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《福建林业科技》2016,(4)
采用标准样地法对色季拉山急尖长苞冷杉在海拔3700~4200 m阴坡与阳坡处种子特征、种子饱满率、种子发芽率及天然更新幼苗状况进行研究。结果表明:同一坡向随着海拔的升高种子带翅长度、种子去翅长度、种子宽度、种子厚度、千粒重、种子饱满率及种子发芽率均呈现先升高后降低的趋势,天然更新幼苗数量亦然;不同坡向同一海拔处,种子带翅长度、种子去翅长度、种子宽度、种子厚度、千粒重、种子饱满率及种子发芽率阳坡优于阴坡,幼苗数量阴坡比阳坡丰富;阴坡、阳坡在海拔3800 m或3900 m处种子带翅长度、种子去翅长度、种子宽度、种子厚度、千粒重、种子饱满率及种子发芽率均出现最优值,此海拔处天然更新效果相对较好。 相似文献
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厚朴不同种源及家系种子性状的变异 总被引：5，自引：0，他引：5
研究厚朴自然分布区内8个省份19个种源的种子长、种子宽、种子厚、种子长宽比及种子百粒重等性状的变异及趋变模式.结果表明:种源间种子长、种子宽、种子厚、种子长宽比等性状的差异均达到极显著水平;种源内不同家系种子长、种子宽、种子厚等性状的差异也均达到极显著水平;种源间种子百粒重变异远远高于种源内家系间变异,前者种子百粒重变异幅度为14.147～24.547 g,后者种子百粒重变异幅度为15.003～17.357 g;种子宽、种子厚和种子百粒重等性状受积温和热量因子控制作用极为明显. 相似文献
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林木种子贮藏的任务,是通过改善种子的贮藏条件,通过管理使种子在贮藏期间的新陈代谢和物质消耗降到最低限度,在较长时间内保持其生命力。一、影响林木种子贮藏的因素1、种子类型：种子类型是影响种子安全贮藏的主要因素。一般而言,在同等贮藏条件下,完全成熟的种子比未成熟的种子保持生命力的时间长;初始发芽率高的种子比初始发芽率低的种子贮藏效果好;种皮坚硬而不透水的种子比种皮柔软而透水的种子保持生命力的时间长;未受机械损伤的种子比受了机械损伤的种子贮藏效果好。2、种子含水量：种子含水量的多少与生命力的保存密切相关… 相似文献
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林木种子是育苗造林的物质基础。为了使需种单位能调入合格的种子,下面介绍几种鉴定林木种子品质的简易方法。一、纯度鉴定。种子纯度是指纯净种子重量占种子总重量的百分率。好子、带有轻伤和发育不够健全但有发芽希望的种子均为纯净种子.发育不完全、破碎和外伤较重没有发芽希望的种子以及土、石、异类种子等都视为夹杂物。二、种皮颜色检查法.每一树种 相似文献
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《中南林业科技大学学报(自然科学版)》2015,(10)
为明确木棉居群种子对环境长期适应产生的变异规律,对西南地区不同居群种子形态指标、种子萌发特性进行调查分析。结果表明:木棉不同居群种子变异系数为10.45%~28.85%,种子形态存在丰富的变异,平均种子长为4.44~7.30 mm,平均种子高为3.11~5.46 mm,勐堆乡居群种子最长,勐罕镇居群种子最高,物茂乡居群种子千粒重最重;东面种子较北方种子圆,年平均温度越高种子越高,西南方种子最重;木棉种子第4 d开始发芽,最高发芽势为49.25%,最高发芽率为57.05%,种子萌发变异系数为53.20%~93.32%,居群间种子萌发差异显著;木棉种子越大,萌发时间越长,但发芽率越高和发芽较整齐;根据种子形态指标可将西南地区木棉种子分为6个种群,种子形态未随居群种子地理位置连续或就近原则分类。可见,木棉局域性居群环境因子形成种子特有形态,影响种子萌发及幼苗生长,温度影响种子长、高及千粒重。 相似文献
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1 感官鉴定用眼睛观察种子外观 ,包括种子的大小、色泽和形状。(1)同一品种的种子粒大、饱满的要好于小粒、干瘪的。如红枫、拐枣种子 ,小粒的几乎无发芽能力。 (2 )有些种子颜色发暗、无光泽 ,说明是腐坏或陈种子 ;颜色浅的是未完全成熟的种子 ;颜色深、有光泽的属于充分成熟的好种子。如黑松、白皮松、杜仲等种子。 (3)种子饱满 ,无虫蛀 ,无畸形 ,是好种子。相反 ,种子萎缩、干瘪、凹陷、虫蛀、变形 ,是劣质种子。2 染色鉴定取蓝色墨水 ,用自来水或蒸馏水稀释成 6 0～ 12 0倍的溶液。随机抽取种子 2份 ,每份 10 0粒 ,大粒种子粒数适当减… 相似文献
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本文通过对花棒、羊柴的生物学特性、分布范围，种子的解剖学特征、采集情况、种子样品净度分析和种子样品处理前、后净度进行分析，初步认为：实际生产中，花棒种子中混有少部分的羊柴种子，通过风选、过筛等一般方法很难将它们分开，在做飞播用花棒种子净度分析时，可视混有一定比例羊柴种子的花棒种子为净种。 相似文献
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Assessing the characteristics of seed supply will be vital to better understand the dynamics of forest regeneration. In this study, we surveyed the aboveground vegetation, the seed rain, the seed bank, and natural seedling emergence in four typical 24-year-old plantations (eucalyptus, mixed-native, mixed-legume, and mixed-conifer) and a naturally successioned shrubland in southern China. The dominant species in the understory were similar among the five plant communities. The seed rain and the seed bank were dominated by shrubs and herbs but indigenous tree species were rare. Species that were common to all five-plant communities represented a great proportion of the seeds in the seed rain and seed bank. The seed rain consisted mostly of seeds derived from the local plant community. Seed abundance was greater in the seed bank than in the seed rain, and species richness was greater in the seed bank and in the corresponding plant community than in the seed rain. Species composition similarity between the seed rain, the seed bank, and the aboveground vegetation was low, because the seed rain contained much fewer species, and the seed bank and aboveground vegetation contained many different species, respectively. These findings indicate that both the seed rain and the seed bank play important roles in providing seeds for plant recruitment in the understory, but the seed bank contributes more than the current seed rain to the diversity of recruited plants. The current plant community has little impact on the qualitative composition of the seed rain and seed bank. Based on these data, it appears that succession to the desired zonal, mature forest community is unlikely to result from seeds in the seed rain or seed bank. Lack of seed availability of desired zonal mature forest species is the main bottleneck currently limiting succession in the plantations. Reintroduction of late-successional species could facilitate the desired succession. 相似文献
