节节麦小穗上不同粒位种子萌发对环境因子的响应

为明确节节麦小穗上不同粒位种子萌发对环境因素的响应差异,采用培养皿法测定了小穗基部小花形成的第1粒种子(S1)和相邻上部位置小花形成的第2粒种子(S2)萌发对酸碱胁迫、盐胁迫和水分胁迫的响应.结果显示:S1和S2萌发均对pH要求不高,但在供试pH为3～10时,S2的萌发速率大于S1.与S1相比,S2萌发具有较强的耐盐性...     

播种时间和播种深度对节节麦繁殖指标和种子性状的影响

为明确播种时间和播种深度对节节麦繁殖指标和种子性状的影响,对不同播种时间和播种深度下节节麦的分蘖数、穗数、每穗小穗数、每小穗籽粒数以及小穗和籽粒性状(长、宽、宽长比、周长和千粒重)进行测定。结果表明,播期对节节麦单株分蘖数、穗数以及每穗小穗数有显著影响,而对每小穗籽粒数无明显影响;随播期的延迟单株分蘖数和穗数呈下降的趋势,而每穗小穗数呈相反趋势。当播种时间为9月30日时,节节麦产种量最大,单株约产生1 173粒种子。此外,播期显著影响了小穗性状,而对籽粒性状的影响相对较小,仅对籽粒宽和千粒重有明显影响。与其他播期相比,节节麦于10月15日播种时,其产生的小穗和籽粒体积较大,重量较高。播种深度对节节麦单株分蘖数和有效穗数有显著影响,而对每穗小穗数和每小穗籽粒数无显著影响。当播种深度大于3 cm时,单株分蘖数和有效穗数随播种深度的增大而减少。当节节麦播种深度为3 cm时,其单株产种量最大。播种深度对小穗性状(除小穗宽长比外)有显著影响,而对籽粒性状无明显影响;当播种深度为5、7 cm时,其产生的小穗体积较大,重量较高。研究结果表明,节节麦播种较早,当播种深度为3 cm左右时,其单株繁殖系数...     

不同途径对节节麦的远距离传播能力研究初报

研究了4种途径远距离传播节节麦的能力。结果表明,商品麦种是节节麦最重要的远距离传播途径,携带率为20%,平均携带量0.51个小穗/kg;联合收割机携带量随疫区节节麦发生密度的增大而增加,且不同部位携带量不同。割台、粮仓(含卸粮筒)2个部位携带量最大;小麦秸秆和收获的籽粒可以大量携带节节麦种子,但其一般不直接进入农田,危险性略低。     

小麦田节节麦的识别及防除

20世纪90年代中期，由于农户自行串换麦种，节节麦(Aegilops tauschii Coss.)先后传入丰县赵庄、师寨、欢口、凤城等乡镇。该草小穗头极易逐节自然脱落掉人土壤，成为田间主要感染源。节节麦分蘖力强，繁殖率高，人工防除难，加之其遗传基因亲缘关系与小麦较近，多年来未找到防除它的特效药剂，     

老芒麦不同品系种子萌发期耐盐性

为了解不同老芒麦(Elymus sibiricus L.)品系的耐盐性差异及培育耐盐老芒麦新品种,以老芒麦14个品系和1个审定品种的种子为试验材料,采用0.2%、0.4%、0.6%、0.8%、1.2%和1.5%共6个浓度的NaCl溶液浸种,进行了发芽率、发芽指数、活力指数、苗长、根长等指标测定。结果表明：1)随NaCl浓度增加,供试老芒麦材料的相对发芽率、发芽指数、活力指数、根长和苗长整体表现为下降趋势,但0.2%～0.4%浓度NaCl处理对部分品系相对发芽率和发芽指数有一定的激发效应。2)与一元直线模型、二次多项式模型相比,三次多项式模型能更好地反映老芒麦相对发芽率随NaCl浓度而变化的趋势。3)综合相对发芽率、发芽指数、活力指数、根长和苗长指标来看,14个品系中21号和9号品系的耐盐性优于当家品种农牧老芒麦,可在盐渍化程度偏高的地区推广种植。     

