播期播量及施氮量对冬小麦生长及光谱指标的影响

为阐明播期、播量及施氮量对冬小麦生长与光谱指标的影响规律,本研究通过开展连续两年不同播期、播量及施氮量的冬小麦田间试验,系统地研究了三因素及其互作对冬小麦产量、关键生育时期叶面积指数(leafarea index,LAI)和归一化红边指数(normalized difference red edge,NDRE)的影响,并进一步分析了三因素对冬小麦冠层NDRE时序曲线的影响。另一方面建立了不同产量水平下冬小麦冠层NDRE适宜时序曲线,以便于实时监测不同产量水平下冬小麦长势动态。结果表明,冬小麦冠层NDRE与LAI随关键生育期的变化相似,且三因素对关键生育时期2个指标的影响规律基本一致。2018—2019年冬小麦产量、不同生育时期LAI和冠层NDRE均随播期推迟而下降;2019—2020年除灌浆期外,晚播冬小麦产量、LAI及冠层NDRE峰值最大。2年冬小麦不同生育时期LAI、冠层NDRE随施氮量增加而增加;而不同播量间无明显差异。三因素中播期、施氮量对冬小麦冠层NDRE时序曲线有显著影响。冬小麦冠层NDRE时序曲线随施氮量增加被纵向拉长;曲线下降部分随播期推迟向左平移,同时2018—201...     

多功能高分子植物生长调节剂在干旱区玉米生产上的试验效果初报

报道了以观测记录和拍照方式研究多功能高分子植物生长调节剂对玉米生长和繁殖的影响结果，分别用玉米生长、结实和产量指标、玉米品质指标以及经济效益指标与对照比较以评定试验效果。结果显示，施用试剂有利于玉米的营养和结实生长，使玉米产量增加11.06%、品质有所改善（试验组玉米粗蛋白和粗脂肪含量有所提升），经济效益有所提高，仅仅考虑增产就净增产值607.95元/hm2。     

粘帚霉菌株对大豆促生及菌核病防效的研究

采用种子处理的方法，测定了5个粘帚霉菌株无菌发酵液对大豆发芽、出苗以及幼苗生长的影响。结果表明：处理后大豆种子的发芽势、发芽率明显高于对照．其中菌株SH-1—1、SS-1-1对种子发芽的促进作用最强；供试菌株能提高大豆种子的出苗率，促进大豆地上部和地下部的生长。所有供试菌株的发酵液处理大豆种子后．大豆菌核病的发病率明显低于对照．防治效果均达到了80％以上。     

Selection for grain yield of oats via vegetative growth rates measured at anthesis and maturity

Summary Grain yield of oats can be improved by increasing either vegetative growth rate or harvest index, but these two traits are negatively associated. Currently, harvest index of oats is near an optimum at 45%, so further improvement in grain yield must come from increased vegetative growth rate. In this study, vegetative growth rate was measured at anthesis and at maturity by dividing vegetative dry weight at anthesis and straw yield, respectively, by days to heading. Genotypic correlations between the two estimates of vegetative growth rate ranged from 0.53 to 0.66. When the highest 10% of the lines were selected for the two growth rate measurements, the actual genetic gain in grain yield was 3.5% when vegetative growth at anthesis was used, and a slight decrease occurred when vegetative growth rate at maturity was used. Selection for either growth rate measurement caused associated increases in biological and straw yields and dry weight at anthesis.Journal Paper No. J-12129 of the Iowa and Home Econ. Exp. Stn., Ames, Iowa 50011. Project 2447. Part of a study conducted by the senior author while a visiting scientist at Iowa State University.     

Influence of the temperature on growth and alkaloid content of first-year Atropa belladonna L.

Summary In breeding Atropa belladonna for high alkaloid content it is of importance to know whether the alkaloid content is affected by the environment. Therefore some experiments on the influence of temperature were carried out in the phytotron of our Institute. As the results were in agreement with each other only one experiment is discussed in which the influence of three constant temperatures, viz. 20°, 23° and 26°C, on growth rate, dry matter, and alkaloid content of yellow-flowered Atropa belladonna L. was studied.It was found that development was quickest at 23°C, followed by 26° and 20°C. Temperature had little or no effect on the height of the plants and weight of dry matter in the corresponding developmental stages. The highest alkaloid content was reached at 23°C; at 26° and 20°C the alkaloid content was lower. The differences were slight but mathematically reliable.     

