Evaluation of aqueous Moringa seed extract as a seed treatment biofungicide for groundnuts

In a search for alternatives to currently used fungicides, the potential of aqueous Moringa seed extract (AMSE) as a seed treatment was evaluated. Seeds of groundnut, Arachis hypogea L cv Dakar, were soaked in AMSE at concentrations of 1, 5, 10, 15 and 20 g litre(-1) for 24 h. Comparison was made with Apron Plus (metalaxyl+carboxin+furathiocarb), until recently a recommended seed-treatment chemical, and distilled water, which was the medium for extraction of Moringa seeds. The results showed that AMSE has potential for use as a biofungicide on groundnut seeds, since all the concentrations used except 1 g litre(-1) brought about significant reduction in the incidence of fungi on the seeds, such reduction increasing as the dosage of AMSE increased. There were no significant differences in control between the highest concentration of AMSE (20 g litre(-1)) and Apron Plus at the manufacturer's recommended level. Water also produced slight reductions in the incidence of fungi, although this was not significant at P = 0.05. The sensitivity to AMSE of the fungi tested varied, Mucor sp being the most sensitive and Aspergillus niger the least, with Rhizopus stolonifer and Aspergillus flavus intermediate.     

剑麻叶不同溶剂浸提液对假臭草萌发和生长的影响

以剑麻园常见伴生杂草假臭草为受体植物,白菜和萝卜为参照受体植物,采用生物测定的方法研究剑麻新鲜叶片石油醚、乙酸乙酯、三氯甲烷、蒸馏水4种溶剂浸提液对受体植物种子萌发和生长的影响。结果表明,4种溶剂浸提液对受体植物种子萌发率、根长和茎长生长均有不同程度的影响。500mg／mL蒸馏水浸提液和三氯甲烷浸提液对假臭草种子的萌发和幼苗的根长总体上具有显著的抑制作用,抑制率分别达到29％和50％;500mg／mL蒸馏水浸提液对萝卜种子萌发和根长生长具有显著的抑制作用,抑制率分别达到45．00％和64．22％;500mg／mL乙酸乙酯浸提液对白菜种子萌发和根长生长的抑制作用较强,抑制率分别达到30．49％和56．59％。说明剑麻不同溶剂、不同浓度浸提液对不同的受体植物均存在不同程度的化感作用,这为进一步开展利用剑麻的化感物质抑制杂草的研究提供了理论基础。     

醋糟、粉煤灰对高粱苗期土壤微生物数量、酶活性及高粱生长的影响

研究了不同醋糟、粉煤灰处理下高粱苗期土壤微生物数量和土壤酶特性的变化特征及对高粱生长的影响,以探讨醋糟、粉煤灰的施用效果及最佳配比,试验设置4个处理,分别是处理1(醋糟100%)、处理2(醋糟∶粉煤灰=1∶1)、处理3(醋糟∶粉煤灰=2∶1)、处理4(醋糟∶粉煤灰=3∶1)和化肥对照。结果表明:施用醋糟、粉煤灰可以有效增加土壤微生物数量和提高土壤酶活性,提高叶片光合速率和高粱产量。处理1～处理4细菌数量分别比对照提高19.66%、31.34%、15.69%、12.54%,放线菌数量分别比对照提高20.99%、32.37%、17.56%、10.43%,真菌数量分别比对照提高22.78%、34.26%、13.54%、9.56%;土壤磷酸酶活性分别比对照提高17.11%、20.85%、12.29%和19.78%;土壤蔗糖酶活性比对照提高了23. 70%、37. 08%、11. 54%和3. 08%,土壤脲酶活性比对照提高了25. 28%、34.77%、19.82%和13.79%;处理2苗期光合速率分别比对照、处理1、处理3和处理4提高13.8%、6.67%、9.98%和13.30%,拔节期提高3.45%、3.22%、3. 21%和4. 05%,抽穗期提高14. 52%、3. 75%、1. 86%和12. 66%,灌浆期提高了13.08%、4.26%、4.08%和9.36%,成熟期提高了3.8%、1.05%、2.12%和2.20%。醋糟含有大量的有机物质和无机物质,可为土壤微生物的生命活动提供能量和养料,进而促进土壤微生物的繁殖和土壤酶活性。     