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苦槠(Castanopsis sclerophylla (Lindl.) Schott.)为壳斗科(Fagaceae)栲属(Castanopsis (D. Don.) Spach.)植物[1],是亚热带地区常绿阔叶林的重要建群树种,也是亚热带常绿阔叶林次生演替阶段重要的先锋树种,对群落的组成、外貌、功能等都有一定控制作用[2].苦槠作为优良多用途树种,其生态效益、经济价值、食品保健功用及其在园林绿化中的地位已逐渐得到认可[3-4].目前,国内对苦槠的研究已有了一定基础,但对苦槠种群遗传学研究较少.种子是物种遗传变异的重要特征之一,在分类和遗传上具有重要的价值[5],种子形态不仅决定其扩散能力,也影响到种子的萌发和幼苗定植,进而影响到种群的分布格局[6].研究苦槠种子性状变异及其地理分化,对了解苦槠种群遗传分布格局具有重要意义,进而也可为苦槠天然林的保护和人工林的营建提供理论参考. 相似文献
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Natural variation in seed characteristics of eastern white pine (Pinus strobus L.) trees and its relationship with the size, form, and crown class of parent trees was examined in second-growth, white
pine mixedwood stands in Ontario. Cones were collected prior to and following partial harvesting of two stands during 2 years
of above-average seed production. Fully enlarged seed extracted from mature cones was X-rayed to determine seed yield per
cone, the percentage of sound, partially filled, and empty seed, and the sound seed mass for each tree. Variation in seed
yield per cone, the proportion of sound, partially filled, and empty seed, and seed mass was much greater among individuals
than between stands or seed years. The strength and significance of the relationship of seed mass with sound seed yield differed
with stand and seed year. In uncut stands, seed mass was higher for trees with dominant crown class, larger live crown ratios,
and smaller height to diameter ratios, suggesting tree vigour and microsite quality influence seed mass. Proportion of partially
filled seeds was significantly reduced in both stands in the second year likely due to increased growing degree days during
female gametophyte development. The implications of these results to natural and artificial regeneration of white pine are
discussed. 相似文献
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种子产业现代化的发展很快,做好种子贮藏工作的一个关键因素是建立环境条件良好的贮藏种子的场所--种子库.本文介绍了国内种子库建设的现状及种子储藏环境,分析了我国种子库房的发展趋势. 相似文献
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The effect of the seed cut of the uniform shelterwood silvicultural system on white pine seed production, seed characteristics, and seed viability during 2 mast seeding events was examined in operationally harvested second growth, white pine-dominated forest stands in central Ontario. Seed traps placed along transects in unmanaged and shelterwood stands in each of 3 blocks were used to monitor seed production in 2000 and 2006 (4 and 10 years after harvesting). During these 2 mast seed years between 386,000 and 2,730,600 seed ha?1 were produced among study stands. Total seed production expressed on a per hectare and unit pine basal area basis did not differ by harvest treatment or among blocks in either year. Variability in seed production among stands was primarily due to differences in stand structure, with seed production positively related to white pine basal area. Seed characteristics were largely similar between harvested and unmanaged stands and between seed years. Seed viability was relatively high in both years, with seed from shelterwoods germinating slightly slower than those from unmanaged stands. Seed quality, as estimated by laboratory germination performance, was higher in 2006 than 2000, likely due to improved seed development and maturation in the warmer, wetter growing season of 2006. Our results suggest that the seed cut of the uniform shelterwood system applied to second growth white pine stands is unlikely to adversely affect white pine seed production, seed quality, or potential for natural regeneration during mast seeding events. 相似文献