用软X射线检验林木种子发芽率的研究

采用HY-35型软X-射线仪对杉木、柳杉,马尾松和香椿等15个树种的种子进行摄影,并进行定位发芽试验。根据各树种种子X光片的成像特征,得出各树种种子各等级的判定粒效(百分比)。将各等级种子进行合理累加,用差异最小的值估测发芽率,其结果与定位发芽试验所得发芽率基本相符。由此认定,此法可以作为测定林木种子发芽率的重要方法加以推广应用。     

用软X射线摄影技术进行侧柏种子品质检验

该文介绍了用软X射线图片判断种子发育状况的方法。用图片判读侧柏种子发芽率的精度达95.5％。表明,软X射线摄影法判断种子的发育状况具有快速、准确、方便的特点。     

层积和变温对十种林木种子萌发的影响

通过对榔榆等十余种树种种子进行层积,变温等处理看出,各树种种子休眠原因不同。必须根据树种特点,采用不同的方法才能打破种子休眠,提高发芽率。     

油松种子生活力测定在生产中的研究与应用

通过对山西、陕西商洛市油松种子生活力与发芽率的测定,建立了发芽率与生活力之间的回归关系式.(1)山西:y=-28.941+1.276X,相关系数为r=0.994；(2)陕西商洛:Y=-23.292+1.194X,相关系数为r=0.992.为及时准确地掌握油松种子发芽率,确定种子的质量等级以及收购使用种子提供了科学依据,...     

湖南省主要经济林树种(品种)种子等级标准的研究

由申南林学院和湖南省林业厅共同研究完成的《湖南省主要经济林树种（品种）种子等级标准的研究》1993年12月通过由省林业厅组织的鉴是。专家认为，该项研究居国内同类研究领先水平。该成果对我省范围内的11个主要经济林树种种子的收购、贮藏和播种实践有一定的指导意义。研究人间建议种子分级指标为：①杜仲：一级种子发芽率为80％，净度为98％；二级种子发芽率为65％，净度98％；三级种子发芽率50％，净度96％。含水量为30％－55％。②葡萄桐：一级种子发芽车95％，净度98％．二级林子发芽率85％，净度98％，三级种子发芽率65％，净度96％…     

种子等级划分指标的确立及其相关关系

依据内蒙古《主要造林树种种子分级》标准，利用数理统计的方法对收集自红花尔基、牡丹江、佳木斯、章古台、蒙古国等地的樟子松种子样品的净度、必芽率、生活力、优良度、千粒重进行检验分析得出：划分种子等级的品质指标应以发芽率、生活力为主要指标；千粒重只能作划分种子等级的参数指标，优良度作划分种子等级的依据值得进一步探讨；净度是种子收购与贮藏的主要指标。     

马尾松等种子技术发芽与场圃发芽相关性试验

本试验以我市造林树种马尾松、杉木等六个树种种子为材料,按中华人民共和国国家标准《林木种子试验方法(G B2771—81)》(以下简称《检验方法》),在室内测定林木种子技术发芽率x,以此为基础,并以本检验的送检样品为试验用种子,按《四川省林木充苗技术规程》(以下简称育苗规程)进行时间试验育苗,测定场圃发芽率y(出苗株数除以播     

静电场对南方4种针叶树种种子萌发的影响

以南方4种针叶树种(杉木、马尾松、湿地松、火炬松)种子为研究对象,采取自主设计的高压静电种子处理装置,设置不同的电场强度(1.5、2.5、3.5、4.5、5.5 k V·cm-1)和处理时间(5、10 min),及不经电场处理的对照组(CK),探讨不同电场处理对杉木、马尾松、湿地松和火炬松干、湿种子萌发规律的影响。结果表明:对4种树种干种子施加不同电场强度处理后,只有马尾松干种子发芽势、发芽率和火炬松干种子发芽势在处理10 min时存在显著影响(P0.05),其它树种干种子发芽势和发芽率在各处理条件下均无显著影响(P0.05)。而4种树种湿种子经不同电场强度处理后,除了杉木湿种子发芽势和马尾松湿种子发芽势和发芽率在不同处理时间下有显著影响(P0.05),其它各树种湿种子在各处理条件下均未达显著水平(P0.05)。     

