Effects of pre-sowing seed treatments and temperatures on tomato seed germination and seedling emergence

Sowing pre-germinated seeds with radicles 2–3 mm long reduced the time from sowing to seedling emergence to 17 days compared with 41 days in untreated seeds at soil temperatures of 10°C, and to 5 days compared with 11 days at 18°C. Sowing pre-germinated seeds also improved percentage seedling emergence and reduced the variability of times of emergence of individual seedlings. Seeds imbibed for 56 h before sowing (radicles just emerging) emerged about 3 days earlier at both 10°C and 18°C than untreated seeds. Seeds soaked in a solution containing 1.5% each of KNO₃ and K₃PO₄ for 5 days at 24°C, or in “Carbowax 20 M” for 20 days at 15°C, and then dried before sowing, gave results similar to imbibed seeds. Soaking seeds in 70% of their weight of water followed by drying for different lengths of time and for different numbers of cycles of wetting and drying did not improve germination or seedling emergence.     

风选和引发处理对甜椒种子萌发及幼苗生长的影响

以甜椒种子为试材,通过风选和硝酸钾引发的方式,研究对甜椒种子萌发和幼苗生长的影响。试验设置1%硝酸钾溶液20℃下分别引发5、6、7 d,以未引发种子为对照,研究不同引发时间对甜椒种子萌发和幼苗生长的影响。结果表明,风选后甜椒种子千粒重较原种子显著增加3.25%,较不合格种子显著增加135.56%,不合格种子发芽势较CK处理显著降低43.42%,优选种子发芽率较CK处理显著提高5%。实验室发芽试验表明,发芽势各处理较CK处理显著提高58.49%、52.83%%、60.38%;发芽畸形数量各处理较CK处理显著降低73.91%、73.91%、69.57%;发芽指数各处理较CK处理显著提高了76.28%、69.87%、78.21%。穴盘育苗幼苗试验表明,在播种后47 d株高较CK处理显著提高13.21%,茎粗显著提高10.29%,叶片数显著提高9.09%,壮苗指数显著增加17.65%。综上可得,风选处理后,选用1%硝酸钾溶液,在20℃条件下,引发处理7 d能够显著提高发芽率和发芽势,促进幼苗生长,提高壮苗指数。     

黑籽南瓜种子基质引发适宜条件研究

以黑籽南瓜种子为材料,研究了不同温度、处理时间和基质含水量对黑籽南瓜种子引发效果的影响。结果表明,基质引发处理能明显提高黑籽南瓜种子发芽势、发芽指数和活力指数,明显减少种子平均发芽天数;基质引发温度明显提高幼苗干鲜质量和根体积等,而基质湿度对幼苗生长性状影响不显著。黑籽南瓜种子基质引发处理以5℃、基质湿度65%时激发种子活力的效果最好,在不同基质引发温度和湿度条件下,改变引发持续时间所产生的效果是不一样的。     

Slow post-hydration drying improves initial quality but reduces longevity of primed bitter gourd seeds

Many environmental factors are known to affect the success of priming, post-hydration drying being critical. Accumulated evidence shows that priming improves the quality of bitter gourd (Momordica charantia L.) seeds. However, the effect of post-hydration drying on the their longevity remains unclear. This study evaluated the effects of post-hydration drying speed on the emergence performance and anti-oxidative activities of primed bitter gourd seeds stored for 48 weeks. Results indicated that priming improved emergence percentage, mean emergence time and seedling growth of treated seeds. Primed seeds also showed lower peroxidation, as indicated by the accumulation of malondialdehyde (MDA) and total peroxide, and higher total anti-oxidative activities (TAA) than non-primed seeds. The seeds receiving slow post-hydration drying treatment exhibited faster emergence and better seedling growth than the seeds receiving fast post-hydration drying treatment and the non-primed control. However, the longevity of slow-dried seeds decreased considerably during 48 weeks of storage as compared to that of non-primed and fast-dried seeds. Fast drying treatment maintained the longevity of primed seeds for up to 24 weeks as compared with non-primed control or slow-drying seeds. Improved longevity was due in part to enhanced TAA that minimized the accumulation of MDA and total peroxide during storage.     

