不同种植密度对棉花生长结铃及产量品质的影响

以冀棉958为供试材料,研究了5个不同密度水平(3.0、5.0、7.0、9.0与11.0万株/hm~2)对棉花生长发育及产量、品质的影响,结果表明:随着种植密度的增大,棉花株高呈增加趋势,果枝台数与果节数呈降低趋势;单株内围铃、外围铃、下部铃、中部铃、上部铃的成铃数呈下降趋势,而单位面积的成铃数,内围铃呈递增趋势,外围铃、下部铃、中部铃与上部铃则先增后减。不同处理之间的子棉产量差异达极显著,单位面积干物重与总生物量差异不显著;不同处理之间的棉花纤维品质只有马克隆值差异显著,其他指标如上半部平均长度、整齐度指数、断裂比强度和伸长率差异均不显著。适宜的种植密度为7.0万株/hm~2。     

种植密度对糜子生长发育及产量影响

采用完全随机区组试验设计,以河曲大红黍为材料,设定6个密度处理,研究不同种植密度对糜子的株高、茎粗、分蘖数等形态指标,单株叶面积、叶绿素相对值、光合速率等光合指标,干物质积累量,产量构成因素及产量的影响;运用非线性回归分析的方法,对密度与作物产量的经验模型进行模拟.结果表明:种植密度超过一定范围值时,随着密度的增加,株高增大,茎粗变细,分蘖数减少和光合生理指标均降低,穗重、穗粒重和有效穗粒数逐渐减少,干物质积累量减少,产量降低;产量随着种植密度增加呈先升后降的趋势,二次曲线模型的方程式为Y=176.78471+ 11.51879X-1.29607X2,理论最适密度范围为4万株/666.7m2-5万株/666.7m2.     

播期和密度对普冰151小麦籽粒产量与品质的影响

为确定关中地区小麦适宜播期和密度,以普冰151为试验材料,于2014年10月—2015年6月设置10月3日、10月8日、10月13日3个播期和基本苗135、195、255、315万·hm~(-2)4个密度,研究了播期和密度对普冰151产量及品质的影响。结果表明,随着播期的推迟,普冰151的籽粒产量降低,通过增加密度可以提高小麦成穗数,达到增加产量的目的。从播期和密度互作对产量的影响来看,普冰151的适宜播期为10月3日至10月8日,播量随着播期的推迟而增加,基本苗由10月3日的195万·hm~(-2)增加到10月8日的255万·hm~(-2)。随着播期的推迟,蛋白质含量和湿面筋含量呈下降趋势,面团稳定时间呈上升趋势;当密度为255万·hm~(-2)时,蛋白质含量、湿面筋含量和面团稳定时间最大,分别为14.25%、30.72%和10.22 min。因此,可根据实际需要,确定最适宜的播期和密度,使产量和品质协调统一。     

不同种植密度对玉米田杂草发生及玉米产量的影响

通过田间小区试验,研究了不同种植密度39 000~63 000株/hm~2对春玉米和夏玉米田间杂草数量和生物量、玉米株高、产量构成因素及产量的影响。结果表明,随着种植密度增加,春玉米田总杂草的数量,春玉米田和夏玉米田总杂草的生物量、穗粒数和千粒质量均呈逐渐降低趋势;春玉米的株高随种植密度的增大而增高,夏玉米的株高变化不明显;随着种植密度增加,玉米的产量呈现增加趋势,尤其是种植密度较低时,春玉米的产量增幅明显。因此,在四川省适当提高玉米的种植密度既可以降低田间杂草发生量,又可以增加玉米产量,但春玉米种植密度不宜高于57 000株/hm~2,夏玉米最高可达63 000株/hm~2。     

