不同播栽方式下杂交籼稻茎秆生长和穗粒形成特点及与气象因子的关系

田青兰　刘波　孙红　何莎　钟晓媛　赵敏　任万军,*

(1四川农业大学 农学院 / 农业部西南作物生理生态与耕作重点实验室 / 四川农业大学 生态农业研究所, 四川 温江611130; 2成都市郫县气象局，四川 郫县 611730; * 通讯联系人， E-mail: rwjun@126.com)



不同播栽方式下杂交籼稻茎秆生长和穗粒形成特点及与气象因子的关系

田青兰1刘波1孙红1何莎2钟晓媛1赵敏1任万军1,*

(1四川农业大学 农学院 / 农业部西南作物生理生态与耕作重点实验室 / 四川农业大学 生态农业研究所, 四川 温江611130;2成都市郫县气象局，四川 郫县 611730;*通讯联系人， E-mail: rwjun@126.com)

TIAN Qinglan, LIU Bo, SUN Hong, et al. Characteristics of stem growth and formation of grain ofindicahybrid rice in different planting methods and their correlation with meteorological factors . Chin J Rice Sci, 2016, 30(5): 507-524.

为探明不同播栽方式下杂交籼稻幼穗分化期茎秆和幼穗生长的规律及差异以进一步明确不同播栽方式穗粒形成特点，于2014年采用两因素裂区试验设计，研究了机直播、机插和手插3种播栽方式下2个不同穗粒型杂交籼稻组合[宜香优2115(中穗型)和F优498(大穗型)]的穗分化期茎秆和幼穗生长规律和穗粒形成特点，并分析了幼穗分化期气象因素与幼穗和茎秆生长的关系。结果表明：1)基部向上第1至第3伸长节间长度分别在抽穗前20 d、16 d、12 d后趋于稳定，故基部第1、2节间的降长增粗应在抽穗前16 d之前；穗干质量和穗茎比在抽穗前12 d后迅速增加。2)从抽穗前16 d开始至抽穗期，穗茎干重比与多数枝梗和颖花性状呈显著或极显著正相关，穗与茎秆竞争同化物的能力直接影响到穗粒形成。3)机插穗分化中后期穗茎干质量比较高，且抽穗期穗干质量显著高于手插和机直播，有利于提高其每穗粒数，且机插拔节后群体生长率及单茎和群体干物质积累量较高，抽穗期叶面积指数较高，粒叶比高于机直播，较机直播更利于粒重的提高和穗长及着粒数的增加；大穗型品种F优498抽穗期穗干质量显著高于中穗型品种宜香优2115，且穗分化后期穗茎干质量比高于宜香优2115，是其每穗粒数高的重要原因；F优498穗部着粒较密，较大的叶面积指数及粒叶比利于大穗的形成。4)机插全生育期最长，机直播最短，且机插穗分化期历时较长，穗分化期积温和日照时数较高，为穗粒形成提供了较好的温光条件；茎秆长度和干质量及穗长受气象因子影响较大，孕穗前适宜的温度和一定的积温有利于茎秆和幼穗伸长及茎秆的物质充实。生产上应针对不同播栽方式及品种的生育进程差异，适时采取措施调节茎秆和幼穗生长及物质分配，在培育壮秆的基础上提高穗分化期穗茎比以达到增粒增产的目的。

水稻； 穗； 茎秆； 穗粒形成； 机插； 机直播； 气象因子

幼穗分化期是产量构成因子的穗粒数形成的关键时期，水稻幼穗经历第一苞分化期、一次枝梗原基分化期、二次枝梗原基及颖花原基分化期、雌雄蕊形成期、花粉 母细胞形成期、花粉母细胞减数分裂期、花粉内容充实期和花粉完成期[1]，部分已分化的枝梗和颖花会在此过程中发生退化，现存的颖花则构成最终的每穗颖花数。不同播栽方式下杂交籼稻的颖花分化及退化存在显著差异[2]，而穗分化期幼穗和茎秆生长直接影响到颖花的分化及退化，因此，探明不同播栽方式间水稻幼穗分化期幼穗及茎秆生长进程、变化规律及差异，对进一步明确机械化播栽及手插的穗粒数形成规律有重要意义。已有研究表明，穗分化期温度条件[3,4]、氮肥施用量及时期[5-8]、播期[9,10]等均会影响水稻的穗茎生长。壮秆是大穗的组织结构和物质基础[11]。单茎茎鞘质量高的植株，茎鞘内贮藏性物质多，对提高结实率和粒重能起稳定性作用，是提高抗倒能力的物质基础[12]。穗分化期幼穗鲜质量大致呈“S”型曲线增长[6]，而穗相对于茎秆来说是一个较弱的库[13]，穗分化期穗与茎秆存在对同化物的竞争，水稻进入花粉母细胞形成期后，穗对于营养物质的竞争能力大于茎秆[6]。前期试验结果表明，不同播栽方式的分蘖特性[14]、氮素积累分配特性[15]、抗倒伏性[16]等均存在差异，机插较机直播和手插有大穗优势[17]，但对于不同播栽方式间水稻穗茎生长规律及差异还不明确。本研究以四川近年推广面积较大的2个不同穗粒型杂交中籼组合宜香优2115(中穗型)和F优498(大穗型)为材料，研究机直播、机插和手插3种播栽方式下水稻穗分化期的幼穗和茎秆生长规律及穗粒形成特点、物质积累与群体生长差异，并探究幼穗和茎秆生长与枝梗和颖花形成的关系以及穗分化期气象条件对幼穗和茎秆生长的影响，以期明确不同播栽方式穗粒数形成的规律，对优化机械化播栽的增产途径提供理论参考。

1　材料与方法

1.1试验地点及供试品种

试验于2014年在四川省成都市郫县三道堰镇程家船村(30°52′N，103°55′E)进行，试验点地处成都平原区，水稻季降水量为1067 mm，平均温度23.2 ℃，试验田前作为甘蓝，土壤类型为中壤土，pH值为6.71，0-20 cm土层有机质含量为28.14 g/kg，全氮含量为1.66 g/kg，全磷含量为0.77 g/kg，全钾含量为19.34 g/kg，碱解氮含量75.51 mg/kg，速效磷含量为183.66 mg/kg，速效钾含量为134.82 mg/kg。供试品种为杂交中籼迟熟组合宜香优2115(宜香1A×雅恢2115)和F优498(FS3A×蜀恢498)。宜香优2115为中穗型品种，每穗着粒数141，主茎伸长节间数为6个，主茎总叶数16片；F优498为大穗型品种，每穗着粒数为212，主茎伸长节间数为6个，主茎总叶数16～17片。

1.2试验设计与田间管理

于2014年采用两因素裂区试验设计。播栽方式(A)为主区(A1， 机直播，MD；A2，机插，MT；A3， 手插，HT)。不同穗粒型品种(B)为副区(B1，中穗型品种宜香优2115；B2，大穗型品种F优498)。主区及副区均随机排列，重复3次。机直播于2014年4月10日应用华南农业大学工学院研制的2BD-10精量穴直播机进行水直播，行穴距设为25 cm×19 cm，播量为5～6粒/穴；机插于4月10日采用钵形塑料软盘旱育秧，于5月10日选用洋马六行插秧机移栽，设定行穴距为30 cm×16 cm，2苗/穴；手插于4月10日播种，采用大田普通旱育，5月10日移栽，栽插行穴距为30 cm×16 cm，拉绳定点栽插，2苗/穴。机直播于播后30 d定苗至2苗/穴；机插和手插于栽后1 d定苗至2苗/穴。小区面积 36 m2(3 m×12 m)。施纯氮180 kg/hm2，按m基蘖肥∶m穗肥=6∶4施入，其中m基肥∶m分蘖肥=2∶1；m促花肥∶m保花肥=5∶5。按mN∶mP2O5∶mK2O=2∶1∶2确定磷、钾肥用量，磷肥作基肥一次性施用，钾肥按m基肥∶m穗肥(促花肥)=5∶5的比例施用。3种播栽方式的总施肥量一致，机直播的基肥在播种前2 d施用，机插和手插的基肥在移栽前2 d施用；机直播的分蘖肥于4～5叶期施用，机插和手插的分蘖肥于栽后10 d施用，促花肥和保花肥按其各自的生育进程在倒4叶和倒2叶抽出时施用。小区间用塑料薄膜包埂隔离，保证可以进行单独肥水管理。水分管理为够苗控水晒田，拔节期施肥时复浅水，然后再次落干，后以浅水层和干湿交替为主，抽穗后25～30 d，以湿润为主。收获前7～10 d，排水以保证田间硬实，以便收割。病虫草害防治等相关栽培措施均按照各自高产栽培要求实施。

