西南桦花粉低温贮藏试验初报

从花粉干燥、真空和低温等方面对西南桦花粉贮藏进行了初步研究,结果表明:西南桦花粉属干燥敏感型花粉,干燥易使其失活,其含水量约为20%,用硅胶稍微干燥至含水量约18%后即可用于低温贮藏;西南桦新鲜花粉在室温下仅可存活4 d,干燥花粉和新鲜花粉在3℃下贮藏约1个月即失去活力,而在-10℃和-20℃条件下应用干燥花粉真空贮藏,83 d后花粉萌发率仍在20%以上,是西南桦花粉贮藏的最佳方案;在-10℃和-20℃下贮藏的花粉在室温(18~30℃)下解冻0.5 h即可检测其萌发率。     

不同贮藏条件对米老排种子含水率和萌发特性的影响

通过设置真空铝箔袋、瓦罐和布袋3种封装材料和-20、-5、4、10℃和室温5种贮藏温度等15个组合,研究不同贮藏条件对贮藏6个月米老排(Mytilaria laosensis Lecomte)种子含水率和萌发特性的影响,以筛选最佳种子贮藏方案。研究结果表明,不同封装材料和贮藏温度对米老排种子含水率和萌发特性具有显著影响。布袋封装时,5种贮藏温度的种子含水率平均为9.61%,发芽率平均为21.5%;瓦罐封装时,种子含水率为11.48%,发芽率为15.8%;而真空铝箔袋封装时,种子含水率高达16.90%,发芽率基本为0。对于贮藏温度,4℃和10℃贮藏的种子发芽效果较好,-20℃和-5℃的效果一般,而常温贮藏的效果最差。不同封装材料和贮藏温度对种子含水率和种子萌发特性具有一定的交互作用,采用布袋或瓦罐封装在4℃和10℃进行冷藏的贮藏条件最佳,其贮藏6个月的种子发芽率约为30%,为新鲜种子发芽率的40%左右。种子含水率与种子发芽率具有较强的关联,其关系大致呈尖峰状分布,适宜的种子含水率有利于保持种子活力,从而促进种子发芽。综合分析,采用布袋或瓦罐封装在4℃和10℃进行冷藏的贮藏条件最佳,其贮藏效果最好。     

包装材料对知母等几种药用植物种子发芽率的影响

在室温条件下，知母、桔梗种子分别放入布袋、磨口瓶、塑料袋内贮藏。贮藏24个月，用布袋贮藏的种子发芽率明显高于用磨口瓶和塑料袋贮藏的种子发芽率。贮藏36个月，用3种包装材料贮藏的种子发芽率均为0；黄芩种子用布袋和磨口瓶贮藏，贮藏12个月，用布袋贮藏的种子发芽率高于用磨口瓶贮藏的种子发芽率，而贮藏24～36个月，用磨口瓶贮藏的种子发芽率高于用布袋贮藏的种子发芽率。     

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。     

水杉种子贮藏试验

为了探寻水杉种子贮藏的适宜含水量、温度和时长，以期为水杉种子的科学贮藏提供参考。本研究以水杉原产地湖北省利川市忠路镇小河村的原生水杉母树上采收的种子为试验材料，通过不同种子含水量、贮藏温度和贮藏时长试验，比较了入库和出库时种子发芽率、发芽势的变化规律。结果表明：种子含水量在10.00%～10.99%时，贮藏期间种子发芽率、发芽势的降低值最小，贮藏效果最佳。种子含水量为10.00%～10.99%,在-5℃贮藏1 a时，发芽率、发芽势降低值最小，贮藏效果最佳；-5℃贮藏1 a、2 a、3 a时，种子的发芽率、发芽势无显著性差异。因此，水杉种子贮藏入库含水量应控制在10.00%～10.99%,贮藏温度推荐-5℃,在-5℃条件下可以贮藏3 a。     

贮藏温度和贮藏时间对垂柳种子生活力的影响

以成熟的垂柳种子为材料,测定了不同贮藏温度和不同贮藏时间下垂柳种子发芽率、发芽势、活力指数等生活力指标的变化,以探索贮藏温度和贮藏时间对垂柳种子生活力的影响。结果表明:适当的低温-10℃、-5℃、4℃可以延缓垂柳种子的劣变,延长其贮藏时间;常温20℃与极低温-20℃条件下会降低种子的生活力,表现为活力指数降低;随贮藏天数的增加,发芽率、发芽势、发芽指数表现出先升高后降低的趋势,发芽速则是先降低后升高。常温20℃贮藏7天种子发芽率显著下降,在-5℃贮藏3天的条件下种子生活力最强,可应用于垂柳种子萌发及人工种苗培育的实践中。     

