Variable dormancy in seed of Pinus contorta

Seeds of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) collected southwest of Grande Praire, Alberta at three different times and altitudes between August 20, 1984 and August 15, 1985 showed variable responses to stratification. The responses were related to seed ripeness, as judged through evaluations of cone moisture contents, and with the length of time that the cones had remained on the trees. Unripe seeds started to lose germination in the third year after pollination when on the tree. Mature seeds which lost germination by late fall 1984 regained it by the next fall, while most unripe seeds did not. Immature seeds increased their need for stratification over time while mature seeds did not. Seeds should be left on the tree until the end of the third year to insure maximum viability because they do not reach maturity until then.     

湿地松种子衬比射线检验方法的研究

对温地松种子进行对比射线方法检验,结果表明,其最佳x射线摄影衬比过程为:将种子在25℃下浸种24h,擦干种子表面水分后,置入40%KI溶液中处理5h,在流水中冲洗5～6min,置于70℃下干燥24h。使用SOⅡ胶片和HY—35型射线机时,拍摄条件为:电压20kV,电流4mA,曝光时间100s,焦片距25cm。由此认为,未被浸渗而胚和胚乳发育良好的种子具生活力,可用来估算种子的发芽能力。用上述衬比方法测定35份湿地松种子,其发芽能力与实际发芽率相当一致。     

植物喷施灵对白皮松种子发芽的影响

设置了植物喷施灵5种浓度处理,分别为0．325g／L0.650g／L,300g／L,2．600g／L,清水对照;研究了植物喷施灵对白皮松种子萌发的影响。结果表明：植物喷施灵对白皮松种子的发芽效果有显著影响,植物喷施灵的浓度为0．325g／L时,对白皮松种子萌发的促进作用最大,发芽率为77％;浓度为0．650g／L。对提高白皮松种子的发芽势最有利,发芽势为44％。     

白皮松大苗栽培的关键技术及措施

通过多年的实践总结出了白皮松大苗栽培的关键技术和措施,为今后培育白皮松大苗起到指导作用,加速城市绿化步伐,提升城市品位。     

白皮松容器育苗及大苗培育技术

本文介绍了白皮松容器育苗采种、选地、作床、配土装袋、种子处理、播种、苗期管理、及大苗培育技术要点。     

白皮松的丰产栽培技术

白皮松是北方松树中抗二氧化硫、烟尘污染能力强的树种,并具有耐干旱、耐贫瘠等特性,是我国北方城市绿化的理想树种,文章着重阐述了其生物学特性和丰产栽培技术。     

Breaking seed dormancy in Cupressus atlantica Gaussen, an endemic and threatened coniferous tree in Morocco

Cupressus atlantica Gaussen (Cupressaceae) is an endemic and endangered coniferous tree geographically restricted to the N’Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dormancy which delays and reduces germination. To improveseed germination, different pre-treatments were conducted on C.atlantica seeds after storage for different periods (one, two and five years) including: scarification with sandy paper; soaking seeds in hot distilled water at 60℃and 80℃for 15 min and soaking seeds for 48 h in agibberellic acid (GA3) at 1,000 and 2,000 mg·L-1. Results showed that scarification with sandy paper increased the germination rate of Atlas cypress by up to 67%, indicating that the species possess essentially anexogenous dormancy (physical dormancy) due to the hard seed coat(hardseededness). Exogenous application of gibberellic acid (GA3) at1,000 mg·L-1 was also effective in breaking seed dormancy and germination induction. These two treatments induced faster speed germination expressed by low number of days to first germination (8 10days) and low values of mean germination times (MGT). However,germination rate, under any treatment, is greatly dependent on the year of seed collection. Seeds collected in year 2004 gave the highest value,suggesting that even after five years of storage, the germination capacity of C. atlantica seeds could remain high. This observation is very interesting in the exsitu conservation of such endemic and endangered species where the production of seeds is irregular over the years.     

陕西白皮松产业化开发的初步探讨

白皮松是太行山、中条山脉、秦岭山脉的特有树种,具有世界"美人松"之称。本文简述了白皮松的生态习性,分析了白皮松资源在陕西省的利用情况及市场需求状况,对白皮松产业化开发提出了指导性建议。     

小陇山林区白皮松容器育苗技术

通过在小陇山林区白皮松容器育苗的实践基础上,总结提出了该树种容器育苗技术措施,对这一省级保护植物的繁殖和发展以及合理利用具有一定的促进作用。     

赤霉素浸种与低温层积对桂花种子发芽的影响

对桂花种子进行了层积前赤霉素浸种与低温层积相结合的催芽试验。结果表明，桂花种子具有休眠特性，低温层积能够增进桂花种子萌发。层积前用赤霉素浸泡促进桂花种子萌发的作用明显，试验以3000mg／L赤霉素浸泡2天和2000mg／L赤霉素浸泡2天或4天最好，极显著或显著地高于其它处理组合。赤霉素浸泡必须与低温层积相结合，其作用效果才能发挥，试验中以层积60天最好。清水浸泡促进萌发的效果不明显。     