18个木兰科树种播种育苗技术初步研究

对引入的18个木兰科树种进行了播种和育苗技术研究,对种子的形态特征、优良度、千粒重及发芽率进行了测定,并记载了种子的发芽过程。结果表明,发芽率为4%~81%,发芽率较高的树种分别为深山含笑、云南拟单性木兰、粗枝木莲、苦梓含笑、麻栗坡老君山含笑,其它多数种类的发芽率均低于50%;落叶木莲及大果木莲,马关木莲发芽率最低。另从种子发芽持续时间来看,大多数树种的发芽持续时间在20天以上,麻栗坡老君山含笑所需时间最多,约为42天。木兰科树种宜采取随采随播的育苗方法,播种期拟定在10月下旬至11月中旬为宜。     

8种造林树种不同催芽方法种子发芽率比较

研究了日本落叶松、山杏等8种造林树种在不同催芽处理下种子的发芽率,得出了8种造林树种的最佳催芽方法：1）日本落叶松种子为雪藏法,发芽率达88．2％。2）刺槐种子播种前10天用10倍体积的90℃水处理,发芽率为91．8％。3）黄菠萝种子宜在保持不干的状态下低温处理,发芽率为85．3％。4）水曲柳、刺五加果实采收、种子取出后立即进行高、中、低温沙藏,其发芽率分别为90．0％和92．0％。5）文冠果种子宜播种前进行3个月的低温沙藏,发芽率为95．3％。6）辽东栎种子应采收后立即低温沙藏,发芽率为94．0％。7）山杏种子宜在1月初浸泡并进行低温沙藏,发芽率为91．7％。     

Effect of the seeds provenance and treatment on the germination rate and plants growth of four forest trees species of C?te d'Ivoire

The rapid rate of deforestation in Cote d'Ivoire has led to loss of plant species diversity and also threatens some commercial tree species with extinction.Some reforestation and afforestation has been completed.However,for some species,the numbers of surviving transplants has declined.Hence,it is necessary to develop properly adapted and resilient genotypes that can effectively support the programs of forest restoration.In this context we evaluated the effects of the provenances of seeds and of various treatments on the germination rates and on plant growth of four commercial trees species(Pycnanthus angolensis,Terminalia superba,Mansonia altissima and Pterygota macrocarpa).We analyzed these parameters for seeds of three provenances(Daloa,Akoupe and Daoukro) of four species and for thirty plants aged 6 months per provenance.Time to begin germination and time to reach maximum germination were similar among species,and were not influenced by either treatment or provenance.Untreated seeds and those soaked for 24 and 48 h in water at room temperature yielded the highest germination rates,irrespective of species or provenance.The one exception was P.angolensis, for which no germination was recorded.Within species,some provenances produced higher germination percentages than did others.No clear relationship was computed between the germination rate and the morphometric characteristics of the seeds which varied significantly between provenances.Plant growth and morphological variability also depended greatly on provenance.Genetic factors might be implicated,therefore provenance trials should be undertaken and evaluated.Furthermore,molecular analysis should be undertaken to confirm the implications of genetic factors and allow for genetic selection.     

Germination requirements of <Emphasis Type="Italic">Allanblackia parviflora</Emphasis> seeds and early growth of seedlings

Allanblackia parviflora A. Chev, is an indigenous fruit tree species that could be used in agroforestry systems with both environmental and economic benefits. The seed oil is of prime importance as a foreign exchange earner and is being developed as a rural based enterprise in many African countries notably Ghana, Nigeria, Cameroon and Tanzania. Methods for propagation and conservation of the species are therefore of prime importance. The seeds of the species are however difficult to germinate hindering its domestication process. Allanblackia parviflora seeds were collected from seven different populations in Ghana and were subjected to four different seed germination trials at the nursery of CSIR-Forestry Research Institute of Ghana at Fumesua, Kumasi. This was followed by studying the effect of stage of seed germination on establishment after potting. Intact seeds began germination at 7 months after sowing and at 24 months, significant (P < 0.001) variations were observed in the seed germination ability of 74 accessions. Mean seed germination ranged from 0 to 35%. Significant differences in seed germination percentages among populations (P < 0.001) and provenances (P < 0.05) were also observed. Removal of seed coat significantly (P < 0.001) enhanced seed germination. Germination percentages of seeds with seed coat removed ranged from 6 to 43% while seed germination percentages for intact seeds were less or equal to 3%. Incubation of seeds with seed coat removed in polythene bags gave an added advantage. Seeds with seed coat removed and kept in polythene bags started germinating from 2 weeks and within 10 months, 75 and 68% germination were obtained for plane and black polythene bags, respectively. Removal of germinants and potting when shoot length was at least 1 cm gave significantly higher growth (P < 0.001 for shoot height, P < 0.05 for stem diameter, P < 0.001 for number of leaves produced) compared to when only radicle had emerged. It became evident in this study that seeds should be classified as fully germinated only when shoots begin to grow.     

