Seed Treatment with Uniconazole Powder Improves Soybean Seedling Growth under Shading by Corn in Relay Strip Intercropping System

The relay strip intercropping system of wheat-corn-soybean is widely used in southwest China. However, it is hard to obtain a stable production of soybean with this system, since soybean plants grow under shading by corn; the stems are thinner and susceptible to lodging. We examined the effects of seed treatment with uniconazole powder (0, 2, 4 and 8 mg kg-¹ seed) on the growth of soybean seedlings under relay strip intercropping, some morphological characteristics and yield. The seedling height, first internode length, cotyledonary node height and leaf area per plant were decreased, while the stem diameter, root dry weight, shoot dry weight, root volume, leaf greenness and root to shoot dry weight ratio were increased by uniconazole treatment. The root vigor and root active absorption area were also increased significantly by uniconazole treatment. Moreover, 2 and 4 mg kg-¹ uniconazole powder treatment increased shoot dry weight, number of pods per plant, number of seeds per pod and seed yield significantly. Thus, the results suggested that seed treatment with uniconazole powder at a suitable concentration can improve soybean seedling growth, resist the lodging and also increase the seed yield under shading by corn in relay strip intercropping system.     

赤霉素及烯效唑对大豆形态、光合生理及产量的影响

为了解赤霉素ＧＡ３和烯效唑的壮苗效果,采用ＧＡ３和烯效唑浸种处理大豆种子,调查大豆茎秆、节长、叶柄、叶片光合特性及产量的变化。两年结果显示,ＧＡ３ 和烯效唑对大豆株高有调控作用,但具有时效性。苗期,ＧＡ３处理增加株高,烯效唑抑制株高;盛花期、结荚期和鼓粒期处理与对照之间株高无显著差异;收获期ＧＡ３处理降低了第１、３、１０、１２、１３、１４节节长,从而显著降低大豆株高,烯效唑降低第１节节长,不影响株高。ＧＡ３和烯效唑 浸种处理均增加大豆茎粗,增强大豆抗倒伏性。ＧＡ３处理降低了８～１０节叶柄长度、增加了１４～１８节叶柄长度;烯效唑增加７～１２节叶柄长度。两种调节剂从节长和叶柄两个方面改变了大豆冠层结构,叶柄长度的变化量与同节位的产量贡献率的变化量显著相关,相关系数为０．６２２和０．５８５,Ｐ＜０．０５。烯效唑浸种处理能够增加７ｄ、１４ｄ叶绿素含量,１４ｄ光合速率,显著提高单株粒数、单株荚数和产量,两年平均增产１５．１４％。说明烯效唑处理可能通过改变大豆冠层结构和光合性质影响大豆产量。     

烯效唑对水稻基质育秧秧苗素质的影响

以淮稻5号为材料,烯效唑浓度分别为0、37.5、75.0、150.0、225.0、300.0 mg/m2,于一叶一心期喷施,三叶一心期分析了秧苗素质。结果表明:随着烯效唑浓度的增加,水稻地上部第二叶、第三叶的叶长显著下降,叶宽显著增加,叶面积显著下降,叶绿素含量先显著增加后显著下降,株高显著下降,茎基宽显著增加;单株根数、最长根长、根干重、根系活力和盘结力均表现出先显著增加后显著下降。综合而言,以烯效唑浓度37.5 mg/m2所育秧苗株高符合机插秧要求,茎粗苗壮,叶绿素含量较高,根数较多,根系活力较高,根系盘结力强,植株生物量大,可以增加秧龄弹性2.1 d。     

Variability and regulation of the number of ovules, seeds and pods according to assimilate availability in winter oilseed rape (Brassica napus L.)

The number of pods per plant and the number of seeds per pod are the most variable yield components in winter oilseed rape (WOSR). Both the number of ovules per pod and the potential for the ovule to develop into a mature seed may depend on pod position in the plant architecture and time of appearance. The complex developmental pattern of WOSR makes it difficult to analyse. The objectives of this study were to investigate the variability of the following yield components (a) ovules/pod, (b) seeds/pod, and (c) pods/axis in relation to two explanatory variables. These two variables include (1) flower and inflorescence position and (2) time of pod appearance, linked to the effect of assimilate availability.Field experiments were conducted with the variety Mendel. Different trophic states were created by clipping the main stem or ramifications. The number and position of flowers that bloomed within the inflorescence were recorded based on observations every two to three days throughout the flowering season.On the control plants, for the main stem we observed that the number of ovules per pod decreased for a few ranks and then tended to increase and again to decrease at the end. On ramification R1 and R4, the number of ovules increased at first, and then remained constant with the pod rank. Furthermore, the number of ovules per pod remained constant along the inflorescence on the other ramifications and increased with ramifications from top to bottom. The number of seeds per pod did not vary with the pod rank at the basal positions on inflorescences and decreased afterwards along the inflorescence. The clipping of the main stem or ramifications increased the number of ovules per pod, seeds per pod and pods per axis. The number of ovules and seeds per pod did not vary with the time of pod appearance for the pods located at normalised rank 0.01-0.1. However, the number of ovules and seeds per pod can be impacted by the time of pod appearance on the plant scale. Thus, our results indicate that the amount of available assimilates was the primary determinant of pod and seed production during the flowering period. The distribution of resources was significantly affected by both the positions of pods within an inflorescence and the position of inflorescences within a plant.     

