黑龙江省大豆疫霉根腐病调查与病原分离

１９９６年对黑龙江省东部和中部大豆产区２３个市、县的大豆苗期疫霉根腐病进行了调查、研究,应用ＰＢＮＩＣ疫霉选择性培养基分离大豆疫霉根腐病病原菌,从牡丹江、穆棱、林口和佳木斯豆田具疫霉根腐症状的大豆植株上分离到大豆疫霉根腐病菌,并从根腐病株上单独或与大豆疫霉菌同时分离到终极腐霉菌,研究进一步证实我国黑龙江省有大豆疫霉根腐病。调查发现,大豆疫霉根腐病和终极腐霉根腐病主要发生在土质粘重、土壤含水量高或易积水的田块。     

鹅掌楸容器育苗轻基质配方研究

选用泥炭、稻壳、森林表土、黄心土混合配制成5种轻基质配方,开展鹅掌楸容器育苗技术研究。结果表明:不同轻基质配方之间的重量,容器苗苗高、地径、根系、单株干物质重量达到极显著差异;4号轻基质配方(泥炭50%+稻壳20%+森林表土20%+黄心土10%)育苗效果最好,苗木粗壮、根系发达、基质重量较轻;1号轻基质配方(泥炭20%+稻壳50%+森林表土20%+黄心土10%)效果最差。研究认为:在鹅掌楸容器育苗生产上宜选用4号轻基质配方。     

Salinity and Temperature Effects on Seed Germination of Milk Thistle

Abstract

Milk thistle [Silybum marianum (L.) Gaertn] is an annual plant belonging to the Asteraceae family whose ripe seeds contain flavonoid substances, which are important in the modern pharmaceutical industry. Seed germination is a major factor limiting the establishment of plants under saline conditions. The effect of salinity and temperatures on germination and seedling establishment was studied in two genotypes of milk thistle, an Iranian wild type and German (Royston) type in the laboratory and in the field. Experiments were done with seven salt concentrations [0.1 (control), 1, 3, 6, 9, 12, and 15 dS/m] and three temperatures (15, 25, and 35°C). There were three replications for each treatment, and the experiment was run three times. The results showed that the percentage of germination and the number of normal seedlings at different salt treatment at 15°C were higher than at 25 or 35°C. The mean time to 50% germination was least at this temperature for both genotypes. Results suggested all germination indices and seedling emergence (50%) were achieved at levels up to 9 dS/m salinity at 15°C. Also, seeds at a salinity of 9–15 dS/m will germinate and up to 25% of the control nonstress treatment could emerge at the low temperature of 15°C.     

宜昌楠苗木繁育技术初步研究

通过对宜昌楠(Machilus ichangensisRehd.Et)进行种子育苗、幼苗移栽和定植苗的修剪等试验,结果表明:宜昌楠种子宜在元旦前后播种并覆盖发酵草,出苗率可达到98%;每年3月幼苗根部打泥浆后移栽,幼苗成活率达到95%;对定植苗进行修剪,特别是春剪有利于侧芽的增长和主茎基部的增粗。     

侧柏种源试验苗期的初步研究

在北京的3个不同海拔高度,对来自31个地区的侧柏种子进行了种源试验。对一年生苗的分析表明,种源间差异显著。一年生苗生长快的种源比生长慢的高3.6倍。通过根系调查及苗高生长量与地表温度和土壤含水量的相关分析,可以看出天然林子代比人工林子代的适应性强。初步研究结果可为北京地区选择适宜的侧柏种源和侧柏的种源区划提供参考。     

A minute P application contributes to a better establishment of pearl millet (Pennisetum glaucum (L.) R. Br.) seedling in P deficient soils

Many soils of the semi-arid tropics are deficient in P, and under such adverse conditions, the establishment of pearl millet seedlings is a critical step to achieve satisfactory crop stands. Phosphorus fertilizer is expensive for small holder farmers and is only applied at low rates, insufficient to give satisfactory crop stands. Methods are needed to enhance productivity at low rates of application. Here, we tested the hypothesis that a minute application of P at early seedling stage, equivalent to 125–500 g P/ha, would enhance the plant establishment under P-limiting conditions. We measured the minimum application of P needed to elicit a response of different genotypes. Pot experiments were conducted with pearl millet ( Pennisetum glaucum (L.) R. Br.) hybrids to measure the response to P placed close to the root system, 5 days after sowing (DAS), compared with a non-limiting P control (DAP). The placement treatments were 0, 0.25, 0.50, and 1.0 mg soluble P per seedling, applied as KH₂PO₄ solution. The localized placement of P increased biomass in all three soils tested. In one soil, plant biomass at 1000 μL (1 mg P) reached about 50% of the non limited control. If applied later than 19 DAS the placement had no effect on the plant biomass. Hybrid ICMP 451-P8 was more responsive than hybrid 81B-P6. Placement to 20 inbred lines of pearl millet increased biomass by an average of 105% compared with no placement with large genotypic variation. Although this work was not intended to be a way of applying P fertilizer to pearl millet under field conditions, it showed that applying minute amount of P to pearl millet seedling (equivalent to 125–500 g P/ha) enhanced their establishment and led to improved growth for at least 5–6 weeks after sowing. Further work is in progress to develop a feasible technology for field crops based on the results of this study.     

