Seed germinating characteristics of 54 gramineous species in the alpine meadow on the eastern Qinghai-Tibet plateau

The germination experiment was started on March 3, 2004, and seeds were collected from July to October in 2003. We analyzed the percentage of germination, days to first germination, germination period and days to 50% germination. Among the 54 examined species, 26 species exceeded 80% germination, 11 species exceeded 60%–80% germination, 8 exceeded 40%–0%, 5 exceeded 20%–40%, and 4 showed less than 20%. A principal-component analysis revealed that the species were distributed along two statistically independent axes, the first primarily represented the germination rate and the second represented the time of germination process. Based on scores of germination characteristics, cluster analysis of the 54 gramineous species could be divided into 4 distinct groups: rapid, slow, intermediate germinating (germination percentage > 50%), and low germinating (germination percentage < 50%). The meaning of different groups to the vegetation regeneration was discussed. __________ Translated from Journal of Plant Ecology, 2006, 30(4): 624–632 [译自: 植物生态学报]     

青藏高原东部高寒草甸54种禾本科植物种子的萌发特性

在实验室条件下观测了青藏高原东部高寒草甸54种禾本科植物的种子萌发特点。结果发现:在54种植物中,有43种植物种子萌发率都达到了50%,其中萌发率80%以上的物种有26种,60%~80%的有11种,40%~60%的有8种,20%~40%的有5种,小于20%的有4种; 萌发开始时间为3~5 d的植物有14种,6~8 d的植物有29种,9~10 d的植物有10种,大于10 d的有1种;萌发持续时间为1~7 d的植物有16种,8~14 d的植物有28种,15~21 d的有10种;达50%萌发率的时间为1~7 d的植物有11种,8~14 d的植物有27种,大于14 d的植物有5种,萌发率一直没达到50%的植物有11种。这些植物显示了4种萌发类型:爆发型、过渡型、缓萌型(萌发率大于50%的物种)和低萌型(萌发率小于50%的物种)。     

濒危植物多毛坡垒种子萌发的生理生态特性

研究了多毛坡垒（Hopea mollissima）种子在自然条件下的寿命及成熟度、温度、光照、土壤水分条件对多毛坡垒种子萌发的影响,结果表明：多毛坡垒种子适宜萌发的温度范围是20～30℃,最适宜温度为25℃;光照对多毛坡垒种子的萌发没有显著性影响,但在周期性光照条件下以25～30℃萌发结果最好,全黑暗条件下以20～25℃萌发结果最好;种子适宜萌发的土壤含水量为20％～60％,最适含水量为50％～60％;种子成熟后在树上长时间宿存明显降低了种子的发芽率和活力;在室内自然摊放条件下,10天后发芽率减半,16天后完全丧失发芽能力。研究认为,该物种对热带湿性季节性雨林原生境有很强的依赖性,目前多毛坡牟的濒危状态主要是由于滥砍乱伐和森林破坏造成的,由于其种子具有顽拗性种子的一些特点,日前该物种宜采取活体保仔的方法,以就地保护为主,活植物迁地保护为辅。     

Secondary leaf fall of Hevea brasiliensis: factors affecting the production, germination and viability of spores of Colletotrichum gloeosporioides

The optimum temperature for growth and sporulation of Colletotrichum gloeosporioides from Hevea brasiliensis was between 26 and 32 ^oC, whereas spore germination exceeded 90% between 21.5 and 30.5 ^oC. Germination decreased in culture after 3 days, and on exposure of spores to sunlight or oven heat (46 ^oC) for 10 min. Spore viability and germination were sensitive to atmospheric humidity; at 99% r.h. germination was half that at 100% r.h. and was negligible below 97% r.h. Germination decreased by up to 30% after 3 h storage at 80% r.h. Continuous light favoured spore production in vitro, but spores produced in the dark had a higher percentage germination. No differences were detected between the numbers of spores germinating on leaves of different ages, although there were slightly more on susceptible cultivars and in the presence of extracts of uninfected susceptible leaves. Extracts from, infected leaves depressed spore germination, as did concentrations above 5 times 10⁵ spores/ml. The highest % germination was observed when naturally infected leaves were dry-stored for up to 20 days and then incubated for 2 days in a moist chamber.     

