Seed Composition, Seedling Emergence and Early Seedling Vigour of Red Kidney Bean Seed Produced at Elevated Temperature and Carbon Dioxide

Understanding the influence of growth temperature and carbon dioxide (CO₂) on seed quality in terms of seed composition, subsequent seedling emergence and early seedling vigour is important under present and future climates. The objective of this study was to determine the combined effects of elevated temperature and CO₂ during seed-filling of parent plants on seed composition, subsequent seedling emergence and seedling vigour of red kidney bean ( Phaseolus vulgaris ). Plants of cultivar 'Montcalm', were grown at daytime maximum/nighttime minimum sinusoidal temperature regimes of 28/18 and 34/24 °C at ambient CO₂ (350 μmol mol⁻¹) and at elevated CO₂ (700 μmol mol⁻¹) from emergence to maturity. Seed size and seed composition at maturity and subsequent per cent emergence, early seedling vigour (rate of development) and seedling dry matter production were measured. Elevated CO₂ did not influence seed composition, emergence, or seedling vigour of seeds produced either at 28/18 or 34/24 °C. Seed produced at 34/24 °C had smaller seed size, decreased glucose concentration, but significantly increased concentrations of sucrose and raffinose compared to 28/18 °C. Elevated growth temperatures during seed production decreased the subsequent per cent emergence and seedling vigour of the seeds and seedling dry matter production of seed produced either at ambient or elevated CO₂.     

Investigations on Seedling Vigour in Cashew (Anacardium occidentale L.)

Seedlings from 27 open pollinated cas-hew genotypes in two environments with five replications in each location were used to investigate the genetic, the environmental, and the nut size effects on cashew seedling vigour during the 12-week pretransplantation period. Enviromental variances, genotype × environment interactions, and broadsense heritability values for the eight studied traits indicated that emergence percentage (L %) and seedling height (SH) were more reliable indices for seedling vigour, since they were more heritable and less influenced by the environment. Seedlings from large cashew nuts were consistently more vigorous than those from small nuts, probably because of the larger food reserve in the two cotyledons.     

直播早稻适宜播种温度分析

为满足近年来直播稻种植的气象服务需求,开展直播早稻适宜播种温度研究。以南昌地区的常规种植早稻‘湘早籼45’为研究对象,设置3月26日、3月29日、4月2日、4月5日以及4月10日共5个播期,研究分析不同播期下直播早稻的出苗率、农艺性状以及产量的特征。结果表明,成苗率与出苗期间平均气温和平均最低气温呈显著正相关关系;适时早播有利于提高直播早稻有效穗数、每穗粒数和结实率;气温对苗高和叶龄变化有明显影响。连续3~5日平均温度达18℃,日最低气温在15℃以上时,有利早稻直播。     

The Effect of Artificial Infestation of Ears by Macrosiphum avenae (F.) on Germination and Seedling Emergence of Two Winter Wheat Cultivars

10 day infestation of two winter wheat cultivars, Regina and Zdar , by grain aphid Macrosiphum avenae (F.) (3 virgines per ear at the anthesis), caused up to 30 per cent loss of seed weight, and accelerated significantly seed germination. The percentage of seed germination was not influenced. First four days after emergence, the sprouts of the seed influenced by aphids were longer than the control, then shorter.
After 8 days, the seedlings from aphid affected seeds had significantly lower dry matter than controls. Cv. Zdar was more sensitive than cv. Regina .     

苗期地温对棉花前期生育进程的影响研究

为研究苗期地温变化对棉花出苗和生长状况的影响,采用田间试验,设置3个不同播期,调查地温与棉花生长变化的关系。结果表明,苗期5 cm地温受气温影响波动要比10 cm和15 cm土层大,且地温相对较高,随播期推后,不同土层温差变化减小;不同播期约4~5天可见苗,受积温影响不大,但随播期推后,进入苗期时间增长;从第一真叶到见蕾一、二播期仅差1天,出叶时间间隔变短,而二、三播期的间隔则变长;不同播期中第三播期棉花株高最高,高出其他播期达20 cm,差异显著,株宽和始节高度差值也达5.5 cm和5.3 cm,且随播期推迟这种差异增大。本试验认为,不论播期怎样变化,只有地温变化趋缓,才利于棉花出苗和稳健生长,构建理想群体结构。     