不同间作种植模式对棉花生长发育及品质影响

本研究旨在通过大田试验,分析塔里木地区不同枣棉间作间距对花铃期棉花生长发育以及品质的影响,为优化枣棉间作种植模式提供理论依据。结果表明:1棉花与红枣行间距主要影响棉花盛铃-吐絮进程。M1模式(距离红枣1.5 m处种植棉花)棉花生育期最短,为143 d;M3模式(距离红枣0.5 m处种植棉花)最长,为149d。2花铃期,M2模式(距离红枣1.0 m处种植棉花)株高、茎粗、成铃数均优于其他模式。3M1模式棉花叶片、茎秆干物质积累显著高于其他模式。4M1模式棉花产量为2 436.79 kg·hm-2,显著低于其他处理,但是衣分率(0.447)、霜前花率(83.24%)显著高于其他处理;M2模式籽棉产量为4 071.87 kg·hm-2,显著高于其他处理。5随棉花与红枣行间距的减小(M1→M3),棉纤维反射率小幅上升,断裂比强度、马克隆值呈降低趋势。结合生产实际,阿拉尔垦区幼龄枣园中棉花与红枣保持1.0 m距离,能够产生较高的经济效益。     

种植密度与施氮量对旱地地膜玉米产量、水分利用效率和品质的影响

试验以旱地地膜玉米'先玉335'为材料,采用二因素随机区组设计,种植密度设3个水平,分别为:4.5×104株·hm-2(低密度:D4.5)、6.0×104株·hm-2(中密度:D6.0)和7.5×104株·hm-2(高密度:D7.5);施氮量(缓释氮肥)设4个水平:0 kg·hm-2(N0)、150 kg·hm-2(N...     

种植方式和密度对谷子光合性能和产量的影响

2019―2020年以豫谷31为试验材料,采用二因素裂区试验设计,主区为种植方式,分别为种2行空1行（P1）和种3行空1行（P2）;裂区为种植密度,分别为低密度27万株·hm^-2（D1）、中密度33万株·hm^-2（D2）和高密度39万株·hm^-2（D3）,设3次重复,探究不同处理组合对谷子群体光合特性和产量的影响。结果表明：年份、种植方式、密度以及处理之间的互作效应均对谷子籽粒产量具有极显著影响（P<0.01）;P1处理的谷子产量(2 971.1 kg·hm^-2)较P2处理高20.37%（P<0.05）,D2处理的谷子产量(2 872.1 kg·hm^-2)较D1和D3处理分别高10.34%（P<0.05）和6.98%（P<0.05）;同一种植模式下,随着密度的增加,叶片SPAD值、净光合速率（Pn）、水分利用效率（IWUE、WUE）和羧化速率（CE）逐渐下降,P1处理的生育期平均SPAD值、Pn、IWUE、WUE和CE较P2处理分别高4.73%、1.95...     

栽培密度对新疆蓖麻产量构成的影响

为探讨盐碱地栽培密度对蓖麻生长和产量变化的影响,研究了4种栽培密度下株高、茎粗、单株有效穗数、百粒重等产量相关因素。结果表明:随着栽培密度的增加,蓖麻产量增加,单株平均穗数降低,平均株粒重降低。密度从31 250株·hm~(-2)增加到41 667株·hm~(-2),产量增加不显著。蓖麻籽百粒重在31 250株·hm~(-2)时达到最大,为30.85 g。主穗出籽率在31 250株·hm~(-2)时达到最大值87.7%。主穗产量在单株总产中的占比在31 250株·hm~(-2)时达到最高,一级穗产量在41 667株·hm~(-2)时最高。蓖麻在41 667株·hm~(-2)的栽培密度下获得最高产量。干物质向生殖器官的分配比例在25 000株·hm~(-2)时达到67.3%。     