成熟度与烘干温度对结球甘蓝种子质量的影响

以结球甘蓝品种冬升种子为材料,研究了不同成熟度和烘干温度下种子秕粒率、千粒重、发芽率、生理活性情况以及不同烘干温度下种子的含水量.结果表明,结球甘蓝冬升开花后45～55 d采收的种子,发芽率均达到了95%以上;随着种子成熟度提高,其种子质量、发芽活力及其超氧化物歧化酶(SOD)、过氧化物酶(POD)、脱氢酶活性显著上升,而相对电导率显著下降.与对照(自然风干)相比,30～50℃的烘干温度对种子千粒重和秕粒率无显著性影响,也仅在50℃下可使种子的发芽活力显著降低;随着烘干温度的升高,种子的SOD、POD和脱氢酶活性逐渐显著下降,相对电导率则逐渐显著上升;30～50℃烘干6 h种子的含水量由13.3%降至5.4%左右.研究发现,结球甘蓝冬升开花授粉后45 d种子已达到了采收程度,30～50℃烘干6 h种子含水量已达到储藏要求,并且愈接近自然干燥温度(30～40℃)的处理,种子发芽能力愈好;甘蓝种子活力与其SOD、POD和脱氢酶活性呈正相关,而与其相对电导率呈负相关.     

Activity of plant and mineral oils in the control of Puccinia pelargonii-zonalis

Effectiveness of plant oils from corn, olive, rape, soya and sunflower, oils recommended for plant protection (Dedal 90 EC, Olejan 80 EC) and mineral oils (Atpolan 80 EC, Ikar 95 EC, Olemix 84 EC and Promanal 60 EC) in the control of pelargonium rust (Puccinia pelargonii-zonalis) was studied. Oils were applied curatively as a plant spray at concentration 1%, 4 times at 7-day-intervals. After 4-week experiment more than 11 uredia per leaf were noted on control plants. At the same time, on plants protected with oils from olive or soya, Ikar 95 EC or Olemix 84 EC uredia number decreased at least 50%. The other oils were not effective in a suppression of uredia formation. On control plants no uredia were destroyed as compared to 11 to 71% destruction on plants protected with the tested oils. Oils from olive, soya and also Atpolan 80 EC, Ikar 95 EC, Olemix 84 EC caused drying off more than 50% uredia. Furthermore, some oils inhibited germination of urediospores on PDA medium (potato dextrose agar). Fourteen days after the last spraying more than 83% of germinating urediospores were found on control leaves. At the same time spores collected from protected plants germinated in 17 to 70%. Among tested products oils from rape, corn, sunflower and Dedal 90 EC, Ikar 95 EC, Olemix 84 EC were the most effective. In the next part of experiment, plants with visible sporulation of P. pelargonii-zonalis were sprayed with 1% oils. After 1 and 7 days of incubation, total number of spores and number of germinating spores were counted. One day after treatment, urediospores collected from leaf blades protected with oils germinated in 20 - 60%. Oils from olive, corn, Atpolan 80 EC and Ikar 95 EC caused inhibition of spore germination at least in 40%. Whereas urediospores from nontreated plants germinated in 86%. After 7 days, urediospores collected from untreated plants germinated in 65% whereas from plants sprayed with tested oils in 23 - 68%. Oils from olive, sunflower and Dedal 90 EC, Atpolan 80 EC were the most effective in suppressing urediospores germination.     

亚热带中山常绿阔叶林木本植物幼苗数量动态及其与生境的相关性

以百山祖自然保护区5 hm2永久样地150个幼苗监测站木本植物幼苗为研究对象,2008—2011年定期调查样方中幼苗的种类、数量、萌发、死亡等,探究亚热带中山常绿阔叶林幼苗种类组成、数量动态及其与生境的相关性。结果表明:1)百山祖样地在2008年至2011年出现的幼苗属于26科,40属,共53个物种,不同物种萌发时段有异;2)2009年样地幼苗存活比率为7.7%,2010年为-20.8%,2011年则是-0.3%,幼苗存活比率不高,种类和数量呈减少趋势;3)存活幼苗中有明显的优势物种,分别为光亮山矾(Symplocos lucida)、尖连蕊茶(Camellia cuspidata)、浙闽新木姜子(Neolitsea aurata var.undulatula)、尖叶菝葜(Smilax arisanensis)和短尾柯(Lithocarpus brevicaudatus),5个物种之和占幼苗总数比例50%;4)种子的萌发与生境有极显著的相关性,且与生境因子中水分关联最大;5)存活幼苗数与样站坡位、水分、落叶层厚度呈现显著相关性,水和光照是影响幼苗存活的主要因素。     