温度对西南桦种子萌发的影响研究初报

对采自广西、云南的9个西南桦地理种源的种子，设置15，20，25，30℃温度处理，研究不同地理种源种子的萌发特征及其受温度条件的影响。结果表明，西南桦种子在不同温度条件下种源间发芽率差异不显著，而发芽速度、芽苗根、茎生长以及发芽始期和子叶出现期均存在显著差异；各种源种子的发芽特征亦存在显著差异，但不存在明显的地理变异趋势；以龙州种源的种子发芽最快，生长最好；25℃是西南桦各种源芽苗茎生长的最适宜温度，而其根生长的最适宜温度多为20～25℃。研究结果为西南桦不同地理种源苗木培育及了解其环境适应性提供了参考依据。     

解除休眠水曲柳种子的再干燥贮藏

以解除休眠的水曲柳种子为材料,研究种子再干燥脱水贮藏的可行性。结果表明:已解除休眠的种子在室温条件下进行再干燥是可行的,干燥处理后种子的萌发率和平均发芽时间没有明显变化;但在5℃条件下再干燥是不可行的,干燥后种子萌发率、发芽指数显著下降,平均发芽时间明显延长。已解除休眠的种子在室温条件下再干燥处理后贮藏16个月内种子的萌发率没有显著变化,但随着贮藏时间的延长种子发芽指数显著下降,平均发芽时间显著延长。已解除休眠水曲柳种子再干燥贮藏后使用KT、GA3和乙烯利处理对种子的萌发都没有明显的促进作用。     

四唑染色法测定在不同贮藏处理下火力楠种子生活力

寻找贮藏火力楠(Michelia macclurei)种子的有效方法,设计在3个温度条件下共计12组贮藏处理进行试验。通过采用四唑(2,3,5-Triphenyl tetrazolium chloride,TTC)染色法,对不同的贮藏方式的火力楠种子生活力进行连续5个月测定。结果 TTC法测定火力楠贮藏在12组处理中,处理h(塑料瓶密封低温冷藏贮藏)的生活力最高,经过聚类分析,处理h和处理g(塑料瓶密封常温贮藏)可作为日常贮藏火力楠种子的有效方法。     

板栗贮藏保鲜条件及品质变化研究

研究了板栗的贮藏方式,贮藏温度及贮藏过程中板栗品质的变化。在０￣２℃温度条件下,冷藏板栗干耗较严重,栗仁失水皱缩,并在贮藏后期发芽,用保鲜袋包装后冷藏,可有效地防止板栗失水,栗仁新鲜饱满,但在贮藏后期发芽;人工气调贮藏能较好的抑制失水和发芽,但贮藏成本较高且对技术要求较严格。采用保鲜袋包装并变温（即在贮藏后期将温度降至－２￣－４℃的临界低温）保持了板栗的新鲜度,贮藏期达８个月以上,干耗率为２．０％     

Longevity of <Emphasis Type="Italic">Juniperus procera</Emphasis> seed lots under different storage conditions: implications for ex situ conservation in seed banks

Juniperus procera Endl. is economically important timber species, but its populations are extremely small and fragmented in its natural habitat, thus, calling for immediate ex situ conservation. Here we examined the effects of seed sources and storage temperature on the longevity of Juniperus procera seed lots through collection and preservation of seeds in seed banks. Seeds were collected from nine sites across the species natural distribution in Ethiopia and stored in four warehouses: modern cold room (5℃), mud house (15℃), concrete block house (17℃ or corrugated iron house (20℃) for 42 months. Every three months, a random sample of stored seeds were drawn and tested for germination. A highly significant variation (p < 0.01) in germination of stored seeds was observed among different storage environments, seed lots, and duration of storage. Over the storage period, seeds stored in the cold room had the highest mean percentage germination, followed by the mud house, corrugated house and blocket house. The cold room (41%) and the mud house (38%) maintained the same level of germination as the intitial germination of the seedlotds (42%). The variation in longevity of stored seeds was significnatly correlated with the initial germination of seed lots (r > 0.80; p < 0.01). Cold storage also resulted in enhancement of germination through its stratification effect that terminated the non-deepphysiological dormancy of juniper seeds. In conclusion, seed lots with good initial germination can be effectively stored in cold room (5℃) up to four years. In the absence of modern cold stores, mud houses can be used as a good alternative to store seeds at local level.     