抗旱剂对棉花生长发育和产量、品质的影响研究

为探明干旱胁迫下不同抗旱剂对棉花生长发育各项指标的影响,设置K1(黄腐酸钾)、K2(植物蛋白免疫剂)、K3(含氨基酸水溶肥)3种类型抗旱剂和A1(蕾期)、A2(蕾期+花期)、A3 (花期)3种喷施时期组合的小区试验,定量分析不同处理对棉花农艺性状、干物质量、叶面积指数、根冠比、根系形态指标及产量和品质的影响,明确3种抗旱剂和喷施时期的最优组合。结果表明：K1A1、K1A3和K3A1处理的株高、果枝台数、蕾数、花数、叶龄分别为70.2、68.8、68.9 cm, 7.9、7.7、7.7台,5.9、5.8、5.9个,1.3、1.3、1.3个和13.7、13.9、13.7,3个处理株高、果枝台数、蕾数及叶龄均显著高于对照且优于其他处理;K2A3处理的干物质量为4.3 t·hm^-2,K2A1叶面积指数为2.8,K1A1、K3A2处理的根冠比分别为0.156、0.156,与对照差异显著,且均优于其他处理;K1A1处理的根长、根面积分别为36.9 cm、0.63 mm²,K2A1处理根直径为0.95 mm, K3A3处理根体积、根面积分别为26.9 cm...     

不同植物生长调节剂对新疆棉花干物质积累、产量和品质的影响

通过大田试验研究了3种不同的植物生长调节剂及其施用方法对棉花干物质积累特性以及品质和产量的影响效应.试验设计为叶面喷施缩节胺、随水滴施多效唑、随水滴施促根剂和随水滴施多效唑+促根剂.结果表明:不同的化控处理棉株干物质积累均随生育期延长而持续增加,动态变化可用"S"曲线方程拟合.干物质积累速率呈单峰曲线变化,峰值出现在出...     

Assessment of yield losses caused by chickpea chlorotic dwarf geminivirus in chickpea (Cicer arietinum) in India

Yield losses caused by chickpea chlorotic dwarf virus in chickpea were estimated by comparing uninfected and infected plants in the field at two locations in India. When infection was before flowering, yield losses of individual plants amounted to nearly 100% in the three cultivars studies. Plants that became infected during flowering had yield losses of 75–90%. Percentage of crop loss is likely to equal percentage of disease incidence, since plant densities in farmers' fields are probably too low to allow uninfected plants around infected ones to compensate the yield losses of infected plants.Submitted as Journal Article No. 1624 by ICRISAT.     

Influence of nitrogen fertilization and isoxaflutole on the nodulation of chickpea (Cicer arietinum)

The effects of soil nitrate and the herbicide, isoxaflutole, on chickpea nodulation were examined in a glasshouse experiment. The treatments consisted of one isoxaflutole‐tolerant and one isoxaflutole‐sensitive chickpea cultivar, five nitrate concentrations (0, 0.75, 1.5, 3.0, and 6.0 mmol L^?1), and three herbicide rates (0, 75 [the recommended rate], and 300 g ha^?1). The sensitive cultivar was more susceptible to isoxaflutole damage with an increasing herbicide rate and nitrate concentration, compared with the tolerant cultivar. Isoxaflutole at the recommended rate reduced the nodule dry weight of the sensitive cultivar by 51% and by 33% in the tolerant cultivar. The nodule dry weight of the sensitive cultivar was reduced by 28%, 40%, 64%, and 76% with the addition of the 0.75, 1.5, 3.0, and 6.0 mmol L^?1 nitrate concentrations, respectively. In comparison, the nodule dry weight of the tolerant cultivar was reduced by 50% and 79% at the 3.0 and 6.0 mmol L^?1 nitrate concentrations, respectively. In addition, the level of damage from increasing rates of isoxaflutole increased with the highest nitrate concentrations of 3.0 and 6.0 mmol L^?1, regardless of the cultivar. Isoxaflutole at the recommended application rate had a detrimental effect on the nodulation of both chickpea cultivars, but the isoxaflutole‐tolerant cultivar suffered less injury than the sensitive one in relation to some growth parameters. The damage to chickpea from the recommended rate of isoxaflutole also increased with soils of higher nitrate content.     