节节麦等三种禾本科杂草对不同性状土壤的适应性

为明确不同性状土壤对小麦田重要的禾本科杂草节节麦Aegilops tauschi、多花黑麦草Alopecurus myosuroides和大穗看麦娘Lolium multiflorum出苗及生长的影响,在盆栽条件下研究了3种禾本科杂草对采自山东省不同区域的24份不同性状土壤的适应性。结果表明,节节麦适应性最强,在所有供试土样中均能正常出苗和生长,出苗率在64.2%～80.8%之间;多花黑麦草也有很强的适应性,在供试24份土样中出苗基本正常,出苗率均在90.1%以上,但有2份土样影响其后期生长的株高、鲜重等生长指标;大穗看麦娘的适应性略差,有4份土样明显影响其出苗,出苗率在32.5%～50.8%之间,在其它20份土样中出苗率均为70.0%左右,有11份土壤影响其生长期株高、鲜重、穗数或结实量。土壤性状中pH是影响杂草出苗及生长的最主要因素,pH小于6.0的强酸土壤和pH大于8.0的强碱土壤均对杂草生长会产生一定影响,另外,黏性土壤质地和高盐分土壤也对杂草生长有影响,其它土壤性状如氮含量、磷含量、钾含量、有机质含量和土壤类型对这3种禾本科杂草出苗及生长无影响。     

警惕麦田恶性杂草节节麦蔓延危害

节节麦是一种进境危险性植物杂草,近年来在河北等省区麦田发生危害,面积迅速扩大,以目前节节麦传播蔓延的速度,节节麦将在各适生区域泛滥成灾,严重威胁我国小麦安全生产和粮食安全。在调查研究的基础上,全面分析了节节麦的来源和成灾原因,提出了应急措施和控制节节麦危害蔓延的建议。     

节节麦防除药剂及其增效助剂筛选

为筛选能有效防除节节麦Aegilops tauschii的除草剂及助剂,通过室内盆栽法评价11种除草剂对节节麦的防除效果,分析比较15种不同助剂对其中2种除草剂甲基二磺隆和异丙隆的增效作用,并明确其最适配比。结果显示,在供试11种除草剂中,甲基二磺隆和异丙隆对节节麦具有较的好防除效果,当其施药量分别为13、1 000 g（a.i.）/hm²时,对节节麦的鲜重抑制率分别达68.40%和76.46%,其余9种除草剂的防除效果较差,鲜重抑制率在4.62%~35.95%之间;筛选到对甲基二磺隆有显著增效作用的2种助剂——乙基和甲基酯植物油、有机硅408,其最适用量分别为甲基二磺隆喷液量的0.5%和0.2%（体积比）,增效分别为15.21%和26.52%;筛选到对异丙隆有显著增效作用的3种助剂——异十三醇聚氧乙烯醚、聚醚改性七甲基三硅氧烷、乙基和甲基酯植物油,其最适用量分别为异丙隆喷液量的0.1%、0.05%、0.25%（体积比）,增效分别为26.24%、21.80%和25.99%。表明甲基二磺隆、异丙隆可用于防除节节麦,添加助剂可进一步提高其对节节麦的防除效果。     

不同环境因素对猪殃殃种子萌发及出苗的影响

为探讨猪殃殃种子萌发的适宜环境条件,通过室内萌发试验研究了温度、光照、pH、水势、盐分对猪殃殃种子萌发以及埋土深度对其出苗的影响。结果表明,猪殃殃种子萌发的适宜环境条件为温度10~20℃、光暗12h交替培养以及pH 4~10,萌发率可达到50%以上。猪殃殃种子对水势比较敏感,萌发率随着水势的降低而降低,当水势为0时,萌发率为50.50%,水势降低至-0.6 MPa时,仅有个别种子萌发,萌发率为3.50%,当水势为-0.7 MPa时,种子萌发完全受到抑制;猪殃殃种子对盐分胁迫有一定忍耐力,当NaCl浓度为0.16mol/L时,仍有少数种子萌发,萌发率为16.50%;适于猪殃殃种子出苗的埋土深度是1~2cm,出苗率达到49.50%。研究结果为猪殃殃的出苗调控和综合治理提供了依据。     