Target seed moisture content,chilling and priming pretreatments influence germination temperature response in Alnus glutinosa and Betula pubescens

Abstract

The response of common alder [Alnus glutinosa (L.) Gaertn.] and downy birch (Betula pubescens Ehrh.) seeds to germination temperature was examined following chilling and priming. Seeds of two seed lots of each species were subjected to combinations of chilling (4±1°C) and priming (20°C) treatments in fully imbibed (FI) state or a lower target seed moisture content (TMC) level (30% and 35% in alder and birch, respectively). After treatment, the seeds were allowed to germinate for 56 days at constant temperatures of 7.5, 10, 15, 20, 25 or 30°C. The response to temperature and pretreatment differed between species, but the effect was consistent in each seed lot within each species. In alder, the TMC seeds germinated well across the full range of temperatures, whereas there was an optimum temperature (22–23°C) for seeds given the FI pretreatment. Priming had no significant effect on the germination response of the TMC seeds in alder, but priming greatly improved germination in the FI seeds, especially at the lower germination temperatures (optimum 18–19°C). In contrast, in birch, the TMC seeds germinated better across the full temperature range, but the optimal germination temperature (15°C) was the same for all seed pretreatments. Priming improved germination in both the FI and TMC seeds in birch.     

Seed Development, Maturation and Storage Behaviour of Mimusops elengi L.

Mass maturity (end of the seed-filling phase) occurred at about 72 days after flowering (DAF) in developing seeds of Mimusops elengi, at which time seed moisture content had declined to about 55%. The onset of ability to germinate was detected at 56 DAF and seeds showed 98% germination by 84 DAF. Tolerance of desiccation to 10% moisture content was first detected at 70 DAF and was maximal by 84 DAF. Delaying collection by a further 14 days to 98 DAF, when fruits began to be shed, reduced seed viability, particularly for seeds first dried to 10% moisture content. Hence the best time for seed collection appears to be about 14 days before fruits shed. In a separate investigation with six different seed lots, desiccation below about 8–12% moisture content reduced viability (considerably in some lots). The viability of dry seeds (below about 10% moisture content) stored hermetically was reduced at cool temperatures (5 °C and below), and none survived storage at sub-zero temperatures. The results suggest that Mimusops elengi shows intermediate seed storage behaviour and that the optimal hermetic seed storage environment is about 10% moisture content at 10 °C, while short-term, moist, aerated storage at high (40%) moisture content is also feasible.     

Seed storage behavior of <Emphasis Type="Italic">Knema attenuata</Emphasis>, an endemic species of Western Ghats,India

We performed desiccation and storage trials to better under- stand storage behavior of Knema attenuata seeds. Mature seeds with moisture content (MC) of 31% exhibited 73% germination. During the period of desiccation (open lab condition) seeds with MC 23% showed 40% germination. After further drying to MC 21% germination was reduced to 16%. Complete loss in viability resulted when seed moisture was reduced to 18%. The seeds stored at -10°C, 0°C, 10°C and 28±2°C (open lab condition) lost their viability within 10 days. Seeds stored in sealed polythene bags and moist sand retained viability for more days than did seeds stored under all other storage conditions. Sensitivity of seeds to lower temperature and desiccation suggest that the storage be- havior of K. attenuata seeds is recalcitrant. Seeds stored in moist condi- tions can, at best, be stored for a period of two months.     

贮藏温度和时间对木棉与美丽异木棉种子活力的影响

利用木棉 Bombax ceiba 和美丽异木棉Chorisia speciosa混合种子,在0、4、和8℃条件下贮藏135d,每隔45 d测定一次种子场圃发芽率和活力指标,用2,3,5-三苯基氯化四氮唑法(TTC法)测定种子的初始和贮藏135 d的生活力。结果如下:木棉种子在相同贮藏温度条件下,随贮藏时间的延长,发芽率、发芽势、活力指数存在显著差异(P<0.05),贮藏温度和贮藏时间有极显著的交互作用,种子活力逐渐下降,贮藏135 d后种子发芽率在8.33%以下,基本失去发芽能力;美丽异木棉种子在不同温度下,随着贮藏时间延长,发芽率、发芽势、活力指数没有显著差异,贮藏温度和贮藏时间没有显著的交互作用,种子发芽率为新鲜种子发芽率的67.46%以上;利用TTC染色法(1.0%浓度)能反映出木棉的种子生活力;木棉种子0℃贮藏90 d发芽率好于4和8℃,可在生产中推广应用TTC染色法检测木棉的种子生活力;美丽异木棉种子0、4、8℃贮藏135 d的发芽率差异很小,0℃贮藏发芽率和活力指数较优。     

13种竹种子低温储存条件及种子育苗环境研究

为解决竹子种子长期保存问题,以马来龙竹、云南龙竹、巨龙竹、金平龙竹、麻竹、长节勒竹、云南箭竹、棉花竹、爪哇巨竹、大泰竹、笻竹、方竹和毛竹13种竹子的成熟种子为材料,通过研究不同低温、低温下不同储存时间、不同含水量、不同发芽设施和不同基质对种子发芽率的影响,来判断竹子种子保存的适合条件。结果表明：1）除笻竹和方竹的种子外,大多数竹种的种子在低温储存5个月内,随着温度由10℃逐渐降低到-16℃,种子发芽率会有不同程度的增高;2）在-16℃条件下,随着储存时间的延长,种子发芽率会有所下降;3）种子含水量会在很大程度上影响种子的发芽率,含水量超过在一定临界值,随着含水量的增加,种子发芽率会显著下降;4）选择不同的种子发芽设施也会影响种子发芽率,生产中宜选用具有微喷灌条件的温室进行育苗;5）在无菌红土、黑土和蛭石这3种基质中,蛭石是竹子播种育苗的适宜基质。     

