植物生长调节剂对再生稻头季抗倒伏能力和两季产量的影响

【目的】为了探明植物生长调节剂对再生稻头季抗倒伏能力及两季产量的影响,【方法】以佳辐占、天优华占和甬优2640为试验材料,于拔节初期叶面喷施多效唑、乙烯利和抗倒酯,研究不同植物生长调节剂对水稻头季茎秆特性、力学指标及两季产量形成的影响。【结果】甬优2640基部节间抗折力和植株抗推力最大,抗倒伏能力强;佳辐占基部节间最长,株高最高,倒伏指数高,抗倒伏能力最差;天优华占基部倒伏指数小,抗倒伏能力介于前二者中间。与喷施清水对照相比,多效唑处理植株节间长、株高、茎壁厚与对照差异较小,增加了倒3节间(N₃)茎粗和倒4节间(N₄)和N₃的抗折力,降低了N₄和N₃的倒伏指数;乙烯利处理则显著增加了N₄长度,N₃茎粗和株高,对茎壁厚没有明显影响, 增强了N₃抗折力,降低了N₃倒伏指数;抗倒酯处理缩短了N₄、倒2节间(N₂)长,降低株高,增加N₃茎粗和N₃、N₂的茎壁厚度,增强了N₄、N₃的抗折力,降低了各节间的倒伏指数。3种植物生长调节剂处理均降低了头季产量,多效唑和抗倒酯处理增加了再生季产量,乙烯利降低了再生季产量。分析产量构成因素,植物生长调节剂处理主要影响了总穗粒数,头季总穗粒数减少,再生季总穗粒数增加。天优华占和甬优2640两季总产量均较对照降低,佳辐占总产量多效唑和抗倒酯处理较对照增加,乙烯利处理较对照降低。【结论】抗倒酯处理增强了再生稻头季茎秆的抗倒伏能力,而对两季总产量无显著影响,对再生稻头季抗倒伏栽培具有现实意义。     

THE EFFECT OF THE TIMING OF AMMONIUM NITRATE DRESSINGS ON THE HEADING OF S48 TIMOTHY (PHLEUM PRATENSE L.)

The response of single plants of Aberystwyth S48 timothy ( Phleum pratense L.) to increasing rates of ammonium nitrate applied in the spring and autumn is described.
All spring treatments markedly increased the number of heads, as well as the total head-length per plant, but autumn dressings had no significant effect. Percentage head-length distribution was also greatly influenced by applications of nitrogenous fertilizer in the spring. Each higher rate of application gave a proportionate increase in the number of heads over 9 cm. in length, and a corresponding reduction in the frequency of those of 4 cm. or less. There was a positive correlation between head-length and number of florets per unit length.
The results are discussed in terms of their relationship to current practices in managing timothy crops for seed.     

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。     

基因型和氮肥对冬小麦叶片形态建成和分蘖的影响

于１９９８～１９９９ 年在浙江大学华家池校区实验农场进行了田间试验,研究基因型和环境对小麦叶片形态建成和分蘖的影响。试验由３ 个基因型（浙麦１ 号,ＺＡＵ９７－２,扬麦５ 号）和３ 种氮肥水平（０,１２０,２４０ ｋｇ／ｈｍ ２）的９ 种组合处理组成。主茎各叶片长度,除第１、９ 和１０ 外,基因型之间差异显著,叶片宽度随叶位高度而增加,各叶片面积的变化与叶长基本一致,第１ 至５ 叶依次增加,第６ 叶明显减小,第７ 叶又逐渐递增;单株分蘖数和分蘖消长动态因基因型而异。氮对叶片形态有明显影响,但除旗叶外,Ｎ１２０ 和Ｎ２４０ 两种氮水平之间叶长无显著差异。氮对分蘖的发生影响较小,但能显著促进其后的生长。基因型和氮肥对叶片形态和分蘖的影响存在着一定的互作效应。     