Inhibition by pulp juice and enhancement by ingestion on germination of bird-dispersedPrunus seeds

To evaluate what prevents seed germination and why ingestion by birds enhances germination, we carried out germination experiments using bird-dispersed seeds of twoPrunus species (Prunus sargentii andP. ssiori) in the laboratory. Germination of seeds with following four treatments was compared: “Ingested seeds” excreted after feeding of fruits to birds; “Extracted seeds” deliberately extracted from the fruit pulp; “Juiced seeds” which were supplemented with the juice of the pulp after seeds had been deliberately extracted from the pulp; and “Intact seeds” in untreated whole fruits. Many ingested (27%, 23% inP. sargentii, 18% inP. ssiori) and extracted seeds (24% inP. sargentii, 17% inP. ssiori) germinated, and difference in germination percentages between ingested and extracted seeds were not significant, for eitherPrunus species. The Juiced seeds rarely germinated (2% inP. sargentii, 6% inP. ssiori), and seeds within intact fruits did not germinate. These results suggest that the fruit pulp and the juice of the pulp inhibit germination and the seeds could germinate without ingestion by birds once they had been manually extracted from pulp. Therefore, it is considered that bird ingestion enahnces germination by removing pulp, especially juice of the pulp, in these twoPrunus species.     

Effect of solid matrix priming during moist chilling on dormancy breakage and germination of seeds of four fir species

The ability of solid matrix priming (SMP) to overcome seed dormancy ofseeds of four fir species (Pacific silver fir, subalpine fir, grand fir andnoble fir), was examined. Seeds were subjected to treatments that combinedmoistchilling and SMP (SMP-chilling) and their germination compared to that elicitedby traditional moist chilling. For the SMP-chilling, six solid matrices withdifferent water holding capacities were tested (sphagnum, cat litter, peatmoss,Agro-Lig Greens Grade, Agro-Lig Micro Fine and sand). For each of the speciestested, germination performance was significantly improved by SMP-chilling; theresults were dependent on the type of solid matrix, the matrix water contentandthe treatment duration. SMP-chilling, using the best solid matrices for each ofthe species tested, resulted in germination percentages and rates that were24–35% and 8–21% higher, respectively, as compared with thatyieldedfrom control moist-chilling. High germination percentages (79% or greater) ofthree of the four species (Pacific silver fir, subalpine fir, and grand fir)were promoted after just four weeks (grand fir in sand) or eight weeks oftreatment (Pacific silver fir in peat moss and subalpine fir in Agro-Lig GreensGrade). The germination rate of grand fir seeds benefited from SMP-chillingperiods longer than four weeks, but this resulted in germination during thedormancy-breaking treatment. The water contents of the solid matrices that wereoptimal in terms of eliciting the best germination performance were 320% (w/w)for peat moss, 40% for Agro-Lig Greens Grade and 5–15% for sand.Conducting SMP at chilling temperatures (4 °C) is a practicalapproach to shorten the time required for effective dormancy termination ofAbies seeds; treatment times were shortened by 27 days forPacific silver fir and subalpine fir and more vigorous seedling growth wasexhibited by grand fir and noble fir.     

Effects of KNO3 pretreatment and temperature on seed germination of Sorbus pohuashanensis

We characterized the effects of KNO3 pretreatment and germination temperature on dormancy breaking and germination of mature mountain ash seeds. Seeds treated with KNO3 and germinated at 25 ℃ followed by 5 ℃ had significantly higher germination percentages and germination potentials (51% and 49%, respectively), compared with controls. These treated seeds also exhibited reduced germination initiation times (minimum of 48 days), and elevated germination rate indices (up to 97). The germination of seeds subjected to long-term cold storage (2 years at 0-5 ℃) was also significantly improved by 3 days of 4% KNO3 pretreatment before germinating under a variable temperature regimen (5 ℃ followed by 25 ℃, and followed by 5 ℃). Germination percentages and germination potentials for these cold-stored seeds reached 67% and 54%, respectively, and the germination rate index increased to 126.99. Pretreatment of mountain ash seeds with KNO3 represents a practical, effective, and pollution-free method for improving germination, and can be implemented easily within a variety of nursery settings.     

