甘薯源库关系建立、发展和平衡对氮肥用量的响应

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宁运旺, 马洪波, 张辉, 汪吉东, 许仙菊, 张永春. 甘薯源库关系建立、发展和平衡对氮肥用量的响应. 41(3): 432-439
NING Yun-Wang, MA Hong-Bo, ZHANG Hui, WANG Ji-Dong, XU Xian-Ju, ZHANG Yong-Chun. Response of Sweetpotato in Source-Sink Relationship Establishment, Expanding, and Balance to Nitrogen Application Rates. Acta Agronomica Sinica, 41(3): 432-439 复制到剪切板

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作物学报编辑部

甘薯源库关系建立、发展和平衡对氮肥用量的响应

宁运旺, 马洪波, 张辉, 汪吉东, 许仙菊, 张永春^*

江苏省农业科学院农业资源与环境研究所 / 农业部江苏耕地保育科学观测实验站, 江苏南京210014

^*通讯作者(Corresponding author): 张永春, E-mail: yczhang1966@sina.com, Tel: 025-84390242

收稿日期:2014-12-19

基金:本研究由国家现代农业产业技术体系建设专项(CARS-11-B-15), 江苏省农业科技自主创新科技资金[cx(14)2005]和IPNI国际合作项目(JIANGSU-11)共同资助

摘要

以盆栽、田间微区和田间裂区试验分析不同氮肥用量对苏薯16 (半直立株型)和苏薯11 (匍匐株型)生长前期(0~30 d)、中期(30~60 d)和后期(60~120 d)根系形态、单株薯数、叶面积指数、茎叶生物量、根生物量和T/R值的影响。结果表明, 在全生育期内, 施氮对甘薯茎叶生长均有显著促进作用, 但对根生长的影响各不相同。生长前期, 低量施氮对根系生长和分化有促进作用, 而适量和高量施氮则表现显著抑制作用, 并使30 d时单株薯数显著降低29.3%~36.6%或1.3~2.0个( P<0.05), 但同一甘薯品种、不同施氮处理的单株薯数在生长中期之后又趋于一致。生长中期, 适量和过量施氮可显著促进源库规模的发展, 并使甘薯茎叶生物量增加量分别显著提高35.5%~48.9%和73.4%~79.8% ( P<0.05), 叶面积指数迅速达到4左右, 而对根生物量增加量无显著影响( P>0.05)。生长后期, 施氮过多时(N32处理)茎叶鲜重持续增加, 到收获时叶面积指数和蔓薯比分别达4.9~5.6和1.50~1.51, 显著高于适量施氮处理时的3.3~3.5和0.58~0.64 ( P<0.05); 施氮过少时(N30处理)则反之, 收获时不施氮处理的叶面积指数和蔓薯比分别为1.6~1.9和0.36~0.42, 其中叶面积指数显著低于适量施氮处理( P<0.05); 不同施氮处理的单个薯重差异越来越大, 适量施氮处理的单个薯重(218~345 g)显著高于不施氮(181~262 g)和过量施氮处理(160~285 g, P<0.05), 所以适量施氮处理的最终单株块根产量(1.02~1.20 kg)也高于不施氮处理(0.88~0.91 kg)和过量施氮处理(0.79~0.87 kg, P<0.05)。表明, 移栽前一次性基施氮的条件下, 不施或少施氮有利于甘薯生长前期源库关系的提早建立, 适量或过量施氮有利于甘薯生长中期源库关系的发展, 而仅有适量施氮有利于维持甘薯生长后期的源库平衡。

关键词: 甘薯; 氮; 源库关系

Response of Sweetpotato in Source-Sink Relationship Establishment, Expanding, and Balance to Nitrogen Application Rates

NING Yun-Wang, MA Hong-Bo, ZHANG Hui, WANG Ji-Dong, XU Xian-Ju, ZHANG Yong-Chun^*

Institute of Agricultural Resources and Environmental Research, Jiangsu Academy of Agricultural Sciences / Scientific Observing and Experimental Station of Arable Land Conservation (Jiangsu), Ministry of Agriculture, Nanjing 210014, China