混合盐碱胁迫对帚用高粱萌发及苗期生长的影响

将NaHCO3和Na2CO3等摩尔混合,NaHCO3、Na2CO3、NaCl等摩尔混合分别得到250 mmol/L的混合溶液T1和T2,对帚用高粱的种子及幼苗进行混合盐碱胁迫处理。结果表明:混合盐碱胁迫导致帚用高粱种子发芽率降低,幼苗相对生长率减小,叶片电解质外渗率提高,可溶性糖含量增加,叶绿素含量减少;碱性盐混合引起的盐碱胁迫(T1)对帚用高粱种子萌发和幼苗生长的抑制作用明显强于中性盐和碱性盐混合引起的盐碱胁迫(T2);渗透胁迫和离子毒害是引起抑制作用的主要原因。     

Inhibition of seed germination and seedling growth by hound's-tongue (Cynoglossum officinale L.) seed leachate

The leaching of phenolics from decoated seeds, seed coats and pericarps of hound's-tongue ( Cynoglossum officinale L.), factors affecting leaching, and seed germination and seedling growth inhibitory activities of the leachate were investigated. Embryonic axes and cotyledons contained a large amount of methanol-soluble phenolic substances. Decoated seeds released phenolics into an aqueous incubation medium and this solution was capable of inhibiting root elongation of several grassy and broadleaf species, but not of hound's-tongue. The leachate and the phenolic fraction of the leachate inhibited germination of bluebunch wheatgrass ( Pseudoroegnaria spicata (Pursh) A. Löve [syn. Agropyron spicatum (Pursh) Scribn. and J. G. Sm.]). The non-phenolic fraction of the leachate did not inhibit seed germination or root and shoot elongation of bluebunch wheatgrass. Low oxygen and an increasing temperature significantly increased the amount of phenolic substances leached from decoated seeds. Increased leaching of phenolic substances related to an increasing temperature was associated with the loss of seed viability. Further investigation of the role of water-extractable hound's-tongue seed phenolics in the interaction of this species with its biotic environment under field conditions is needed to determine the ecological significance of these findings.     

蒙古扁桃种子萌发和幼苗生长对渗透胁迫的响应

以天然生长于祁连山自然保护区隆畅河自然保护站的濒危植物蒙古扁桃(Prunus mongolica)去内果皮的种子为材料,以不同渗透势PEG-6000溶液模拟干旱条件,研究了种子萌发和幼苗生长对干旱胁迫的响应特征。结果表明,随着干旱胁迫程度的加剧,蒙古扁桃种子吸胀速率、萌发率、萌发指数、活力指数、苗高和根长、组织饱和含水量等指标均表现出明显降低的趋势,而幼苗初生芽干重、根干重和根冠比均呈先升后降的趋势。蒙古扁桃种子对水势变化既敏感又抗旱,种子能够萌发的最低渗透势阈值为-0.65 MPa。干旱胁迫未能萌发的种子复水后萌发率较高。分析认为,蒙古扁桃种子萌发和幼苗生长对干旱胁迫的响应特征对种的延续具有重要意义,但在人工栽培时保证 土壤墒情应是保障建植成功的关键措施。     

Influence of imidacloprid seed treatments on rice germination and early seedling growth