赤峰文冠果引种种源苗期初步选择研究

为筛选出吉林省西部适宜的文冠果优良速生种源,在继续文冠果不同群体资源果实和种子性状评价基础上,以赤峰8个引种种源的文冠果种子出苗率及其1~3年生苗的连年高生长和地径生长进行调查和对比分析。结果表明,不同种源的出苗率存在显著差异,其中4#、7#、8#种源的出苗率较高,而且7#种源的出苗率要好于其他种源,其出苗率为95.33%;不同种源第1年高生长和地径生长范围为23.9~44.4 cm和0.398~0.610 cm,第2年分别为42.6~69.5 cm、0.556~0.774 cm,第3年分别为51.2~63.1 cm、0.676~0.836 cm,其连年生长增加趋势明显。同时,不同种源间的高生长和径生长存在明显差异,其中4#、6#、7#、8#种源的高生长和地径生长要优于其他种源;不同种源的出苗率、苗高年生长、地径年生长、3年生苗高和3年生地径等数据的聚类分析表明,8个种源可分为4类,其中第1类的7#种源的综合表现最优,其3年生苗高和地径分别为177.1、2.224 cm。研究结果为后续吉林省文冠果的遗传改良和优质苗木的推广和利用提供了参考。     

Water Deficit during the Reproductive Period of Grass Pea (Lathyrus sativus L.) Reduced Grain Yield but Maintained Seed Size

The grain legume grass pea (Lathyrus sativus L.) is adapted to drought‐prone environments, but the extent and mechanisms of its tolerance are not well understood. In a pot experiment, water deficit was imposed on plants by withholding water from first flowering until predawn leaf water potential (LWP_pd) was ?3.12 MPa. Water deficit reduced dry matter, seed yield, harvest index and water use efficiency by 60 %, 87 %, 67 % and 75 %, respectively, when compared with the controls. Flower production stopped when LWP_pd fell to ?1.8 MPa. At LWP_pd?1.5 MPa, only 25 % of flowers resulted in filled pods (compared with 95 % filled pods in the control) with the rest aborted as flowers (48 %) or pods (27 %). Filled pods had more aborted ovules than controls, resulting in 29 % less seeds per pod. Water deficit reduced pollen viability, germination and the number of pollen tubes reaching the ovary by 13 %, 25 % and 31 %, respectively. Emergence from seeds produced from water‐deficient plants was 21 % less than controls, but seedling shoot dry mass was 18 % higher, in accordance with the 19 % higher seed mass. The sensitivity of flowering to drought limited pod numbers but enabled plants to retain existing pods and develop near‐normal seeds with low β‐N‐oxalyl‐l ‐α‐β‐diaminopropionic acid toxin concentrations. This trait is useful for farming systems reliant on harvested seed for the next crop and in cases where seed size influences the value of the product.     

成都平原水稻直播方式对出苗状况及产量形成的影响

为研究水稻不同直播方式在成都平原的适应性,确定最佳的直播方式,以杂交稻‘川优6203’和常规稻‘金农丝苗’为材料开展了田间试验,研究了成都平原生态条件下翻耕旱直播、免耕旱直播及翻耕水直播3种直播方式对直播稻出苗状况、生长发育、水分利用及产量形成的影响。结果表明：不同类型品种直播方式间产量的差异主要取决于有效穗数的多寡。翻耕旱直播处理前期出苗状况好、有效穗多,产量潜力最高;翻耕水直播处理前期出苗状况和产量虽不及翻耕旱直播处理,但有利于减少杂草和落田谷发生,播种后所需灌水量也最少;免耕旱直播处理存在着杂草和落田谷滋生严重、出苗差及播种后田间耗水量大等问题,产量最低。这表明翻耕条件下旱直播和水直播在成都平原各有优点,但从生产实用的角度考虑水直播更为适合。     