提高雾化栽培马铃薯微型薯结薯能力的初步研究

用 3种处理方法 ,下放植株 ,激素 (CCC) ,剪尖对雾化栽培室内的脱毒苗进行随机区组处理。结果表明 :激素和剪尖对叶面积系数 (LAI)、株高、茎粗等营养器官生长特征影响一致 ,可用剪尖替代激素促进形态建成 ;下放植株可极显著促进根系发育 ,促使腋芽向匍匐茎转化 ,可极显著提高微型小薯的产量 ;同时 ,相关分析表明 ,LAI与单株薯数呈极显著正相关 (r =0 874 8 ) ;根系体积与单株薯数显著相关 (r=0 82 0 1 ) ,与单株匍匐茎数极显著相关 (r =0 8770 )。     

有序摆抛栽对超级稻植株抗倒伏能力的影响

以粳型超级稻武运粳24和南粳44为试材,设置摆栽、点抛和撒抛三种抛栽方式,并以机插为对照,从茎秆抗折力、茎秆壁厚、节间长度、粗度、干质量等方面系统研究了有序摆抛稻的茎秆特性及其抗倒伏能力,结果如下:1)超级稻不同抛栽方式间抗倒伏能力差异显著,茎秆倒伏指数不同抛栽方式间表现为摆栽点抛撒抛、机插,基部节间抗折力、弯曲力矩和抗倒伏能力均表现为摆栽点抛撒抛、机插。就各抛栽方式下不同连孔处理而言,基部N1节间倒伏指数差异不显著,N2、N3、N4抗倒伏能力表现为2连孔、3连孔单孔。2)有序摆抛栽水稻相对重心高度稍低,成熟期茎鞘干物质量大,单穗干质量大,尤其2连孔和3连孔植株优势明显。不同抛栽方式间基部节间粗度、壁厚、节间质量和单位干质量表现为摆栽点抛撒抛,不同连孔处理间为2连孔3连孔单孔。除基部第1节间外,节间长度在抛栽方式间表现为摆栽点抛撒抛的趋势,不同连孔节间表现为2连孔、3连孔单孔的趋势。2连孔、3连孔钵苗有序摆抛在高产条件下稻株茎秆粗壮,节间短粗,节间壁厚,茎秆单位节间重,基部节间抗折力大,抗倒伏能力强,是一种利于提高水稻抗倒能力的新型水稻轻简高产栽培方式。     

植物生长调节剂拌种对扬麦13茎秆生长及籽粒产量的影响

为给高产小麦合理选用生长调节剂提供科学依据,以弱筋小麦扬麦13为试验材料,研究了不同生长调节剂(矮壮素、拌种剂、种衣剂、多效唑)拌种对不同群体小麦茎秆生长及籽粒产量的调节效应。结果表明,拌种处理均能有效降低扬麦13的株高、重心高度及基部节间长度,对茎秆粗度、茎壁厚度、茎秆干重的调节效应因生长调节剂种类不同而存在差异,其中,低密度条件下拌种剂处理的小麦茎壁厚度增加显著,而高密度条件下多效唑处理小麦的茎壁厚度增加显著。生长调节剂拌种处理提高了扬麦13的抗倒伏能力,其作用效果表现为多效唑种衣剂拌种剂矮壮素。相关分析表明,降低植株株高、基部第一节间长度,增加基部第一、二节间壁厚有利于提高植株抗倒性能。拌种处理下小麦产量均高于对照,300×104株·hm-2群体的产量高于150×104株·hm-2群体,均以种衣剂拌种处理增产最明显,平均增幅达11.68%,在倒伏年拌种处理增产效果更显著。     

水稻秸秆还田和耕作方式对小麦抗倒伏能力的影响

为了解水稻秸秆还田与耕作方式对小麦抗倒伏能力的调节作用,分析了不同耕作方式(免耕、旋耕、浅翻耕、深翻耕)下水稻秸秆还田后小麦茎秆基部第1至第4节间主要物理性状及抗倒性的变化.结果表明,水稻秸秆还田后小麦株高降低,茎秆节间变短,基部节间茎秆抗折力增强,花后倒伏指数降低,抗倒性提高,尤以深翻耕处理表现最好;茎秆基部节间茎壁加厚,茎秆干重增加,充实度提高,从而增强了茎秆抗折力.     