The effects of ripening and drying of carrot seed (Daucus carota) crops on germination

Carrot seeds taken from the parent plant were capable of germinating before the stage when maximum seed dry weight was reached but even after this stage, when the seed moisture content had fallen below 20%, improvement in seed germination characteristics continued. In the latter stages of seed growth losses by shedding were 12–20 kg/ha/day. For low density crops (10 plants/m²) the yield of viable seed was at a maximum in crops whose seed was harvested with a moisture content of between 20 and 40% but no consistent relationship could be established for high density crops (80 plants/m²). There were no effects of umbel order or plant density on mean germination time or spread of germination. At any early harvest, percentage germination was highest for primary-umbel-seeds and seeds from low density crops but the differences between the seed origins diminished with later harvests. Drying the seeds on the umbels improved the percentage germination, reduced the mean germination time and the spread of germination particularly at the early harvests compared with seeds removed from the umbels and germinated immediately without drying.     

The performance of carrot seeds in relation to their viability

The germination and emergence characteristics, and early seedling growth, of carrot seeds cv. Chantenay red-cored from different sources with a range of germination from 54–94%, was compared. Seeds from protected crops (mean temperature of growth 21°C, r.h. 45–70%) gave higher percentage germination than those from crops grown outdoors (mean temperature 15°C, 70–100% r.h.). Germination was also higher from mature (seed moisture content at harvest 20% or lower) than immature seed (seed moisture content at harvest between 20 and 60%). High percentage germination (>90%) was associated with low mean germination times and low spreads of germination times whilst the reverse was true for low percentage germination. Similar relationships were found for seedling emergence characters in the field although a lower proportion of the viable seeds produced seedlings from slowly than rapidly germinating seed lots. In general, seed lots having a low percentage germination gave greater variability in plant weight than those of higher percentage germination. There was no effect of seed source on radicle or shoot relative growth rates or on post-emergence seedling growth rates.     

Seed dormancy patterns in Epipactis palustris (Orchidaceae): Requirements for germination and establishment of mycorrhiza

Some terrestrial orchid species, including Epipactis palustris (L.) Crantz, are considered extremely difficult to germinate and cultivate in vitro. Observations of orchids germinating in nature are very few, and the timing and requirements for seedling establishment are unknown for most species. Seeds of E. palustris were incubated in vitro with an appropriate fungus, but germination was poor unless several other conditions were also met: scarification of the testa in Ca(OCL)₂, an initial incubation for several weeks at 27°C, and a subsequent cold stratification for 8–12 weeks at 4–8°C, With these pretreatments, germnation responses exceeded 50% after incubation for 4 weeks at 20°C. Healthy protocorms with normal organ development were only produced by symbiotic culture following this lengthy seed preparation. The findings suggest that under natural conditions the seeds need some after-ripening, and the testa needs to be partially decomposed before germination. The requirement for chilling suggests that germination of seeds in situ occurs in spring.     

Seed Germination and Radicle Growth of a Halophyte, Kalidium caspicum(Chenopodiaceae)

Effects of temperature, light, NaCl and polyethylene glycol(PEG)-6000 on seed germination and radicle growth in a halophyticshrub, Kalidium caspicum(L.) Ung.-Sternb. were investigated.When seeds were incubated in deionized water at constant temperaturesbetween 10 and 30°C, the percentage germination in the darkexceeded 75%; light suppressed seed germination at alternatingtemperatures. Incubating seeds with a hypersaline solution ofNaCl for 30 d had no adverse effect on their germinability.The percentage germination of seeds incubated with a –0.8MPa NaCl solution was 73, 80 and 54% at 10, 20 and 30°C,respectively, but all radicles died before their length exceeded5 mm. In contrast, when seeds were incubated with a –0.8MPa PEG solution at 20°C, 68% of seeds germinated, and 95%of the emerging radicles survived beyond 5 mm. The high sensitivityof small radicles of this species to salinity indicated thatsalt must be removed from the soil surface for seedling establishment.Copyright2000 Annals of Botany Company Chinese desert, radicle growth, germination, halophyte, Kalidium caspicum, salinity     

不同培养基及激素对铁线蕨孢子离体繁殖的影响

铁线蕨Adiantum capillus-veneris L.是一种常绿草本,植株高15—40厘米,叶片小、纸质,叶片排裂似云片状,是一种优雅的室内观叶植物。多年来,在生产上我国仍采用分株繁殖的方法。用组织培养的方法进行蕨类植物的孢子繁殖工作,国内做得很少。现将我们所做的铁线蕨孢子离体繁殖工作,报道如下。     