Responses of non-primed or primed seeds of ‘Marketmore 76’ cucumber (Cucumis sativus L.) slurry coated with Trichoderma species to planting in growth media infested with Pythium aphanidermatum

Aqueous slurries of commercial preparations of Trichoderma harzianum Rifai strain KRL-AG2 G41 (Th), T. virens Strain G-41 (Tv), or their combination (ThTv, at half rates each of the single application rate) were applied to ‘Marktetmore 76’ cucumber seeds (Cucumis sativus L.) that were non-primed or primed for 3 days at 25 °C either osmotically (−2.5 MPa from 0.337 molal Ca(NO₃)₂) or osmomatrically (−1.0 MPa from 0.135 molal Ca(NO₃)₂ plus −1.5 MPa from 50% water in exfoliated grade 5 vermiculite). Slurries were applied to seeds (1 mg per seed) either before or after priming. Seeds were sown in soilless, peat-based media with or without inoculation with Pythium aphanidermatum (Pa). Protection against damping-off caused by high pressures of Pa (16% emergence in non-coated, non-primed seeds) was increased by slurry coating Th on non-primed (76.4% emergence) or on osmotically primed seeds, with coating either before or after priming having no effect on efficacy (average 62.6% emergence). Slurry coating Th on osmomatrically primed seeds failed to increase final emergence percentage (FEP). Colony forming units per three seeds (CFU, all 10³) was 2.8 for non-primed seeds, and 3.2 and 2.6, respectively, when osmotically and osmomatrically primed seeds were coated after priming. In a second study with lower disease pressure (58.1 FEP from non-coated, non-primed seeds), slurry coating of non-primed or osmotically primed seeds with Th, Tv or ThTv reduced percentage damping-off and increased FEP. The combination coating eliminated damping-off only in non-primed seeds, and tended to reduce percentage damping-off in osmotically or osmomatrically primed seeds compared to coating with Th or Tv alone. In a third study using only non-primed seeds, slurry coatings with mefenoxam fungicide, Th, Tv, or ThTv decreased total damping-off to 2.6%, 7.4%, 2.0%, and 0%, respectively, from the 30.1% occurring in non-coated seeds. Th, Tv or ThTv applied to growth media at the same rate as the seed coating (1 mg per seed) were generally as effective as the seed coatings, and only the ThTv growth medium application eliminated damping-off. A fourth experiment revealed that Th, Tv or ThTv remained viable on non-primed seeds for up to 4 weeks (the longest storage duration) at 21 or 4 °C, but 21 °C storage resulted in faster seed germination by week 3 and higher CFU per three seeds by week 4. In summary, coating of non-primed seeds with Th, Tv or ThTv was more effective than coating primed seeds in reducing percentage damping-off. While priming treatments generally led to faster seedling emergence and greater seedling shoot fresh weight than was achieved with non-primed seeds, only for non-primed seeds was damping-off eliminated by the ThTv seed coating or growth medium application.     

火棘容器育苗技术研究

采用L₉（3⁴）正交实验设计方法,进行了基质配比、种子处理方法和容器规格对火棘出苗率、苗木生长质量影响的研究。结果表明:不同基质配比、种子处理方法、容器规格对火棘出苗率、苗高、地径、根系及生物量等指标均有显著影响。经多重比较分析,提高火棘容器播种出苗率及苗木质量的最佳组合方案为:先将种子消毒后,用100 mg/kg GA₃溶液浸种4 h,然后将种子与湿沙按1:3的比例混合层积于瓦盆内,置于室温（18～23℃）催芽,待1/3种子咧嘴后,播种在规格为12 cm×15 cm,装有腐殖土55%+河沙20%+有机肥22%+过磷酸钙3%基质的容器中,出苗率达91.63%,平均苗高为11.5 cm,地径0.55 cm。     