刈割对玉米生长发育及产量的影响

2016年以郑单958和先玉335为研究对象,研究不同叶龄期刈割对玉米生长发育及产量的响应。2017年以相对耐密品种郑单958为研究对象,研究增密刈割的产量效应。结果表明,不同叶龄期刈割影响玉米生长发育,随刈割时间的延后对玉米影响越大,表现为抽雄、吐丝时间推迟,郑单958抽雄时间推迟2～8 d,吐丝期推迟3～6 d;先玉335抽雄时间推迟2～8 d,吐丝期推迟4～8 d。株高和穗位高降低,穗位高系数和茎秆长粗比降低。绿叶数目减少,叶面积下降。两个品种单穗重较对照分别降低4.6%～21.7%和1.4%～24.5%,穗粒数3叶龄期刈割最高,其他处理穗粒数较对照降低。产量降低,以3叶期刈割减产幅度最小,5叶期在1叶位刈割基本全部死亡,6叶以后刈割叶位提高至4叶以上但减产幅度较大,且较对照产量差异达显著水平。随着刈割密度的增加,产量性状呈下降趋势,产量较对照先降低后增加,密度达到1.08万株/hm~2时,产量与对照相当;密度达到1.2万株/hm~2时,产量较对照提高7.3%,增加密度可弥补刈割对产量的影响。     

不同春生叶龄期追氮对冬小麦产量形成和抗倒性能的影响

为明确兼顾冬小麦高产和抗倒伏的春季最佳追氮时期,设置品种、追氮期二因素裂区试验,其中,2015-2016年以山农16（SN16）和石新828（SX828）2个品种为主区,2016-2017年以藁优2018（GY2018）、科农2009（KN2009）和石4366（SH4366）3个品种为主区,两年均以春3、4、5、6叶伸出时分别追施总施N量240 kg·hm^-2中的50%氮肥（分别用N3～N6表示）为副区。在关键生育时期调查群体总茎数,成熟期调查茎秆抗倒伏相关性状及产量构成因素。结果表明,拔节至孕穗期一般以N3或N4处理总茎数最多,开花至成熟期一般以N4处理的穗数最多,N5处理的成穗率最高;孕穗期至开花后24 d,N4处理的叶面积指数（LAI）最大,N6处理的最小;大部分品种以N4处理的株高最高,不同叶龄期追氮处理的重心高度则因品种而异;N4处理小麦基部第2节间最长,节间充实度和机械强度最小,N3和N4处理的抗倒指数最低。抗倒指数和机械强度与株高、重心高度、节间长度均呈极显著负相关,与节间直径、茎壁厚度和充实度均呈极显著正相关。不同叶龄期追氮对每公顷穗数和穗粒数的影响较小,大部分小麦品种以N4处理的穗数最多,且施氮处理间的差异一般不显著。石新828和藁优2018各施氮处理千粒重的差异不显著,另外3个品种N4处理的千粒重高于其他处理。5个品种中除藁优2018以N5处理的籽粒产量最高外,其他品种均以N4处理的籽粒产量最高,且均与N5处理的差异不显著。综合来看,春4叶期追氮产量性状最优而倒伏风险最大;春5叶期追氮的籽粒产量与春4叶期追氮的差异不显著,但其抗倒能力显著提高,可以兼顾高产和抗倒伏,因此,春5叶期为河北平原春季最佳追氮时期。在灌水条件常成为限制因素的该地区小麦生产中,春4叶至春5叶期根据水源情况灌水和随水追施氮肥,都是比较适宜的。     

