鄂尔多斯高原20个种源文冠果种子发芽特性

为筛选适合鄂尔多斯高原地区的文冠果优良种源,在达拉特旗对20个种源文冠果种子及发芽特性进行试验研究。结果显示:不同种源间和种源内文冠果种子百粒重均存在明显差异,种源内变异系数为3.47%～29.18%,种源间变异系数为15.52%;不同种源文冠果种子发芽率均达到80%以上;发芽势变化范围为18.41%～74.80%,种源间变异系数为35.63%;发芽指数变化范围为16.72～32.49,种源间变异系数18.24%;发芽速度变化范围为3.47～7.01 d,种源间变异系数为20.74%。不同种源的种子发芽率、发芽势、发芽指数及平均发芽速度存在极显著差异(P0.001),说明文冠果不同种源间种子发芽特性已明显分化。通过对文冠果种子发芽特性进行聚类分析,将20个种源文冠果种子至少划分为3类,初步筛选种源地编号为NTB,NTK,NCH,NCK,SYJ的5个种子质量最优种源。研究结果可为文冠果良种选育和优良种源选择提供科学依据。     

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。     

北美红杉种子育苗试验

对不同种源的北美红杉种子作不同试剂浸种处理和控制不同发芽温度的发芽试验 ,以及开展不同种源种子的播种育苗试验 ,结果表明 :种子发芽率和发芽势最好的方案是用SYA6种源 ,种子经 10 0 0mg/L的KMnO4溶液浸泡 12h ,发芽温度采用 2 0℃。参试的 3种因素中 ,种源因素对种子发芽率和发芽势影响显著 ;北美红杉各个种源苗木生长迅速 ,1年生苗木除苗木侧根数外 ,各种源间苗木的苗高、地径、主根长度、苗木鲜重和苗木干重差异极显著     

兴安落叶松不同种源发芽特性研究

对9个种源兴安落叶松种子的发芽特性进行研究的结果表明,不同种源间的发芽率、发芽势、发芽指数及平均发芽速度显著不同,显著水平均达到0．0001。利用发芽率、发芽势和发芽指数对不同种源的种子进行聚类分析,利用类平均法筛选的兴安落叶松最佳种源,种子为黑龙江省呼中、内蒙古金河和黑龙江省阿木尔;利用最短距离法筛选的兴安落叶松最佳种源种子为呼中和金河。     

不同种源华北落叶松种子发芽特性研究

对9个种源的华北落叶松种子的发芽特性进行研究,结果表明：不同种源间的发芽率、发芽势、发芽指数及平均发芽速度是显著不同的,显著水平均达到0.0001。利用发芽率、发芽势和发芽指数对华北落叶松9个种源的种子进行聚类分析,利用类平均法和最短距离法筛选出的华北落叶松优质种源种子是相同的,均为山西交城庞泉沟种源、河北坝上2种源、山西交城东坡底种源、河北坝上1种源。     

温度对不同种源地岷江柏种子发芽的影响

为了探求岷江柏种子的适宜发芽温度,选择四川省岷江流域(理县、汶川、茂县)、大渡河流域(马尔康、小金、金川、丹巴、康定)及甘肃省的白龙江流域(武都、舟曲、文县)的优良种源进行育苗试验,设4个恒温梯度(10℃、15℃、20℃、25℃),分别测定岷江柏种子的发芽率、发芽势、发芽指数,并进行统计分析,研究温度对11个种源地岷江柏种子发芽的影响。结果表明:岷江柏种子的适宜发芽温度不是固定的,而是随种源地环境变化而变化。其中,马尔康的适宜发芽温度为10℃,金川为15℃,理县、丹巴、康定为20℃,茂县、武都、舟曲3地为25℃。相关分析表明海拔越高,种源地的降雨量越多,种子的适宜发芽温度越低。不同种源地岷江柏种子的发芽能力存在显著差异,综合来看,马尔康的岷江柏种子发芽情况极显著(P0.01)优于其他地区,其次为金川、理县和舟曲,上述4个地区可作为岷江柏优良种子的采集地。     