种子处理对西瓜细菌性果斑病的防治效果

利用干燥与药剂相结合、引发与药剂相结合的种子采后处理方法对西瓜种子的除菌效果进行了研究。应用PCR方法检测未经人工接种的西瓜种子,幼苗生长方法检测人工接种和自然带菌(Ac)的西瓜种子,结果表明,未经人工接种的西瓜种子中,从没有发酵经室内阴干4h后热风烘干、以及不管是否发酵室内阴干的种子上均检测到Ac菌的特异性条带。人工接种Ac菌的西瓜种子随着室内阴干时间的延长,幼苗细菌性果斑病(BFB)的发病率呈上升的趋势,由阴干3h的0.9%上升到阴干6h的20.4%。同时随着阴干时间的延长,种子的成苗率降低,由阴干3h的52.6%下降到阴干6h的23.9%。说明快速干燥能有效控制带菌种子幼苗BFB的发生,提高种子的健康质量。不同杀菌剂对自然带菌(Ac)西瓜种子杀菌效果的研究结果表明,不管是药剂处理种子还是含药的固体基质引发处理种子,其种子质量都没有显著的差别。药剂处理的种子平均每株幼苗的鲜质量均高于含药的固体基质引发处理的种子幼苗的鲜质量。通过幼苗生长鉴定,含药固体基质引发处理的相对防治效果在57.1%～78.6%之间,而药剂处理的相对防治效果在84.6%～100.0%之间。含药的固体基质引发处理对降低幼苗BFB发病率的效果要差。     

无籽西瓜种子引发技术的研究

对无籽西瓜种子进行引发处理试验,研究其对种子萌发特性及幼苗苗期生长的影响,引发过程影响处理效果的因素,处理种子保存过程中活力的变化。结果表明,引发处理显著提高了种子萌发速度和整齐度,提高了三倍体西瓜种子萌发率,还提高了出苗速度和幼苗特性,增加了幼苗质量和胚轴长度。引发处理的效果与种子自身及处理条件相关,处理后的干燥速度对引发效果影响极大,过快、过慢都会降低引发效果。将处理后的2个西瓜品种的种子与未处理的种子一起放在4℃或室温下保存约1年,种子活力未发生明显变化,引发效果得到保持。对引发方法的选择、引发效果的影响因素、引发与种子健康的关系以及商业应用的风险进行了分析。     

菜芸豆种子淋雨后生命力的变化研究

为探索芸豆种子受到雨淋后活力的变化规律和将损失降到最低的措施,以自然风干种子为材料,人工模拟降雨条件,当经不同雨淋处理的种子含水量达到入库标准后,进行室内发芽势、发芽率检测,室外单粒点播、室外穴播试验,鉴定种子活力和田间出苗情况。试验结果表明,在收储晾晒过程中,种子遭受雨淋,其发芽势、发芽率均有降低,田间出苗数减少,发芽势下降尤为显著。种子淋雨后只要马上沥干水分并及时晾晒,不会造成田间的缺苗断垄,仍能达到国家二级种子质量标准,不会给种子加工企业和菜农带来损失。     

Promotion by 5-aminolevulenic acid of pepper seed germination and seedling emergence under low-temperature stress