Cu2+、Zn2+胁迫对黄瓜种子萌发及幼苗生长的影响

利用发芽和出苗试验,设置单一重金属铜锌及复合污染胁迫浓度,研究对黄瓜种子萌发及幼苗生长的影响.结果表明:一定浓度的重金属铜、锌对黄瓜种子发芽率、根的伸长、幼苗生长都有一定的抑制作用.发芽初期,低浓度Cu2 、Zn2 刺激种子萌发,当溶液中铜和锌的浓度达到20mg/L和80mg/L时,黄瓜的根芽长受到明显的抑制,与对照相比差异显著.在单一重金属胁迫条件下,当溶液中铜和锌的浓度分别达到80mg/L和20mg/L时,幼苗体内的丙二醛含量先下降后上升,同时,幼苗的过氧化物酶(POD)活性随重金属浓度的提高先增加后下降,而游离脯氨酸含量相应上升.     

"浸种灵"药剂浸种对"常优一号"杂交水稻生长的影响

为了深入了解"浸种灵"药剂浸种对"常优一号"杂交水稻种子发芽、幼苗生长以及大田性状的影响,我们采用不同浸种时间、不同药剂浓度的裂区设计,分析种子萌动速度、发芽势、发芽率、秧田成苗率、幼苗素质、大田生育期、穗粒结构和产量水平等指标.结果表明,"浸种灵"药剂处理浓度以5000倍液、24 h浸种为宜,既可以保证种子萌动较快,又可以保证较高的秧田成苗率,且能获得较高的产量.     

Regional metropolitan and nonmetropolitan trends in annual growth rates of total personal income and population: 1959-1987

"The annual growth rates of total personal income and population in regional metropolitan and nonmetropolitan areas [of the United States] are examined for the period 1959-87, partitioned into sub periods. Statistical testing for equality of rates shows no perceptible differences in growth rates between the major categories, metro and nonmetro. Further, this study uses a model similar in scope to shift-share analysis to test for convergence of the growth rates within these categories. It was found that for both regional nonmetro and metro areas, there was a general trend toward convergence with the exception of the 1970s decade. In that decade total population growth rates in the nonmetro areas and total income and total population growth rates in the metro areas showed significant divergences."     

叶幕微区光环境对果树生长发育的影响

通过对国内外有关叶幕微气候及叶幕微区光环境文献质料的研究,对果树叶幕中光能的截获与分配、光谱与光质的变化以及对果树生长发育的影响进行了分析。在文献综述的基础上,提出了改善苹果园光环境的可能途径。     

采种季节和设施对矮生菜豆种子产量和质量的影响

以SG259和Provider两个矮生菜豆品种为材料，分春秋两季在不同设施下进行了采种试验。结果表明，采种季节、采种设施以及品种对矮生菜豆的生育期、单株分技数、单株结荚数、种子产量、种子千粒重以及发芽势和发芽率均有明显的影响。在杭州的气候条件下，Provider的种子产量和质量明显优于SG259；秋季采种时的种子质量优于春季采种。春季采种时，无论是种子产量或是种子质量均以温室采种较为理想；秋季采种时温室的优势不是非常明显。根据本试验结果，从种子产量、质量以及生产成本考虑，杭州地区矮生菜豆原种的繁殖宜在秋季露地进行。     

Influence of plant growth regulators on somatic embryogenesis in Niger (Guizotia abyssinica Cass.): an edible oilseed crop

Journal of Crop Science and Biotechnology - An improved protocol of direct somatic embryogenesis (SE) and shoot regeneration was developed, for the first-time, using leaf explants from in vitro...     

不同生育期温光条件对宣城地区水稻生长和产量的影响

水稻分期播种是研究温光条件对水稻生长和产量影响,确定最佳播期的便捷途径。本试验以宣城地区水稻品种‘两优6326’、‘南粳44’为研究对象,对不同播期试验下水稻生长情况和产量及产量构成因素进行分析。结果表明：随着播期的推迟,水稻的生育进程也相应顺延,2 种水稻全生育期均缩短。‘两优6326’各阶段籽粒灌浆速率随着播期延迟而逐渐上升,‘南粳44’全生育期灌浆速率在D2 播期最高,其他阶段籽粒灌浆速率随播期延迟反应不一;‘两优6326’的产量及产量构成要素随播期延迟均呈递减趋势,‘南粳44’理论产量以D3 播期最高,D2 播期最低。此外,通过不同阶段积温、日平均气温和日照时数与各阶段灌浆速度、产量及产量构成的相关分析,得出不同温光条件下的影响结论。     

