影响绿菜花游离小孢子培养的因素

对绿菜花“Ｇａｌａｘｙ”、“ｂｃ－０”和“ｂｃ－４”３个基因型进行了渗透压、外源激素、热激处理温度和时间、花蕾长度或小孢子发育时期的影响因素研究。结果表明,激素的作用并不明显,但相比之下,单独加入６－Ａ比同时加入６－ＢＡ、ＮＡ采花游离小孢子培养的最适热激处理温度和时间为３２．５℃,２４ｈ;绿菜花游离小孢子的最适培养花蕾长度因基因型而异,如基因型“ｂｃ－４”蕾长为４．１－５．０ｍｍｈｘ ｊｆ ｄｄ     

酸奶生产工艺

酸奶是以新鲜全脂牛奶为原料，经乳酸菌发酵制成的乳制品。酸奶中蛋白质、脂肪、糖类、矿物质及各种维生素含量丰富，营养价值很高。１原料 鲜奶必须选用不合抗菌素，不含防腐剂，脂肪含量不低于３％，非脂干物质大于 ８．５％，酸度小于 ０．１６％的新鲜牛奶为原料。２加糖 加糖量一般控制在５％～１０％之间。３杀菌 将称重后的鲜奶按比例加入上等白糖煮沸３ｍｉｎ，过滤。４降温、接种 将煮沸过滤后的牛奶迅速降温到３８－４２℃后接入乳酸菌种。 ５发酵、冷却及成品抽 样检验 接入乳酸菌种后 的鲜奶装瓶后及时封口 ３６－３８℃恒温发…     

观赏羽衣甘蓝的离体繁殖

以花蕾为外植体，离体繁殖羽衣甘蓝８个杂各一代材料。培养基为（ｍｇ／Ｌ）：ＭＳ＋ＢＡ１－２＋ＮＡＡ０．１－０．２＋ＩＡＡ０．５＋（或不加）ＧＡ３０．３＋３％蔗糖。平均１８％－６７％的接咎花蕾产生不定芽；药有３０％的不定芽发育成完整植物。培养物的严重褐化和再生植物的普遍玻璃质化是影响植株成活的主要因素。培养基中加入活性炭和青霉素，并给以强光照射，可提高植株成活率。     

后熟阶段的人参（Panax ginseng C.A.Mey）种子对脱水和贮存温度的反应

完成形态后熟和生理后熟期中的人参湿润种子的含水量由４７％降至９．４％和５．８％,形成干籽后保存于室温,０￣５℃和－１９６℃条件下１￣３年。保存后的形态后熟干籽再低温处理,继续完成生理后熟,结果显示,完成形态后熟的种子在１￣５℃保存１年后,种子胚根能萌发,但胚轴,胚芽不能正常生长,保存３年,种子丧失生活力;生理后熟期中的各子在０￣５℃保存１年尚能正常出苗,出苗率为４４．０％,保存３年,种胚已不能正常     

超干燥水稻种子贮藏研究

硅胶作干燥剂,超干燥水稻种子（灿,粳）。研究不同干燥方式的干燥速度及对种子生活力的影响。由含水量８．１％￣９．４％干燥至７％、５％、４％、３％,２％后密封贮存于０℃,温室（１５￣３０℃）,４５℃。定期测定种子生活力和活力。结果表明,种子与硅胶重量之比１：１０加风扇干燥速度最快,几种干燥方式对种子生活力没有影响。水稻种子的超干燥临界含水量为３％。经过５年３个月的贮藏后表明,贮于４５℃老化的籼,粳稻种     

几种食用菌保健饮料加工技术

１．灰树花保健饮料（１）工艺流程菇体粉碎→热水浸提→过滤→浓缩→低温沉淀→分离→配制→装瓶→杀菌→成品。（２）操作要点将灰树花子实体用粉碎机粉碎，然后用热水浸提，料水比为１∶（１０～１５），水温为９６℃～１００℃，加热２h～３h，使子实体中的可溶性成分转移至液相，之后过滤去渣。为提高浸提率，可将残渣加热水再过滤１次。滤液中的主要成分除灰树花多糖和果胶外，还含有氨基酸、肽类、核酸以及少量矿物质。此时滤液的固形物质量分数约为１％～２％。采用减压浓缩法。为了分离所产生的沉淀物，需把浓缩液置于４℃～５℃下…     