不同环境因素对苘麻种子萌发及出苗的影响

苘麻Abutilon theophrasti Medikus具有生长旺盛、结籽量大和适应性强等特点,已成为多种农田中的恶性杂草,研究环境条件对苘麻萌发的影响对进一步探究其生物学特性与综合防治技术具有重要意义。通过室内试验研究温度、光照、酸碱度、水分胁迫、盐胁迫与苘麻种子萌发及埋土深度与其出苗的关系。结果表明,在10～35℃下苘麻种子均可萌发,20～30℃为其最适萌发温度范围;种子萌发对光照不敏感;适应pH范围广,在pH 4～9条件下种子发芽率均在70%以上;水势在-0.2～0 MPa范围内种子发芽率最高,当水势小于-0.7 MPa时,种子萌发受到完全抑制;有较强的耐盐性,NaCl浓度为160 mmol/L时发芽率超过40%;种子对播种深度适应性较强,覆盖不超过8 cm的土层均可出苗。     

Factors affecting seed germination and emergence of Aegilops tauschii

Information on seed germination and emergence ecology of Aegilops tauschii is scant, despite it being a widespread invasive weed in China. We conducted this study to determine the effects of various factors on seed germination and seedling emergence in three A. tauschii populations. Seeds germinated across a wide range of temperatures (5–35°C), with germination of over 90% at 15–20°C. Germination was completely inhibited when dry seeds were exposed to a temperature of 160°C for 5 min; a similar response was observed for pre-soaked seeds at 100°C. Light was neither required for nor inhibited germination. Germination was not significantly affected by pH. Aegilops tauschii was relatively tolerant to low osmotic potential and high salt stress: over 80% of seeds germinated at −0.3 MPa, and all three populations germinated in the presence of 400 mM salt (NaCl) although salt tolerance varied among the populations. Seeds buried at depths of 1–3 cm emerged well, but emergence was completely inhibited at depths greater than 8 cm. The addition of maize straw caused a linear reduction in seedling emergence, although the rate of reduction varied among the populations. The results of this study have contributed to understanding the requirements of A. tauschii germination and emergence and optimising an integrated management system for this weed in Huang–Huai–Hai Plain of China. In addition, our study provides data for development of models to predict the geographical distribution of this weed.     

苦豆子种子发芽特性研究

对苦豆子破除种子硬实、提高活力指数的方法及最适发芽的土壤含水量和播深进行了测定与研究,结果表明:苦豆子种子发芽困难的原因是种皮致密,吸胀困难;提高发芽率的措施是砂纸摩擦或65%H2SO4处理20 min;提高种子活力的措施是65% H2SO4处理20 min后,再用0.02%GA3处理;苦豆子种子萌发的适宜土壤含水量为8%～12%,播种的最适深度是0～3 cm.     

马唐种子萌发及幼苗建成对不同环境因子的响应

马唐是我国常见的旱田杂草之一,然而近年来在部分地区直播稻田危害十分严重.本研究测定了马唐种子萌发和幼苗建成过程中对不同环境因子的响应特征,以期为直播稻田马唐综合防控提供科学依据.结果表明:马唐在 L//D=12 h//12 h,光照/黑暗阶段温度分别为40℃/30℃、35℃/25℃、30℃/20℃、25℃/15℃、20...     

Factors affecting seed germination and emergence of button grass (Dactyloctenium radulans) (R.Br.) P.Beauv.

Button grass (Dactyloctenium radulans) is a native, widely spread summer grass weed species in Australia. However, limited information is available on the seed germination biology of this species. Experiments were conducted to evaluate the effect of environmental factors on the germination and emergence of two populations of D. radulans. The seeds of these populations were collected separately from Dalby, Queensland and Coleambally, NSW. Seeds were germinated at a range of constant and alternating temperatures (25/15, 30/20, 35/25 and 40/30°C day/night). The greatest seed germination was at a constant temperature of 30°C. Seed germination was reduced at the lowest alternating temperature (25/15°C). Germination of both populations was strongly stimulated by light, suggesting a great amount of emergence of D. radulans on bare ground, such as crop seedbeds. Germination of the D. radulans population collected from a northern cotton farming system (Dalby) was more tolerant to a greater range of salt stress than the population sourced from the south (Coleambally). Seeds of both populations germinated over a wide range of pH, between 4 and 10. However, germination was the greatest in a high pH buffer solution, indicating that the species prefers to germinate in alkaline soil. These results showed that D. radulans seeds possess a wide range of tolerance mechanisms to different environmental stresses. Information obtained in this study will help in developing more sustainable and effective integrated weed management strategies for the control of this weed and weeds with similar responses in summer cropping systems, such as cotton.     