种植密度对小麦群体质量叶绿素荧光参数和产量的影响

为进一步改善小麦群体质量,研究了不同密度下皖麦52和烟农19主要生理指标及产量间的差异。结果表明：烟农19的叶面积指数在基本苗120×104株·hm-2（M1）和210×104株·hm-2（M2）下高于皖麦52,而在300×104株·hm-2（M3）和390×104株·hm-2（M4）下低于皖麦52;皖麦52和烟农19各生育期的叶绿素含量及灌浆期的各叶绿素荧光参数（Fo、Fm、Fv/Fm、qP、ETR和ΦpsI ）皆随种植密度的增加而降低,且同一密度下两品种间的差异皆不显著;皖麦52和烟农19的产量随种植密度的增加呈现先增加后下降的趋势,在M1和M2下,烟农19的产量高于皖麦52,分别增加了13．4％和2．4％,在M3和M4下,皖麦52的产量高于烟农19,分别增加了10．7％和1．0％;皖麦52和烟农19的经济系数随密度的增加而降低,两品种间存在一定差异,但同一密度下不显著;相关分析表明,小麦实际光化学效率（ΦpsI ）与单茎干物重、叶绿素含量呈直线正相关关系,叶面积指数与单茎干物重呈直线负相关关系,与产量呈二次抛物线的关系。研究得出,烟农19的高产适宜密度为基本苗120万～210万株·hm-2,皖麦52为210万～300万株·hm-2。     

Effect of different levels of bruchid,Callosobruchus chinensis (L.) infestation on chickpea,Cicer arietinum L. in India

Abstract

In a study of the effect of initial infestation of chickpea, with one, two, three, four and five sexual pairs of pulse bruchid, up to F₁ (one generation) and F₂ (two generations), a highly positive correlation (r = 0.949) occurred between population in the F₁ and the number of pairs of beetles, but not up to F₂ generation. Significant correlations of r = 0.921 and r = 0.385 between grain damage (%) and final population also occurred for the F₁ and F₂ generations, respectively, also high positive correlations (r = 0.974 for F, and r = 0.959 for F₂) between loss in grain weight and population. The coefficients of determination revealed that 97% and 92% variability in loss in grain weight was due to the number of pairs of beetles initially released, their final population and per cent grain damage, for the F₁ and F₂ generations, respectively.     

不同复水措施对油菜生长、产量及品质性状的影响

以2个油莱品种为材料,在播后30~100 d的苗期干旱胁迫后采取"水"、"水+钾肥"、"水+钾肥+赤霉素"、"水+尿素"、"水+尿素+赤霉素"等5种复水处理,研究干旱胁迫后各复水措施对油菜生长、产量及品质的影响,分析不同复水措施增产的成因。结果表明:苗期干旱胁迫后,与未复水对照相比,除在皖油19中"水"处理未显著提高地上部干重和"水+尿素"处理未显著提高总根干重外,5种干旱恢复措施都显著提高了天禾油11和皖油19的地上部干重、总根干重、小区产量和产油量;5种复水处理对2个油菜品种的地上部干重、总根干重、小区产量和产油量,平均增幅分别达到11.6%、22%、19%和23.7%。5种复水措施中,地上部干重、总根干重、籽粒产量、产油量增幅最大的都是"水+尿素+赤霉素",分别增加24.7%、27.7%、34.2%和36.8%。与未复水对照相比,5种复水措施产量增幅由高到低依次为:"水+尿素+赤霉素"、"水+尿素"、"水+钾肥+赤霉素"、"水+钾肥"和"水"。关联及相关分析表明,5种复水措施促进增产的主要原因是复水显著增加了单株总角果数。     

