Increased Germination Rates of Baldcypress and Pondcypress Seed Following Treatments Affecting the Seed Coat

The effects of seed-coat removal, warm-water soaking, cold stratification, dry-cold storage and acid treatment on the germination of baldcypress (Taxodium distichum (L.) Rich.) and pondcypress (Taxodium distichum var. nutans (Ait.) Sweet) seed were studied. Removal of the hard seed coat resulted in a prompt and high percent germination, indicating that there was no physiological embryo dormancy. Cold stratification, warm-water soaking and acid treatment did not increase percent germination over the control after a 60-day germination period. They did promote the rate of germination however, having a significantly higher germination at 30 days. Dry-cold storage promoted the initial rate of germination, but resulted in a decreased percent germination below the control after 60 days. The above results suggest that moisture, and not cold, was the crucial component of stratification. The improved germination rate following acid treatment further suggests that any treatment which rendered the seed coat more permeable or softened it was more effective in increasing the rate of germination of baldcypress and pondcypress seed.     

三种植物生长调节剂对降香黄檀种子发芽的影响

采用三种植物生长调节剂GA3、IBA和6-BA不同浓度按正交设计方法,搭配处理组合,对降香黄檀种子进行处理,通过对种子发芽率、发芽势和发芽指数指标的测定,研究不同浓度的植物生长调节剂对珍贵用材树种降香黄檀种子萌发的影响。结果表明:3种植物生长调节剂浸种对降香黄檀种子萌发以6-BA的促进效果较好,GA3次之,而IBA对降香黄檀种子的发芽促进作用不明显,以处理组合6-BA50mg/L6h为最优,显著提高种子的萌发率。     

‘勐海大叶茶’种子萌发特性

以大叶茶品种‘勐海大叶茶’ （Camellia sinensis var. assamica cv. Menghai Dayecha） 种子为材料,进行种子萌发特性的初步研究。研究发现,种皮对‘勐海大叶茶’种子的萌发存在一定的作用,含水量较高时,人为破除种皮有助于种子的萌发,随着含水量的降低,人为破除种皮反而降低了种子的萌发率。‘勐海大叶茶’种子的最适萌发温度为30℃,15℃以下时萌发率较低,容易发生低温伤害,变温处理对提高种子萌发率的效果不明显。基质对大叶茶种子萌发的影响不明显,四种不同种植基质条件下,种子的萌发率趋于相同水平,证明基质类型并非影响种子萌发的关键因子。     

The BHLH Transcriptional Factor PIF4 Competes with the R2R3-MYB Transcriptional Factor MYB75 to Fine-Tune Seeds Germination under High Glucose Stress

It is known that the high level of sugar including glucose suppresses seed germination through ABA signal. ABI5 is an essential component to mediate ABA-dependent seed germination inhibition, but underlying mechanism needs more investigation. Previous study demonstrated the PIF4 activated the expression of ABI5 to suppress seed germination in darkness. Here we reported that PIF4 also mediated the seed germination inhibition through ABI5 under high concentration of glucose treatment. Furthermore, we found that PIF4 interacted with PAP1, the central factor to control anthocyanin biosynthesis. Such interaction was confirmed in vitro and in planta. Biochemical and physiological analysis revealed that PAP1 bond the promoter of ABI5 to suppress its expression, thus enhanced seed germination under high concentration of glucose treatment. Specially, PAP1 competed with PIF4 to antagonize the activation of PIF4 on ABI5 expression, thus promoted seed germination under high glucose treatment. Given these, we uncover a novel role for PIF4 and PAP1 in controlling seed germination under high glucose treatment, and reveal their antagonistic mechanism by which coordinates ABI5 expression to control seed germination in response to the glucose signal.     