不同钠盐对班克松种子萌发的影响

采用不同浓度的NaCl、Na2SO4和Na2CO3溶液处理班克松种子,测定发芽率、发芽势和发芽指数,研究钠盐胁迫对班克松种子发芽的影响。结果表明:低浓度(10、20 mmol·L-1)的NaCl、Na2SO4可以促进种子萌发,随着浓度增加,抑制作用加强,250 mmol·L-1的各项指标降到最低。Na2CO3溶液对种子萌发有较强的抑制作用,浓度相同时,Na2CO3胁迫下的各指标值均小于NaCl、Na2SO4。250 mmol·L-1时各项指标为0。由此可以得出,班克松种子具有耐盐性,但对不同钠盐的敏感性不同,对NaCl、Na2SO4的耐受性要高于Na2CO3。     

Success rate of supplemental mass pollination in a seed orchard of Pinus sylvestris L.

Two experiments (Expt 1, Expt 2) with supplemental mass pollination (SMP) were carried out in a seed orchard of Pinus sylvestris L. in order to assess the biological and operational prospects for SMP. The success of the SMP was studied by means of allozyme markers. In Expt 1 the pollen mix was applied very close to each female strobilus. The estimated success rates for treatments varied between 66% and 84%. When supplemental pollination was done at peak receptivity, one single pollination was enough to obtain high success rates. In Expt 2 the pollen mix was dusted over clusters of receptive strobili on whole‐trees. The estimated success rates for treatments varied between 10% and 23%. The success rates improved when the trees were pollinated on more than one occasion per day during the receptive period. The overall conclusion is that SMP is practical for P. sylvestris seed orchards.     

Effect of different seed treatments on dormancy breaking and germination in three species in arid and semi-arid lands

Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of scarification treatments on seed dormancy and germination of Acacia nilotica (L.) Willd. ex Del., Prosopis juliflora (Sw.) DC. and Dodonaea viscosa (L.) Jacq. The following treatments were applied: T1, untreated seed (control); T2, sulphuric acid (97%) for 45 min; T3, boiling water for 5 min. The seeds were cultured on a Murashige and Skoog (MS) medium after sterilization. The responses of seeds to treatments were compared with each other and with the control treatment. Germination was observed daily for a 30-day period. Results indicated positive responses to treatments, while impermeable seed coats may be responsible for low germination rates in intact seeds as seen experimentally in the untreated control. The highest germination was obtained for P. juliflora and D. viscosa acid-scarified seeds (80.8%-90.8%) and for scarified seeds of A. nilotica (50.2%) boiled in water. The germination indices, i.e., final germination percentage (FG), mean daily germination (MDG) and germination rate (GR), were significantly affected by treatments and species (p<0.01).     

不同引发处理对了哥王种子萌发的影响

以了哥王种子为材料,通过比较不同浓度的GA3、PEG、NaCl、复合盐KNO3·KH2PO4预浸种处理后种子发芽率、发芽势、发芽指数、活力指数等指标,研究不同引发剂对了哥王种子萌发的影响,结果表明：4种引发剂浸种处理均显著促进了哥王种子的萌发及幼苗生长,各指标提高效果均以GA3处理最好,PEG次之,再之为复合盐KNO3·KH2PO4, NaCl引发效果较差,并且随着引发剂浓度的升高呈先升高后降低的趋势。     

油松最佳采种时期的研究

对油松不同采种时期对种子质量影响问题进行了试验研究 ,结果表明 ,各种处理即不同的采种时期对种子质量影响明显 ,从 8月 15日开始 ,到 9月 2 9日的处理 ,种子千粒重、发芽率、发芽势差别极显著。从 8月 15日到 9月 14日种子质量虽有显著差异 ,但都属于不合格种子 ;从 9月 14日到 9月 2 9日种子都达到省标和国标 ,但种子质量随生长期延长 ,种子质量逐渐提高。综合研究可以确定油松最佳采种时期应为 9月 19～ 2 9日     