两段留叶技术对烤烟上部烟叶质量的影响

以烤烟品种K 326为试验材料,设计6个两段留叶处理与常规打顶留叶比较试验,结果表明：两段留叶处理能增加主茎烟上部叶片长、宽,其杈烟的长、宽在57.40~65.33 cm和22.53~24.53 cm之间,比主茎叶片减小;两段留叶有4个处理降低上部烟叶比例作用明显,较对照降低0.49~6.67个百分点;两段留叶处理对主茎烟上部烟叶的还原糖和总糖影响不大,但可明显降低主茎上部烟叶植物碱含量,总氮也有一定程度的降低,钾含量无规律性变化;两段留叶处理的上部烟叶外观质量有较大提高;烟叶产量随着总留叶数的增加而增加,其中主茎18和16片叶打顶杈烟留8片叶的产量分别比对照提高10.28%和3.33%;但两段留叶处理的烟叶产值、均价、中上等烟比例和上等烟比例均比对照有不同程度的降低。     

灌浆后期6-BA灌根对玉米衰老和产量形成的影响

以郑单958为材料,用浓度为10 mg/L的6-苄基腺嘌呤(6-BA)溶液在玉米灌浆期(花后40 d)浇灌根系,研究6-BA对玉米根系与叶片衰老及产量形成的影响。结果表明,花后6-BA灌根处理能延缓玉米根系的衰老,使收获期单株总根长显著高于对照,增长48%,其中,轴根长与对照相比差异不显著,侧根长显著高于对照。6-BA灌根处理同样延缓叶片衰老,使成熟期绿叶面积增加。6-BA灌根处理显著增加吐丝期-成熟期植株吸氮量和植株干物质积累量,不影响营养器官中氮素与干物质的转运。6-BA灌根处理显著提高单株子粒产量,与对照相比增产16%,其中,主要是百粒重的增加,同时保持子粒中氮浓度不变。通过细胞分裂素延缓后期根系衰老,可能是协调玉米后期氮素吸收与转运、提高玉米子粒产量的一条途径。     

Development of introgression lines of an Indica-type rice variety, IR64, for unique agronomic traits and detection of the responsible chromosomal regions

A total of 334 introgression lines (INLs: BC₃-derived lines) derived from crosses between a recurrent parent of Indica rice cultivar IR64 and 10 donor parents, including new plant type (NPT) lines IR65600-87-2-2-3, IR65598-112-2, IR65564-2-2-3, IR69093-41-2-3-2, IR69125-25-3-1-1, Hoshiaoba, IR66215-44-2-3, IR68522-10-2-2, IR71195-AC1, and IR66750-6-2-1, have been developed. These INLs with IR64 genetic background were characterized for eight agronomic traits: days to heading, culm length, leaf width, leaf length, panicle length, panicle number, 100-grain weight, and total spikelet number per panicle at the International Rice Research Institute from 2005 to 2007. To identify introgressed segments from the donor parents, genotypes of the 334 INLs were detected using more than 200 polymorphic simple sequence repeat markers. These segments detected on chromosomes 1, 2, 4, 5, and 6 were commonly introgressed across the INLs from more than four donor varieties. Based on the data of phenotype and genotype for the 334 INLs, associations between agronomic traits and introgressed chromosomal segments in the 334 INLs were investigated. A total of 54 regions for the eight traits were detected: seven regions for days to heading, eight regions for culm length, eight regions for leaf width, four regions for leaf length, six regions for panicle length, three regions for panicle number per plant, seven regions for 100-grain weight, and 11 regions for total spikelet number per panicle. Among them, the region on the long arm of chromosome 4 was associated with characteristics of the NPT such as long leaf, broad leaf, and high spikelet number. The developed 334 INLs with the IR64 genetic background will be useful materials for genetic analysis of agronomic traits.     