1.3测定项目与方法

1.3.1穗茎生长动态测定

分蘖期每小区选取长势一致的200株植株将主茎挂牌，从穗分化开始至抽穗期，每4 d取样1次，每次取挂牌主茎15根，将叶片摘下，茎鞘则剥离为茎秆和叶鞘，穗分化前期将幼穗在体视显微镜下剥离，拍照并用配套软件测量穗长，穗分化后期直接用直尺测量穗长，并用直尺测量每根茎秆各伸长节间的长度，用数显游标卡尺测量各伸长节间的长轴直径和短轴直径，将测量后的茎秆按伸长节间的节位进行切分，相同节位的伸长节间放在一起，将叶片、叶鞘、穗及不同节位伸长节间分别装于牛皮纸袋中，置于80℃恒温烘箱中烘干至恒重并称重。茎秆基部向上的伸长节间依次记为N1～N6，单个茎秆的质量为各节间质量之和，单个茎秆的长度为各节间长度总和；外径为长轴直径(mm)与短轴直径(mm)的平均值；节间扁平率(%)=(1-短轴直径/长轴直径)×100；秆型指数=外径(cm)/节间长度(cm)，穗(茎秆)干质量增长速率(%)=[抽穗前nd穗(茎秆)干质量-抽穗前n+4 d穗(茎秆)干质量]/4×100。文中数据均为样本的平均值即单个主茎的指标。

1.3.2枝梗和颖花性状测定

齐穗期每小区选取长势一致的挂牌主茎10根，用于枝梗及颖花分化、退化的测定，观察并记录每穗一次枝梗及着生其上的一次颖花、二次枝梗及着生其上的二次颖花、三次枝梗(着生在二次枝梗上的枝梗)及着生其上的三次颖花的退化数及现存数，每穗枝梗及颖花的分化数为退化数与现存数的总和。此部分相关数据已发表[17]，在本文中仅用于相关分析。

1.3.3主要生育时期干物质量的测定

于拔节期、抽穗期、成熟期每小区调查20穴茎蘖数，按平均茎蘖数取样2穴，剪除根部后洗净并装于牛皮纸袋中，150℃下杀青1 h后于80℃恒温烘箱中烘干至恒重并称重。各生育时期群体生长率(g/m2·d)=(W2-W1)/(t2-t1)。式中，W1和W2分别指前后两次测定的干物质量，t2-t1指前后两次测定相隔的天数。

1.3.4叶面积及收获的穗部性状测定

抽穗期将用于测定干物质的植株样用长宽系数法(校正系数取0.75)测定倒3叶及其余叶的叶面积并计算高效叶面积率及叶面积指数。成熟期每小区调查60穴的有效穗数，按平均穗数取样5穴，考查穗长、单穗实粒质量、每穗着粒数及实粒数，计算着粒密度及粒叶比。颖花叶面积比(粒/cm2)=每穗着粒数×单位面积有效穗/抽穗期单位面积叶面积；实粒叶面积比(粒/cm2)=每穗实粒数×单位面积有效穗/抽穗期单位面积叶面积；粒重叶面积比(mg/cm2)=单穗实粒质量×单位面积有效穗/抽穗期单位面积叶面积。

1.3.5气象数据的收集

相关气象数据资料来源于四川成都郫县气象局，包括2014年四川郫县三道堰镇4月初至9月中旬的气象数据。

1.4数据处理

用Microsoft Excel 进行数据的输入、整理及作图；用DPS 7.05系统进行数据的方差分析，并采用LSD法进行样本平均数的多重比较；用SPSS 18 软件进行数据的相关分析。

2　结果与分析

2.1不同播栽方式下杂交籼稻茎秆和穗的生长规律及差异

2.1.1茎秆生长特点

中籼迟熟杂交稻的穗分化期开始于拔节期，结束于抽穗期。由图1可以看出，茎秆长度从穗分化始期至抽穗前8 d大致呈线性缓慢增长，之后增长迅速，这主要是由于穗颈节间在抽穗前8 d开始迅速伸长。不同播栽方式间，茎秆长度机插和手插高于机直播，两品种一致。而F优498抽穗期茎秆略长于宜香优2115。

穗分化期茎秆基部节间陆续长出并伸长，各伸长节间的长度变化有一定规律。由图2可以看出，N1长度在抽穗前20 d后趋于稳定，N2长度在抽穗前20 d之前增长较快，在抽穗前16 d之后趋于稳定；N3长度在抽穗前12 d之前增长迅速，之后趋于稳定。N4、N5和N6抽穗期时仍在伸长，尚未达到最终长度。其中，宜香优2115的N4在抽穗前20 d之后一直稳定持续快速伸长，而F优498的N4在抽穗期伸长放缓；N5在抽穗前12 d开始迅速伸长，N6在抽穗前8 d开始迅速伸长，且N1～N4的最终长度随节位上升而增加。比较不同播栽方式的差异可知，除N3及F优498的N4外，幼穗分化期的N1～N5长度均为机插大于手插和机直播，抽穗期N6长度为机插和手插大于机直播，两品种一致；品种间比较可知，抽穗期N1～N4长度宜香优2115长于F优498，N5、N6长度则为F优498长于宜香优2115。

由于N1～N3的节间形态在抽穗前12 d后均趋于稳定，故将N1、N2、N3在抽穗前12 d至抽穗期的节间性状取平均值进行方差分析。由表1可知，各播栽方式间和品种间的基部伸长节间性状存在较大差异。N1和N2的长度均表现为机插>手插>机直播，其中，机插N1和N2长度较机直播分别长24.3%和12.1%，差异达极显著，各播栽方式N3长度差异不大；品种间为宜香优2115的N1和N2长度显著或极显著大于F优498。N1、N2、N3长轴直径和短轴直径均为手插>机插>机直播，且手插和机插显著大于机直播，品种间差异不大。N1、N2扁平率为手插和机插大于机直播，N3的扁平率为宜香优2115显著高于F优498。N1、N2、N3的外径均为手插和机插显著或极显著大于机直播，且机直播中为宜香优2115大于F优498，在手插中则相反。此外，机插的N1和N2的秆型指数最小，各播栽方式N1和N2的秆型指数均为F优498大于宜香优2115。由以上分析可以看出，手插基部伸长节间短而粗，而机直播基部节间较细，机插基部伸长节间则较长。

2.1.2幼穗生长特点

穗分化期穗与茎秆同步伸长，由图3可以看出，穗长大致呈“S”型曲线增长，在抽穗前16d到抽穗前8 d这一阶段增长最快，随后缓慢增长并趋于稳定。不同播栽方式间，机插穗长高于机直播和手插，两品种一致。由图4和图5可以看出，不同播栽方式下杂交籼稻穗分化期的穗干质量增加趋势为穗分化始期至抽穗前16 d增长缓慢，抽穗前12 d至抽穗期持续快速增长，穗茎干质量比与穗干质量变化趋势一致。抽穗前24 d至抽穗前4 d宜香优2115的机插处理的穗干质量增长速率均明显快于手插和机直播。抽穗前4 d和抽穗期穗干质量表现为机插(分别为0.71 g和1.04 g)显著或极显著高于手插(分别为0.52 g和0.90 g)和机直播(分别为0.56 g和0.84 g)，而F优498穗干质量显著高于宜香优2115；抽穗前12 d至抽穗期，宜香优2115的穗茎干质量比表现为机插>机直播>手插，F优498各播栽方式间差异不大但以机插较高，且F优498穗分化后期穗茎干质量比均高于宜香优2115。

MD-机直播； MT-机插； HT-手插。下同。

MD, Mechanized direct-seeding; MT, Mechanized transplanting; HT, Hand transplanting. The same as below.

图1不同栽插方式下籼稻穗分化期茎秆长度变化

Fig.1. Changes in the length of stem of indica hybrid rice at the panicle differentiation stage in various planting methods.

图2不同栽插方式下籼稻穗分化期各伸长节间(N1～N6)的长度变化

Fig. 2. Change in the length of N1-N6 elongated internodes ofindicahybrid rice at the panicle differentiation stage in various planting methods.

表1不同栽插方式下杂交籼稻基部伸长节间性状比较

Table 1. Comparison of the characters of basal elongated internodes of indica hybrid rice in various planting methods.