理化因子对龙血树柴胡种子萌发的影响

本研究以龙血树柴胡（Bupleurum dracaenoides Huan C.Wang,Z.R.He&H.Sun）的种子为材料,采用不同温度、不同浓度赤霉素、不同化学试剂以及紫外线照射和微波辐射等方式处理后,统计其发芽率、发芽势、发芽指数和发芽时间等指标。结果表明：龙血树柴胡种子萌发最适温度为20℃;100 mg/L的GA₃、0.5％的KMnO₄和3％的H₂O₂处理均能促进其种子萌发,但不能使种子萌发和出苗时间提前;25 s微波辐射处理可大幅提高种子发芽率;紫外线照射处理种子0.5 h,萌发效果最佳,但随照射时间的延长对种子萌发则有不同程度的抑制。     

野生药食两用植物青葙种子萌发的初步研究

测定青葙种子吸水和温度、光、暗、不同浓度GA,和0．2％KNO,影响其种子发芽的结果表明：青葙种子于25℃恒温下浸种8h后吸水达到饱和,其适宜发芽温度为30-35℃,萌发受光照抑制。10、50和100mg·L^-1GA3浸种的发芽率分别为61％、66％和72％,0．2％KNO3处理的发芽率达到81％。     

干旱胁迫下白刺花种子大小与萌发对策

种子大小与种子萌发及其与环境因子的关系是植物种子萌发对策研究中的重要科学问题之一。采用PEG模拟干旱法研究不同干旱胁迫强度(0,5%,10%,15%,20%)下,白刺花(Sophora davidii)种子萌发进程、种子大小与种子萌发及种子命运的关系。结果表明:不同干旱胁迫下,白刺花种子具有相似的萌发进程,但中度干旱处理(10%PEG)萌发率显著高于零干旱(0%PEG)和重度干旱处理(P0.05),重度干旱处理(20%PEG)种子萌发开始时间晚于零干旱和中度干旱处理;种子大小与种子萌发开始时间的关系表现为零干旱处理下呈极显著负线性关系,中度干旱处理(5%PEG,10%PEG)下无相关关系,重度干旱处理(15%PEG,20%PEG)下呈负二次曲线关系;种子大小对种子命运的影响表现为零干旱处理有利于大、小种子萌发和小种子休眠,中度干旱处理(10%PEG)增加中等种子萌发、大种子休眠和小种子死亡风险,重度干旱处理(15%PEG,20%PEG)增加大种子死亡风险、中等种子和小种子休眠。综合分析表明,白刺花种子大小与萌发行为及种子命运的关系具有较强的环境依赖性,即种子萌发行为表现为顺境下种子越大萌发越快,逆境下小种子和大种子较中等种子萌发更快;种子命运表现为顺境增加种子死亡的风险,中度干扰有利于种子萌发,逆境则有利于种子休眠。     

旋转磁场对小麦种子萌发及幼苗生长的影响

以“淮麦19”小麦种子为研究对象,采用磁场强度为11 mT的旋转磁场进行处理,设定不同的时间梯度(10、20、30、60 min),以未经磁场处理的为对照,研究了不同处理时间下旋转磁场对小麦种子发芽指标及幼苗生理特性的影响。结果表明：旋转磁场处理对小麦种子萌发具有促进作用,不同处理时间下,种子的发芽势、发芽率、发芽指数均有显著提高,随着时间的增加呈现先上升后下降的趋势,以处理30 min为最高,分别比对照提高了8.24％、7.37％、11.24％。经旋转磁场处理后,小麦根系发达,根长、根数均显著高于对照;幼苗生长加快,株高除处理60 min外,其他处理均显著高于对照,以处理30 min为最大,高出对照11.13％;叶片数除处理10 min外,其他处理均高于对照,以处理30 min为最大,比对照高出38.89％,且差异显著。旋转磁场处理显著增加了小麦幼苗的物质积累,不同处理时间表现出不同的效果,对幼苗生物积累量影响最佳的是处理20 min。这说明旋转磁场处理提高了小麦种子的萌发能力,加快了小麦幼苗的生长速度。     

Seed aging,delayed germination and reduced competitive ability in Bromus tectorum