遮光对玉米干物质积累及产量性能的影响

选用玉米品种郑单958与先玉335,在大田条件分别于7叶全展期（T1）、13叶全展期（T2）、吐丝期（T3）、吐丝后15 d（T4）进行50%遮光处理,研究不同时期遮光对玉米干物质积累与产量性能的影响。结果表明,不同时期遮光均导致玉米终极生长量（a）、干物质积累速率最大时的生长量（W_max）、最大干物质积累速率（G_max）、平均叶面积指数（MLAI）、平均净同化率（MNAR）和收获指数（HI）降低,致使干物质积累与产量不同程度降低,吐丝后15 d遮光对干物质与产量影响最大。在产量构成因素中,遮光处理对穗粒数与千粒重影响较大,穗粒数减少占主导,其次是千粒重的降低。     

Culm sucrose accumulation promotes physiological decline of mature leaves in ripening sugarcane

Photosynthetic activity in C₄ sugarcane has been suggested to be regulated by the demand for photoassimilate from sink tissues, including culm storage of sucrose and other components of the plant (e.g. roots and shoot primordia). This study examined the extent to which sink-demand influences leaf photosynthetic activity and controls leaf turnover in field-grown sugarcane. To increase sink-demand on selected leaves, plants were defoliated apart from the immature leaf before the first fully expanded leaf (2nd leaf) and the mature 8th leaf. Changes in leaf gas exchange and fluorescence characteristics were recorded for both leaves over a 28 d period. Variations in leaf and culm sucrose and hexose concentrations and allocation of ¹⁴C-labelled photosynthate were also measured. A decrease in culm internodal sucrose concentrations in partially defoliated plants was associated with significant increases in assimilation (A) and electron transport rates (ETR) for both leaves 2 and 8. Conversely, accumulation of sucrose in the culms of control plants was related to a decline in photosynthetic rates in leaf 8 during the treatment period. Leaves 2 and 8 of defoliated plants (27 d) were characterised by an increase in partitioning of ¹⁴C to mature and immature internodes, respectively, compared to control plants. In addition, hexose levels in leaves of defoliated plants decreased significantly (36% and 48% decrease in leaves 2 and 8, respectively) compared to corresponding leaves of untreated controls over the duration of the experiment, indicating that the signaling mechanisms regulating the decline in leaf photosynthetic activity are likely hexose-mediated. It was concluded that leaf physiological ageing in sugarcane was promoted by sucrose accumulation during culm maturation as a consequence of decreased sink-demand for photosynthate.     

减氮对机插杂交籼稻茎秆生长及抗倒伏特性的影响

以宜香优2115和F优498为材料,设置4个不同氮肥用量处理,研究减氮对机插杂交籼稻产量和茎秆生长特性的影响,及其与抗倒伏能力的关系。结果表明,与对照（品种最高产施氮量,180 kg/hm²）相比,随着减氮量的增加,参试两个水稻品种的产量均逐渐降低,但N150处理（施氮量150 kg/hm²）的产量降低不显著,而N120处理（施氮量120 kg/hm²）和N0处理（不施氮）的产量降低显著;水稻株高和重心高度均降低,基部节间长度缩短,基部节间的秆型指数逐渐增加,节间充实度（节间干物质量、单位长度节间干物质量和单位体积节间干物质量）先增加后降低,弯曲力矩逐渐减小,折断弯矩逐渐增加,倒伏指数降低,抗倒伏能力增强。相关分析表明,倒伏指数与产量、株高、重心高度、弯曲力矩和节间长度整体上呈正相关;与节间粗度、折断弯矩、茎壁厚度、秆型指数和节间充实度整体上呈负相关。综上,适宜减氮（N150）能够同步实现机插杂交籼稻减氮稳产和高抗倒伏能力;而过量减氮（N120或N0）虽能大幅度提升抗倒伏能力,但难以实现高产或稳产。     

红壤稻田钾肥施用量对超级稻生长及产量的影响

 以超高产水稻中浙优1号、甬优9号为材料,研究土壤不同钾素水平(50 mg/kg、90 mg/kg)及钾肥用量(0、75、150、225 kg/hm2氯化钾)对水稻生长和产量的影响。土壤不同钾素水平对穗数、成穗率、每穗粒数、着粒密度、株高、叶片叶绿素含量（SPAD值）和光合速率有显著影响,差异达显著水平;不同时期施用钾肥对产量的贡献依次为：基肥>分蘖肥>穗肥,产量差异达到3%~10%;随着施钾量增加植株高度明显增加,中浙优1号上表现更为明显,且随着施钾量增加,茎秆加粗,特别是基部节间粗度增加尤为明显。施钾与不施钾相比,两个品种产量分别增加5.6%和8.8%,但产量增加并不与施钾量成正比,不同施钾水平间产量差异不显著。     