烯效唑浸种对玉米壮苗的形态效应

研究了烯效唑浸种对玉米苗期形态特征的影响.结果表明:烯效唑对叶片和叶鞘的伸长生长有明显的抑制作用,第7叶时抑制效应明显减弱,且抑制效应随浓度的增大而增强.但烯效唑处理的植株粗壮,比叶重、叶宽和茎基宽增加,根数增多,根长显著高于对照,根于重增加,根冠比和苗粗壮度提高,表现出明显的壮苗长相;对根系的促进作用10～40 mg/kg范围内随浓度增大而增强,当浓度达到80 mg/kg时,促进作用显著减弱。     

夏大豆花荚期受渍胁迫对农艺性状、产量与品质的影响

为了探索平原湖区易涝易渍耕地种植夏大豆的排水管理 ,选择大豆关键生育期—花荚期进行了不同水处理试验 ,研究了夏大豆不同受渍胁迫对农艺性状、产量及品质的影响。结果表明 ,受渍胁迫引起大豆单株粒数、单株荚数、单株粒重、百粒重等降低 ,从而导致减产。随着受渍时间的延长 ,减产幅度增大 ;籽粒中粗脂肪含量增加 ,粗蛋白含量下降 ,但是 ,各受渍处理间两者总含量差异不明显。     

不同生育期施用"奥普尔"对夏大豆生长发育的影响

用奥普尔液肥处理土壤，可提高大豆出苗率９．１％。除鼓粒期外，其余生育期使用该液肥，株高降低，分枝数增加，株英数增加百粒重降低；而鼓粒期施用，株高、分枝数没有变化，株英数和百粒重增加，综合效果，大豆施用奥普尔液肥，株粒数增加，产量提高，经济效益提高。以上土壤处理和花期喷施效果最好，增产率分别达１１．８％和９．６％；两次是复加施用，增产率达１３．６％，投放产出比达１：５．３。     

白菜型春油菜不同密度的产量及其构成因素分布特性

白菜型春油菜（ＢｒａｓｓｉｃａＣａｍｐｅｓｔｒｉｓ）两个品种８种栽培密度的产量及其构成因素分布特性分析结果表明，单位面积产量与各枝序粒重和角果数占单株粒重和角果数的比率有密切关系。角粒重较高，较稳定下，单位面积产量随一次分枝粒重比率和角果数比率的下降，或主序粒重比率和角果数比率的上升而提高；角粒重低，且随一次分枝粒重比率和角果数比率的下降，或主序粒重比率和角果数比率的上升而降低．一次分枝粒重比率和角果数比率为５０％－５５％，或主序粒重比率和角果数比率为２５％－３０％，同时每角粒重较高，可获得最高单位的面积产量。     

生育后期湿涝胁迫对不同种植方式花生产量性状及品质的影响

本文采用模拟人工淹水逆境的试验方法,研究花生生育后期,湿涝胁迫对不同种植方式下花生产量、品质的影响。结果表明:湿涝胁迫可使花生的百果重、百仁重、饱果率、出仁率、单株生产力、单株结果数和产量明显降低,籽仁脂肪和油酸含量有所降低,蛋白和亚油酸含量有所提高。湿涝胁迫对花生产量及品质的影响程度:结荚期胁迫危害大于成熟期,平作种植危害大于起垄种植。     