In annual plants, increased competitive advantage has often been attributed to rapid germination and early establishment. In contrast, many annual species exhibit some degree of delayed germination (i.e., seed dormancy) that results in the formation of age structure within the seed population. Delayed germination can be an effective bet-hedging strategy in variable or unpredictable environments as a seed bank can buffer against years with reproductive failures and reduce the probability of local extinction. However, there has been little consideration of the direct effects of aging within the seed pool although the potential demographic costs of such a strategy (e.g., mortality in the seed bank or delayed reproduction) are well known. We used aged (4 year-old) and freshly produced seed from meadow steppe and sagebrush steppe populations of an annual grass (Bromus tectorum)to investigate the importance of seed age on seedling vigor and competitive ability. Aged seed from the meadow steppe population exhibited delays in germination that reduced plant growth and final biomass when the plants were grown with competition. Aged seed from the sagebrush steppe population did not exhibit delays in germination. By including a treatment that experimentally delayed the germination of freshly produced meadow steppe seed, we also examined the effects of delayed germination alone. A comparison of results from this delay treatment with those from the aged seed treatment suggested that the reduced competitive ability of meadow steppe plants produced from aged seed, although largely a result of the temporal delay in germination, was partly due to reduced seed vigor. Together these results indicate that physiological costs associated with seed age may affect aboveground competitive interactions and, in turn, the relative fitness of older cohorts in the soil seed bank.     

四种野生报春花种子萌发生物学特性

以多脉报春Primula polyneura、钟花报春P. sikkimensis、桔红灯台报春P. bulleyana 和粉被灯台报春P. pulverulenta 的种子为材料,研究其形态及光照、GA3 对种子萌发的影响。结果表明,4 种报春花种子形态各异,钟花报春种子质量最大,千粒重达0.458 g,粉被灯台报春种子质量最小,千粒重为0.192 g。光照处理及不同浓度GA3 处理对4 种报春花种子萌发的影响存在差异。光照对多脉报春的萌发效果最好,其次为钟花报春与桔红灯台报春,对粉被灯台报春无明显促进作用。光照条件下,400 mg·L^-1 GA3 处理对桔红灯台报春和粉被灯台报春的萌发效果较好,发芽率显著提高,发芽持续时间缩短;钟花报春萌发适宜的GA3浓度为200 mg·L^-1。     

脱落酸引发对夜香紫罗兰种子萌发的效应

研究脱落酸引发及其与植物生长调节剂的复合处理对夜香紫罗兰(Matthiola bicornis)种子萌发的效应.结果表明,将夜香紫罗兰种子于20℃下在2.5×10-5 mol/L脱落酸(ABA)溶液中引发7 d,能显著缩短种子平均萌发时间,增加种子萌发指数.在ABA溶液中加入吲哚乙酸(NAA)未能进一步改善夜香紫罗兰种子萌发,但其他复合处理均显著提高正常幼苗百分率.ABA和细胞分裂素(KT)及NAA复合处理进一步增加种子萌发指数,不仅比单独用ABA引发的效果好,而且也比用聚乙二醇(PEG)引发的效果好.ABA引发和PEG引发的夜香紫罗兰种子相对吸水量显著不同.对ABA引发机理和应用潜力进行了讨论.     

盐胁迫对蓝蓟种子萌发及早期幼苗的影响

研究了不同浓度盐(NaCl)处理对蓝蓟种子发芽势、发芽率及幼苗生长的影响。结果表明:(1)不同盐胁迫处理对蓝蓟种子的萌发具有显著影响。随着盐处理浓度的增加,发芽率呈下降趋势,蓝蓟在无盐环境(蒸馏水)和低盐环境中(0.05 mol/L)长势最好、发芽率最高、发芽速度最快。(2)将不同盐溶液处理5 d的未萌发种子转移到蒸馏水后,蓝蓟种子的萌发能力均可恢复,原来较高盐浓度(0.3 mol/L～0.5 mol/L)下的种子在恢复后,其萌发恢复率均在75%以上,发芽率基本上随着原浓度的升高呈上升的趋势。研究表明,NaCl处理对蓟种子没有造成伤害,其抑制萌发是通过渗透效应而不是离子毒害。     