Abstract

The pot, field mini-plot, and field split-plot experiments were carried out to investigate sweetpotato roots morphology (RM), number of tuberous roots per plant (NTR), leaf area index (LAI), shoots biomass, roots biomass and ratio of top to root (T/R-value) at 30, 60, 90, and 120 days after planting (DAP). At the whole growth period (0-120 d), nitrogen application promoted shoots growth, but had different effects on roots growth. At the early growth stage (0-30 d), low nitrogen rate (NR, N21) promoted roots growth and differentiation, but proper NR (N11, N22, N31) and excessive NR (N12, N23, N32) apparently inhibited roots development, causing NTR to decrease by 29.3%-36.6% (or 1.3-2.0 per plant) ( P<0.05). The NTR at different nitrogen rates tended to be same in the split-plot experiment after 60 DAP. At the middle growth stage (30-60 d), proper or excessive nitrogen rates were in favor of expansion of sweetpotato source-sink relationship (SSR), enhancing shoots biomass by 35.5%-48.9% and 73.4%-79.8%, respectively ( P<0.05), LAI rapidly ran up to four, but had no influence on roots biomass ( P>0.05). At the late growth stage (60-120 d), excessive NR sustained shoots biomass growth, LAI and T/R at harvest reached 4.9-5.6 and 1.50-1.51, respectively, which were apparently higher than those (3.3-3.5 and 0.58-0.64) under the proper NR ( P<0.05). When no nitrogen application, LAI and T/R at harvest were only 1.6-1.9 and 0.36-0.42, of which LAI was apparently lower than that under the proper NR ( P<0.05). At the same time, there was a difference in fresh weight of individual tuberous root (FWITR) under different nitrogen rates. FWITR (218-345 g) under the proper NR was higher than those under no NR (181-262 g) and excessive NR (160-285 g, P<0.05), therefore, the final yield per plant under the proper NR (1.02-1.20 kg) was higher than that under no NR (0.88-0.91 kg) and excessive NR (0.79-0.87 kg, P<0.05). It is showed that nitrogen as base fertilizer, its less or no application is favorable for the establishment of SSR, its proper or excessive application delays SSR at early growth stage, its right or excessive application promotes the expandation of SSR at middle growth stage, and only right application would keep SSR balance at late growth stage.

Keyword: Sweetpotato; Nitrogen; Source-sink relationship

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源和库是作物形成经济产量的2个重要方面, 对大多数作物而言, 其源库关系都有一个建立、发展和平衡的过程, 甘薯具有典型的源库关系, 其协调发展是甘薯高产的保障^{[1, 2]}。氮素养分是影响作物源库关系的主要因素之一, 解析甘薯源库关系、探明氮肥施用对甘薯源库关系建立、发展和平衡的影响对合理施用氮素肥料、提高甘薯生产水平具有重要意义。

甘薯库建立的时间远比一般作物早, 如水稻、小麦和玉米等均在穗分化之后, 而甘薯则在移栽后4周左右, 因此甘薯形成产量的时间远比一般作物长、产量也远比一般作物高^[3]。甘薯的生长分为前期(发根分枝结薯期)、中期(薯蔓并长期)和后期(薯块盛长期)^[3], 在长江中下游和南方薯区的夏秋薯, 前、中和后期一般可界定为移栽成活后30 d、30~60 d和60~120 d。甘薯移栽后很快在茎基部长出4~10对相邻的不定根, 之后不定根分化增粗并逐渐膨大成为膨大根(库)^{[4, 5, 6]}, 因此在生长前期甘薯的“ 库” 经历了从无到有的过程, 生长前期是甘薯源库关系建立的时期, 即促进不定根向膨大根分化, 尽早使库的数量(单株薯数)趋于稳定。其后, 为了满足膨大根继续膨大(成为块根)的物质需要, 源叶在规模和总量上不断增加, 生长中期是源库关系发展壮大的时期, 即促进源叶生长以充分发挥其光合效能, 并在本期末使源叶合成的光合产物主要用于块根膨大, 达到源库平衡。源库平衡是甘薯生长后期的一种理想状态, 此时源叶的光合效率最高, 合成的光合产物向块根分配的比例最大, 生长后期源库关系较长时间维持平衡状态, 就是既要防止源叶生长不足(光合效率降低), 又要防止源叶生长过旺(光合产物向块根的分配比例降低)。