BACKGROUND: Seed treatments with the chloronicotinyl insecticide imidacloprid (Gaucho 600 FS) were evaluated to determine whether differences in concentration and exposure regime influence the germination and early growth of rice. RESULTS: Continuous exposure to imidacloprid (4 days at 2000 mg AI L(-1)) significantly (P < 0.001) reduced normal germination by an average of 18% across the 15 cultivars examined. Nine days after sowing, plants showed no adverse effects from continuous imidacloprid treatment during germination, with shoot lengths and root system dry weights equalling, or occasionally exceeding (P < 0.05), those of untreated plants. Short-term imidacloprid exposure (2 h at 2000 mg L(-1)) at initial seed wetting did not affect germination (P > 0.05), and short-term (1 h) exposure of 48 h pregerminated seed to imidacloprid (2000 mg L(-1)) similarly had no significant effect on early subsequent growth. Plants arising from 48 h pregerminated seed exposed to imidacloprid (1 h) at concentrations up to 4000 mg L(-1) immediately before sowing were not significantly different from control plants at either 9 or 25 days post-sowing. CONCLUSION: Results show that imidacloprid will have no adverse effects on plant growth if applied to pregerminated rice shortly before sowing. Continuous exposure of seed during germination had more pronounced effects, and the initial response of different cultivars was highly variable. Cultivars with high levels of sensitivity (such as IR72) require further testing before continuous exposure to imidacloprid during germination can be recommended.     

聚乙二醇胁迫下赤霉素浸种对番茄种子萌发和幼苗生长的影响

以番茄幼苗为材料,研究了50 mg/g 的赤霉素(GA3)和清水浸种后用不同浓度的聚乙二醇(0、40、80、120 mg/g)胁迫对番茄种子萌发及幼苗生长的影响.结果表明:40 mg/g的聚乙二醇胁迫对番茄种子的萌发率、发芽指数、幼苗株高、根长有促进作用,120 mg/g的聚乙二醇明显抑制种子的萌发率、发芽指数、幼苗株高、根长;不同浓度的聚乙二醇胁迫明显降低了幼苗的叶绿素含量.用50 mg/g GA3浸种后明显增加聚乙二醇胁迫下番茄种子的萌发率、发芽指数、幼苗株高、根长和叶绿素含量.用50 m g/g GA3浸种对番茄幼苗的生长有一定的促进作用.     

剑麻提取液对芒果炭疽病菌的抑制作用及苗期防治效果

本文利用剑麻提取液对芒果炭疽病的防治进行了研究,结果表明,剑麻叶片水提液对芒果炭疽病菌的菌丝扩展速度以及菌丝生长量均有明显的抑制作用,且随着处理浓度的增高,抑制效果增强,当每100mL培养基中加0．2mL提取液处理时,抑制率达到50％以上;对孢子产孢能力以及孢子萌发率也有明显抑制作用,当100mL培养基中加5mL提取液处理时,产孢抑制率为98．18％,孢子萌发抑制率为97．43％;用提取液处理菌丝后电导率升高,表明该提取物对芒果炭疽病菌菌丝体细胞结构有影响,导致菌丝体电解质外渗;芒果苗期盆栽试验表明,处理后21d,对照发病率达到92．22％以上,而处理仅为44．44％,表明该提取物对芒果炭疽病有明显的防治效果。     

BS-12对小麦种子萌发与幼苗生长的影响

通过水培和盆栽试验,研究了不同浓度BS-12污染对小麦种子萌发与小麦幼苗生长的影响.结果表明,水培中10 mg/L的BS-12能够促进小麦种子萌发,BS-12浓度大于10 mg/L时,随BS-12浓度增大小麦萌发受到的抑制作用增大;土壤中BS-12添加比例以0.5%为分界点,高于0.5%时小麦幼苗受到伤害与抑制作用,低...     

NaCl胁迫对草木樨种子萌发及幼苗生长的影响

采用室内种子萌发及温室幼苗培养实验方法,研究不同浓度NaCl胁迫对耐盐植物草木樨种子萌发及幼苗生长的影响,结果表明：低浓度的NaCl胁迫可以提高种子的萌发率、累积发芽率、发芽势,增加幼苗地上部分的鲜干比、叶绿素含量,并促进幼苗根和芽的生长,而高浓度的NaCl胁迫则对其有显著的抑制作用;不同浓度的NaCl胁迫对草木樨种子的发芽指数均有一定的抑制作用,而对幼苗叶片的丙二醛含量却有一定的促进作用。因此得出：低浓度的NaCl胁迫对草木樨种子萌发及幼苗生长具有一定的促进作用,而高浓度的NaCl胁迫则对其有一定的抑制作用。     