Effects of presowing treatments, desiccation and storage conditions on germination of Strychnos nux-vomica seeds, a valuable medicinal plant

Seeds of Strychnos nux-vomica have slow and erratic germination; thus different presowing treatments were applied to enhance the germination of its seeds collected from Tamaraikulam, Tamil Nadu, India. In addition, the effects of desiccation and different storage conditions on the germination of S. nux-vomica seeds were investigated. The results show that soaking in 500 ppm gibberellic acid (GA₃) for 24 h, incubation of seeds at 40 °C for 3 days and alternate water soaking (16 h) and drying (8 h) for 14 days significantly increased the percentage germination compared to the control. Desiccation of seeds down to 10% moisture content resulted in better germination. Germination of S. nux-vomica seeds differed significantly between different storage periods, moisture contents of the seed and for first and second order interactions (p<0.001). The highest germination (92%) was achieved when seeds with 10% moisture content were stored at ambient temperature for 30 weeks. Evidence from the present study indicates that S. nux-vomica seeds possess physiological dormancy that can be broken effectively by after-ripening. As seeds of S. nux-vomica are found to be desiccation tolerant, dry seed (10% moisture content) can be hermitically stored at ambient temperature for 30 weeks without losing their viability.     

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.     

Effects of seed water content and storage temperature on the germination parameters of white spruce, black spruce and lodgepole pine seed

The effect of seed water content (WC) (2–3, 5–6 and 22–25%, on a fresh weight basis), storage temperature (+4, −20, −80 and −196°C) and storage duration (6, 12, 24, 48 and 60 months) on the germination of white spruce (Picea glauca (Moench) Voss), black spruce (Picea mariana (Mill.) B.S.P.) and lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) seed was investigated. Germination of white spruce control (untreated) seeds and seeds adjusted to 2–3% and 5–6% WC declined after 48 months of storage at −80 and −196°C, with a further decline at 60 months at −20, −80, −196°C. Germination remained high when control white spruce seeds and seeds with 2–3, 5–6% WC were stored at +4°C, over all storage durations. Generally, black spruce and lodgepole pine exhibited high germination at all storage temperatures at 2–3% and 5–6% WC as well as the control (untreated) seed, for up to 60 months in storage. Germination declined for all three species when seed was conditioned to 22–25% WC. This loss in germination was partially recovered in white spruce seed stored at +4, −20 and −80°C after storage durations of 24, 12 and 48 months, respectively, and in black spruce seeds stored at −20 and −196°C after storage durations of 24 months. Mean germination time (MGT) was relatively constant for all species, under all conditions, except for seed conditioned to 22–25% WC, where MGT increased for white spruce seed stored 48 months at −80 and −196°C, and for black spruce seed stored 24 months at +4 and −80°C and 60 months at −196°C. These results show that the optimal storage temperatures are 4°C for white spruce, and 4, −20, −80, and −196°C for black spruce and lodgepole pine, and 2–6% water content is optimal for all 3 species at these temperatures.     

Germination ecology of twelve indigenous and eight exotic multipurpose leguminous species from Ethiopia

The germination requirements of seeds of 20 leguminous species were studied in three experiments. In the first experiment, seeds were subjected to mechanical scarification, sulphuric acid and boiling water treatments. In the second experiment, they were treated with dry heat at 60, 80 and 100°C. In the third experiment, seeds were placed at different temperature regimes (10, 15, 20, 25 and 30°C) on a thermogradient. Sulphuric acid treatment improved germination in all the species while mechanical scarification improved germination in 18 out of 20 species. Boiling water treatment improved germination in 15 species but proved to be lethal to five species. Similarly, germination was significantly improved in 11 out of 16 species treated with dry heat. Germination was faster and higher at both 25°C and 30°C and the optimum temperature for germination was between 20°C and 30°C for all the species. Mechanical scarification, sulphuric acid and boiling water treatments as well as dry heat were effective to overcome seed coat imposed dormancy in the species studied. It was not possible to recommend a treatment which is equally effective for all the species. However, boiling water is a practical method for achieving rapid, uniform and high germination except in five of the species for which it proved to be lethal. In the latter case, either mechanical scarification or sulphuric acid treatment should be used. Seeds of Millettia ferruginea should be sown when they are fresh to get high germination as they tend to lose their viability during storage. Results from the present study show that once the dormancy in leguminous species with hard seed coats is broken, the seeds germinate in wide ranges of temperature.