山东间作大豆产量与主要农艺性状关联分析

为明确间作大豆的性状表现,筛选适宜间作的高产、稳产性大豆品种,本研究在玉米大豆间作模式下,对50份大豆材料在两年的产量与11个主要农艺性状进行相关性及灰色关联度分析,并采用GGE双标图法进行品种适应性及稳产性分析。结果表明：50份材料的主要农艺及产量性状的变异系数在6.87%~77.32%,广义遗传力为0.62~0.97,且生育期、营养生长期、百粒重等9个性状的广义遗传力均大于0.8;相关性分析表明,单株产量与茎粗(0.75**)、生育期(0.76**)呈极显著正相关,其次为株高、主茎节数、分枝数、底荚高、营养生长期、百粒重、单株荚数、单株粒数;灰色关联度分析表明,单株产量与各农艺性状的关联顺序为茎粗>生育期>营养生长期>单株荚数>百粒重>底荚高>单株粒数>分枝数>主茎节数>株高>生殖生长期;GGE双标图法表明汾豆79、中作J7018和皖豆30为适宜间作的高产、稳产性较好的品种。     

国家区试鲜食夏大豆品种重要农艺性状的演变

为指导鲜食夏大豆高产优质新品种的选育与推广,分析了2006-2018年国家区试鲜食夏大豆13年的品种试验数据,研究了鲜食夏大豆品种14个重要农艺性状的演变规律。研究结果表明:2006-2018年8个鲜食夏大豆新品种通过国家审定;14个农艺性状的变异范围在6.75%～38.67%之间,A级口感率的变异系数最大,标准二粒荚宽最小;参试品种的平均鲜荚产量为10 468.9 kg·hm^-2,较对照减产1.7%;随着年度的推进,鲜荚产量得到了提升,采青天数、株高、主茎节数、单株有效分枝数、单株有效鲜荚数有下降趋势,而多粒荚率、单株鲜荚重有上升趋势,百粒鲜重、标准二粒荚长和宽、标准荚率、A级口感率逐步提升。相关性分析表明,鲜荚产量与多粒荚率、单株鲜荚重、百粒鲜重、标准二粒荚长和宽、标准荚率极显著正相关,A级口感率与百粒鲜重、标准二粒荚长和宽极显著正相关。主成分分析表明,影响鲜食夏大豆性状变异的最主要因子是标准二粒荚长和宽、荚数、多粒荚率及株型因子,在鲜食夏大豆选育过程中应注重选择多粒荚多、荚长、荚大、粒大的品种进行组配,以提高鲜食夏大豆的产量和品质。     

黑龙江省早熟大豆品种 主要农艺性状演变趋势

黑龙江省近20年来早熟大豆品种遗传改进的明显趋势是三四粒荚数、单株荚数、单株粒重、株高、分枝 数和有效节数增多,底荚高度降低,单株粒数、每荚粒数、百粒重和蛋白质含量呈现先增后减的趋势,脂肪含量呈现 先减后增的趋势。     

叶面喷施吲哚乙酸对油菜蕾薹期渍水的缓解效应

以油菜品种秦优7号(敏感)和苏油4号(耐渍)为材料,通过盆栽试验研究吲哚乙酸(IAA)对油菜蕾薹期渍水的缓解效应。蕾薹期渍水持续10d,渍水结束后,叶面喷施浓度为0.1mmol/L的IAA,随后的0~15d调查油菜的生理变化。结果发现:渍水后生物量和叶片光合色素含量降低;谷胱甘肽、抗坏血酸含量和超氧化物歧化酶活性升高;丙二醛含量升高;蔗糖合成酶、蔗糖磷酸合成酶活性上升,蔗糖和可溶性糖含量增加。渍水结束后喷施IAA,对敏感的秦优7号缓解效应更明显;叶片中的光合色素含量升高,5d后显著恢复生长;蔗糖磷酸合成酶活性降低,降低蔗糖含量;蔗糖合成酶活性降低,减少蔗糖的分解;尤其是喷施15d后IAA对渍水胁迫的缓解作用最明显,苏油4号根干重显著增加,而秦优7号的根干重和茎干重均显著增加。叶面喷施IAA有效缓解单株角果数、每角粒数和产量的降低,但对抗氧化系统影响较小。     

Influence of Seed Treatment with Uniconazole Powder on Soybean Growth,Photosynthesis, Dry Matter Accumulation after Flowering and Yield in Relay Strip Intercropping System