不同促芽肥施用量对再生稻生长及效益的影响

以籼稻‘两优6326’、‘岳优9113’、‘黄华占’为试验材料,在头季稻齐穗后15天进行促芽肥的不同施N量处理,探明促芽肥与再生稻的再生力、产量和综合效益的关系,为豫南稻区再生稻科学高效施肥提供依据。结果表明:不同促芽肥施N量对头季稻产量影响差异不显著,但对再生稻产量存在显著的差异,二者呈抛物线型相关,且影响再生稻产量因素以再生穗数量为主;当促芽肥施尿素量为345.00 kg/hm~2时,‘两优6326’和‘岳优9113’再生稻产量及综合效益最高,促芽肥施尿素量为390.00 kg/hm~2时,‘黄华占’的再生稻产量及综合效益最高。     

播种量和穗肥施氮量对优质食味直播水稻产量和品质的影响

播种量是影响直播水稻产量的关键因素之一,但其对优质食味水稻产量和品质的影响研究相对较少。施用穗肥是水稻高产栽培的重要措施,但穗肥施氮量对优质食味直播水稻产量和品质的调节效应尚不清楚。本研究以3个江苏省代表性优质食味水稻苏香粳3号、南粳5055和南粳9108为材料,在行距固定为25 cm条件下,分析了60、90、120、150和180 kg hm–2等5个播种量对上述品种产量和品质的影响,并观察了适宜播种量条件下穗肥施氮量对优质食味水稻产量和品质的调节效应。主要结果表明:(1)苏香粳3号、南粳5055和南粳9108的产量均随播种量增加呈先升后降的趋势。3个品种高产最适播种量分别为130.2～136.5、118.3～119.3和90.0～96.4 kg hm–2。稻米加工品质与播种量呈不同程度负相关,而垩白粒率、垩白度、蛋白质含量、米粉消解值与播种量呈显著或极显著正相关。胶稠度、直链淀粉含量、食味值和崩解值与播种量均呈显著或极显著负相关。(2)在高产适宜播种量条件下,与常规穗肥施氮量相比,穗肥施氮量减半对南粳5055和南粳9108的产量无明显影响,但可明显改善稻米的外观品质和食味值。上述结...     

Influence of delayed emergence and canopy skips on the growth and development of maize plants: a plant scale approach with CERES-Maize

Our objective was to study by observation and simulation the effects of (1) three different dates of seedling emergence and (2) presence of short sequences of missing plants in rows of maize canopies which we refer to as skips. Trials were carried out in Belgium and France during two consecutive years. We had eight trials in total (i.e. two experimental designs in two locations for 2 years). In a field mechanically sown with a precision drill to give ‘normal plants’, ‘late 1 plants’ and ‘late 2 plants’ (respectively) were sown by hand when ‘normal plants’ had germinated or emerged. The radiation available at the top of the plants was measured for each cohort which allowed the calculation of a ‘coefficient of correction for light climate’ corresponding to the ratio of incident light at the top of each cohort relative to normal. Heterogeneity (skips) was created in maize canopies by removing three adjacent plants situated in the same row at 16 different locations across the field. The part of the canopy affected by the presence of these skips was considered to consist of the 12 plants bordering each skip. Radiation was measured near soil level on both sides of these plants: plants of the part of the canopy affected by skips received on average the same amount of radiation as a uniform stand with a population density equal to three quarters of the density of the parts of the stand without skips. To test if differences in radiation reaching the level of plants in each cohort could explain the effects on the plants the behaviour of each cohort of plants in each location x year was modelled separately with CERES-Maize after introducing into the model a ‘coefficient of correction for light climate’ corresponding to each cohort×location×year combination. Simulations generally reproduced correctly decreases in LAI, total biomass, grain number and total grain yield in the late 1 and late 2 cohorts, but not decrease in individual grain weight. The observed loss of grain yield per unit surface area in the parts of the canopy disturbed by skips was between 7 and 15%, whereas corresponding simulated values were between 6 and 11%. In the absence of compensation, values in the disturbed parts would have been 20%. Thus in our conditions amount of light reaching the different cohorts explained a large part of the treatments effects.     

不同基质对大岩桐移栽成活率的影响研究

本文研究了不同基质上大岩桐组培苗的移栽成活率情况及生长健壮度。结果表明,质地疏松,保水保肥性好,且本身富含有机质的松针土是最适宜于大岩桐成活的基质,成活率可达91.7%,1：1的松针土和蛭石次之,成活率为80%,1：1的草炭和河沙最小为57%。这些结果对指导大岩桐组培快繁具有重要参考价值。     

对棉花种子解除休眠前后发芽率的分析

棉花种子收获后一般要经过一段时间的休眠,休眠是种子一种重要的生理现象.种子休眠的解除一般分为人工和自动 2种方法.前者通常采用 40℃高温来解除,后者则是种子收获后经过一段时间由其自然解除.本文通过对棉花种子用 2种方法解除休眠前后发芽率的比较和分析,试图找出种子解除休眠前后发芽率的变化规律,为种子的贮藏、加工、检验和播种提供科学依据.     