凋落物物理阻隔对格氏栲种子萌发及胚根生长的影响

为了探讨凋落物物理阻隔对格氏栲天然林自然更新状况的影响,通过模拟野外凋落物覆盖,设置格氏栲种子上层覆盖厚0 cm(CK)、2 cm(D2)、4 cm(D4)、6 cm(D6)、8 cm(D8)及种子下层铺垫厚2 cm(U2)、4 cm(U4)凋落物等7个处理,分析凋落物覆盖方式及厚度对格氏栲种子萌发及胚根生长的影响。结果表明:(1)凋落物覆盖方式及厚度对种子萌发进程存在显著影响。CK萌发持续时间最长,上层覆盖处理(D)次之,下层铺垫处理(U)的种子起始萌发时间显著滞后。(2)CK种子萌发率最高,其次D6处理发芽速度较快,发芽整齐;U处理较D处理的发芽率及发芽势均显著降低,且萌发抑制率显著增加。(3)D处理的种子胚根生长速度快,胚根长度大于CK;U处理的种子胚根生长速度呈先慢后快趋势。可见,凋落物是影响格氏栲种子萌发及胚根生长的重要因素,主要通过阻碍种子与土壤接触而抑制萌发,影响格氏栲林更新。     

不同种子预处理对10种沙拐枣植物萌发的影响

为了确定沙拐枣植物种子的萌发特性及最优播前预处理方法,在实验室条件下,对10种沙拐枣植物的种子进行了磨砺、硫酸和热水浸泡、冷藏、种子浸出液处理,然后进行发芽实验研究。萌发实验的结果表明,10种沙拐枣植物对于不同的种子预处理,均表现出相似的萌发反应。磨砺、硫酸浸泡和冷藏处理对种子萌发有明显地促进作用。与对照相比,种子浸出液处理对种子的发芽率、发芽速度均具有明显地抑制作用,并能增强种子的休眠。冷藏处理具有打破有活力的种子休眠、促进种子萌发的作用,但它与热水浸泡处理一样,对有活力种子表现出一定的致死作用。沙拐枣植物的萌发模式在不同种子预处理问均表现出明显的差异性。机械磨擦和硫酸处理能够促进种子的萌发率及发芽势。泡果沙拐枣(Callingonum junceum)在本项实验中表现出很强的萌发能力。     

香圆种子萌发特征及催芽技术

以香圆（Citrus wilsonii Tanaka）种子为实验材料,通过测定种皮透水性、种皮机械障碍、发芽温度等对种子萌发的影响从而探讨种子萌发特征;通过切割种子、热水浸种、赤霉素浸种、低温层积等处理方式探索种子的催芽方法。结果显示：香圆种皮不存在透水性障碍,但其机械障碍对种子萌发具有抑制作用,且内种皮对萌发影响较大;种子在15℃、25℃、35℃恒温及15℃/30℃变温条件下均可萌发,其最适萌发温度为25℃;采用低温层积、热水浸种、切除1/3种子等方法均可一定程度上促进种子萌发。生产中宜采用始温60℃热水浸种24h的方法对香圆种子进行催芽。     

化学诱变剂EMS对知母种子萌发的影响

以知母（Anemarrhena asphodeloides）种子为材料,分别采用1%、2%、4%、6%浓度的EMS处理6、8、12和24 h,在恒温培养箱内进行种子萌发实验,研究不同浓度的化学诱变剂甲基磺酸乙酯（ethyl methane sulfonate,EMS）处理对知母种子萌发的影响,筛选适宜的诱变浓度和诱变时间。结果表明：随EMS浓度的增加和处理时间的延长,知母种子发芽率呈现逐渐降低的趋势,以相对发芽率达到半致死浓度为标准,6%EMS浸种12和24 h可作为EMS诱导知母建立突变体库的适宜条件。     

The use of water and some inorganic salt solutions to advance sugar beet seed. I. Laboratory studies

