地被菊花粉萌发及花粉活力的研究

用ME的盐类和维生素附加16％聚乙二醇4000(PEG4000)和15％蔗糖对野菊及新红、塞旗红、玫瑰红的花粉进行培养。结果表明，萌发率分别为80．2％、85．3％、61．3％和46．5％。PE‰对菊花萌发有明显促进作用。但庶糖的作用不能被PEG所取代。菊花花粉萌发较合适的温度为10-20℃，在4-8℃时，萌发率及速度迅速降低，35℃萌发虽快。但花粉管短且破裂。在4℃条件下花粉可贮藏4-14d。但不宜干燥贮藏。     

Mid-storage and pre-sowing seed treatments for lettuce and carrot

Mid-storage hydration-dehydration treatments with medium-vigour lettuce seed very effectively reduced physiological deterioration in storage and ultimately showed better field emergence and final yield. Soaking-drying treatment of high-vigour lettuce seed was not effective. Pre-sowing treatment of medium-vigour lettuce seed, though less effective than mid-storage treatment, gave better field performance, but high-vigour seed did not benefit from the treatment. For carrot, both mid-storage and pre-sowing seed treatments proved beneficial, with the former showing better performance than the latter. Unlike lettuce, well-preserved carrot seed responded positively to the pre-sowing treatment.     

NM－1号抗旱剂的研究

试验结果表明谷子在—１３．９Ｐａ的负压下发芽率只有２４．０％，在—１６．７３Ｐａ时发芽率为１６．３％。用０．５％的ＮＭ—１号抗旱剂包衣后，在—１６．７３Ｐａ的负压下发芽率可达６５．６％，比对照提高４９．３％。同０．５％的ＮＭ—１抗旱剂在大豆现蕾期喷施叶面１次，相对收获株率为１１５．３８％，相对千粒量为１０７．７％，增产率为４０，２７％。玉米在６叶期喷施０．５％的抗旱剂后，饱和亏减少４．０９ｇ，是对照的４３．８１％；干物质积累比对照快６７．１９％，蒸腾系数减少８．３６ｇ。     

不同条件下蒙古冰草种子产量及产量构成因子的分析

在西苏旗对蒙古冰草的种子产量及产量构成因子进行了分析得出结果为冰草的实际种子产量与潜在种子产量差别很大，蒙古冰草种子产量的主要限制因子为抽穗率和结实率。     

Organic substance metabolism during seed germination ofPinus bungeana

The metabolism of fats, proteins and carbohydrates and change of enzyme of seeds ofpinus bungeana during the germination were conducted by the methods of gas-liquid chromatography, flow injection, colorimetric analysis of spectrophotometer, to provide theoretical basis for seeds dormancy, germination and storage of seeds of forest tree. The results indicate that (1) carbohydrates were first utilized during germination of seed ofpinus bungeana; (2) stored substances in seeds began to decompose quickly after radicale broke through seed coats; (3) the activity of enzymes in the seeds does not always coincides with the increase or decrease in quantity of its responsible substance during germination of the seed. Changes in stored substance relate to metabalism of other metabolism of other materials and the use of hydrolysates.     

NaCl胁迫对4种豆科牧草萌发的影响

为研究盐渍化对4种牧草种子盐胁迫下发芽成苗的影响,探索不同牧草种子盐胁迫下的萌发表现,试验借鉴农作物研究的理论和方法,并在实验室条件下用不同浓度的NaCl溶液对种子进行处理,并观察其萌发特性,以期为生产实践提供有用的依据,减少在生产中的损失,提高草业生产的经济效益。1     

杏种子与种胚的超低温保存研究

含水量为６．９％带有内果皮的种子，以－５Ｃｍｉｎ＾－１速率降至－８０℃，放入ＬＮ２，在室温缓慢解冻，成活率可达９１．５％。去掉内果皮含水量为７．１％的种仁，以上述方式保存，成活率也可达到８８．２％。含水量是超低温保存杏种子最重要的因素。研究表明：冰冻保护剂ＤＮＳＯ对杏种子的超低温保存影响不大。含水量为４．８％￣８．１％去掉子叶的种胚超低温保存后ＴＴＣ染色成活率为８２．８％，并能在ＭＳ培养基上发育为     

台湾青枣不同品种花粉萌发和生活力测定

以5个台湾青枣品种盛花期花粉为试材，应用正交试验测定不同品种花粉萌发率及适宜的萌发条件，并用4种不同方法测定花粉生活力。结果表明：（1）不同品种的花粉萌发率存在显著差异，其中大世界的花粉萌发率最高。（2）硼酸浓度、培养温度等因素对花粉萌发率有极显著影响。最适培养基为含琼脂1％、蔗糖15％、硼酸0．02％的组合，适宜温度为30—32℃。（3）花粉生活力的测定中，离体萌发法是最佳选择，I—KI染色法、醋酸洋红染色法和TTC染色法不适宜用作台湾青枣花粉生活力的测定。     

Variation in the development of secondary dormancy in oilseed rape genotypes under conditions of stress

Summary A substantial amount of seed is left in the fields before and during harvest of oilseed rape. Although this crop exhibits little or no primary dormancy, the absence of certain environmental cues that promote germination of imbibed seeds induces secondary dormancy. The work reported investigated the extent to which environmental stress conditions, including osmotic stress, low oxygen stress and anaerobiosis, induce secondary dormancy in oilseed rape, and examined the variation in development of secondary dormancy between and within genotypes. Osmotic stress was most effective in inducing dormancy. Anaerobic treatment produced very few dormant seeds, as did an atmosphere low in oxygen and high in nitrogen. The development of secondary dormancy under osmotic stress varied considerably between and within genotypes. Dormancy ranged from almost zero to about 60% for winter genotypes and about 85% for spring types. Within genotypes, variations occurred between seed lots and years of harvest. Temperature variations affected the percentage of dormant seeds. More dormant seeds were likely to be produced with incubation under water stress at 20 °C than at 12 °C. In winter genotypes, fewer dormant seeds were produced when incubation temperature and germination test temperatures differed. Thus, incubating at 20 °C and 12 °C, followed by germination tests at 20 °C and 12 °C, respectively, produced most dormant seeds. Also, in the winter genotypes, the potential development of secondary dormancy was positively correlated with the pattern and speed of germination of untreated seeds.     

Prepenetration stages in infection of clematis by Phoma clematidina

A detailed study of conidial germination, germ-tube growth and the formation of infection structures in Phoma clematidina , the causal agent of clematis wilt, is described for two clematis varieties differing in disease resistance. On both the resistant and susceptible varieties, the fungus entered leaves and stems by direct penetration of the cuticle, often, but not always, following the formation of infection structures. More germ tubes per conidium were formed on the susceptible host, but these germ tubes were on average shorter than on the resistant host. Although germ tubes regularly entered the plant via trichomes, stomata were not found to be sites of entry. Following penetration of the cuticle of resistant plants, germ-tube growth was sometimes restricted to the subcuticular region, and halo formation occurred at the sites where penetration was attempted. Subcuticular growth and halo formation were not observed on susceptible plants. These observations may partly explain the resistance of small-flowered clematis varieties to P. clematidina .