川东鸭茅的生产试验研究

在影响川东鸭茅种子产量的诸多因素中，播种量和行距是主要因素之一。本试验采用的行距是30、60、90cm，10m^2小区的播种量分别为10、15、20g，进行2因子9处理3重复的生产试验。结果表明，组合A2B3的种子产量最高，达799g／10m^2,极显著高于其它组合。因此，建议种植川东鸭茅采用行距90cm、播种量0．67kg／667m^2。     

华北落叶松种子贮藏试验浅析

在三种库房里对五种不同含水率、两种包装的华北落叶松种子进行了60个月的贮藏试验。结果认为，含水率5．19／5～8．0％的落叶松种子可以在三种库房密封贮藏39个月。种子贮藏的最佳含水率为6．6％～8．0%，最佳的库房是冷库(0C～5C)。磨口瓶与布袋在冷库贮藏效果差异不明显；地下库不能用布袋贮藏；在普通常温库中磨口瓶比布袋能多贮藏12个～18个月。     

加快淮北地区杂交粳稻发展的几个问题

回顾了淮北地区十多年来杂交粳稻示范推广的发展过程，分析了影响杂交粳稻发展的主要原因，并论述了加快该地区杂交粳稻发展的几个主要问题。     

应用种子蛋白电泳图谱对高羊茅品种进行鉴别与聚类研究

利用种子贮藏蛋白进行二二烷其磺酸钠－聚丙烯酰胺凝脉电泳,对２３个高羊茅品种进行了 分析。表明该方法成本低,效率高,重复性好,能有效地反应高羊茅品种的遗传差异和亲缘关系。电泳谱带聚类分析所得到的类群,能代表生产上,饲用,草坪用类型以及两种用途中的主要生态类型。     

光敏核不育水稻选育与利用的几个问题讨论

对现有光敏核不育材料进行了分类,分为４种遗传类型;其中,温光弱感到光敏核不育系是最为理 想的遗传工具,并就其选育途径和选择“粳不籼恢”繁殖制种技术体系进行了论证．     

“复激保果剂”在杂交水稻制种上应用技术总结

复激保累剂,在杂交稻制种上使用,能促使花器发育良好,调节父母本花期,提高结实率,增加每穗实粒和粒重,提高产量。且成本低,有显著的经济效益。     

A grower-friendly method to transfer predacious mites to commercial orchards

The establishment of predacious mites in commercial orchards may be accelerated by the transfer of pruned wood in winter and summer from donor orchards to release orchards. Following winter pruning, 3-year-old and older wood is collected and transported as soon as possible in bundles to a release orchard for distribution. If the release orchard is composed of dwarf trees, then one or two bundles of 5 kg each are placed vertically at the base of the trunk of every tree in the block (0.5 to 1 ha); if the trees are of standard size, then four or five bundles used. Following summer pruning, annual shoots and suckers are distributed immediately in a release orchard composed of dwarf trees by placing 12–15 branches on the foliage of fruit-bearing branches; if the release orchard is composed of standard trees, then 50 branches are used. The pruned wood should have 20–25 leaves and not less than one predator per leaf. The release orchard should have a light infestation (two or three mites per leaf) of pest tetranychids. These phytophagous mites would serve as food and help establish the predators. The release orchard grower should develop a pest management program based on the same groups of pesticides used in the donor orchard. http://www.phytoparasitica.org posting Aug. 31, 2005.     

葡萄子油及原花青素研究与开发利用

综述了葡萄子油、葡萄子原花青素等天然产物的提取与保健作用的研究进展,原花青素的生物活性及药理研究的现状,葡萄子油成分分析方法和葡萄子,提取物中原花青素含量测定的方法;介绍了用超临界CO2萃取法制取高质量的葡萄子油和应用夹带剂提取葡萄子中的原花青素的方法。分析了葡萄子的综合开发的应用前景。     

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.     

Movement of Xanthomonas campestris pv. vitians in the stems of lettuce and seed contamination

Xanthomonas campestris pv. vitians , the causal agent of bacterial leaf spot of lettuce (BLS), can be seedborne, but the mechanism by which the bacteria contaminates and/or infects lettuce seed is not known. In this study, the capacity of X. campestris pv. vitians to enter and translocate within the vascular system of lettuce plants was examined. The stems of 8- to 11-week-old lettuce plants were stab-inoculated, and movement of X. campestris pv. vitians was monitored at various intervals. At 4, 8, 12 and 16 h post-inoculation (hpi), X. campestris pv. vitians was recovered from 2 to 10 cm above (depending on stem length) and 2 cm below the inoculation site. Xanthomonas campestris pv. vitians was also recovered from surface-disinfested stem sections of spray-inoculated plants. Together, these results are consistent with X. campestris pv. vitians invading and moving systemically within the vascular system of lettuce plants. To investigate the mechanism of seed contamination, lettuce plants at the vegetative stage of growth were spray-inoculated with X. campestris pv. vitians and allowed to develop BLS. Seed collected from these plants had a 2% incidence of X. campestris pv. vitians external colonization, but no bacteria were recovered from within the seed.