The emergence of sugar beet seedlings is often slow or irregular and insufficient plants may be established for the crop to yield fully. Treating the seed prior to sowing, such that the subsequent germination percentage is not reduced but germination is more rapid and better synchronised should be beneficial. A series of laboratory experiments was made to investigate seed treatment procedures involving water and various inorganic salt solutions. Many treatment combinations were identified which gave faster germination without decreasing germination percentage and left the seed dry and intact and suitable for sowing with conventional precision drills. No treatment was found which ‘primed’ the sugar beet seed and the term seed ‘advancement’ describes, more accurately, the effects observed. There was little difference in the performance of seeds optimally treated with water or some salt solutions generating an osmotic potential of between about –10 and –20 bars. However, the use of salt solutions, although more complicated, was preferred to water as inadvertent germination during treatment was less likely. The optimum treatment for the one bulk of sugar beet seed studied was, firstly, to wash the seeds for 3.5 h with water, then after air-drying, to moisten them on filter paper dampened with –15 bar (0–34 M) sodium chloride solution for 6 days at 15^oC followed by a final wash and air-drying.     

水杨酸调控盐胁迫下羽衣甘蓝种子萌发的机理

盐胁迫是植物种子萌发与植株生长的重要限制因子。以羽衣甘蓝(Brassica oleracea var.acephala)名古屋为材料,研究不同盐分对其种子萌发的影响,探索水杨酸(SA)及其合成抑制剂氨基茚磷酸(AIP)处理对羽衣甘蓝种子萌发的调控效应。实验结果表明,150与200 mmol·L^–1 NaCl处理后的羽衣甘蓝种子活力显著降低。盐胁迫显著降低种子的吸水速率、种子活力与幼苗质量,降低苯丙氨酸裂解酶活性与内源SA含量,提高过氧化氢(H2O2)与超氧阴离子(O2^–.)含量。SA可以缓解盐胁迫对羽衣甘蓝种子活力的抑制作用,通过促进内源SA合成,从而提高种子吸水率与种子活力,促进种子对K^+、Mg^2+的吸收,降低Na+含量。此外,外源施加SA能够显著增强超氧化物歧化酶和过氧化物酶活性,降低H2O2与O2^–.的积累。相反,氨基茚磷酸(AIP)处理能够增强盐胁迫对种子萌发的抑制作用,推测这与AIP处理能够显著降低种子内源SA含量密切相关。研究表明外源SA主要通过提高保护酶活性、降低活性氧积累和维持体内离子平衡来增强羽衣甘蓝的耐盐性。     

云锦杜鹃种子萌发及对干旱胁迫的响应

以不同渗透势的PEG-6000溶液模拟干旱胁迫条件, 研究云锦杜鹃种子的萌发、幼苗生长和累积吸水率对干旱胁迫的响应。结果显示：种子于第14 d开始萌发,萌发期为8 d,总萌发率为45.5%±1.7%。在渗透势为-0.3～-0.6 MPa的溶液中, 种子的累计吸水率在第5 d就超过对照(蒸馏水中), 种子的萌发和幼苗的生长也优于对照, 说明云锦杜鹃种子不适合过于湿润的土壤环境中萌发。但溶液的渗透势≥-0.9 MPa时, 种子的吸水减缓、萌发率下降, 同时幼苗的生长也慢, 而当渗透势≥-1.8 MPa时, 种子不能充分吸涨、萌发, 说明云锦杜鹃种子对干旱胁迫比较敏感。另外, 经PEG溶液浸种2天后移入蒸馏水中,萌发率均有一定程度的提高, 其中经-0.3～-1.5 MPa的PEG溶液浸种后, 萌发率显著高于对照。提示用一定浓度范围的PEG溶液浸种可使休眠种子活化, 提高种子繁育的效率。     

影响翅果油树种子萌发及幼苗生长的几种因素的比较研究

通过对翅果油树种子进行了适温处理、变温处理、激光处理、超声波处理、H₂O₂处理、PEG处理,对发芽实验进行研究,然后测定发芽率、发芽势、萌发指数、根长、芽长、株高、茎粗以及叶绿素含量。萌发实验的结果表明, 变温预处理和PEG预处理能最有效地解除抑制物对种子萌发的影响,对种子进行变温处理和PEG处理是解除种子休眠和提高萌发率的有效途径。本实验为促进濒危植物翅果油树的种群繁衍以及对翅果油树的可持续利用提供一定的科学依据。