Desiccation and storage behavior of bay laurel (Laurus nobilis L.) seeds

The effect of seed moisture content (m.c.) and seed storage conditions of bay laurel (Laurus nobilis L.) was investigated in relation to seed viability. In the first experiment, the effect of drying rate on seed moisture and seed germination was investigated. Fresh seeds, with their original moisture content displayed a germination percentage of 55.1%. When the seed moisture content was reduced by 2.0% in an oven, the germination percentage rose to 81.0%. When the seed moisture content was reduced even more by using the same method, the germination percentages decreased dramatically. Reducing the seed moisture content to 28.7 and 23.5% by drying the seeds in alternating room conditions resulted in an increase of seed germinability to 84.3 and 90.9%, respectively. The drying of the seeds for 45, 60 and 75 days reduced their seed germination to 66.8, 49.4 and 48.0%, respectively. Reducing seed moisture content below 15.0% resulted in practically nullifying seed germinability. The fact that bay laurel seeds cannot retain their germinability at lower moisture contents demonstrates that it is a species with recalcitrant seeds. In the second experiment, moist and dry storage conditions were tested under different temperatures and moisture contents. The storage experiment showed that the most effective way of conserving the bay laurel seeds is moist storage at 0 ± 1°C for 4 months without previous drying of the seeds.     

云南红豆杉种子贮藏过程中胚的变化

采用显微测量、石蜡切片和离体培养法研究了云南红豆杉种子在贮藏过程中胚的长度、结构和萌发率的变化,结果显示:新鲜种子胚的长度差异明显,在种子贮藏过程中胚的长度变化不明显;多数情况下,成熟种子的胚分化完全,在种子贮藏过程中胚的结构没有发生明显变化;在离体培养中,新鲜种子胚在2周左右萌发,萌发率为70%,随着贮藏时间的延长,胚的萌发率会逐渐降低.因此推测种子休眠不是由胚的生物学特性引起的;胚在种子中能较长时间的保持活力,这是长期适应的结果,但却是以损失萌发率为代价的.     

Optimal and synchronized germination of Robinia pseudoacacia,Acacia dealbata and other woody Fabaceae using a handheld rotary tool:concomitant reduction of physical and physiological seed dormancy

The Fabaceae(legume family) is one of the largest families of plants with a worldwide distribution and a major role in agriculture and in agroforestry.A hard seed coat impermeable to water is a typical feature of several species.Physical dormancy delays and reduces germination so that mechanical,physical and chemical scarification methods have been classically used to break seed dormancy of many species.We evaluate the effectiveness of a methodology to scarify seeds of several woody Fabaceae of ecological and economical importance,including Robinia pseudoacacia and Acacia dealbata and the shrubs Cytisus scoparius,C.multiflorus and Ulex europaeus.We describe the optimized use of a handheld rotary tool(HRT),and compare its effectiveness with other scarification methods reported to break dormancy such as boiling or dry heating.Total germination and/or speed of germination were enhanced after the application of the HRT,with germination percentages significantly higher than those achieved by other methods of scarification.Based on a thorough literature review,a mode of action for the HRT is suggested which could operate by breaking the physical and physiological dormancy of treated seeds through thecombined action of coat abrasion and moderate temperatures.Considering these results,we recommend the application of this rapid,effective,low-cost and highly reproducible HRT method to break seed dormancy and enhance germination of these species and others with similar dormancy constraints.     

乐昌含笑繁殖初探

乐昌含笑是中国特有的经济、园林树种之一,本文中,主要对乐昌含笑的生物学特性、播种繁殖育苗及组织培养进行了探讨。结果表明：乐昌含笑在播种繁殖时,完全成熟种子出苗率可达71％以上,种子切忌掠青,同时,圃地积水时间不宜太长,在进行组织培养时可优先考虑采用其茎作为外植体进行愈伤组织诱导,其诱导率可达50％。