北美红杉种子育苗试验

对不同种源的北美红杉种子作不同试剂浸种处理和控制不同发芽温度的发芽试验，以及开展不同种种子的播种育苗试验，结果表明：种子发芽率和发芽势最好的方案是用SYA6种源，种子经1000mg/L的KMnO4溶液浸泡12h，发芽温度采用20℃。参试的3种因素中，种源因素对种子发芽率和发芽势影响显著；北美红杉各个种源苗木生长迅速，1年生苗木除苗木侧根数外，各种源间苗木的苗高、地径、主根长度、苗木鲜重和苗木干重差异极显著。     

凤凰木种源与家系种子育苗试验研究

2013-2014年进行凤凰木不同种源与家系的种子育苗试验研究,结果表明:不同种源与家系间的千粒重、种子发芽能力与1年生苗木的地径及苗高生长存在较大差异,而冠幅生长差异不明显。经相关分析,凤凰木种源与家系间种子的发芽率与千粒重、平均发芽率分别呈极显著正相关和显著负相关;苗高生长与地径、平均发芽率分别呈较显著正相关和显著负相关。     

青藏高原特有种砂生槐不同种源地种子萌发特征研究

对采自6个种源地砂生槐的种子进行了萌发研究,分析了种子大小、萌发特性与海拔之间的关系。结果表明:1)每荚种子数变幅为2.96 4.50粒;种子千粒质量变幅为30.639 47.415 g;种子纵径变幅为4.3144.962 mm;种子横径变幅为3.244 3.693 mm;种子纵横径比变幅为1.306 1.383,差异较小。方差分析结果显示,种源间每荚种子数(F=8.52**)、千粒质量(F=19.73**)、种子纵径(F=6.17**)和种子横径(F=5.79**)差异均达到极显著水平,而种子纵径与横径的比值差异不显著(F=1.47)。2)6个种源砂生槐种子发芽率变幅为43.16%90.03%。其中萨迦种源发芽率90.03%为最高,最低是米瑞种源为43.16%。3)6个砂生槐种源的种子在发芽起始时间上仅差异1 d;萌发持续时间在14 23 d之间,种源间持续发芽时间差异最多达到9 d;萌发高峰期在17 27 d之间,种源间差异较大,其中萨迦种源最短,朗县种源最长。4)每荚种子数随着海拔的升高而显著降低(R=-0.844 3,P0.05),而种子千粒质量则随着海拔的升高而显著升高(R=0.614 3,P0.05)。5)种子发芽起始时间与海拔之间呈现出负相关的关系,但不显著(R=-0.505 6,P0.05);种子萌发持续时间与海拔具有显著的负相关关系(R=-0.883 6,P0.05),而种子发芽率则与海拔具有显著的正相关关系(R=0.804 7,P0.05)。     

高温生境对青海云杉种子萌发的影响

以青海云杉(Picea crassifolia)为材料,研究了不同高温生境对种子发芽率、发芽势、发芽指数、胚根长、胚根鲜质量、简化活力指数和a-淀粉酶活性的影响。结果表明:20~25℃范围内青海云杉种子发芽能力显著升高,25℃时发芽率、发芽势和发芽指数最高值分别达到80%、42%和19.51。30~35℃范围内种子发芽能力显著降低,35℃时发芽率、发芽势和发芽指数最低值分别达到25%、22%和5.01。当温度超过40℃时,种子停止发芽。建议在20~25℃气温范围内选择青海云杉育苗地。     

Study on the germination ofPaulownia tomentosa seeds in different provenances and its cluster

This paper dealt with the studying the germination percentage, germination potential and analyzing the germination of the seeds with different treatments by systematic statistics method. Seeds were collected from 14 provenances in September 1994. The results indicated that the germination percentage and germination potential of the seeds in various provenances were different. Both indexes in Nanchang, area was much lower than those in the rest provenances. The germination percentage and germination potential of the seeds in different provenance declined after the seeds were treated with aging for one year. The light treatment might promotes the germination percentage more effectively than the germination potential. In addition, fuzzy cluster may reflect the relationship among germination in different provenances. (Responsible Editor: Dai Fangtian)     

Provenance and pretreatment effect on seed germination of six provenances of <Emphasis Type="Italic">Faidherbia albida</Emphasis> (Delile) A. Chev