Influence of the root endophyte Piriformospora indica on the plant water relations,gas exchange and growth of Chenopodium quinoa at limited water availability

This study aimed to evaluate the ability of Piriformospora indica to colonize the root of Chenopodium quinoa and to verify whether this endosymbiont can improve the growth, performance and drought resistance of this species. The study delivered, for the first time, evidence for successful colonization of P. indica in quinoa. Hence, pot experiment was conducted in the greenhouse, where inoculated and non‐inoculated plants were subjected to ample (40%–50% WHC) and deficit (15%–20%WHC) irrigation treatments. Drought adversely influenced the plant growth, leading to decline the total plant biomass by 74%. This was linked to an impaired photosynthetic activity (caused by lower g_s and C_i/C_a ratio; stomatal limitation of photosynthesis) and a higher risk of ROS production (enhanced ETR/A_gross ratio). P. indica colonization improved quinoa plant growth, with total biomass increased by 8% (controls) and 76% (drought‐stressed plants), confirming the growth‐promoting activity of P. indica. Fungal colonization seems to diminish drought‐induced growth hindrance, likely, through an improved water balance, reflected by the higher leaf ψ_w and g_s. Additionally, stomatal limitation of photosynthesis was alleviated (indicated by enhanced C_i/C_a ratio and A_net), so that the threat of oxidative stress was minimized (decreased ETR/A_gross). These results infer that symbiosis with P. indica could negate some of the detrimental effects of drought on quinoa growth, a highly desired feature, in particular at low water availability.     

Post-emergence application of herbicides and growth regulators on soybean growth and agronomic performance

Journal of Crop Science and Biotechnology - Plant lodging is among the factors that limit the productive potential of the soybean crop. Growth regulators or even herbicides may be used in pre- and...     

Effect of hyperbaric pressure and temperature on respiration rates and quality attributes of tomato

Previous work with hyperbaric treatment of tomato focused on application at lower temperature (13 °C). In this work, hyperbaric treatment at varying pressure levels (i.e., 0.1, 0.3, 0.5, 0.7 and 0.9 MPa) at ambient temperature (20 °C) was tested as a potential alternative to conventional refrigerated storage (0.1 MPa at 13 °C) to preserve tomato quality. The experiments were divided into 3 phases: (1) 4 day of hyperbaric treatment, (2) 5 day of post-treatment ripening, and (3) 10 day of post-treatment ripening. Respiration rate (RR) of the tomatoes was continuously monitored during the course of the hyperbaric treatments. Quality attributes were assessed immediately after removal from the hyperbaric treatments and after 5 and 10 day ripening at 20 °C after removal from the treatments. Hyperbaric treatments at ≥0.3 MPa resulted in RR equal or higher than the RR in control fruit (0.1 MPa at 20 °C). The lowest RR was obtained from tomato stored at 0.1 MPa at 13 °C. Hyperbaric treatment at 0.5, 0.7 and 0.9 MPa significantly reduced weight loss, retained color, firmness, total soluble solid (TSS), titratable acidity (TA) and TSS:TA ratio at similar levels as the tomato treated at 13 °C and 0.1 MPa. Firmness after treatment was highest for fruit from 0.1 MPa at 13 °C and from 0.5, 0.7 and 0.9 MPa at 20 °C. The higher firmness advantage declined by 5 day of ripening after treatment, with higher firmness only being retained for fruit from the 0.9 MPa at 20 °C and the 0.1 MPa at 13 °C treatments. After 10 day ripening, firmness was similar for all treatments. Lightness (L*) and hue angle were greater for all treatments compared with the 0.1 MPa at 20 °C treatment. However, only the greater hue angle difference was maintained after 5 day of ripening. After 10 day ripening, no significant differences were found in color attributes. Only 0.1 MPa at 13 °C retained higher soluble solids, lower titratable acidity and higher TSS:TA ratios after treatment and after 5 day ripening. At 10 day of ripening none of the quality attribute differences noted were retained for any of the treatments. These results show that the only consistent effect of hyperbaric treatment at 0.5, 0.7 and 0.9 MPa was to reduce weight loss and enhance firmness retention up to 5 day ripening after treatment.