播栽方式Plantingmethod长度Length/cmN1N2N3长轴直径Longaxisdiameter/mmN1N2N3机直播MD 宜香优2115YXY21152.54±0.44a7.58±0.79Aa10.47±0.42a7.02±0.197.07±0.12 6.55±0.10 F优498FY4982.03±0.16b6.02±0.4Bb9.43±0.55b6.73±0.016.95±0.076.47±0.01机插MT 宜香优2115YXY21153.18±0.31a8.48±0.14Aa9.89±0.657.34±0.207.36±0.116.78±0.08 F优498FY4982.50±0.33b6.75±0.41Bb10.15±0.357.35±0.227.36±0.296.75±0.22手插HT 宜香优2115YXY21152.96±0.47a7.65±0.78a10.74±0.247.39±0.34b7.48±0.176.74±0.06 F优498FY4982.45±0.11a6.35±0.37b10.01±0.717.92±0.23a7.47±0.146.86±0.10平均值Mean 机直播MD2.29±0.36Bb6.80±1.1Bb9.95±0.736.87±0.2Bc7.01±0.09Bb6.51±0.06Bb 机插MT2.84±0.48Aa7.62±1.22Aa10.02±0.197.34±0.004Ab7.36±0.002ABa6.76±0.02Aa 手插HT2.71±0.36Aa7.00±0.91Bb10.38±0.517.65±0.37Aa7.47±0.004Aa6.80±0.08Aa 宜香优2115YXY21152.90±0.32Aa7.90±0.50Aa10.37±0.43a7.25±0.207.30±0.216.69±0.12 F优498FY4982.54±0.44a7.58±0.79Aa10.47±0.42a7.33±0.597.26±0.286.69±0.20F值Fvalue 播栽方式PM21.05**20.41**1.5435.24**16.93*31.90** 品种V15.87**38.48**6.32*0.860.430.00 播栽方式×品种PM×V0.150.263.89(*)7.33*0.351.06播栽方式Plantingmethod短轴直径Shortaxisdiameter/mmN1N2N3扁平率Oblaterate/%N1N2N3机直播MD 宜香优2115YXY21156.42±0.12a6.29±0.045.74±0.048.53±1.0511.03±0.9312.32±0.84a F优498FY4986.19±0.06b6.24±0.115.78±0.108.06±0.8810.10±1.8710.61±1.35b机插MT 宜香优2115YXY21156.61±0.196.67±0.075.98±0.089.91±0.959.38±1.7811.69±0.26a F优498FY4986.45±0.166.63±0.256.11±0.2512.16±0.879.88±0.629.53±0.69b手插HT 宜香优2115YXY21156.68±0.196.49±0.105.89±0.03b9.47±1.85b13.20±1.34a12.54±0.75Aa F优498FY4986.75±0.306.81±0.266.21±0.15a14.64±2.76a8.72±2.60b9.36±0.92Bb平均值Mean 机直播MD6.30±0.16Bb6.27±0.04b5.76±0.03Bb8.29±0.34b10.56±0.6611.45±1.21 机插MT6.53±0.11ABa6.65±0.03a6.05±0.09Aa11.01±1.59a9.63±0.3610.58±1.53 手插HT6.72±0.05Aa6.65±0.23a6.05±0.23Aa11.94±3.65a10.86±3.1710.90±2.25 宜香优2115YXY21156.57±0.146.48±0.195.87±0.129.30±0.70b11.16±1.9212.18±0.44Aa F优498FY4986.46±0.286.56±0.296.03±0.2311.47±3.32a9.56±0.749.83±0.68BbF值Fvalue 播栽方式PM15.85*13.74*16.78*10.04*0.631.52 品种V3.060.945.25(*)7.60*3.88(*)27.86** 播栽方式×品种PM×V2.222.271.393.88(*)3.231.00

同列同一项中标以不同大小写字母分别表示其值差异达0.01和0.05显著水平,未标注字母的均未达显著性差异；(*),*和**分别表示差异达到0.1、0.05和0.01显著水平。下表同。

Values within a column and item followed by different uppercase and lowercase letters are significantly different atP<0.01 andP<0.05, respectively. Values which have no markers are not significantly different. (*),*,**Denote significant difference at the 0.1, 0.05 and 0.01 probability levels， respectively. MD-Mechanized direct-seeding; MT-Mechanized transplanting; HT-Hand transplanting; PM-Planting method; V-Varieties; YXY2115-Yixiangyou 2115; FY498-F you 498; The same as below.

续表1：

播栽方式Plantingmethod外径Stemdiameter/mmN1N2N3秆型指数StemtypeindexN1N2N3机直播MD 宜香优2115YXY21156.72±0.15a6.68±0.086.15±0.070.270±0.045b0.089±0.009Bb0.059±0.002b F优498FY4986.46±0.03b6.59±0.076.13±0.050.320±0.026a0.110±0.006Aa0.065±0.004a机插MT 宜香优2115YXY21156.98±0.197.01±0.066.38±0.080.220±0.015b0.083±0.002Bb0.065±0.004 F优498FY4986.90±0.186.99±0.276.43±0.240.278±0.032a0.104±0.003Aa0.063±0.001手插HT 宜香优2115YXY21156.68±0.197.04±0.26b6.98±0.136.32±0.040.240±0.027b0.092±0.007Bb0.059±0.001b F优498FY4987.34±0.24a7.14±0.196.53±0.120.300±0.024a0.113±0.009Aa0.066±0.006a平均值Mean 机直播MD6.59±0.18Bc6.64±0.06Bb6.14±0.01Bb0.295±0.035a0.099±0.015ab0.062±0.004 机插MT6.94±0.06ABb7.00±0.01Aa6.40±0.04Aa0.249±0.041b0.093±0.015b0.064±0.001 手插HT7.19±0.21Aa7.06±0.11Aa6.43±0.15Aa0.270±0.042ab0.102±0.015a0.062±0.005 宜香优2115YXY21156.91±0.176.89±0.186.28±0.120.243±0.025Bb0.088±0.005Bb0.061±0.003b F优498FY4986.90±0.446.91±0.286.36±0.210.299±0.021Aa0.109±0.005Aa0.065±0.001aF值Fvalue 播栽方式PM30.94**19.59**24.14**5.31(*)8.80*0.74 品种V0.030.061.7521.98**47.37**6.32* 播栽方式×品种PM×V6.04*1.131.270.060.002.84

2.1.3粒叶比及收获后穗部性状

粒叶比是衡量植株源库是否协调的重要指标。由表2可知，虽不同播栽方式抽穗期高效叶面积率无差异，但机插和机直播的叶面积指数高于手插。而粒叶比手插和机插高于机直播，其中，颖花叶面积比手插和机插分别较机直播高19.30%和10.97%，实粒叶面积比手插和机插较机直播分别高17.47%和7.34%，粒重叶面积比手插和机插分别较机直播高17.85%和7.00%。品种间，宜香优2115的叶面积指数高于F优498，但F优498的颖花叶面积比、实粒叶面积比和粒重叶面积比均极显著高于宜香优2115，3种播栽方式一致。收获的单穗实粒重和着粒密度为手插和机插大于机直播，F优498极显著大于宜香优2115。此外，播栽方式对穗长有显著影响，机插的穗长显著长于手插，极显著高于机直播，而宜香优2115的穗长显著长于F优498。由以上结果可以看出，机插叶面积指数较高，且粒叶比高于机直播，较机直播更利于粒重的提高和穗长及着粒数的增加；F优498着粒较密，较大的叶面积指数及粒叶比利于其大穗的形成。

图3不同栽插方式下籼型杂交稻穗分化期穗长变化

Fig. 3. Change of the length of panicle of indica hybrid rice at the panicle differentiation stage in various planting methods.

图4不同栽插方式下籼型杂交稻穗分化期每穗干质量变化

Fig. 4. Change of panicle dry weight of indica hybrid rice at the panicle differentiation stage in various planting methods.

图5不同栽插方式下籼型杂交稻穗分化期穗茎干质量比变化

Fig. 5. Change of the dry weight ratio of panicle to stem of indica hybrid rice at the panicle differentiation stage in various planting methods.

2.2不同播栽方式下杂交籼稻物质积累与群体生长

2.2.1穗分化期各器官物质积累与分配变化

穗分化期不仅穗干质量在持续增长，叶片、叶鞘、茎秆干质量整体也呈上升趋势(表3)。由表3可知，叶片干质量在抽穗前24 d和抽穗前20 d为手插>机直播>机插，抽穗前12 d至抽穗期则为机插>手插>机直播。叶鞘干质量在抽穗前12 d至抽穗期均为机插>手插>机直播，且抽穗前12 d和抽穗前8 d达显著差异；抽穗前12 d F优498的叶鞘干质量高于宜香优2115，而抽穗期则为宜香优2115高于F优498。抽穗前24 d至抽穗期茎秆干质量均为机插高于手插和机直播，且除抽穗前20 d外，均达显著或极显著差异；抽穗前12 d至抽穗期宜香优2115茎秆干质量均高于F优498，各播栽方式一致。

表2不同播栽方式下杂交籼稻粒叶比及收获后穗部性状

Table 2. Grain leaf ratio and character of harvested panicle of indica hybrid rice in different planting methods.