基于壤土含水量的南疆“干播湿出”棉田出苗水调控研究

通过分析新疆南疆壤土条件下不同土壤含水量的棉田“干播湿出”滴施不同频率出苗水;对棉田出苗率、农艺性状和根系分布的影响;探索壤土条件下“干播湿出”适宜出苗水频率;为新疆南疆棉花“一播全苗”提供理论支撑。以陆地棉‘J8031’为供试材料;在土壤含水量10%~15%、15%~20%、20%~25%条件下;分别设置滴1、2、3次出苗水。结果显示;随着滴出苗水频率的增加;土壤紧实度下降;土壤EC值逐渐降低;同一土壤深度下种穴的土壤EC值小于膜边位置;同一种穴或膜边位置下土壤深度5 cm土壤EC值小于10 cm处;出苗率表现为滴2次出苗水时最大;滴1次出苗水时最小;且有“断头苗”和“卡脖子苗”现象出现;株高、茎粗、地上干物质积累量均表现为随着出苗水频率的增加呈逐渐增加趋势;高频率出苗水与根系生长发育有密切关系;出苗水滴水频率的增加和侧根系的向水特性;使根重密度、根长密度、根表面积、根体积逐渐增加;但根直径在滴3次出苗水时最小。分析结果表明;壤土条件下;在土壤含水量10%~15%、15%~20%、20%~25%时;棉花“干播湿出”滴2次出苗水可以满足棉种萌发、出苗;且在苗期农艺性状和根部形态表现较好。     

从不同营养生长积温分蘖间的差异探讨小麦分蘖成穗的生理原因

运用营养生长积温对冬小麦分蘖的生长发育特点及其Ｃ、Ｎ、Ｐ代谢状况进行分组研究表明：①京郊小麦生产中分蘖的有效营养生长积温临界值约为２５０℃，营养生长积温不足１７５℃的冬前、春生蘖群很难成穗。②分蘖发育成穗及其穗部性状的改良与起身拔节阶段分蘖体内的Ｃ、Ｎ代谢水平密切相关。在良好Ｎ素代谢基础上增加拔节期间分蘖体内的糖分积累既有利于分蘖成穗率的提高，也有利于分蘖穗部性状的改善。③不同蘖群间，Ｃ素代谢优势始终表现为大蘖群＞中蘖群＞小蘖群；Ｐ素营养返青初为小蘖群＞中蘖群＞大蘖群，拔节后呈大蘖群＞中蘖群＞小蘖群，返青—拔节为优势转化阶段；Ｎ素营养的优势转化期同Ｐ素相比明显滞后     

基于种子萌发出苗过程中弯钩建成和下胚轴生长的棉花出苗壮苗机制与技术

苗全苗壮是实现棉花丰产丰收的基础, 但棉花属于子叶全出土的双子叶植物, 播种出苗易受环境条件和播种技术的影响, 一播全苗、壮苗的难度很大。棉苗顶端弯钩及时建成和下胚轴稳健生长是棉花出苗壮苗的关键, 本文首次以单粒精播调控种子萌发出苗过程中的顶端弯钩建成和下胚轴生长的生理与分子机制为核心, 系统评述了棉花成苗壮苗的调控机制。棉花种子单粒精播、适当浅播, 促进下胚轴伸长、弯钩建成和展开的关键基因HLS1和COP1适时、适量表达, 棉苗下胚轴伸长、弯钩及时建成, 保证出土并适时展开弯钩和脱掉种壳, 正常出苗。单粒精播种子出苗后通过调控下胚轴生长关键基因HY5和ARF2表达, 下胚轴稳健生长, 形成壮苗。在此基础上, 总结提出了以单粒精播、适当浅播为核心, 配合精细整地、提高种子质量、地膜覆盖、膜下滴灌等措施的棉花成苗壮苗关键栽培技术, 为实现一播全苗、壮苗早发提供了重要参考和指导。     

不同地膜覆盖对玉米生长和产量的影响

为进一步研究验证不同类型环保地膜的田间应用效果,在大田条件下以露地栽培为对照,进行了普通地膜、可降解地膜和液态地膜覆盖玉米栽培试验,对不同地膜覆盖下玉米的生长发育状况、产量及构成因子进行了测定分析。结果表明,可降解地膜覆盖能够明显提高玉米出苗率,比露地对照高5.0%,差异显著;增加地上部干物质积累,使株高、茎粗、叶面积增加,促进穗的生长发育,使秃尖缩短,增加穗粒数和千粒重,产量比露地对照提高40%,差异显著;可降解地膜覆盖效果与普通地膜相似。而液态地膜覆盖对玉米出苗、干物质积累及株高、茎粗、叶面积变化的影响作用较小,虽然在一定程度上提高了玉米产量,但仅比露地对照高0.5%,差异不显著。     