Abstract

The relay strip intercropping system of wheat-corn-soybean is widely used in southwest China. However, it is hard to produce soybean stably with this system, since the growth of soybean plants is slower under shading by corn at the seedling stage, and it is compensated by accelerated growth after the symbiotic stage. Soybean plants show excessive vegetative growth due to more rain during the flowering stage, which results in fallen petals, fallen pods and lower yield. This study investigated whether seed treatment with uniconazole powder (0, 2, 4 and 8 mg kg^–1 seed) suppresses excessive vegetative growth of soybean plants during the flowering stage and delays senescence of photosynthetically active leaves at the pod-setting stage. If such events are correlated with changes in photosynthesis, they may affect dry matter accumulation and seed yield in the relay stripping system. Uniconazole promoted biomass accumulation from 31 (R₃) to 61 (R₅) days after flowering (DAF) and seed yield. Seed treatment with uniconazole raised the net photosynthetic rate, stomatal conductance, transpiration rate, and total chlorophyll and chlorophyll a contents. In contrast, uniconazole reduced leaf area index (LAI) from 1 DAF (R₁) to 46 DAF (R₄) with the increase in uniconazole concentration, whereas, uniconazole significantly increased LAI at 61 DAF, and the greatest promotion occurred at 2 mg kg^–1 treatment. The study clearly showed that uniconazole effectively suppressed excessive vegetative growth of soybean during flowering stage, delayed senescence of photosynthetically active leaves at pod-setting stage and induced higher yield, which were related to the changes in photosynthetic rate, chlorophyll content, dry matter accumulation and LAI in the relay strip intercropping system.     

遮光和渍水对小麦幼苗形态和生长的影响

为了解遮光、渍水及其互作对小麦幼苗形态及生长性状的影响,以长江中下游不同年代小麦品种扬麦1号(20世纪70年代)、扬麦158(20世纪90年代)和扬辐麦4号(21世纪正在应用)为材料,通过盆栽试验研究了遮光、渍水后小麦幼苗主茎叶龄、单株茎蘖数、单株次生根数、苗高、叶面积、干物重、比叶重和根冠比的变化。结果表明,遮光处理显著延缓幼苗叶龄,抑制分蘖的发生,而渍水处理影响不显著;遮光和渍水处理均显著降低单株次生根数、叶面积、比叶重及地上部和根干重,遮光影响程度重于渍水,遮光和渍水同时处理仅对比叶重、地上部和根干重、根冠比表现出一定的累加效应。处理结束后经20d恢复,仅不遮光+渍水处理下叶龄、苗高和比叶重基本恢复到正常生长水平;不遮光+渍水处理下单株次生根数及各处理下根干重表现出恢复趋势。不同品种间幼苗形态和生长性状表现出显著的差异。扬辐麦4号和扬麦158单株次生根数和比叶重均显著高于扬麦1号。不同处理下扬辐麦4号幼苗形态和生长性状相比正常生长幼苗的变化幅度总体上小于其他品种,表现出较好的苗期抗渍及抗弱光能力。     

甘蓝型黄籽油菜主要性状的遗传相关分析

采用混合线性模型分析方法，以7个不同遗传来源的甘蓝型黄籽品系为材料配制完全双列杂交，用ADM模型对甘蓝型黄籽油菜主要性状进行遗传相关分析。结果表明，主序有效角果数与单株有效角果数以显性相关为主。主要体现在杂种一代。单株有效角果数与千粒重、千粒重与单株粒重在遗传上没有紧密的联系。每角粒数、一次有效分枝数、单株有效角果数、角果长度、株高、纤维素含量和黄籽度等是影响单株粒重的主要遗传因子，通过单个性状间接选择不能有效改良单株粒重。     

THE GROWTH AND DEVELOPMENT OF SOME GRASS SPECIES UNDER COMPETITIVE STRESS

Three experiments were carried out in a semi-controlled glasshouse environment to determine the response of individual plants to competition; (i) between seedlings of different species, (ii) between seedlings derived from seeds of differing sizes within a species, and (iii) between seedlings and established plants.
Differences were detected in seedling competitive ability between species and between plants derived from differing seed sizes. In associations of species of very high and very low competitive ability the differences in competitive ability were accentuated by an increase in plant density.
Established plants of Phalaris coerulescens were less aggressive to seedlings growing in close proximity than were plants of Lolium rigidum and H1 ryegrass. Despite the early death of established swards of L. rigidum , and the consequent removal of competitive stress, there was no rapid increase in the growth and development of seedlings in these swards. Possible mechanisms causing this effect are discussed.
There was evidence of a specific relationship between the species of the established sward and the seedling species, in particular seedlings of HI ryegrass were particularly susceptible to competition from established plants of their own species.
Dry weight per plant, tiller production, rate of leaf appearance and leaf size were ail affected by competition between seedlings; however, tiller production was generally more severely affected than rate of leaf appearance and leaf size.
Dry weight per plant, tiller production, seedling height, number of leaves per tiller and number of seeds per seedling were all affected by competition from established plants.     

