌ胁迫的增加，苜蓿的Ｎ素含有率变化不大，但积　累量显著减少；Ｋ＋、Ｃａ２＋的比吸收率（ＳＡＲ）显著降低，植株Ｋ＋、Ｃａ２＋含　量减少，而植株Ｎａ＋、Ｃｌ－的比吸收率ＳＡＲ显著提高，牧草体内Ｎａ＋、Ｃｌ－含量不断积　累增加，植株Ｋ／Ｎａ值降低．对Ｐ、Ｍｇ２＋的吸收在不同水盐条件下变化不一致．苜蓿根系　吸收钾钠离子后，向茎叶运输钾的选择性随ＮａＣｌ胁迫的不同而呈现出不同的趋势．     

红枣带肉果汁的稳定性研究

对红枣带肉果汁的稳定性研究结果表明，配料中枣汁辅料汁以７３的比例较适宜。在稳定剂的使用中，０．１％的ＬＭ果胶配以０．２％的ＣａＣｌ_２，或使用０．２％的ＣＭＣ－Ｎａ，或以０．１％的ＣＭＣ－Ｎａ配以０．１％的琼脂，均起到了较好的稳定作用。同时结果表明，经过两次均质处理，可以改善饮料的悬浮稳定性。     

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.     

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.     

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.     

细菌、真菌及植物氮营养信号研究进展

氮素吸收代谢是所有生物生命活动的核心部分,因此,各种生物对氮的吸收与同化过程都有精细的调节。这种调节依赖于生物对体内氮素状况信号及体外（生长介质中）氮素信号的感受。过去几十年中,在细菌、真菌中已经对氮素营养信号有了较好的研究,而植物中则相对缓慢,但也有了一定的认识。本文重点比较细菌、真菌及植物中氮信号系统的组成,以期为进一步认识植物中的氮信号接受与转导系统提供启示。     

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.     

“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。