Long-term variation in Scots pine seed crop size and quality in northern Finland

Abstract

Quantitatively and qualitatively good Scots pine (Pinus sylvestris L.) seed years are rare in northern areas because of the short growing seasons. The seed crop size was studied in four natural pine forests in northern Finland during 1960–2004. Data on seed crop quality were collected during 1986–2004 and quality was determined by X-ray radiography. The long-term average annual seed crop of pine was 77 seeds m^?2, varying from 5 to 225 seeds m^?2. The expected average annual germination percentage of the seed crop was 61%, varying from 7 to 81%. General linear models were used to analyse the size and quality of the seed crop. Independent variables explained 52% of the variation in annual seed crop quality, and no proper model was found for determining the size of the seed crop; the coefficient of determination was only 5%. A combination of more than 100 seeds m^?2 and an expected germination percentage of over 50% was observed once during the years 1986–2004. In most years, natural regeneration in northern Finland is difficult and often limited by the seed crop's quality as well as quantity. These results confirm the importance of seed tree cutting in abundant seed crop years to enable the natural regeneration of pine.     

Autumn frost hardiness of Pinus sylvestris offspring from seed orchard grafts of different ages

Autumn frost hardiness of offspring from clones (originating from 66.0–68.8° N) in six southern (62° N) and one northern (66.5° N) Pinus sylvestris seed orchards in Finland, was evaluated. One‐year‐old seedlings derived from open pollinated grafts of young, intermediate, and fairly mature age, and natural stand seedlings, were artificially freeze tested. The northerly located orchard produced the least injured offspring. There were no significant systematic differences between age classes. Neither were there any indications of decreased freezing injury with later age classes. The family variance was significant in four orchards. The estimated injury levels of orchard offspring were, in general, closer to those of natural stands in the neighbourhood of the orchard than natural stands at the place of clonal origin. It is suggested that not only differences in mother clone hardiness but also clonal differences in pollen contamination rate caused the observed family variation.     

卫星搭载华山松、白皮松种子苗木培育试验研究初报

以2004年甘肃省林业厅组织搭载我国第20颗返回式卫星的华山松、白皮松种子为试材,开展苗木培育研究。通过试验研究,初步认为,经过太空诱变处理的华山松形态与对照无差异、白皮松种子颜色变浅;太空华山松种子较对照发芽早、播种早,但出苗时间无差异;太空白皮松种子较对照发芽晚、播种也晚,但出苗时间差异不明显。华山松太空种子苗在1年生时,苗高、地径比对照分别大12.27%、29.41%,2年生时,苗高、地径依然比对照大9.86%、28.24%;最突出单株的苗高、地径分别为9.3 cm、0.41 cm,比对照平均值大50.00%、13.89%。白皮松太空种子苗在1年生时,苗高、地径不如对照,但在2年生时,苗高、地径比对照大6.55%、25.00%;最突出单株的苗高、地径分别为10.6 cm、0.54 cm,比对照平均值大46.61%、63.64%。     

Effects of priming treatments on germination and biochemical characteristics of Pinus bungeana seeds

This experiment was conducted to evaluate the effect of seed priming on the germination and physiology of Pinus bungeana seeds.Seeds were treated by hydropriming with distilled water,halopriming with potassium nitrate (KNO 3) at 0.3,0.6,1.2 MPa respectively (untreated dry seeds were taken as control).Properties of seed germination and physiology were determined and the effect of hydro-and halopriming on germination and physiology of P.bungeana seeds were investigated.The results showed that,compared with control,each priming treatment had increased the germination percentage (GP) and germination index (GI),shortened the mean germination time (MGT) and the time required for 50% of the seeds to germinate (G 50).Primed P.bungeana seeds significantly decreased the relative conductivity and the amount of malondialdehyde (MDA).Of all the treatments applied to seeds of P.bungeana,halopriming at 0.3 MPa KNO 3 produced the highest GP (65.0%) and the shortest MGT (18.8 d) and G 50 (18.2 d).     

水分胁迫对3个不同种源柔枝松种子萌发的影响

用不同浓度PEG-6000的Hoagland溶液模拟水分胁迫条件,通过萌发率、幼苗鲜重、活力指数、抗旱指数4个指标对来自美国的3个柔枝松种源种子的发芽特性进行研究,并运用隶属函数法对其进行综合评价。研究结果表明:(1)随着干旱胁迫程度的加剧,3个柔枝松种源的萌发率、幼苗鲜重、活力指数、抗旱指数都出现了不同程度的下降。且亚利桑那州种源下降的幅度最大。(2)亚利桑那州种源在发芽期的抗旱性好于另外两个种源。3个种源的综合评价值从大到小依次分别为:亚利桑那州0.561;犹他州0.380;内华达州0.132。(3)低浓度的PEG-6000的Hoagland溶液对亚利桑那州和犹他州种源的柔枝松发芽生长具有一定的促进作用。