34份粗山羊草抗白粉病性鉴定及遗传分析

粗山羊草为小麦D基因组的供体,通过对来自不同产地的粗山羊草抗病性进行鉴定,用离体叶段接种方法接种12个小麦白粉病菌株(E02、E03、E05、E06、E07、E09、E11、E15、E18、E21、E23、E25),鉴定了34份不同产地的粗山羊草抗病性。结果表明:9份粗山羊草(Y170、Y186、Y189、Y192、Y201、Y206、Y212、Y214、Y215)对12个小麦白粉病菌株完全免疫,有3份山羊草(Y126、Y208、Y185)对12个菌株全部感病,其余的材料抗白粉病的部分菌株。田间全生育期用混合菌种鉴定粗山羊草抗性,其结果与离体叶鉴定的结论相一致。粗山羊草Y219与Y122杂交的后代的遗传分析发现抗病基因是1对显性基因控制;Y215与Ae43杂交后代的遗传分析表明抗病基因是1对隐性基因控制。     

盐分和水分胁迫对补血草种子萌发的影响

在不同昼夜温度条件下用不同浓度NaCl(mmol/L)溶液及等渗聚乙二醇溶液处理大叶补血草(Limo-nium gmelinii(Willd.)Kuntze)和耳叶补血草(Limonium otolepis(Schrenk)Kuntze)种子,分别测定其萌发率、发芽势和发芽指数,测定处理9 d未萌发的种子移入蒸馏水后的萌发恢复率,以研究温度、盐胁迫和模拟干旱胁迫对种子萌发的影响。结果表明:两种补血草种子萌发的最适温度为25~15℃,在蒸馏水中的萌发率最高,随着盐浓度和PEG6000溶液浓度的增加,种子的萌发率、发芽势和发芽指数递减,对萌发产生抑制作用;PEG6000溶液对种子的萌发抑制程度与等渗NaCl溶液相当。较高盐浓度和PEG6000溶液处理下的种子复水后萌发可以恢复。     

Effects of environmental factors and burial depth on seed germination and emergence of two populations of Caucalis platycarpos

Caucalis platycarpos is a weed species in irrigated and dry land farming systems in East Azerbaijan and Kermanshah provinces of Iran. Experiments were undertaken to compare C. platycarpos seed germination and emergence of a population from each province over a range of environmental factors, burial depth and crop residue treatments. The Azerbaijan population required lower temperatures (20/10°C day/night temperature) for its highest (90%) germination, compared with the Kermanshah population (88% germination at 25/15°C day/night temperature). In both populations, germination was 84–90% over a wide range of light/dark periods (10–24 h light), but considerable reduction (up to 42%) occurred under continuous darkness. The osmotic potential required for 50% inhibition of germination was ?0.54 and ?0.40 MPa for Azerbaijan and Kermanshah populations respectively. The NaCl concentration of 8.83 and 5.71 dS m^?1 caused 50% inhibition of germination in Azerbaijan and Kermanshah populations respectively. The X₅₀ parameter (the burial depth at which emergence is reduced by 50%) for Azerbaijan and Kermanshah population was 2.18 and 2.86 cm respectively. Crop residues had more inhibitory effects on the Azerbaijan than Kermanshah population. Adaptive differentiation of C. platycarpos populations has also resulted in smaller seeds of the Azerbaijan compared with the Kermanshah population and resulted in higher emergence for Kermanshah population seedlings from greater soil depths. These results suggest that differences in germination requirements, drought and salinity tolerance of C. platycarpos populations are correlated with environmental conditions of the habitats of the studied populations.