播栽方式与品种PMandV高效叶面积率HELR/%叶面积指数LAA颖花叶面积比RSLA/(粒·cm-2)实粒叶面积比RFSLA/(粒·cm-2)机直播MD 宜香优2115YXY211568.85±1.349.92±0.19a0.34±0.03Bb0.31±0.01Bb F优498FY49868.99±1.718.58±1.63b0.55±0.06Aa0.51±0.06Aa机插MT 宜香优2115YXY211564.36±0.949.43±0.620.41±0.04Bb0.35±0.05Bb F优498FY49862.37±6.119.10±0.410.58±0.03Aa0.53±0.03Aa手插HT 宜香优2115YXY211566.80±1.939.70±0.24Aa0.38±0.04Bb0.33±0.04Bb F优498FY49867.53±5.776.93±0.21Bb0.68±0.05Aa0.63±0.04Aa平均值Mean 机直播MD68.92±0.109.25±0.940.44±0.15b0.41±0.15 机插MT63.37±1.419.26±0.230.49±0.12ab0.44±0.13 手插HT67.17±0.528.32±1.960.53±0.22a0.48±0.21 宜香优2115YXY211566.68±2.259.68±0.25Aa0.37±0.03Bb0.33±0.02Bb F优498FY49866.33±3.488.21±1.13Bb0.6±0.07Aa0.56±0.06AaF值Fvalue 播栽方式PM3.792.755.39(*)3.42 品种V0.0619.36**150.05**209.07** 播栽方式×品种PM×V0.294.47(*)4.31(*)5.62*播栽方式与品种PMandV粒重叶面积比RGWLA/(mg·cm-2)单穗实粒重GWPP/g穗长LP/cm着粒密度GD/(粒·cm-1)机直播MD 宜香优2115YXY211510.28±0.33Bb3.89±0.14Bb25.47±0.48a5.03±0.28Bb F优498FY49814.96±1.76Aa5.26±0.54Aa25.11±0.71a7.71±0.94Aa机插MT 宜香优2115YXY211511.95±1.44b4.51±0.44Bb28.74±0.14Aa5.33±0.32Bb F优498FY49815.06±1.13a5.78±0.72Aa26.84±0.37Bb8.26±0.47Aa手插HT 宜香优2115YXY211511.15±1.31Bb4.27±0.27Bb27.48±0.32a5.26±0.18Bb F优498FY49818.6±1.41Aa6.03±0.11Aa26.29±0.61b8.41±0.16Aa平均值Mean 机直播MD12.62±3.31b4.58±0.9725.29±0.25Bc6.37±1.89 机插MT13.51±2.2ab5.15±0.9027.79±1.35Aa6.79±2.08 手插HT14.87±5.27a5.15±1.2526.88±0.84Ab6.84±2.23 宜香优2115YXY211511.13±0.83Bb4.23±0.31Bb27.23±1.65Aa5.21±0.16Bb F优498FY49816.21±2.07Aa5.69±0.39Aa26.08±0.88Bb8.13±0.37AaF值Fvalue 播栽方式PM4.135.39(*)47.19**2.09 品种V86.39**150.05**22.17**171.41** 播栽方式×品种PM×V5.38*4.31(*)3.360.38

HELR, High effective leaf area ratio; LAA, Leaf area index; RSLA, Ratio of spikelets to leaf area; RFSLA, Ratio of filled spikelets to leaf area; RGWLA, Ratio of grain weight to leaf area; GWPP, Grain weight per panicle; LP, Length of panicle; GD, Grain density.

比较穗分化期各播栽方式下的杂交籼稻各器官干物质分配比例变化(图6)，发现穗分化中后期叶片和叶鞘的干物质分配比例整体呈阶梯下降的趋势，而茎秆和穗的干物质分配比例整体呈上升趋势，两品种一致。穗分化期叶片和叶鞘所占的干物质比例最大且为主要部分，穗占比最小。其中，抽穗前24 d叶片、叶鞘、茎秆和穗所占的干物质比例分别为40%～51%、34%～42%、13%～17%、0.03%～0.06%；抽穗前12 d叶片、叶鞘、茎秆和穗所占的干物质比例分别为33%～38%、34%～38%、21%～29%、1%～4.6%。随着穗分化进程，穗和茎秆不断生长，抽穗期叶片、叶鞘所占的干物质比例分别下降为25%～28%、29%～31%，而茎秆和穗的占比分别增加至24%～29%、12%～19%。说明穗分化中后期茎秆和穗较叶和叶鞘对同化物的需求更大。

不同播栽方式间，抽穗前24 d至抽穗期，叶片干质量占比均为手插高于机直播和机插。各播栽方式间叶鞘干质量占比差异不大，品种间差异主要在抽穗前16 d和抽穗前12 d，为F优498高于宜香优2115。除抽穗前8 d外，茎秆干质量占比均为机插高于机直播和手插，抽穗前12 d至抽穗期各播栽方式的茎秆干质量占比均为F优498高于宜香优2115。抽穗前24 d至抽穗期穗干质量占比为机插和机直播高于手插，F优498高于宜香优2115。

2.2.2各生育时期物质积累与群体生长率

由表4可以看出，不同播栽方式抽穗期及成熟期单茎干物质量差异较大，均为机插>手插>机直播，而群体干物质量在拔节期以机直播最高，抽穗期和成熟期则为机插最高。群体生长率播种至拔节期以机直播最高，而拔节至抽穗期和抽穗至成熟期则以机插最高，两品种差异不大。故机直播生长优势在拔节前，但后劲不足；机插的生长优势则在拔节后，其群体生长率增加，物质积累也随之增加。

2.3穗茎生长与枝梗和颖花分化及退化的关系

不同播栽方式间，机插有较高的总枝梗数和总颖花数[17]。穗粒形成于穗分化期，其主要构成因子包括一次、二次枝梗数和一次、二次颖花数，相关分析表明，总枝梗数和总颖花性状与穗干质量普遍正相关，而与茎秆干质量普遍呈负相关，但后者大多未达显著相关(表5)。进一步分析穗茎物质竞争与协调和枝梗与颖花分化及退化的关系(表6)，从抽穗前16 d开始直至抽穗期，穗茎干质量比对枝梗和颖花性状产生较大影响，与多数枝梗和颖花性状呈显著或极显著正相关；抽穗前20 d至抽穗前12 d的穗干质量增长速率及抽穗前8～4 d的穗茎干质量增长速率之比也与多数枝梗和颖花性状呈显著或极显著正相关，而抽穗前8～4 d茎秆干质量增长速率与总枝梗和总颖花现存数、分化数等性状呈显著负相关。由此可知，穗分化期穗与茎秆竞争同化物的能力直接影响到枝梗和颖花形成。

表3不同栽插方式下杂交籼稻穗分化期各器官的干质量变化

Table 3. Change of the dry matter of different organs of indica hybrid rice in panicle differentiation stage in various planting methods.g

同一行同一项中标以不同大小写字母分别表示其值差异达0.01和0.05显著水平。DBH，抽穗前天数。

Values within a line and item flanked by different capital and small letter are significantly different atP<0.01 andP<0.05，respectively. DBH,Days before heading.

表4不同栽插方式下杂交籼稻各生育时期物质积累与群体生长率

Table 4. Dry matter weight during various growth stage and crop growth rate of indica hybrid rice in different planting methods.

DMWS, Dry matter weight per stem; DMWP, Dry matter weight of population; CGR, Crop growth rate; S-J, Seeding-Jointing; J-H, Jointing-Heading; H-M, Heading-Maturity.

图6不同栽插方式下杂交籼稻穗分化期各器官干物质分配比例变化

Fig.6. Change of the ratio of dry matter in different organs at the panicle differentiation stage of indica hybrid rice in different planting methods.

表5不同栽插方式下籼型杂交稻穗分化期茎秆和穗生长与总枝梗和总颖花性状的相关分析1)

Table 5. Correlation analysis of the growth of stem and panicle with rachis branches and spikelets characters of indica hybrid rice at the panicle differentiation stage in various planting methods(n=18).1)

抽穗前天数与性状Daysbeforeheadingandcharacter总颖花现存数SS总颖花退化数RS总颖花分化数DS总颖花退化率RPS总枝梗退化数RB总枝梗现存数SB总枝梗分化数DB总枝梗退化率RPB24DBH 茎秆长LS-0.088-0.195-0.14-0.254-0.539*-0.077-0.298-0.734** 茎秆干质量DWS0.168-0.1480.048-0.329-0.2930.146-0.048-0.538* 穗长LP-0.139-0.236-0.191-0.218-0.509*-0.130-0.316-0.607** 穗干质量DWP0.4530.1510.362-0.0630.0460.4680.306-0.30020DBH 茎秆长LS-0.162-0.333-0.248-0.383-0.598**-0.161-0.376-0.748** 茎秆干质量DWS0.161-0.080.072-0.188-0.0390.1560.077-0.205 穗长LP0.1570.2710.2190.3490.4090.1780.2990.456 穗干质量DWP0.0900.0570.0830.0780.3230.0760.1960.41216DBH 茎秆长LS-0.061-0.224-0.135-0.254-0.447-0.059-0.244-0.577* 茎秆干质量DWS-0.111-0.196-0.156-0.147-0.394-0.093-0.239-0.480* 穗长LP0.4100.3320.4110.2370.497*0.4200.486*0.366 穗干质量DWP0.556*0.486*0.572*0.3350.680**0.560*0.656**0.525*12DBH 茎秆长LS-0.050-0.157-0.100-0.186-0.369-0.063-0.210-0.445 茎秆干质量DWS-0.109-0.155-0.138-0.150-0.509*-0.097-0.296-0.629** 穗长LP0.475*0.3080.4430.0310.3500.485*0.4570.076 穗干质量DWP0.601**0.507*0.610**0.2650.543*0.625**0.632**0.2588DBH 茎秆长LS0.172-0.0100.109-0.135-0.2120.139-0.014-0.423 茎秆干质量DWS-0.119-0.098-0.120-0.064-0.393-0.110-0.25-0.498* 穗长LP0.3140.0520.229-0.1420.0310.3150.206-0.259 穗干质量DWP0.673**0.3290.582*0.0170.4210.674**0.605**0.0394DBH 茎秆长LS0.2310.1820.2290.1340.0410.2200.152-0.126 茎秆干质量DWS-0.403-0.452-0.457-0.322-0.674**-0.41-0.563*-0.623** 穗长LP-0.221-0.312-0.278-0.240-0.567*-0.215-0.394-0.620** 穗干质量DWP0.689**0.469*0.652**0.2300.496*0.677**0.642**0.1710DBH 茎秆长LS0.542*0.2310.455-0.109-0.0080.533*0.320-0.468 茎秆干质量DWS-0.230-0.438-0.337-0.446-0.654**-0.249-0.456-0.729** 穗长LP-0.378-0.489*-0.456-0.397-0.783**-0.375-0.592**-0.783** 穗干质量DWP0.878**0.677**0.865**0.3100.653**0.871**0.832**0.209

1)枝梗和颖花性状相关内容已发表，详见参考文献[17]。*和**分别表示达到0.05和0.01显著水平,下同。

1)denote the contents of branches and spiklets was published, please see reference [17].*,**Significance at the 0.05 and 0.01 probability levels， respectively. LS， Length of stem; DWS， Dry weight of stem; LP， Length of panicle; DWP， Dry weight of panicle; SS, Survived spikelets; RS, Retrograded spikelets; DS, Differentiated spikelets; RPS, Retrograded percentage of spikelets; RB, Retrograded branches; SB, Survived branches; DB, Differentiated branches; RPB, Retrograded percentage of branches. The same as below.