A nursery experiment was conducted to determine the effects of seed pretreatment methods on the germination of Faidherbia albida at ICRAF, Nairobi from six provenances consisting of Awassa, Taveta, Lake Koka, Maseno, Chinzombo and Wagingombe. Seeds were subjected to five pretreatment methods namely nicking, soaking in acid, hot water, cold water and control. Germination percentages (GP), mean germination time (MGT) and germination index (GI) were calculated and the data was subjected to ANOVA. The study revealed significant (p ≤ 0.05) differences in seed treatments among provenances in all studied parameters. Highest germination among pretreatments in Awassa (99 %) and Wagingombe (80 %) was observed in nicked seeds, Chinzombo (81 %) in nicked and acid treated seeds, Lake Koka (90 %) in acid treated seeds and Taveta (28 %) and Maseno (64 %) in cold water treated seeds. Nicking gave the highest cumulative GP (69.67) while lowest GP was observed in hot water treated seeds (23.17). Acid treatment exhibited lowest MGT (8.85 days) and highest GI (2.29) while highest MGT (24.35 days) and lowest GI (0.31) were observed in control and hot water treatment respectively. Although acid treatment gave a high GP and lowest MGT and GI, nicking and soaking in cold water for 24 h is being recommended as cheaper and less hazardous pretreatment methods to improve germination in F. albida since sulphuric acid is expensive and requires proper handling techniques. Significant correlation between geo-climatic data and germination parameters of seeds subjected to different pretreatments indicates that provenances are as important as pretreatments in germination of the species.     

Germination of <Emphasis Type="Italic">Juniperus procera</Emphasis> seeds in response to stratification and smoke treatments,and detection of insect-damaged seeds with VIS + NIR spectroscopy

Seeds of Juniperus procera collected from five provenances across its geographic range in Ethiopia were subjected to cold-moist stratification at 5°C or 10°C for 6–12 weeks. The effect of aqueous smoke solution in overcoming the light requirement for germination, and the potential of visible (VIS) and near infrared reflectance (NIR) spectroscopy for sorting sound and insect-damaged seeds were also investigated. Highly significant differences in germination were detected among provenances (P < 0.0001) and stratification periods (P < 0.0001), but not between temperature regimes (P=0.111). Seeds from the south and southeast distribution ranges had higher percentage germination after 6 weeks of stratification than seeds collected from north, northwest and central ranges of distribution. The smoke treatment did not affect germination regardless of whether the seeds were exposed to light. Exposure to light increased germination capacity three fold. Sound and damaged seeds were distinguished with 90% accuracy using VIS + NIR spectroscopy. It can be concluded that dormancy in juniper seeds varies with provenances, and cold stratification for 6 weeks alleviates dormancy in some seed lots. Tentatively, smoke treatment seems ineffective in overcoming photo-dormancy in juniper seeds. VIS + NIR spectroscopy has demonstrated a great potential for sorting damaged seeds, thereby upgrading seed lot purity.     

Preliminary study on the germination of Toona sinensis (A. Juss.) roem. seed from eleven Chinese provenances

A preliminary germination study was carried out on seed of eleven provenances of Chinese mahogany [Toona sinensis (A. Juss.) Roem.]. The species is native to China and characterized by high density and dark colored wood, which is used mainly in furniture making. Seeds of the eleven provenances were tested on a thermoplate gradient germinator at temperatures of 15°C, 18°C, 22°C, 25°C, and 28°C. The three upper temperatures (22°C, 25°C, and 28°C) provided the fastest and highest germination among the eleven provenances, and on the average 25°C was considered as optimum temperature for the species.Based on mean time to germination, germination values, root length and hypocotyl length, it was possible to delineate the eleven provenances into three geographic groups.Additional studies using more evenly distributed samples from the whole range of the species are expected to further define seed collection zones for this important species in China.     

巨桉子代测定林与引种改良策略的研究

在福建省华安县建立的巨桉子代测定林，包含代表全分布区的１５０个自由受粉家系。对树高、胸径、枝角和木材基本密度进行研究的结果表明，生长性状在家系间存在着极显著的遗传差异，木材基本密度在种源间和家系间都存在着显著的差异。     

Study on the Germination of Paulownia Tomentosa Seeds in Different Provenances and Its Cluster

lntroductionPuult,hwiaIOmentosaisoneofthethstestgrowingtreesandspreadsinmostprovincesofChina,butthesamecharacterindifferentareaisvarious.ThephysiologyandecoIogyofthetreehavebeenstudiedmostIy.However-thepaperonthegerminationstateandthereIationoftheseedsamo…     