The effects of incorporating 5-aminolevulenic acid (ALA) into the priming solution on low-temperature germination and emergence percentage performance of red pepper (Capsicum annuum cv. Sena) seeds before and after seed storage were investigated. Seeds were primed in 3% KNO₃ solution for 6 days at 25 °C in darkness containing 0 ppm, 1 ppm, 10 ppm, 25 ppm, 50 ppm or 100 ppm ALA. Following priming, seeds were either immediately subjected to germination and emergence tests at 15 °C or stored at 4 °C or 25 °C for 1 month after which they were subjected to germination and emergence tests at 15 °C. Priming pepper seeds in the presence of ALA improved final germination percentage (FGP) and germination rate (MGT) at 15 °C compared to non-primed seeds. The highest FGP was obtained from seeds primed in the presence of 25 ppm and higher ALA concentrations while the highest MGT was obtained from seeds primed in KNO₃ supplemented with 10 ppm ALA. Emergence percentages were the highest for the seeds primed in the presence of 25 ppm ALA and 50 ppm ALA while non-primed seeds had the lowest emergence percentage. Highest emergence rates (MET) and heaviest seedlings were also obtained from seeds primed in KNO₃ supplemented with 50 ppm ALA. Although all priming treatments improved germination and emergence performance of pepper seeds at 15 °C following 1 month of storage under two different temperatures, inclusion of 25 ppm and 50 ppm ALA into the priming solution resulted in higher germination and emergence percentages and faster germination and emergence compared to seeds primed in KNO₃ only and non-primed seeds. These results indicate that priming seeds in 25 ppm and 50 ppm ALA incorporated into the KNO₃ solution can be used as an effective method to improve low-temperature performance of red pepper seeds and that these seeds can be stored for 1 month at 4 °C or 25 °C and still exhibit improved germination and emergence performance at 15 °C.     

A cold-treatment technique to improve the germination of vegetable seeds prior to fluid drilling

A simple method capable of treating large quantities of seeds prior to germination and fluid drilling is described. After an initial imbibition period at 20°C, seeds were placed at a temperature of 1°C; high enough for continued metabolism but too low for radical emergence. This treatment reduced the spread of time of germination, increased the percentage of seeds germinating and brought forward the mean germination time of seeds when transferred back to 20°C. Treated seeds emerged earlier and more uniformily than untreated seeds following pre-germination and fluid drilling in the field.     

引发处理对番茄种子保存和寿命的影响

用30%PEG溶液和3%KNO3溶液分别对番茄种子进行引发处理,引发处理提高了种子的发芽速度和整齐度。PEG引发处理的种子在室温下保存5.5 a依然保持明显的引发效果,没有表现出比未引发的对照种子衰老快的趋势。对引发种子进行加速老化试验,结果表明:PEG引发种子比未引发的对照种子和KNO3引发种子表现出明显的抗老化能力。与先老化再引发处理相比,先引发再老化处理对种子活力影响较小。     

The effects of sub-seed placement of liquid N and P fertilizer on the growth and development of bulb onions over a range of plant densities using primed and nonprimed seed

Phosphates-of-ammonium “starter” fertilizer solution was injected below onion seeds at sowing on a fertile sandy loam soil given basal N, P and K applications. Bulb crops were grown from primed and non-primed seed drilled at six sowing rates to give a threefold range of plant density. Irrigation and nitrogen application were monitored to ensure that plants remained unstressed throughout growth. The starter fertilizer resulted in increased P and N and reduced K content during seedling growth. In both an early-sown and a late-sown experiment, shoot growth was accelerated by starter fertilizer and shoots became approximately 50% heavier than those without starter. Growth curves showed that this was equivalent to a 3-3.5 d advancement of growth. Starter fertilizers resulted in 1-2.5 d advancement of crop maturity as shown by the date of 50% foliage fall-down. In the later sown experiment, starter fertilizer reduced the percentage of non-maturing ‘thick-necked’ bulbs. Bulb yields were not significantly increased by starter fertiliser. Data showing similar enhancements of seedling growth on other soils are also discussed. Seed priming advanced the date of seedling emergence but had no significant effects subsequently. Increases in plant density advanced the date of crop maturity and increased total bulb yields.     