2.4各生育时期气象条件差异及与穗茎生长的关系

不同播栽方式的生育进程不同，必然会对穗茎生长产生影响。比较不同播栽方式间生育进程，由图7可知，机直播全生育期较机插和手插分别缩短了5 d和3 d(宜香优2115)、7 d和4 d(F优498)，主要是因为机直播没有移栽和返青环节，生育进程加快，而宜香优2115全生育期较F优498长8～10 d。机插孕穗前生育进程较慢而孕穗后生育进程加快，其穗分化期历时较长，而F优498穗分化期较宜香优2115短。比较各生育时期气象条件(表7)可知，机插在孕穗前积温高于机直播和手插，而孕穗后的积温低于机直播和手插，但机插全生育期积温最高；此外，机插拔节至抽穗期日照时数高于机直播和手插，为穗粒形成提供了较好的条件。

表6不同栽插方式下籼型杂交稻茎秆和穗物质竞争与枝梗和颖花性状的关系1)

Table 6. Relationship of competing in assimilate between stem and panicle of indica hybrid rice which with branches and spikelets characters in various planting methods1)(n=18).

枝梗和颖花参数Parametersofrachisbranchesandspikelets穗茎干质量比Dryweightratioofpanicletostem16DBH12DBH8DBH4DBH0DBH穗干质量增长速率WIP20DBH～16DBH16DBH～12DBH茎秆干质量增长速率WIS8DBH～4DBH穗与茎秆干质量增长速率之比RWIPS8DBH～4DBH一次枝梗退化数RPB0.3500.3450.2820.3380.3880.2260.1520.193-0.098一次枝梗现存数SPB0.737**0.681**0.567*0.716**0.901**0.699**0.621**-0.2970.540*一次枝梗分化数DPB0.747**0.690**0.574*0.726**0.908**0.698**0.613**-0.2710.517*一次枝梗退化率RPPB0.3280.3220.2610.3150.3700.2110.1330.186-0.104一次颖花退化数RPS0.770**0.608**0.602**0.755**0.887**0.783**0.416-0.3490.506*一次颖花分化数DPS0.2770.3600.2100.2140.3320.1330.4330.0970.080一次颖花退化率RPPS0.790**0.698**0.613**0.746**0.917**0.727**0.575*-0.2440.471*二次枝梗退化数RSB0.765**0.597**0.599**0.748**0.877**0.784**0.398-0.3530.505*二次枝梗现存数SSB0.856**0.661**0.604**0.722**0.875**0.773**0.420-0.3410.498*二次枝梗分化数DSB0.609**0.513*0.686**0.795**0.860**0.693**0.529*-0.553*0.739**二次枝梗退化率RPSB0.783**0.633**0.708**0.828**0.944**0.792**0.525*-0.493*0.679**一次枝梗退化数RPB0.627**0.4350.2100.3060.4450.4530.1050.0080.063二次颖花现存数SSS0.609**0.511*0.688**0.793**0.850**0.699**0.525*-0.550*0.727**二次颖花分化数DSS0.610**0.502*0.589*0.765**0.888**0.693**0.511*-0.602**0.779**二次颖花退化率RPSS0.3810.3210.0560.3560.529*0.4170.276-0.2930.516*二次颖花退化数RSS0.4590.3650.2050.490*0.669**0.507*0.341-0.475*0.675**三次枝梗退化数RTB0.1860.1770.1600.3930.574*0.2640.335-0.4640.672**三次枝梗现存数STB0.3000.4420.511*0.4620.523*0.4570.636**-0.549*0.568*三次枝梗分化数DTB0.2870.3560.3780.499*0.665**0.4120.557*-0.571*0.715**三次枝梗退化率RPTB-0.227-0.351-0.434-0.164-0.157-0.297-0.3700.2180.006三次颖花现存数STS0.2150.3390.555*0.513*0.4480.3650.562*-0.556*0.621**三次颖花分化数DTS0.1950.2870.2550.390.574*0.3290.522*-0.550*0.665**三次颖花退化率RPTS0.1960.1340.0850.2070.2390.1840.0670.0150.178三次颖花退化数RTS0.2630.3260.2730.4510.646**0.3850.523*-0.538*0.711**总颖花现存数SS0.605**0.526*0.686**0.783**0.845**0.681**0.555*-0.528*0.713**总颖花退化数RS0.536*0.4610.3490.609**0.807**0.605**0.463-0.531*0.740**总颖花分化数DS0.625**0.542*0.599**0.773**0.898**0.704**0.562*-0.572*0.783**总颖花退化率RPS0.3580.2730.0400.3400.512*0.3980.220-0.3270.505*总枝梗退化数RB0.777**0.611**0.557*0.724**0.906**0.729**0.451-0.4180.611**总枝梗现存数SB0.604**0.544*0.682**0.776**0.854**0.692**0.582*-0.558*0.732**总枝梗分化数DB0.728**0.614**0.673**0.808**0.940**0.759**0.563*-0.533*0.729**总枝梗退化率RPB0.622**0.4210.2360.4080.581*0.483*0.158-0.1100.256

RPB， Retrograded primary rachis branches; SPB， Survived primary rachis branches; DPB， Differentiated primary rachis branches; RPPB， Retrograded percentage of primary rachis branches; RPS， Retrograded primary spikelets; DPS， Differentiated primary spikelets; RPPS， Retrograded percentage of primary spikelets; RSB， Retrograded secondary rachis branches; SSB， Survived secondary rachis branches; DSB， Differentiated secondary rachis branches; RPSB， Retrograded percentage of secondary rachis branches; RSS， Retrograded secondary spikelets; SSS， Survived secondary spikelets; DSS， Differentiated secondary spikelets; RPSS， Retrograded percentage of secondary spikelets; STB， Survived third branches; DTB， Differentiated third branches; RTS， Retrograded third spikelets; STS， Survived third spikelets; DTS， Differentiated third spikelets; RPTS， Retrograded percentage of third branches.

参照穗分化期的日均温度和降雨量(图8)可知，穗分化期日均温度在20℃至29℃间波动，日最高气温在22℃～36℃间变化，但降雨量变幅较大。进一步分析穗分化期气象因子与穗茎生长的关系，发现抽穗前31～28 d、抽穗前23～20 d以及抽穗前15～12 d是气象因子对穗茎生长影响较大的时段。表8中列出了抽穗前12 d(接近孕穗期)及抽穗期的穗茎性状与气象因子的相关系数。从表中可以看出，抽穗前12 d茎秆长度和干质量与抽穗前31～28 d、抽穗前23～20 d以及抽穗前15～12 d的多数气温因素呈显著或极显著正相关；抽穗前12 d穗长和穗干质量与气象因子呈负相关，且与抽穗前23～20 d平均气温及积温相关性达到极显著。抽穗期茎秆长度和穗干质量受气象因子影响不大；抽穗前31～28 d、抽穗前23～20 d以及抽穗前15～12 d的积温(≥10℃)、最高气温及平均气温与抽穗期茎秆干质量和穗长呈显著或极显著正相关。

柱形图中的数值表示该时段经历的天数(d)

Values in the column chart donate the number of days in that period.

图7不同播栽方式下杂交籼稻的生育进程

Fig. 7. Growing process of indica hybrid rice under different planting methods.

图8不同栽插方式下籼型杂交稻穗分化期温度和降雨量

Fig. 8. Temperature and rainfall at the panicle differentiation stage in various planting of indica hybrid rice methods.