Ecophysiological characteristics of the seed of the tropical forest pioneer Urera caracasana (Urticaceae)

Urera caracasana (Jacq.) Griseb is a small, fast-growing evergreen pioneer tree which colonizes openings in the tropical rain forest of 'Los Tuxtlas', Veracruz, Mèxico. Annual seed production by 10 trees was estimated to range from 0.4 x 10(5) to 1.6 x 10(6) seeds per tree. Fifteen species of resident and migratory birds were observed to visit the plants and disperse the seeds. Most seeds imbibed in petri dishes placed on the forest floor beneath a small opening in the canopy, where the red/far-red ratio of the light was around 1.0, germinated within 2 weeks. Germination beneath the forest canopy, where the red/far-red ratio of the light was approximately 0.2, was much slower and did not exceed 40%. A minimum of 4 h daily exposure to unfiltered natural light was required for rapid germination in the forest. In the laboratory rapid germination at 25 degrees C required a minimum of 4 h white light. However, if temperature during the light period was 35 degrees C, 30 min exposure to white light daily was sufficient to induce germination. Seeds that failed to germinate when imbibed for 60-360 days in petri dishes placed on the forest floor beneath the forest canopy, germinated rapidly in the laboratory when held at 25 degrees C and exposed daily to 12 h white or red light. Seeds imbibed for 120 days or more beneath the forest canopy were also induced to germinate by 12 h daily exposure to far-red light when this was combined with a 35/25 degrees C day/night temperature regime. Seeds buried in vermiculite-filled nylon mesh bags disappeared rapidly with few remaining after 2 months. Seeds that survived remained viable and germinated when incubated in petri dishes at 25 degrees C. Initially, buried seeds required light for germination. However, after 17 months' burial, seeds germinated in darkness when transferred to the laboratory and incubated on agar at 25 degrees C.     

Effects of drought stresses induced by polyethylene glycol on germination of Pinus sylvestris var. mongolica seeds from natural and plantation forests on sandy land

Effects of drought stresses induced by polyethylene glycol (PEG) (0.0%, 10%, 15%, 20%, 25%, and 30%, with four replicates) on germination of Mongolian pine (Pinus sylvestris var. mongolica) seeds produced in plantations (southern Keerqin sandy land) and natural forests (Hulunbeier sandy plain) were observed. The results indicated that the seeds from both provenances did not germinate when PEG concentration was more than 25%. The time of initial germination and that of its completion of stressed seeds from both provenances were delayed when compared with the unstressed seeds. The germination capacity and germination rate of natural seeds were significantly higher than those of plantation seeds for all treatment levels (P < 0.05). The mean growth rates of radicle and hypocotyl from natural seeds were significantly higher than those from plantation seeds at all treatment levels below 20% PEG treatment (P < 0.05). The ratios of radicle to hypocotyl of 20% PEG treatment were significant higher than those of the corresponding controls for both provenances (P < 0.05). These results suggested that Mongolian pine seeds/seedlings had stronger resistance to PEG drought stresses; 10% PGE stress did not significantly influence germination. Natural seeds exhibited more resistance to PEG stress than plantation seeds. It was concluded that drought stress on seed germination might be one cause of obstructed natural regeneration of Mongolian pine plantations on sandy land. It is recommended that natural seeds be used for afforestation, and light drought stress (e.g., 10% PEG stress) may be useful in improving seed germination and the growth of radicles and hypocotyls.     

核桃楸不同种源苗期试验初报

从6个核桃楸优良种源地采集种子进行播种育苗,调查出苗率、苗高、地径生长量,进行核桃楸种源试验。结果表明:出苗率较高的两个种源为上庄种源(77%)、大南坪(69%),各种源间在苗高、地径生长方面差异不显著,变化幅度较小,说明核桃楸种源种子遗传特性较好。     

樟子松沙地种源试验

通过对2批樟子松不同种源试验林的调查分析得知，地理种源不同，樟子松的高生长、生长节律及适应性均存在着明显差异，树高生长差异大于胸径生长差异。不同种源物候期略有差别，纬度高的种源，物候期到来略早，纬度低的到来略迟，相差1～4d。一般人工林种源生长好于天然林种源，低纬度种源好于高纬度种源。经过十几年的种源试验表明，9007（净月潭）、9014（章古台）、9006（高峰）、9012（青山）号为最佳种源（产地）。