Genetic basis of rate-temperature characteristics for germination in oilseed rape

Genetic control of germination time in oilseed rape might enablesome cultivars to adapt locally as a volunteer weed or a feralplant. The heritability of within-population germination characteristicswas therefore investigated for the oilseed rape cultivar Martina.Two groups of seed were selected from a batch of seeds germinatedat 5C: those germinating up to about the 20th percentile, termedearly germinators, and those above the 80th percentile, viablenon-germinators, which did not germinate at 5C but did so subsequentlywhen moved to a higher temperature. The groups of seeds wereisolated, grown to flowering and the plants self-pollinated.Germination of the new seed from the two groups was then comparedwith seed from the original population at temperatures between4C and 19C on a thermal plate. Differences between seed lotswere small at 19C, but large below 10C. The differences inspread of time were analysed by fitting exponential curves tothe non-linear relation of 1/time on temperature for each offive percentiles, 10, 20 50, 80, and 90. The fitting proceduretested the extent to which variation within and between seedlots was caused by variation in the base temperature, the curvatureof the relation and a parameter for scaling the curve betweenpercentiles. Progeny of the early seed germinated much morerapidly than the original, and germinated completely even atlow temperature. The more rapid germination was attributed toa lower extrapolated base temperature of –2.3C, comparedto –0.7C for the original, and slightly greater curvature.Progeny of non-germinator seed contained a higher proportionof viable non-germinating seed (for example, 20% germinationat 4C, compared to 50% for the original), but the germinatingseed differed only slightly from the original in time to germination.Among the germinating percentiles, both types of progeny displayedless spread in time to germination than the original seed. Itwas concluded that the cultivar had the potential to give riseto genetically distinct populations able to exploit differentseasonal opportunities. Key words: Oilseed rape, germination, temperature, heritability     

A study of the relationship between seedling characters and rate of germination within a seed lot

The relationship between seedling characters and germination rate within a seed lot was studied in cauliflower, leek and onion seeds. Newly germinated seeds were selected after successive days of imbibition at 20°C and placed on slope tests to assess early seedling growth. In all three species seedling length decreased and the coefficient of variation of those seedling lengths increased with increasing number of days of imbibition required for germination. Slow germinating seeds in all three species produced fewer normal healthy seedlings than faster germinating seeds. The relevance of these results to pre-germinated seed sowing techniques is discussed.     

Incapacity for work of employees of the selected metallurgical plant related to age

Evaluation of the health state of employees in relation to the working environment is one of the main tasks of occupational medicine. The specified results represent a part of a methodically oriented project which was focused on evaluation of: age structures of employees in the metallurgical plant being monitored in comparison with the age structure in the whole region, evaluation of the health status of employees in the plan by means of absolute and relative indicators of morbidity and even their dependence on age. The analysis was carried out during three successive years in approximately 10 000 employees of a metallurgical plant. The selected six groups of diagnoses represented from 40 % to 50 % of all employees suffering from a disease. Particularly the following diagnoses according to the International Classification of Diseases were involved there: I10-I15 (hypertensive disease), I20-I25 (ischaemic heart disease), J00-J06 (acute infections of upper respiratory airways), K20-K31 (diseases of oesophagus, stomach and duodenum), M15-M19 (arthroses) and M50-M54 (dorsopathies). The age structure of employees related to men and women was considerably statistically significantly different from the age structure of the region. From the economic point of view on incapacity for work, we consider the number of days of absence from work for the reason of the disease as an indicator with the highest informative value. We noted two dominative maxima in men and women for this characteristic. A proportion of patients with acute infections of upper respiratory airways ranged from 40 % to 50 % out of total cases of diagnoses we have followed up, the highest number of patients was in men aged 20-24 with a subsequent significant decrease. We did not find any noticeable dependence on age for this diagnosis in women, only a slight increase in older age categories was evident. Dorsopathies are the second most frequent group; they were from 30 to 38 % out of all monitored diseases. The age dependence was evident especially in women aged 40+. Considering duration of incapacity for work and its repeatability, dorsopathies seem to be the most relevant health problem in employees in heavy industry, and especially in women. The participation of the remaining four selected groups of diseases is relatively low. Both in men and women, the hypertensive disease ranged from 1.9 %-3.7 %, ischaemic heart disease from 0.4 %-6.5 %, diseases of oesophagus, stomach and duodenum from 5.3 %-9.0 % and arthroses from 4.7 %-6.8 % in three years in question.     