Relationship of growth parameters and nutrients uptake with canola (Brassica napus L.) yield and yield contribution at different nutrients availability

A field experiment was conducted to evaluate the effect of different nutrients on canola (Brassica napus L.) growth parameters, nutrient uptake and ultimately on seed yield. For this purpose a split plot experimental design, with 10 treatments in 4 replications was carried out in 2004-2005, in silt-clay soil at Baiecola Agricultural Research Station, Mazandaran Iran. Canola seed yield, growth parameters (CGR, LAI, RGR and NAR), dry matter accumulation and HI and nutrient content of the leaf were examined. NPK fertilizers together with S and Zn, singly or in combination were applied. The results showed that at treatments T5 (NP), T8 (NPK), T9 (NPKS) and T10 (NPKZn) the higher seed yield (> 2600 kg ha(-1)) coincided with TDM > 880 g m(-2) the peak CGR > or = 13.9 g m(-2) day(-1) and the maximum LAI > or = 4.1. The higher seed yield at T5, T8, T9 and T10 coincided with higher concentrations of nutrients: N, P, K, S and Zn in leaf at flowering having > or = 3.40%, > or = 0.25%, > or = 1.53%, > or = 110 ppm and > or = 22.7 ppm, indicating substantial levels of translocation of nutrients at various stages of plant growth and higher number of pods per plant (> or = 179). Combined application of NPKZn at T10 resulted in maximum seed yield (3090 kg ha(-1)), coinciding with the maximum number of pods per plant (230), maximum TDM (1043 kg ha(-1)), maximum CGR (20.09 g m(-2) day(-1)) and maximum LAI (4.69).     

群体密度对夏玉米穗下茎秆性状及抗倒伏力学特性的影响

设置5个密度处理,2015～2016年研究种植密度对川中丘区夏玉米穗下茎节性状和抗倒伏力学特性的影响。结果表明,随群体密度增加,穗下由基部向上第2～5节节长增长;第3、5节7.50万株/hm~2密度处理较4.50万株/hm~2分别增加了19.04%、13.93%(2015)和22.84%和26.76%(2016);第6～8节变化不显著,穗下各节节粗变细。节干重、单位茎长干物质重、穿刺强度和压碎强度均随密度的增加而降低。相关分析结果表明,茎秆倒伏率与茎秆节间直径、茎秆干重、单位茎长干物质重呈极显著负相关,与种植密度、节间长度呈显著正相关;与第3～5节和第8节(穗下第1节)穿刺强度和压碎强度均呈极显著负相关,茎秆压碎强度和外皮穿刺强度相关系数为r=0.96**。     

水稻叶片氮含量与荧光参数的关系

在3个供氮水平和2个水稻品种(华粳2号和武香粳9号）的田间试验条件下,测试分析了不同处理水稻顶部4张完全展开叶片氮含量及对应的荧光参数。不同供氮水平的水稻叶片氮含量和荧光参数差异明显,均随施氮量的增加呈上升趋势。叶片荧光参数随生育期推迟呈抛物线型变化,以抽穗期为界先上升后下降,直到成熟期降为最低。叶片荧光参数随不同叶位的变化规律为：顶1叶>顶2叶>顶3叶>顶4叶。同一水稻品种各叶位叶片氮含量分别与荧光参数呈极显著相关,且华粳2号的相关性高于武香粳9号。综合水稻品种的不同叶位,叶片氮含量与荧光参数ΦPSⅡ、qP均呈良好的线性相关。基于ΦPSⅡ和qP宜采用不同的回归方程来反演不同叶位叶片氮含量。因此,荧光参数ΦPSⅡ和qP有可能用来估算水稻叶片氮含量。