樟子松温棚容器育苗技术

温棚樟子松容器育苗,改善了生长环境,缩短了育苗时间,苗木质量好,造林成活率高。     

Glycinebetaine Improves Chilling Tolerance in Hybrid Maize

Plant growth and development is hampered by various environmental stresses including chilling. We investigated the possibility of improving chilling tolerance in hybrid maize by glycinebetaine (GB) seed treatments. Maize hybrid (Hycorn 8288) seeds were soaked in 50, 100 and 150 mg l^?1 (p.p.m.) aerated solution of GB for 24 h and were dried back. Treated and untreated seeds were sown at 27 °C (optimal temperature) and at 15 °C (chilling stress) under controlled conditions. Germination and seedling growth was significantly hindered under chilling stress. Moreover, chilling stress significantly reduced the starch metabolism and relative water contents (RWC), and increased the membrane electrolyte leakage. However, activities of antioxidants (catalase, superoxide dismutase and ascorbate peroxidase) were increased under stress conditions. Seed treatments with GB improved the germination rate, root and shoot length, seedling fresh and dry weights, leaf and root scores, RWC, soluble sugars, α‐amylase activity and antioxidants significantly compared with untreated seeds under optimal and stress conditions. Induction of chilling tolerance was attributed to maintenance of high tissue water contents, reduced membrane electrolyte leakage, and higher antioxidant activities and carbohydrate metabolism. Seed treatment with 100 mg l^?1 GB was the best treatment for improving the performance of hybrid maize under normal and stress conditions compared with control and other levels used.     

马铃薯试管苗蓟马防治的研究

摘要：为防治蓟马为害马铃薯组培苗，降低蓟马对组培苗的污染，以石薯1号为试验材料，在MS培养基中加入不同浓度的吡虫啉、噻虫嗪药剂，研究不同药剂对蓟马的防治效果及组培苗生长发育的影响。结果表明：在蓟马防治试验中，在MS培养基中添加70%吡虫啉水分散粒剂和25%噻虫嗪水分散粒剂的药剂，可以有效降低试管苗根长、株高，且B1处理（25%噻虫嗪水分散粒剂2 000倍液）对试管苗生长抑制最显著；70%吡虫啉水分散粒剂10 000～20 000倍液或25%噻虫嗪水分散粒剂2 000～4 000倍液，均可以有效防治蓟马，降低试管苗发病率，其中A1处理（70%吡虫啉水分散粒剂10 000倍液）、B1处理（25%噻虫嗪水分散粒剂2 000倍液）、B2处理（25%噻虫嗪水分散粒剂3 000倍液）的试管苗发病率均为0.00%，对蓟马防效较好。在药剂解除试验中，C3处理的根长、株高、节间距均显著高于C1处理，且均与对照无显著差异；D3处理根长、株高均显著高于D1处理，且均与对照无显著差异，说明在药剂培养基扩繁3次后，再采用无药剂培养基扩繁2次可以快速解除杀虫剂生长抑制作用，达到与正常植株同等的生长状况。因此，70%吡虫啉水分散粒剂10 000倍液、25%噻虫嗪水分散粒剂2 000倍液均可以防治试管苗中的蓟马，且在采用无药剂培养基扩繁2次可以快速解除杀虫剂生长抑制作用。     

无柄小叶榕等4种容器苗质量评价中关键生理因子筛选的初步研究

本研究通过栽培无柄小叶榕等4种乔木在15种轻基质中不同组合的苗圃期和出圃实验，建立容器苗质量评价及预测线性回归模型，探讨了苗圃期植株生理指标在解释苗圃期生长表现（干重总生物量、干重根茎比）和预测出圃生长表现中（存活率、株高、地径、相对生长速率）的作用，推荐叶片总叶绿素含量为容器苗质量评价体系中的最关键生理因子。