冷层积和室温干燥贮藏对河西走廊8种荒漠植物种子萌发的影响

不同贮藏和处理条件对不同植物的种子萌发有不同的影响。该文以河西走廊干旱半干旱区8种荒漠植物为研究对象, 探讨了种子经历不同冷层积(4 ℃、-5 ℃、-26 - 10 ℃)和室温干燥贮藏后的萌发响应。研究结果表明: 1)冷层积可使种子萌发率提高、保持不变或降低, 冷层积的有效温度下界可降至-5 ℃或更低。4 ℃和-5 ℃的冷层积使多裂骆驼蓬(Peganum multisectum)和驼蹄瓣(Zygophyllum fabago)种子的萌发率升高、萌发速度加快, 冬季过低的气温以及较大的温度变幅(-26 - 10 ℃)使部分种子萌发率升高。3种冷层积和室温干燥贮藏使黑果枸杞(Lycium ruthenicum)种子萌发率达到90%-100%。唐古特白刺(Nitraria tangutorum)、甘草(Glycyrrhiza uralensis)、苦马豆(Sphaerophysa salsula)种子经过3种冷层积和室温干燥贮藏后萌发率变化较小。中亚紫菀木(Asterothamnus centrali-asiaticus)种子对各种贮藏条件的响应不明显, 部分种子活性丢失。刺沙蓬(Salsola ruthenica)种子扩散时有较高的萌发率(84%), 经-5 ℃和-26 - 10 ℃冷贮藏后, 种子仍具有较高的萌发率, 经4 ℃冷贮藏后几乎不萌发, 大部分种子活性丢失。2)不同物种的种子经过不同方式的贮藏后, 萌发对温度的响应不同。经冷层积后的多裂骆驼蓬种子萌发响应于恒温, 驼蹄瓣和刺沙蓬种子萌发更加响应于变温条件; 多数植物种子在变温培养下萌发速度慢于恒温下。     

中、旱生植物萌发特性及其与种子大小关系的比较

不同生境的植物有不同的生活史对策。该文对分布于河西走廓的42种常见中生植物和22种常见旱生植物种子的萌发特性以及种子大小对萌发能力的影响进行了比较。结果显示,64种植物中最终萌发率超过90%的有9种: 虎尾草(Chloris virgata)、蒲公英(Taraxacum mongolicum)、腺独行菜(Lepidium apetalum)、膜果麻黄(Ephedra przewalskii)、沼生蔊菜(Rorippa islandica)、白草(Pennisetum centrasiaticum)、霸王(Zygophyllum xanthoxylon)、反枝苋(Amaranthus retroflexus)和黑果枸杞(Lycium ruthenicum),占14.06%,其中黑果枸杞、腺独行菜、膜果麻黄、虎尾草的萌发在10 d内完成; 萌发率达到80%~90%的有5种: 毛果群心菜(Cardaria pubescens)、窄叶小苦荬(Ixeridium gramineum)、牛蒡(Arctium lappa)、鞑靼滨藜(Atriplex tatarica)和苣荬菜(Sonchus brachyotus)占7.8%; 萌发率达到60%~80%的有16种,占25%;萌发率在20%~60%的有17种,占26.56%; 萌发率不足20%的有17种: 柠条锦鸡儿(Caragana korshinskii)、野苜蓿(Medicago falcata)、扁蓄(Polygonum aviculare)、苦参(Sophora flavescens)、河西沙拐枣(Calligonum potanini)、白刺(Nitraria tangutorum)、甘草(Glycyrrhiza uralensis)、苦豆子(Sophora alopecuroides)、骆驼蓬(Peganum harmala)、画眉草(Eragrostis pilosa)、多裂骆驼蓬(Peganum multisectum)、老瓜头(Cynanchum komaroviil )、骆驼蒿(Peganum nigellastrum)、田旋花(Convolvulus arvensis)、酸模叶蓼(Polygonum lapathifolium)、卷茎蓼(Polygonum convolvulus)、蝎虎驼蹄瓣(Zygophyllum mucronatum),占25.56%。有26种植物的萌发持续在30 d以上,15种植物在15 d内完成萌发,有31种植物在1~3 d内开始萌发,4种植物在10 d以后才开始萌发。主成分分析和聚类分析显示,中、旱生植物的萌发主要有爆发型、过渡型、缓萌型和低萌型,以过渡型和缓萌型为主;中生植物中萌发率不足20%的有6种,占14.28%, 旱生植物中萌发率不足20%的有11 种,占50%,显示了较多的旱生植物有延迟萌发的行为,这种萌发的延迟及萌发时间的异质性可使物种在不可预测、高死亡风险的环境中仍能确保种的延续。中生植物的种子大小对萌发能力有显著的影响,小种子的物种有较高的萌发率和较快的萌发速率,并且完成萌发所需要的时间较短,而旱生植物的种子萌发不受种子大小的影响。以上结果说明中生植物和旱生植物长期适应于不同的湿、旱生环境,在不同的选择压力下,生活史对策也出现了较明显的差异。     