施氮量品种与密度互作对豫西烟叶产量和质量的影响

为探讨豫西烟区最优的栽培措施组合,采用正交试验研究了不同品种、氮用量和密度对烟叶化学品质和经济性状的影响。结果表明：3个因素相比,品种对总糖和还原糖影响最大;施氮量增加使烟叶总氮含量增加;3个因素对中部叶化学成分协调性综合评价得分的影响大小顺序为施氮量＞品种＞密度,获得化学成分最协调的栽培组合为A1B2C2（品种：秦烟96;移栽密度：16500株·hm-2;施氮量：67．5 kg·hm-2）;从产量上分析,3个因素对产量的影响大小顺序为品种＞施氮量＞密度,要获得产量最高的组合为A3B3C3（品种：豫烟6号;移栽密度：18000株·hm-2;施氮量：90．0 kg·hm-2）;从产值上分析,最好的组合为A1B2C2（品种：秦烟96;移栽密度：16500株·hm-2;施氮量：67．5 kg·hm-2）,其产值、均价和上等烟比例分别为62770．5元·hm-2、19．21元·kg-1和58．6％。综合分析,在豫西烟区前期干旱后期降水分配较均匀且光照充足的条件下,可选择品种秦烟96,种植密度16500株·hm-2,氮肥施用量67．5 kg·hm-2的栽培技术进行推广应用。     

DNA methylation changes in fusarium wilt resistant and sensitive chickpea genotypes (Cicer arietinum L.)

DNA methylation plays an important role in the regulation of gene expression in biotic and abiotic stresses. In the present study, a methylation-sensitive amplified polymorphism (MSAP) analysis was performed to profile DNA methylation changes in seven resistant and sensitive chickpea genotypes following inoculation with Fusarium oxysporum f. sp. ciceris. In all, 27468 DNA fragments, each representing a recognition site cleaved by either or both of two isoschizomers, were amplified using nine selective primer pairs. DNA methylation was evaluated in leaves, stems and roots in control and inoculated plants. Extensive cytosine methylation alterations were found in the pathogen-treated genotypes compared with the corresponding control, including hypermethylation and demethylation as well as the potential conversion of methylation types. For all genotypes, the percentage of demethylated sites were more than methylated sites in infected plants compared with the corresponding control. No significant differences were observed for banding patterns in infected and control leaf tissues, while the differences between percentage of unchanged, methylated and demethylated sites were significant in stem and root tissues. The total numbers of methylated polymorphic bands ranged from 137 to 154 bands in Sel95th1716 and Arman, accounting for 36.81%–44.64% of all bands, respectively. Ten fragments that were differentially amplified between infected and control plants were isolated and sequenced in three tissues separately. Most of sequenced fragments showed homology with disease related genes in GenBank. The results suggest that significant differences in cytosine methylation exist between resistant and sensitive chickpea genotypes, and that hypermethylation or hypomethylation of specific genes may be involved in the chickpea resistance to Fusarium wilt.     

陇南雨养旱区播期与密度对冬小麦产量与品质的影响

通过田间试验和室内品质分析,研究了播期和密度对冬小麦天选45号产量和品质的影响.结果表,明:随着播期的推迟,小麦的产量降低,通过增加密度可以提高小麦成穗数,达到提高产量的目的.从播期与密度互作对产量影响来看,适宜播种期为9月25日至10月1日,播量随播期的推迟而增加,基本苗由9月25日的390万/hm2增加到10月1日...     

密度对大豆群体碳氮代谢相关指标及产量、品质的影响

以垦农4号大豆为试验材料,在大田条件下,研究了密度对大豆群体碳氮代谢相关指标及产量品质的影响.结果表明,群体单株叶片氮素、可溶性蛋白、淀粉及蔗糖积累量均随着密度的增加而下降,低密度与高密度群体间差距显著;随着种植密度的增加,大豆子粒中蛋白质的含量有所上升,脂肪的含量有所下降;各生育时期氮素、可溶性蛋白、淀粉和蔗糖积累量...