不同播种情况下谷子出苗率差异性分析

为了给谷子简化栽培提供一些理论依据,探明谷子出苗是否需要“群体顶土”协助,特做了本项研究。连续2 年在条播、穴播、不同播深、不同播量等情况下,对谷子出苗率进行调查,并统计分析其差异性。试验结果表明：只要在相同的种植条件下,谷子的出苗率与播量没有关系。通常在整地质量较好、土壤墒情较好的情况下,每公顷播量4 kg 左右就能达到生产用苗数,基本可以做到少间苗或不间苗。谷子出苗不需要“群体顶土”协助。     

Chilling Tolerance in Hybrid Maize Induced by Seed Priming with Salicylic Acid

The optimum temperature for maize germination is between 25 and 28 °C. Poor and erratic germination at suboptimal temperature is the most important hindrance in its early sowing. This study was conducted to induce chilling tolerance in hybrid maize (Zea mays L.) by seed priming with salicylic acid (SA) and to unravel the background biochemical basis. For seed priming, maize hybrid (Hycorn 8288) seeds were soaked in 50, 100 and 150 ppm (mg l^?1) aerated solutions of SA for 24 h and were dried back. Treated and untreated seeds were sown at 27 °C (optimal temperature) and at 15 °C (chilling stress) under controlled conditions. Performance of maize seedlings was hampered under chilling stress. But seed priming with SA improved the seedling emergence, root and shoot length, seedling fresh and dry weights, and leaf and root score considerably compared with control both at optimal and chilling temperatures. However, priming in 50 mg l^?1 SA solution was more effective, followed by priming in 100 mg l^?1 SA solution. Seed priming with SA improved the chilling tolerance in hybrid maize mainly by the activation of antioxidants (including catalase, superoxide dismutase and ascorbate peroxidase). Moreover, maintenance of high tissue water contents and reduced membrane permeability also contributed towards chilling tolerance.     

Corn Genotypic Variation Effects on Seedling Emergence and Leaf Appearance for Short-Season Areas

Identifying corn ( Zea mays L.) genotypes with faster rates of seedling emergence and leaf appearance is important in developing a corn crop with earlier canopy closure and better seasonal light interception. A greenhouse experiment was conducted twice to investigate whether corn genotypes known to vary in canopy architecture and yield potential differed in rates of seedling emergence and leaf appearance. The experiment was arranged in a randomized complete block design utilizing seven genotypes: five of the newly developed Leafy reduced-stature (LRS) types (LRS1, LRS2, LRS3, LRS4 and LRS5), one conventional type [Pioneer 3979 (P3979)], and one late-maturing big-leaf (LMBL) type. Five seeds were planted in each pot and seedling emergence was recorded every day until all seeds emerged. Leaf appearance was recorded from seedling emergence until the plants reached anthesis. There was variability among the genotypes for both seedling emergence and leaf appearance rate. Mean seedling emergence values of greater than 90 % were achieved by four of the five LRS genotypes, and the LRS types generally emerged more rapidly than the others. Leaf appearance rate showed linear increases over time; however, LRS genotypes (in particular LRS3, LRS4 and LRS5) had more rapid leaf appearance rates than the others. The LMBL hybrid ranked last for both seedling emergence (<80 %) and leaf appearance rate. Rapid seedling emergence and leaf appearance by early-maturing genotypes (LRS and P3979, especially LRS) may help these types of genotypes achieve earlier canopy closure and better use of the light available during the growing season, which is critical in a short growing season environment.     