3　讨论

3.1不同播栽方式下杂交籼稻茎秆生长和穗粒形成特点

茎秆是水稻植株的重要器官，除具有支撑、联络、输导、光合和贮藏功能外，还有合理配置叶系，改善受光姿态，提高光合效能的作用[18]，与植株抗倒伏及产量有密切关系[19-21]。水稻生长过程中，叶鞘、叶和节间相继伸长。拔节后的节间长度一般随节间序数的增加而增加，且栽培措施对秆长有显著影响[22]。茎秆节间发育经历组织分化、伸长增粗和物质充实三个时期，而伸长增粗是同一时期完成[23]。本研究发现，茎秆的伸长存在一定规律，基部向上第1至第3伸长节间长度分别在抽穗前20 d、16 d、12 d后趋于稳定，N5和N6则分别在抽穗前12 d和8 d开始迅速伸长，以助力抽穗。基部第1和第2伸长节间形态与植株抗倒伏性密切相关[24]，因此，生产上可根据不同播栽方式及品种的生育进程，在抽穗前16 d前采取措施使基部第1、2节间降长增粗以达到提高抗倒能力的目的。水稻基部伸长节间过长不利于抗倒伏[24]，手插基部伸长节间短而粗，而机直播基部节间较细，机插基部节间较长，因而手插基部节间形态更利于抗倒伏。机插和机直播可通过适宜穴苗数栽插[16]、化控[25]及优化养分管理等构建合理的群体结构实现高产与抗倒的协调。

表7不同播栽方式下杂交籼稻各生育时期气象条件比较

Table 7. Comparison of the meteorologic conditions in growth stages of indica hybrid rice in different planting methods.

指标Index播栽方式PM宜香优2115Yixiangyou2115机直播MD机插MT手插HTF优498Fyou498机直播MD机插MT手插HT≥10℃积温播种-拔节期Seeding-jointing1518.71626.31603.11468.51583.21562.5Accumulated拔节-孕穗期Jointing-booting560.9732.8625.3508.4594.7483.4temperature孕穗-抽穗期Booting-heading372.1299.1270.4309.7320.9313.2above10℃抽穗-成熟期Heading-maturity1154.21050.61170.21077.41023.81091.0全生育期Wholegrowthduration3605.93708.83669.03364.03522.63450.1日照时数/h播种-拔节期Seeding-jointing223.5229.9226.4215.4226.4226.4Illumination拔节-孕穗期Jointing-booting71.1116.085.652.478.843.0hours孕穗-抽穗期Booting-heading76.644.763.463.070.269.6抽穗-成熟期Heading-maturity107.988.5103.7124.194.6117.6全生育期Wholegrowthduration479.1479.1479.1454.9470456.6

表8穗分化期气象因子与穗茎生长的关系(n=18)

Table 8. Relationship of meteorological factors with the growth traits of panicle and stem in panicle differentiation stage(n=18).

时段与气象因子Periodandmeteorologicalfactors12DBH茎秆Culm长Length干质量DW穗Panicle长Length干质量DW抽穗期Maturity茎秆Culm长Length干质量DW穗Panicle长Length干质量DW抽穗前31-28d 最高气温AHT0.4480.768**-0.289-0.1020.2840.671**0.768**-0.089 最低气温ALT0.530*0.807**-0.347-0.1930.1090.653**0.892**-0.332 平均气温AT0.532*0.823**-0.265-0.1140.1880.653**0.863**-0.249 ≥10℃积温ATA0.532*0.823**-0.265-0.1140.1880.653**0.863**-0.249 日照时数IH0.0640.0970.476*0.4240.310-0.051-0.1110.299抽穗前23-20d 最高气温AHT0.0750.378-0.713**-0.4110.1730.615**0.4600.067 最低气温ALT0.505*0.515*-0.029-0.2950.3370.3800.585*-0.270 平均气温AT0.492*0.752**-0.562*-0.529*0.4130.806**0.864**-0.170 ≥10℃积温ATA0.492*0.752**-0.562*-0.529*0.4130.806**0.864**-0.170 日照时数IH-0.284-0.105-0.373-0.009-0.1250.106-0.1130.223抽穗前15-12d 最高气温AHT0.656**0.913**-0.235-0.2470.4200.750**0.953**-0.235 最低气温ALT0.1410.2630.1700.370-0.2110.0240.210-0.134平均气温AT0.668**0.816**-0.046-0.1920.3830.585*0.854**-0.300 ≥10℃积温ATA0.668**0.816**-0.046-0.1920.3830.585*0.854**-0.300 日照时数IH0.600**0.867**-0.415-0.3850.3610.787**0.959**-0.263

AHT， Average highest temperature; ALT， Average lowest temperature; AT， Average temperature; ATA， Accumulated temperature above 10℃; IH， Illumination hours.

穗分化期穗与茎秆同步伸长，在生长的同时竞争着同化物。不同播栽方式穗分化期穗干质量和穗茎干质量比增长趋势一致，在穗分化始期至抽穗前16 d增长缓慢，抽穗前12 d至抽穗期持续快速增长。穗分化期穗、茎秆、叶片及叶鞘干质量整体均呈上升趋势，但穗分化中后期茎秆和穗较叶片和叶鞘对同化物的需求更大，体现在前两者干质量占比增加而后两者占比下降。孕穗后穗和茎秆生长加速，二者物质竞争增大。王惠芝等[6]认为，水稻进入花粉母细胞形成期后，穗对于营养物质的竞争能力大于茎秆，但也有研究认为，穗分化期非结构性碳水化合物的分配没有向着利于幼穗生长的方向进行，但抽穗至成熟期茎鞘将绝大部分贮藏的同化物转运至穗部[17]。

穗与茎秆竞争同化物的能力直接影响到穗粒形成，体现在穗茎干质量比与多数枝梗和颖花性状呈显著或极显著正相关。已有研究表明，抽穗前16 d至抽穗前8 d较高的幼穗非结构性碳水化合物积累量是大穗形成的基础[17]。Horie等[26]也认为，抽穗前14 d到抽穗时的干物质积累速率对产量影响较大，这一时期作物生长速率更快则能积累更多的非结构性碳水化合物，对于成穗率、千粒重都有关键的作用。在3种播栽方式均为双本栽插的基础上，机插穗分化中后期有较高的叶、叶鞘及茎秆干物质积累量，穗茎干质量比较高，且抽穗期穗干质量显著高于手插和机直播，因而有利于提高其枝梗和颖花分化数，从而增加穗粒数。此外，机插拔节后群体生长率及单茎和群体干物质积累量较高，抽穗期叶面积指数较高，粒叶比高于机直播，较机直播更利于粒重的提高和穗长及着粒数的增加。因而，从机械化播栽的角度考虑，机插的群体建成和产量潜力均优于机直播。大穗型品种F优498抽穗期穗干质量显著高于中穗型品种宜香优2115，且穗分化后期穗茎干质量比高于宜香优2115，是其穗粒数较高[17]的重要原因，且F优498穗部着粒较密，较大的叶面积指数及粒叶比利于其大穗的形成。而茎秆干物质量对提高每穗颖花现存数有重要作用[11, 28]，故在培育壮秆的基础上提高穗分化期穗茎比是保证穗粒数及抽穗后物质向穗部转运的基础，而F优498较宜香优2115更易获得高产。

3.2不同播栽方式下杂交籼稻穗茎生长与气象因子的关系

不同播栽方式生育进程不同，机插因栽插秧苗低位分蘖缺失[14]且机械植伤大、返青期较长致其孕穗前生育进程缓慢，机直播则无移栽和返青期，较早适应大田环境而生育进程较快，全生育期缩短；而机插生育期相对延长，在选择前后茬时应作考虑。生育进程的不同使不同播栽方式穗分化经历的温光条件有差异。而每完成一个幼穗分化阶段，都需要一定的积温[27]，且机插穗分化期历时较长，穗分化期积温和日照时数较高，为穗粒形成提供了较好的温光条件。本研究发现，抽穗前31～28 d、抽穗前23～20 d以及抽穗前15～12 d是气象因子对穗茎生长影响较大的时段，茎秆长度和干质量及穗长受影响较大，但穗干质量与气象因子相关不大。而孕穗前适宜的温度和一定的积温有利于茎秆和幼穗伸长及茎秆的物质充实。前人研究认为穗分化期温度与穗粒形成有密切关系[29-32]。穗分化期高温会使穗部物质代谢紊乱从而不利于颖花分化[29-31]。夜间高温则会缩短早稻的始穗期，减少颖花分化[32]。娄伟平[3]等认为适宜形成大穗的最高温度为30.1℃。穗分化期低温也会降低每穗枝梗和颖花的分化数[4,33]。而穗分化期光照亏缺会抑制花前物质的积累、运转率及对籽粒贡献率，也会使穗粒数降低[34]。但遗传因素还是控制穗粒形成数的主要因素，栽培上可通过适时晒田、合理的栽植密度等培育壮秆，整合并参考地方多年气象资料，调节播期以使穗分化期避开高温和降雨较大时段，或在孕穗前遇高温可采取干湿交替灌溉等降温措施，而遇低温则可保持一定水层以保持叶温[35]；此外，还要注重穗肥施用以增强穗部物质积累，提高穗分化期穗茎比，从而实现增粒增产。

茎秆的伸长存在一定规律，基部向上第1至第3伸长节间长度分别在抽穗前20 d、16 d、12 d后趋于稳定，基部第1、2节间的降长增粗应在抽穗前16 d之前；手插基部伸长节间相对短而粗更利于抗倒伏。穗分化中后期茎秆和穗较叶和叶鞘对同化物的需求更大，孕穗后穗和茎秆生长加速，物质竞争加大。穗与茎秆竞争同化物的能力直接影响到穗粒形成，机插抽穗前12 d至抽穗期穗茎干质量比较高，有利于提高其穗粒数。机插拔节后群体生长率及干物质积累量较高，抽穗期叶面积指数较高，粒叶比高于机直播，较机直播更利于粒重的提高和穗长及着粒数的增加。不同播栽方式生育进程不同，机插穗分化期历时较长，穗分化期积温和光照时数较高；茎秆长度和干质量及穗长受气象因子影响较大，孕穗前适宜的温度和一定的积温有利于茎秆和幼穗伸长及茎秆的物质充实。生产上应结合不同播栽方式和品种的生育进程差异及茎秆和幼穗生长特点，在培育壮秆的基础上提高穗茎比以保障穗粒数。

[1]丁颖, 李乃铭, 徐雪宾. 水稻幼穗发育和谷粒充实过程的观察. 农业学报, 1959, (10): 59-85.