不同双砧木嫁接对黄瓜长势、产量及蜡粉性状的影响初报

采用生产上常用的3种南瓜砧木（黑籽南瓜、褐籽南瓜、白籽南瓜）互相组合进行双砧木嫁接,研究不同双砧木嫁接对黄瓜植株长势、产量及瓜条蜡粉性状的影响。结果表明：双砧木嫁接后,植株长势、产量较自根苗对照明显增强,但与单砧木嫁接相比,产量差异表现不同,黑籽南瓜与白籽南瓜双砧木组合的产量最高,显著高于黑籽南瓜或白籽南瓜单砧木嫁接的产量;黑籽南瓜与褐籽南瓜双砧木组合的产量显著高于褐籽南瓜单砧木嫁接的产量,但与黑籽南瓜单砧木嫁接产量差异不显著;而褐籽南瓜与白籽南瓜双砧木组合的产量与褐籽南瓜或白籽南瓜单砧木嫁接的产量差异不显著。3种南瓜砧木对黄瓜果面蜡粉的影响存在明显差异,黑籽南瓜不具脱蜡粉能力,而褐籽南瓜脱蜡粉能力较强,其所生产的瓜条亮绿、无蜡粉、商品性好;双砧木嫁接对瓜条蜡粉的影响介于两个单砧木嫁接之间,并趋向于蜡粉较重的砧木。     

The effects of pre-sowing seed treatments on the germination and emergence of lettuce seeds at high salt concentrations

Radicle emergence in lettuce seeds cultivar ‘Hilde’ was reduced by NH₄NO₃ above 8×10^?2M, while radicle extension was inhibited by 8×10^?2M NH₄NO₃ and no seedlings emerged. Inhibition of radicle emergence by 8 and 16×10^?2M NH₄NO₃ was prevented by soaking seeds for 4 h before sowing in a mixture of $\text{GA}{}_{\mathrm{<mtext>4</mtext><mtext>7</mtext>}}$ and kinetin+phosphate buffer, and was partially prevented by soaking them for 4 h before sowing in phosphate buffer. These treatments did not prevent inhibition of radicle emergence by 32×10^?2M NH₄NO₃, but seeds soaked in growth regulators or phosphate buffer before sowing and taken from this NH₄NO₃ solution after 7 days and washed to remove excess salt gave 45–52% germination compared with 12 % for untreated seeds. Pre-treatment of the seeds did not prevent the inhibitory effect of NH₄NO₃ on radicle extension. In field experiments seeds treated with growth regulators + phosphate buffer or phosphate buffer alone gave a higher final percentage emergence from soils given 125 kg N/ha than did untreated seeds.     

EMS诱变对刺梨种子出苗及早期生长性状的影响

以刺梨品种‘贵农5号’的种子为试材,种皮经砂纸磨损后用浓度为0.1%、0.3%、0.6%、0.9%的甲基磺/酸乙酯(EMS)分别浸种处理12h和24h后播种,研究了出苗率、成苗率并观测幼苗早期生长表型性状,以期筛选出最适诱变剂量和处理时间,为后期构建大量刺梨EMS突变群体奠定技术基础。结果表明:0.1%~0.3%的低浓度EMS处理能提高种子的出苗率和成苗率,但随着EMS浓度升高或处理时间的延长,出苗率和成苗率均显著降低,当浓度升至0.9%处理12h或0.6%处理24h时其种子死亡率为100%。成活幼苗的生长性状可在株高、株型、叶型、分枝等方面表现出不同的表型变异,且在一定浓度范围内其变异率随着处理浓度增加而增加。综合考虑成苗率和表型变异率等数据,筛选得出0.3%EMS浸种12h为刺梨种子突变的适宜剂量条件。     

Comparisons of the use of pre-germinated,dry and pelleted seeds for block-raising of glasshouse lettuce