黄顶菊水提取液对植物种子发芽及胚根伸长的化感作用研究

采用培养皿滤纸法研究黄顶菊水提取液对30种受体植物种子发芽及胚根伸长的化感作用。结果表明，浓度为0.1g（干重）／ml的成熟黄顶菊植株水提取液对供试的29种植物种子发芽和28种植物胚根伸长有不同程度抑制作用，对2种植物胚根伸长有促进作用。该浓度下，有24种植物的发芽率或胚根长降低50％以上，占供试植物种数的80％。提取液浓度越高对受体植物发芽和胚根伸长的抑制作用越强。黄顶菊不同生育时期和不同器官提取液对受体植物种子发芽及胚根伸长的抑制程度有差异，表现为成熟期植株〉营养生长期植株；叶片〉花（果实）〉茎〉根。揭示黄顶菊可能通过产生化感物质抑制周围生境中植物的萌发和早期生长，从而降低这些植物在群落中的多度。一旦黄顶菊大面积、高密度发生，就有可能导致入侵地植物多样性的降低。     

水分胁迫下不同化学物质浸种对玉米发芽及幼苗生长的影响

通过室内培养试验研究了不同水分胁迫条件下不同化学物质浸种对玉米种子发芽和幼苗生长的影响。结果表明：水分胁迫下使用化学物质浸种对玉米种子的发芽率和发芽势无显著影响,但却不同程度提高了玉米幼苗的株高和壮苗系数;使用化学物质浸种增加了玉米幼苗的生物量,且水分胁迫下幼苗干重增加幅度明显高于正常水分处理;水分胁迫下使用化学物质浸种提高了玉米幼苗的总根长,其中中度水分胁迫(ψs=0．4MPa)根长的增加幅度高于轻度水分胁迫(ψs=0．2MPa),前者增加的幅度为5．01％～50．83％,后者为0．32％～23．38％。与其他处理相比,水分胁迫下CCC ZnSO4处理的玉米幼苗的根长、根系干重和壮苗系数均较高,说明利用CCC ZnSO4处理具有促进根系生长,培育玉米壮苗的突出作用。     

土习脱拌种防治棉苗病害研究初报

商品土习脱(Tuz)为双福美(TMTD)、福美锌(Zerlate)、有机砷 Urbazid(甲基胂双 N,N′-二甲基二硫代氨基甲酸酯)等杀菌剂的混合物。据国外研究,处理棉种后有一定的保苗效果。为明确这种新药剂在沿海盐土棉区的应用价值,并与常用的0.5%五西合剂及0.8%赛力散拌种比较,于1961及62年进行了上列药剂的保苗效果比较。     

Factors affecting weed seed germination and seedling growth in lowland rice in Indonesia

Experiments were carried out in Indonesia to see whether weeds of lowland rice fields could be managed by manipulation of the water table and what factors affected germination of their seeds. It was found that seeds of two Scirpus spp. germinated when buried in anaerobic soil but not when on the surface, whereas seeds of two Echinochloa spp. germinated when on the surface of both aerobic and anaerobic soils but when buried germinated only in aerobic soil. The germination of weed seeds was affected to differing extents by submergence in water at depths down to 20 cm. Germination of Fimbristylis littoralis seeds was greatly reduced and of Ludwigia hyssopifolia was complétély inhibited by submergence. Conversely, germination of Monochoria vaginalis seeds was virtually unaffected. It is suggested that the effect of submergence on germination of some species may be due to their reaction to the amplitude of temperature fluctuation. The germination and emergence of seedlings under water were greatly reduced by a cover of Salvinia molesta. The practical importance of these findings is discussed.     