Ding Y, Li N M, Xu X B. Observation of panicle development and courses of gain of rice.AgricSci, 1959, (10): 59-85. (in Chinese with English abstract)

[2]刘利, 雷小龙, 王丽, 等.种植方式对杂交稻枝梗和颖花分化及退化的影响. 作物学报, 2013, 39(8): 1434-1444.

Liu L, Lei X L, Wang L, et al.Effect of planting method on differentiation and retrogression of branches and spikelets of hybrid rice cultivar.ActaAgronSin, 2013, 39(8): 1434-1444. (in Chinese with English abstract)

[3]娄伟平, 孙永飞, 张寒, 等. 温度对每穗颖花数的影响. 浙江农业学报, 2005, 17(2): 101-105.

Lou W P, Sun Y F, Zhang H, et al. Effects of temperatures on spikelets per panicle of rice.ActaAgricZhejiangensis, 2005, 17(2): 101-105. (in Chinese with English abstract)

[4]曾研华, 张玉屏, 向镜, 等. 籼型常规早稻穗分化期低温对颖花形成和籽粒充实的影响. 应用生态学报, 2015, 26(7): 2007-2014.

Zeng Y H, Zhang Y P, Xiang J, et al. Effects of low temperature on formation of spikelets and grain filling of indica inbred rice during panicle initiation in early-season.ChinJApplEcol, 2015, 26(7): 2007-2014. (in Chinese with English abstract)

[5]李刚华, 王惠芝, 王绍华, 等. 穗肥对水稻穗分化期碳氮代谢及颖花数的影响. 南京农业大学学报, 2010, 33(1): 1-5.

Li G H, Wang H Z, Wang S H, et al. Effect of nitrogen applied at rice panicle initiation stage on carbon and nitrogen metabolism and spikelets per panicle.JNanjingAgricUniv, 2010, 33(1): 1-5. (in Chinese with English abstract)

[6]王惠芝, 尤娟, 王绍华, 等. 迟熟中粳稻穗茎生长与每穗颖花数的关系. 作物学报, 2007, 33(5): 820-825.

Wang H Z, You J, Wang S H, et al. Relationship between panicle and stem growth and spikelets per panicle in late-maturing medium japoncia rice.ActaAgronSin, 2007, 33(5): 820-825. (in Chinese with English abstract)

[7]杨世民, 谢力, 郑顺林, 等. 氮肥水平和栽插密度对杂交稻茎秆理化特性与抗倒伏性的影响. 作物学报,2009, 35(1): 93-103.

Yang S M, Xie L, Zheng S L, et al. Effects of nitrogen rate and transplanting density on physical and chemical characteristics and lodging resistance of culms in hybrid rice.ActaAgronSin, 2009, 35(1): 93-103. (in Chinese with English abstract)

[8]李国辉, 钟旭华, 田卡, 等. 施氮对水稻茎秆抗倒伏能力的影响及其形态和力学机理. 中国农业科学, 2013, 46(7): 1323-1334.

Li G H, Zhong X H, Tian K, et al. Effect of nitrogen application on stem lodging resistance of rice and its morphological and mechanical mechanisms.SciAgricSin, 2013, 46(7): 1323-1334. (in Chinese with English abstract)

[9]陈小荣, 钟蕾, 贺晓鹏, 等. 稻穗枝梗和颖花形成的基因型及播期效应分析. 中国水稻科学, 2006, 20(4): 424-428.

Chen X R, Zhong L, He X P, et al. Effects of genotype and seeding-date on formation of branches and spikelets in rice panicle.ChinJRiceSci, 2006, 20(4): 424-428. (in Chinese with English abstract)

[10]曾研华, 张玉屏, 王亚梁, 等. 籼粳杂交稻枝梗和颖花形成的播期效应. 中国农业科学, 2015, 48(7): 1300-1310.

Zeng Y H, Zhang Y P, Wang Y L, et al. Effect of sowing date on formation of branches and spikelets in indica japonica hybrid rice.SciAgricSin, 2015, 48(7): 1300-1310. (in Chinese with English abstract)

[11]凌启鸿. 水稻茎秆维管束数与穗部性状关系及其应用的研究. 江苏农学院学报, 1982, (3): 48-58.

Ling Q H. The relationship between the number of macro-vascular bundles in culm and the panicle characters in rice plant and its application.JJiangsuAgricColl, 1982,(3): 48-58. (in Chinese with English abstract)

[12]苏祖芳. 水稻单茎茎鞘重与产量形成关系及其高产栽培途径的探讨. 江苏农学院学报, 1993, 14(1): 37-39.

Sun Z F. Discussion on the relationship between the culm-sheath weight per shoot and yield in rice and its cultural approaches of high yield.AcadJJiangsuAgricColl, 1993, 14(1): 37-39. (in Chinese with English abstract)

[13] Takai T,Matsuura S, Nisiho T, et al.Rice yield potenital is closely related to crop growth rate duirng late reproductive peirod.FieldCropsRes,2006,96:328-335.

[14]雷小龙, 刘利, 刘波, 等. 杂交籼稻机械化种植的分蘖特性. 作物学报, 2014, 40(6): 104-1055.

Lei X L, Liu L, Liu B, et al. Tillering characteristics of indica hybrid rice under mechanized planting.ActaAgronSin, 2014, 40(6): 104-1055. (in Chinese with English abstract)

[15]刘利, 雷小龙, 黄光忠, 等. 机械化播栽对杂交稻氮素积累分配及碳氮比的影响. 植物营养与肥料学报, 2014, 20(4): 831-844.

Liu L, Lei X L, Huang G Z, et al.Influences of mechanical sowing and transplanting on nitrogen accumulation, distribution and C/N of hybrid rice cultivars.JPlantNutrFert, 2014, 20(4): 831-844. (in Chinese with English abstract)

[16]雷小龙, 刘利, 苟文, 等.种植方式对杂交籼稻植株抗倒伏特性的影响. 作物学报, 2013, 39(10): 1814-1825.

Lei X L, Liu L, Gou w, et al.Effects of planting methods on culm lodging resistance ofindicahybrid rjce(OryzasativaL.).ActaAgronSin, 2013, 39(10): 1814-1825. (in Chinese with English abstract)

[17]田青兰, 刘波, 钟晓媛, 等. 不同播栽方式下杂交籼稻非结构性碳水化合物与枝梗和颖花形成及产量性状的关系. 中国农业科学, 2016, 49(1): 35-53.

Tian Q L, Liu B, Zhong X Y, et al. Relationship of NSC with the formation of branches and spikelets and the yield traits ofindicahybrid rice in different planting methods.SciAgricSin, 2016, 49(1): 35-53. (in Chinese with English abstract)

[18]冯永祥, 徐正进, 王聪. 水稻株型的研究进展. 内蒙古民族大学学报：自然科学版, 2003, 18(3): 260-264.

Feng Y X, Xu Z J, Wang C. Advance on research of rice plant type.JInnerMonUniv, 2003, 18(3): 260-264. (in Chinese with English abstract)

[19]艾志勇, 马国辉. 超高产杂交稻茎秆特征与抗倒性关系研究. 杂交水稻, 2010, 25(6): 65-69.

Ai Z Y, Ma G H. Studies on relationship between culm characteristics and lodging resistance of super-high-yield hybrid rice.HybridRice, 2010, 25(6): 65-69. (in Chinese with English abstract)

[20]马均, 马文波, 田彦华, 等. 重穗型水稻植株抗倒伏能力的研究. 作物学报, 2004, 30(2): 143-148.

Ma J, Ma W B, Tian Y H, et al.The culm lodging resistance of heavy panicle type of rice.ActaAgronSin, 2004, 30(2): 143-148. (in Chinese with English abstract)

[21]吴晓然, 张巫军, 伍龙梅, 等. 超级杂交籼稻抗倒能力比较及其对氮素的响应. 中国农业科学, 2015, 48(14): 2705-2717.

Wu X R, Zhang W J, Wu L M, et al, Tang S, Ding C Q, Zhang S H, Ding Y F. Characteristics of lodging resistance of super-hybridindicarice and its response to nitrogen.SciAgricSin, 2015, 48(14): 2705-2717. (in Chinese with English abstract)

[22]龚振平. 不同营养水平水稻株高及构成变化的研究. 黑龙江农业科学, 1997, 19(6): 18-20.