Some studies on secondary dormancy inLimnanthes seed

The seeds of 10 accessions ofLimnanthes, representing 7 species and their varieties were moistened and placed in an 80°F cabinet for up to 14 days. Then they were transferred to 40, 50 or 60°F temperatures for germination. In two accessions, 85% of the seeds became dormant after only 2 days at 80°F. In 6 accessions, up to 80% of the seeds became dormant after 14 days at 80°F. In two other accessions there was little or no dormancy induced. After 16 months, one half the ungerminated seeds in each treatment were dried under room conditions for 2-1/2 months. Then they were again moistened and placed under germination temperatures. Up to 78% of the seeds thus treated germinated, compared with few or none of those maintained continuously under germination conditions.     

Thiamine binding and metabolism in germinating seeds of selected cereals and legumes.

The basic characteristics of thiamine metabolism in germinating seeds of maize (Zea mays), oat (Avena sativa), faba bean (Vicia faba) and garden pea (Pisum sativum) are presented with a special emphasis of a possible thiamine storage function of seed thiamine-binding proteins (TBPs). Seeds were germinated for 6 d in the dark. Thiamine-binding activity in seeds decreased during germination by 50% in cereals and by 30% in legumes. The degradation of TBPs was also detected by polyacrylamide gel electrophoresis. The total thiamine content decreased rapidly to 20-40% of the initial value in cereal seeds during first 3 d of germination while in legume seeds thiamine content started changing from the fourth day and dropped by 50% at the sixth day. A composite pattern was found for the changes in thiamine pyrophosphate (TPP) contribution to total thiamine during seed germination. A peak of the coenzyme percentage was usually detected at the second day of germination. Another gain of TPP was often seen toward the sixth day of germination. The activity of thiamine pyrophosphokinase (EC 2.7.6.2) was high in resting legume seeds and did not significantly change during germination. In contrast, the low activity of this thiamine-activating enzyme in cereal seeds progressively increased during germination. Thiamine phosphate synthase (EC 2.5.1.3) was also detected in seeds and was shown to contribute significantly to the balance of thiamine compounds during seed germination.     

温带半干旱地区一年生植物种子的萌发特性

在实验室条件下研究了中国温带半干旱地区科尔沁沙地的23种1年生植物的种子萌发特性（新采集种子、冷藏和干藏种子）.大籽蒿、虎尾草、冠芒草、沙蓬和地锦的新种子萌发率达90%左右,11种植物新种子萌发率均低于70%,说明这些植物的新种子具有或多或少的休眠属性.经过150d的冷干藏后,大籽蒿、虎尾草萌发率保持在90%以上,说明这两种植物完全没有休眠机制;冠芒草、沙蓬和地锦的种子萌发率下降较多,可能是储藏的环境条件导致的2次休眠现象;冷藏和干藏处理均能使绿珠藜、毛马唐、细叶益母草、雾冰藜、金狗尾草、苋菜、马齿苋、碱地肤和水稗草的种子在生长季开始时完成生理后熟,萌发率达到80%以上;干藏有利于促进毛马唐、细叶益母草、马齿苋和鹤虱的种子成熟,冷藏有利于促进绿珠藜和金狗尾草的种子成熟;黄蒿、灰绿藜、画眉草和烛台虫实在不同处理下的萌发率都比较低,说明种子内在生理休眠作用较强,具有减少种子一次性萌发数量的风险分摊策略.大多数1年生植物均能在较短时间内达到最终萌发率的90%,表现出迅速萌发的特性;黄蒿、灰绿藜、碱地肤和沙蓬种子则在不同处理中表现出延长萌发时间的策略来适应半干旱地区不确定的环境条件.最后,探讨了几种主要1年生植物的种子萌发对策与其对环境适应机制之间的关系.