盐碱土上3种植物出苗研究

通过在育苗盘上进行种子出苗试验,研究了不同草种（披碱草、草木樨和紫花苜蓿）、不同土壤（pH 10.03、9.36、8.68、8.12,电导率(EC)为2.02、1.237、0.962、0.454 mS/cm）、不同播深(1、3 cm)和不同种子播种前处理（晒种浸泡处理和未处理）对出苗时间和出苗率的影响。结果表明：披碱草耐盐碱性最好,草木樨最差;超过一定限度(pH＞8.68,EC＞0.962 mS/cm),pH或电导率增加,均会造成出苗时间增长,出苗率下降;播深1 cm比3 cm出苗时间显著缩短,出苗率显著提高;种子晒种浸泡处理可以显著缩短出苗时间,提高出苗率,对种子出苗有一定帮助。试验同时表明,在盐碱土上缩短出苗时间,对提高出苗率有利。     

不同生育期温度逆境处理对早稻产量的影响

为研究温度逆境对水稻的响应,采用盆栽种植的方法,在早稻分蘖期、孕穗期、灌浆期,利用人工智能气候室,通过不同时期的温度逆境处理,分析其对早稻产量及构成。结果表明:生物量表现为低温中温高温,灌浆期孕穗期分蘖期处理;分蘖期和孕穗期的温度变化对有效穗影响较大,灌浆期的温度变化对有效穗基本无影响;孕穗期进行温度处理对结实的影响最明显,且高温会显著降低结实率;孕穗期高温处理显著降低千粒重,其余各时期温度处理的千粒重差异不显著;单株产量表现为低温中温高温,灌浆期处理分蘖期处理孕穗期处理,孕穗期高温处理的产量最低,较同时期低温处理减少26.80%~42.46%,较同时期中温处理减少21.16%~36.22%。试验表明,高温对早稻产量及产量构成影响最大,3个时期中,孕穗期是早稻产量及产量构成的最敏感时期。     

冬小麦冬前旺长类型及形成相应类型的积温条件

利用济宁市1987~2007年连续20年气象资料及小麦冬前生长发育资料,对济宁市20年来小麦不同年份发生的冬前旺长表现进行了连续观察和系统分析。结果表明:济宁市冬小麦冬前旺长分营养型旺长、生殖型旺长和重叠型旺长3种类型。形成营养型旺长的积温条件是冬前大于12℃的营养生长积温偏高所致;形成生殖型旺长的积温条件是冬前0~12℃穗分化积温偏高所致;形成重叠型旺长的积温条件是冬前营养生长积温和穗分化积温共同偏高所致。     

大蒜素对3种蔬菜种子发芽和幼苗生长的影响

采用浸种法和叶面喷雾法,研究不同浓度大蒜素对白菜、萝卜和莴笋种子发芽和幼苗生长的影响。结果表明,大蒜素浸种对白菜、萝卜和莴笋种子发芽有一定的影响,不同作物和品种间存在差异。大蒜素200 mg/L浸种12 h对萝卜和莴笋种子发芽无不良影响,但可延缓白菜种子发芽,降低种子发芽势和发芽指数,对最终发芽率无影响。400和800 mg/L浸种12 h可延缓白菜、萝卜种子发芽和降低种子发芽率、发芽势及发芽指数,其活力随处理浓度的提高而下降,白菜和萝卜的最终发芽率显著降低,而对莴笋最终发芽率无影响。200 mg/L浸种对白菜苗鲜重、根鲜重、下胚轴宽有显著的促进作用,400和800 mg/L处理的促进作用不显著,品种间存在较大差异,幼苗主根和下胚轴长度均随处理浓度的提高而缩短。200和400 mg/L处理能促进萝卜种子出苗,对幼苗鲜重、根鲜重和下胚轴宽有显著的促进作用,而对幼苗主根和下胚轴生长均有抑制作用,800 mg/L处理对萝卜种子出苗有明显的抑制作用。大蒜素200~800 mg/L浸种能促进莴笋种子出苗,对幼苗鲜重、根鲜重及下胚轴粗均有显著促进作用,而对幼苗主根长、下胚轴长有明显的抑制作用。大蒜素200~800 mg/L叶面喷施对3种蔬菜幼苗生长均有明显的促进作用,主要表现在幼苗鲜重和根鲜重提高、株高和下胚轴宽增加,而对主根长有明显的抑制作用,不同浓度处理间差异不显著。