Gong Z P. Plant height and its constitutive variation the conditions of different fertilities in rice.HeilongjiangAgricSci, 1997, 19(6): 18-20.(in Chinese with English abstract)

[23]凌启鸿, 张洪程, 苏祖芳, 等. 稻作新理论——水稻叶龄模式. 北京: 科学出版社, 1994：19-82.

Ling Q H, Zhang H C, Su Z F, et al. New Theory of Rice—Rice Leaf Age Model. Beijing: Science Press, 1994, 19-82. (in Chinese with English abstract)

[24]杨惠杰, 房贤涛, 何花榕, 等. 福建超级稻品种茎秆结构特征及其与抗倒性和产量的关系. 中国生态农业学报, 2012, 20(7): 909-913.

Yang H J, Fang X T, He H R, et al.Relationship of characteristics of culm construction to lodging resistance and yield of Fujian-bred super-rice cultivars.ChinJEco-Agric, 2012, 20(7): 909-913. (in Chinese with English abstract)

[25]赵黎明, 萧长亮, 顾春梅, 等.植物生长调节剂在水稻倒伏上的研究进展. 北方水稻, 2009, 39(3): 114-117.

Zhao L M, Xiao C L, Gu C M, et al.Research advantage of plant growth regulation on lodging rice.NorthRice, 2009, 39(3): 114-117. (in Chinese with English abstract)

[26] Horie T, Shiraiwa T, Homma K, et al.Can yields of lowland rice resume the increases that they showed in the 1980s?PlantProdSci, 2005,8(3): 259-274.

[27]王亚梁, 张玉屏, 曾研华, 等. 水稻穗形成期高温影响的研究进展. 浙江农业科学, 2014(11): 1681-1685.

Wang Y L, Zhang Y P, Zeng Y H, et al. Research progress of effect of high temperature on rice panicle formation stage,ZhejiangAgricSci, 2014(11): 1681-1685. (in Chinese with English abstract)

[28]姚有礼, 王余龙, 蔡建中. 水稻大穗形成机理的研究(3)品种间每穗颖花现存数与颖花分化和抽穗期物质生产的关系. 江苏农学院学报, 1995, 16(2): 11-16.

Yao Y L, Wang Y L, Cai J Z. Formation of large panicle in rice (3) varietal difference of survived spikelet number per panicle and its relations with differentiated spikelet number and biomass at heading.AcadJJiangsuAgricColl, 1995, 16(2): 11-16. (in Chinese with English abstract)

[29] Yao Y, Yamamoto Y, Yoshida T, et al. Response of differentiated and degenerated spikelets to top-dressing, shading and day/night temperature treatments in rice cultivars with large panicles.SoilSciPlantNutr, 2000, 46(3): 631-641.

[30]张顺堂, 张桂莲, 陈立云, 等. 高温胁迫对水稻剑叶净光合速率和叶绿素荧光参数的影响. 中国水稻科学, 2011, 25(3): 335-338.

Zhang S T, Zhang G L, Chen L Y, et al.Effects of high temperature stress on net photosynthetic rate and chlorophyll fluorescence parameters of flag leaf in rice.ChinJRiceSci, 2011, 25(3): 335-338. (in Chinese with English abstract)

[31]张桂莲, 陈立云, 张顺堂, 等. 高温胁迫对水稻剑叶保护酶活性和膜透性的影响. 作物学报, 2006, 36(9): 1306-1310.

Zhang G L, Chen L Y, Zhang S T, et al.Effect of high temperature stress on protective enzyme activities and membrane permeability of flag leaf in rice.ActaAgronSin, 2006, 36(9): 1306-1310. (in Chinese with English abstract)

[32]魏金连, 潘晓华. 夜间温度升高对早稻生长发育及产量的影响. 江西农业大学学报, 2008, 30(3): 428-432.

PAN J L, Pan X H. Effects of night temperature increase on growth and yield of early season rice.ActaAgricUnivJiangxiensis, 2008, 30(3): 428-432. (in Chinese with English abstract)

[33]耿立清, 王嘉宇, 陈温福. 孕穗-灌浆期低温对水稻穗部性状的影响. 华北农学报, 2009, 24(3): 107-111.

Geng L Q, Wang J Y, Chen W F. Effect of low temperature on panicle characters of rice during booting and grain filling period.ActaAgricBoreali-Sin, 2009, 24(3): 107-111. (in Chinese with English abstract)

[34]杨东, 段留生, 谢华安, 等. 花前光照亏缺对水稻物质积累及生理特性的影响. 中国生态农业学报, 2011, 19(2): 347-352.

Yang D, Duan L S, Xie H A, Li Z H, Huang T X. Effect of pre-flowering light deficiency on biomass accumulation and physiological characteristics of rice.ChinJEco-Agric, 2011, 19(2): 347-352. (in Chinese with English abstract)

[35]谭孟祥, 景元书, 薛杨, 等. 水层深度对早稻有穗分化期遭遇低温过程时叶片生理特性的影响. 中国农业气象, 2015, 36(5): 553-560.

Tan M X, Jing Y S, Xue Y, et al. Effects of different water depth on leaf physiological characteristics of early rice during panicle primordium suffered to low temperature.ChinJAgrometeorol,2015, 36(5): 553-560. (in Chinese with English abstract)

Characteristics of Stem Growth and Formation of Grain of indica Hybrid Rice in Different Planting Methods and Their Correlation with Meteorological Factors

TIAN Qing-lan1, LIU Bo1, SUN Hong1, HE Sha2, ZHONG Xiao-yuan1, ZHAO Min1, REN Wan-jun1,*

(1College of Agronomy, Sichuan Agricultural University / Key Laboratory of Crop Physiology, Ecology, and Cultivation in Southwest China / Institute of Ecological Agriculture, Sichuan Agricultural University, Wenjiang 611130, China;2Pixian Meteorological Bureau, Pixian 611730, China;*Corresponding author， E-mail： rwjun@126.com)

The objective of this study is to explore the growth pattern and differences of stem and panicle ofindicahybrid rice under various planting methods in panicle differentiation stage, and to investigate the effects of planting methods on grain formation. A split plot experiment was carried out in 2014 with two factors, including variety (Yixiangyou 2115 and F you 498) and planting method (mechanized direct-seeding, MD; mechanized transplanting, MT; hand transplanting, HT).The Growth pattern of stem and panicle, the formation characteristics of grain were researched, and the relationship between meteorological factors in panicle differentiation stage and the growth of stem and panicle were analyzed. The results were as follows: 1) Length of first to third elongated internodes from the base stablized 20 d, 16 d and 12 d before heading,respectively, indicating that reducing length and increasing roughness of basal first and second internodes should be done 16 d before heading. Dry panicle weight and ratio of panicle to stem increased rapidly 12 d before heading. 2) Dry weight ratio of panicle to stem was significantly positively correlated with rachis branches and spiketets from 16 d before heading to heading date. The ability that panicle competing assimilates with stem directly affected the formation of grain. 3) MT had higher dry weight ratio of panicle to stem in middle and late differentiation stage of panicle, MT also had higher dry matter accumulation of panicle than MD and HT in heading stage. So MT had an advantage in the number of grains. MT also had higher crop growth rate of population and higher dry matter accumulation per stem and population than MD and HT after jointing. MT also had higher leaf area index in heading, and its grain leaf ratio was higher than MD, so MT contributed to more grains and spikelets, longer panicle length. F you 498 with large panicle had higher dry matter weight of panicle in heading than Yixiangyou 2115 with middle panicle, and it had higher dry matter weight ratio of panicle to stem than Yixiangyou 2115, these were the important reason for that F you 498 had higher number of grains. Denser grain of F you 498 compared to Yixiangyou 2115 resulted from its larger leaf area index and grain to leaf ratio.4) MT had the longest growth duration,while MD had the shortest. MT had a longer panicle differentiation stage, higher accumulated temperature and illumination hours, providing a good temperature and light condition for the formation of grain in MT. Length and dry weight of stem and length of panicle were greatly influenced by meteorological factors. Suitable temperature and a certain amount of accumulated temperature before booting was conducive to the elongation of stem and panicle and filling of stem. Given the differences in growth under different planting methods and of varieties, we should take measures to regulate growth of stem and panicle and the distribution of assimilates in an appropriate time. In order to achieve the goal of increasing grain yield, the dry weight ratio of panicle to stem should be increased on the basis of cultivating strong stalk.

rice; panicle; stem; formation of grain; mechanized transplanting; mechanized direct-seeding; meteorological factors.

2016-01-26； 修改稿收到日期: 2016-05-14。

国家粮食丰产科技工程资助项目(2013BAD07B13-02, 2011BAD16B05)； 国家公益性行业(农业)科研专项(201303102)。

S511.01

A

1001-7216(2016)05-0507-18

田青兰, 刘波, 孙红, 等. 不同播栽方式下杂交籼稻茎秆生长和穗粒形成特点及与气象因子的关系. 中国水稻科学， 2016， 30(5)： 507-524.