黄花刺茄浸提液对番茄种子萌发及幼苗生长的影响

为明确入侵植物黄花刺茄对当地主栽经济作物番茄种子萌发和幼苗生长的影响,本文采用培养皿滤纸法,在智能光照培养箱的变温控制条件下,分别研究了黄花刺茄根、茎、叶浸提液对番茄种子发芽率、发芽指数及幼苗根长和苗高的影响。结果表明:(1)黄花刺茄不同器官的浸提液对番茄种子发芽率、发芽指数、幼苗根长和苗高的影响不同,其茎、叶浸提液的化感作用较为显著(P<0.01)。(2)黄花刺茄同部位浸提液对番茄种子发芽率、发芽指数、幼苗根长和苗高不同指标的影响也不同。根浸提液对种子发芽率、幼苗根长影响不显著(P>0.05),但对种子发芽指数的影响极显著(P<0.01)。茎和叶浸提液各浓度对种子发芽指数的影响比种子发芽率、幼苗根长和苗高的影响显著(P<0.01)。     

Pantoea agglomerans,a seed-borne plant pathogenic bacterium,decreased seed germination,seedling growth and seed quality of oat

European Journal of Plant Pathology - Germination characteristics and nutritional qualities of oat seed are the most important factors influencing plant growth, crop yield and food quality. Pantoea...     

小桐子不同产地种子性状及苗期生长差异研究

对小桐子22个产地种子性状及苗期生长差异进行研究,共测定种子千粒重、纵径、横径、侧径、纵横径比、出苗率、苗高、地径等8个指标。分析表明不同产地小桐子种子形态、出苗率及苗高存在显著差异,但地径无显著差异。种子大小具有一定的经向变异。种子大小及千粒重分别受产地的年均温及降雨量影响。种子形态及千粒重与苗高、地径等生长特征无相关性,但种子千粒重对出苗率有较大的影响。根据种子形态特征将22个产地种子性状自然分布区初步划分为三个组群。结果表明:小桐子种子及苗期生长产地间存在一定分化,具有种源选择潜力;不能仅依据种子形态对幼苗生长做预测;较大区域内种子调拨及生产潜力大。研究结果对于小桐子种源选择及种子调拨生产等具有重要参考价值。     

Seed germination, seedling establishment and growth patterns of wrinklegrass (Ischaemum rugosum Salisb.)

Several laboratory and glasshouse experiments were conducted to assess seed germination, seedling establishment and growth patterns of wrinklegrass (Ischaemum rugosum Salisb.) influenced by temperature and light regimes, and chemical media. Wrinklegrass was a positively photoblastic species, and seed germination was temperature‐dependent and light‐mediated. Seeds soaked in distilled water for 24 h, or oven‐dried at the respective temperature regimes of 15, 20, 25, 30, 35, or 40°C prior to treatment in distilled water and incubated in darkness, failed to germinate. Likewise, no germination prevailed when the seeds were exposed to similar temperature regimes and treated with 0.2 m KNO₃, 5% H₂O₂ or 0.01 m HNO₃, and incubated under continuous darkness. Seeds treated with 5% H₂O₂ at 30°C, or oven‐dried and treated with 0.01% M HNO₃ at 35°C registered 10 and 20% germination. Approximately 75 and 90% of the light‐exposed seeds for all treatments germinated in the first three and six days at 25°C. No germination occurred at 15°C in the first three days after treatment. Seeds subjected to 40°C for six days after treatment recorded 36% germination. The optimum temperatures for seed germination were 25–30°C. Seed drying and soaking treatments widened the windows of the optimal temperatures for wrinklegrass germination. The acidic media of KNO₃, H₂O₂ or HNO₃ favored seed germination. Less than 5% of seed germination occurred with burial or water inundation at depths exceeding 2 cm. Seed burial or inundation at ≥2 cm depths inhibited seed germination. Seeds sown onto moist paddy soils registered ca. 50% germination. Free‐floating seeds on the water surface registered ca. 98% germination within the first six days after seeding. The mean number of seedlings that survived was inversely proportional to water depths, with close to 100% mortality at the 14 cm depths of inundation. Both plant height and seedling survival were linearly proportional to the amount of root mass of seedlings which penetrated the soil. The weed was a prolific seed producer (ca. 6000 seeds/genet or 18 000 seeds/genet per year). The vegetative and reproductive efforts of each wrinklegrass plant registered values of 0.68 and 0.32, respectively.