小麦种衣剂──17％种衣剂17号

小麦种衣剂──１７％种衣剂１７号北京农业大学种衣剂实验厂杨金朝１主要成分：三唑醇１．５％，多菌灵１１．２％，呋喃丹４．３％，农药总含量１７．０％，微量元素和稀土金属含量３．０％，为药肥复合型种衣剂。２适用范围：主要用于小麦种子包衣。３作用与防治对象：...     

温度在温光型雄不育小麦育性转换中的作用

重庆温光型雄不育小麦Ｃ４９Ｓ的育性转换,受孕穗期（减数分裂期）温度制约,又受到抽穗期（小孢子至单核期）温度的严重影响。当孕穗期平均最低温度（Ｔｍｉｎ１）≤８．５℃,抽穗期平均温度（Ｔ２）和平均最低温度（Ｔｍｉｎ２）分别≤１３．５℃、≤１０．５℃时,Ｃ４９Ｓ高度不育,结实率在４％以下,可安全制种;当Ｔｍｉｎ１≥１１．５℃、Ｔ２≥１５．０℃、Ｔｍｉｎ２≥１２．５℃时,育性恢复正常,结实率在５０％以上,可以繁种。另外,抽穗期高温可导致不育低温下的Ｃ４９Ｓ育性部分恢复,低温引起可育高温下的Ｃ４９Ｓ育性下降。     

金必生叶面肥对烤烟产质的影响

叶面肥是根据施肥的一种有效补充途径。１９９５年和１９９６年两年试验结果表明，施用金必生叶面肥促进烟叶产量提高３．７－８．１％，产值增加５．７－２２．１％，改善烟叶品质。投入与产出比达１：５．５以上。     

浅析几个因子对甘蓝型油菜游离小孢子胚胎发生的影响

为了快速纯舍杂交后代材料,提高重组基因型的选择几率,对40个杂交F1代组合进行小孢子分离培养。其中,有9个材料产生小孢子胚（占22.5％）,仅4个材料（10.0％）获得了再生植株并种植大田,表明基因型是影响小孢子胚胎发生的一个主要因素。4个杂交组合材料的胚胎发生率为0.08～0.86胚／蕾,平均为0.25胚／蕾。细胞学检测表明,本试验杂交组合材料的最适取样花蕾长度为3.5mm。大田取样采取切取花序,然后在4℃冰箱中插水加散射光保存4～5d不影响胚胎发生。热激培养2d后小孢子的膨大率是衡量小孢子胚胎能否发生的一个有效指标。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Breeding forage grasses for organic conditions

Herbage yield trials are necessary to test if candidate varieties are well suited for organic conditions. In order to elucidate a particular suitability for organic conditions, we run such trials in parallel under both organic and conventional conditions. Here, we report on second and third year results of the sowings 2004 and 2005. These trials are part of a targeted breeding programme for organic conditions. Irregular colonisation of pure grass plots with adventitious plants, in particular white clover, was recognized as a major constraint to the quality of the results obtained under organic conditions. The coefficients of variance in dry matter yield almost doubled when compared to conventional trials, and significant differences in annual yield among varieties were rare. However, when herbage yield was corrected for the estimated fraction of adventitious plant colonization at each cut, the number of instances with statistically significant differences for annual yield among varieties increased more than fourfold. Dry matter yields under organic and conventional conditions were significantly and positively correlated. However, analysis of variance showed a significant culture type by variety interaction for annual dry matter yield in 12 out of 24 trials. When diploid and tetraploid varieties of the same Lolium species were tested in one common trial, only tetraploid varieties were identified as being particularly well suited for organic conditions, while in these trials, the great majority of apparently poorly suited varieties were diploid. This suggests that breeding tetraploid Lolium varieties is promising when aiming at a favourable response to organic agriculture.