The use of pre-germinated seeds for establishing glasshouse lettuce in peat blocks was compared with dry and pelleted seeds. Sowing pre-germinated seeds gave between 1 and 6% higher seedling emergence than from pelleted seeds and between 1 and 3% higher emergence than from dry seeds. Seedling emergence was reduced from 100% to 56% when the seeds were covered with 5 mm of silver sand compared with no cover. Seedling emergence from seeds covered with Agrigel (sodium alginate) was reduced by 24% at a concentration of 0.25% and by 62% at 0.7% compared with no cover.Guar (a natural gum) and Laponite (a synthetic clay) gels also reduced emergence on certain occasions but not by as much as Agrigel. Satisfactory levels of emergence were obtained when seeds were sown into blocks having an inverted, cone-shaped depression for locating the seeds, but the seedlings showed poor root-hair development and had elongated hypocotyls. Normal seedling growth and high levels of emergence were obtained from the seeds sown into blocks having cylindrical holes 10 mm in depth and 5 or 10 mm in diameter. Pre-germinated seeds invariably emerged earlier than pelleted or dry seeds. At low propagating-temperatures (12.0°C maximum and 5.0°C minimum), emergence was 4 days earlier from pre-germinated than from dry or pelleted seeds and 2–3 days earlier at high temperatures (21.0°C maximum and 9.0°C minimum). Coefficients of variation of seedling weight at planting were lower from sowing pre-germinated than pelleted or dry seeds, but these differences were not evident at harvest.     

不同药剂处理对西瓜细菌性果斑病带菌种子的影响

采用菌悬浮液浸种方式对西瓜种子接菌,利用6种药剂对带菌种子进行浸种处理,并调查各处理对种子发芽、幼苗生长的影响及对西瓜幼苗细菌性果斑病(BFB)的防治效果。试验结果表明,播种前带菌种子采用40%甲醛100倍液浸种1 h,对西瓜幼苗BFB的防效达到100%,对西瓜种子的发芽和幼苗的生长无不良影响。     

In vitro asymbiotic seed germination and seedling growth of Ansellia africana Lindl.

The effects of sodium hypochlorite treatment and growth medium on in vitro seed germination and seedling growth of the leopard orchid (Ansellia africana Lindl.) were investigated. Forty minutes treatment of seeds with 1.75% sodium hypochlorite stimulated germination (70.6%) and seedling development when measured at Stage 5 (emergence of first leaf) on P668 medium after 8 weeks of culture. The growth medium played a significant role in determining the germination response of A. africana seeds. Dark pretreatment of seed cultures significantly enhanced the germination percentage and the growth of rhizoids on the protocorms. Leaf growth in terms of length was substantially enhanced on P668 medium. It was significantly reduced in modified Knudson C medium after 16 weeks of culture. Seedlings developed on P668 medium showed a significantly better growth performance in relation to leaf length, leaf number, root length, fresh and dry weights per plant in vermiculite after 12 weeks of ex vitro growth in a mist house with 90% relative humidity. Further studies developing a suitable method for in vitro symbiotic germination could assist in reintroduction of this threatened orchid species into the wild.     

Fast germination of parsley seeds

The time from sowing to 50% radicle protrusion of parsley seeds (Petroselinum crispum L.) was about 1 month at 5°C and about 1 week at 15°C. Osmotic pre-treatment (“priming”) with a polyethylene glycol “6000” solution of ?12 bars water potential (302 g PEG “6000” per 1 kg distilled water) at 15°C for 3 weeks under aerobic conditions reduced this median radicle protrusion time at 15°C to 1 or 2 days for seeds which had been surface-dried after treatment, 2 or 3 days when they had been air-dried and stored for 1 week, and 3 or 4 days after 10 weeks' dry storage. The uniformity in germination time of an untreated seed population was usually good, and care was needed not to make this worse by “over-priming”. An appropriate pre-treatment could, however, slightly improve the uniformity. Germination percentage remained unaffected but the pre-treatment could appreciably improve the emergence percentage of seeds sown in wet soil. In a small-scale experiment out of doors, the weight of plants from certain seed treatments was significantly greater after 14 weeks' growth than that from untreated seeds.