不同来源的小豆品种在中泰之间的遗传差异与聚类分析

通过对来自中国北部、中部和南部不同纬度地区的114个小豆品种在江苏南京和泰国农业大学的农艺性状进行研究。研究结果表明：与栽培在江苏相比，小豆品种在泰国热带地区表现为株高降低、生育期缩短，百粒重、每荚粒数、和单株产量均有所降低，但分枝数和每荚粒数变化不大。从不同来源的群体来看，来自中国北部的品种的农艺性状在泰国的变异系数大于中部品种，而南部品种引种至泰国后农艺性状的变异系数最小。通过对产量因子的相关分析表明，单株荚数对产量的相关系数最大（0．75）。而其它性状如分枝数（0．30）和每荚粒数（0．21）与产量的相关系数不大，而百粒重（0．07）对产量的相关系数最小。聚类分析的结果表明，以上114个小豆品种可划分为中国北部1、中国北部2、中部、南部4个大类。显示了北部品种之间有较大的遗传差异。     

苗期渍水对直播冬油菜产量和农学利用率的影响及油菜在不同氮肥施用下的响应

在轻简化施肥背景下，为减少渍害损失，解决长江流域冬油菜产区生产面临的重要问题，开展氮肥施用 对油菜渍害的缓解作用研究。设置三因素田间试验，分别为不同氮肥用量（0、60、120、180、240和300 kg N/hm2）、氮 肥类型（油菜专用控释尿素和普通尿素）和水分处理（苗期渍水和正常排水），测定各处理产量和氮肥农学利用率， 明确苗期渍水对不同氮素供应水平油菜的影响，并比较油菜专用控释尿素一次性施用和普通尿素分次施用下油菜 对苗期渍水的响应。结果表明，直播冬油菜产量随氮肥施用量增加而提高，至240 kg N/hm2时不再增加。油菜专用 控释尿素一次性施用，在氮肥用量为60～180 kg N/hm2时产量高于普通尿素分次施用；在氮肥用量为240～300 kg N/hm2时，两种氮肥类型产量基本相当。氮肥施用通过增加收获密度、单株角果数和每角粒数提高产量。苗期渍水 导致直播冬油菜产量损失1.1%～41.9%，随氮肥用量增加，渍水引起的产量损失率呈先增加后降低趋势。0～60 kg N/hm2处理时，渍水使收获密度显著降低（降幅达29.4%~45.0%），单株角果数增加；施氮量为120~180 kg N/hm2时， 渍水导致收获密度和单株角果数分别降低19.5%~33.7%和1.4%~17.7%；施氮高于180 kg N/hm2时，收获密度和单 株角果数降幅减小（降幅分别为5%~30.9%和3.6%~9.5%）。普通尿素分次施用和油菜专用控释尿素一次性施用， 分别在施氮量为120和180 kg N/hm2时产量损失率最高，分别达29.8%和41.9%。相同氮肥用量下油菜专用控释尿 素一次性施用的产量损失率大于普通尿素分次施用。渍水显著降低氮肥农学利用率，降幅为8.4%～51.9%，施氮充 足（240～300 kg N/hm2）时氮肥农学利用率降幅低于氮素用量较低处理（120～180 kg N/hm2），油菜专用控释尿素一 次施用处理的农学利用率平均降幅（36.5%）高于普通尿素分次施用（17.3%）。综上可知，苗期渍水时，油菜专用控 释尿素一次施用，会加重油菜受渍影响；土壤氮素供应能力较低时，渍害逆境解除后，适量追施速效氮肥可有效缓 解产量损失，实现油菜稳产。     

烯效唑喷施方式对无土基质育秧秧苗素质的影响

为探究合理的秧苗调控方式,以华优2号为试验材料,设置不同烯效唑喷施浓度(C0,0 mL/L,喷施等量清水;C1,25 mL/L;C2,50 mL/L;C3,100 mL/L)和喷施时期(T0,播种时;T1,5 d秧龄;T2,10 d秧龄),研究了不同烯效唑喷施方式对无土基质育秧秧苗株高、叶绿素含量、根系长度、根系数量、根系活力等的影响。结果表明,喷施烯效唑显著降低了秧苗株高,喷施浓度越高,控苗效果越佳,喷施时间推迟控苗效果减弱;烯效唑浓度过高会降低秧苗叶绿素含量;喷施烯效唑可显著增加秧苗根长和数量,并增强秧苗根系活力,但浓度过高则抑制根系的生长。综合秧苗株高、叶绿素含量、根长、根数及根系活力等指标,播种后5 d喷施50 mL/L稀效唑(T1C2)对秧苗素质提升效果最佳。