氮素养分通过影响源库关系而影响作物产量在水稻、小麦和玉米等作物上已有许多研究报道, 根据作物源库特性对氮素养分的响应来调节氮素养分管理措施, 提出施氮建议也不乏有益的探索^{[7, 8, 9, 10, 11]}。对甘薯的类似研究较少且主要针对生长后期的源库平衡, 提出的施氮建议也多为甘薯生长后期的氮素管理^{[12, 13, 14, 15, 16]}, 对于甘薯生长前期和中期源库关系建立和发展过程中氮素养分的响应则鲜有研究报道。在甘薯的生产实际中, 氮肥多以基施为主, 对于这种施用方式是否合理也缺乏有益的探索。本文拟根据甘薯的生长发育特点, 采用盆栽试验研究氮肥用量对甘薯生长前期根系分化、库形成和源库关系建立的影响, 并在田间微区试验中进一步验证, 采用田间裂区试验研究氮肥用量对全生育期内甘薯生长前期源库关系建立、生长中期源库关系发展和生长后期源库关系平衡的影响, 分析源库关系在建立、发展和平衡过程中的变化特征及其对氮素养分(基施)的响应, 以期为甘薯的合理施肥提供依据。

1 材料与方法

1.1 室内盆栽试验

于2012年8月至9月在江苏省农业科学院大棚进行。设不施氮(N10)、适量施氮(N11)和过量施氮(N12) 3个氮肥用量处理, 分别为0、150和300 mg N kg^-1土, 磷钾用量均一致, 分别为100 mg P₂O₅ kg^-1土和200 mg K₂O kg^-1土, 4次重复。试验土壤采自里下河地区的高沙土, 其基本理化性状为容重1.21 g cm^-3, pH 7.05, 有机质6.36 g kg^-1, 碱解氮44.14 mg kg^-1, Olsen-P 6.71 mg kg^-1, 速效钾52.0 mg kg^-1。盆钵为上口直径12 cm、底部直径10 cm、高22 cm的褐色塑料盆钵, 每盆装土2.5 kg。肥料用分析纯尿素(N 46.2%)、磷酸一钙(含P₂O₅ 28.2%)和硫酸钾(含K₂O 50.0%)。土壤与肥料充分混匀, 装盆后先浇底水至土壤饱和持水量的60%。选用江苏省农业科学院育成的甘薯品种苏薯16, 取生长一致的薯苗, 剪切茎尖以下约35 cm长的薯蔓, 移栽时薯苗埋入钵内约10 cm, 每盆移栽1株。移栽后再浇水至土壤田间持水量的80%。整个试验过程中以称重法控制土壤水分在饱和持水量的75%, 于2012年8月25日移栽。移栽后30 d取样, 取样时先沿茎基部剪断, 称取地上部分鲜重, 地下部分取样时将盆钵倒扣, 小心将土壤中的根系悉数拣出, 洗净晾干后称取鲜重, 用根系扫描仪扫描。

1.2 田间微区试验

于2013年6月至7月在位于江苏省南京市六合区金磁村的江苏省农业科学院试验基地进行微区试验, 面积8 m², 重复4次。试验土壤为马肝土, 容重1.18 g cm^-3, pH 6.24, 有机质20.8 g kg^-1, 碱解氮128.6 mg kg^-1, Olsen-P 12.8 mg kg^-1, 速效钾120 mg kg^-1。采用可降解稻草盆钵带土大田移栽方式(盆钵为江苏省农业科学院自主研制产品, 降解期30 d, 规格为高10 cm、上口直径6 cm、底部直径4 cm), 即先将盆钵按照常规栽培密度(52 500株hm^-2)埋入预先准备好的大田垄中(垄宽85 cm, 垄距90 cm), 每个盆钵摆放薯苗1株, 再取预先准备好的基质土壤150 g (取自田间原位, 风干、去杂、过20目筛)与不同处理的试验肥料充分混匀后连同薯苗一起装入盆钵, 使薯苗立于盆钵中央, 随即浇水100 mL。设基质土壤不施氮(N20)、低量施氮(N21)、适量施氮(N22)和过量施氮(N23) 4个处理, 分别为0、60、120和240 mg N kg^-1土。磷钾用量一致, 分别为100 mg P₂O₅ kg^-1土和200 mg K₂O kg^-1土, 肥料和甘薯品种均同1.1。薯苗移栽成活后30 d挖根取样, 每个重复取连续相邻的5株, 调查地下部分膨大根数量和地上/地下部分鲜重。

1.3 田间裂区试验

2013年6月至10月在微区试验的相同试验基地进行裂区试验, 地属山前平原, 具灌排条件。试验土壤为马肝土, pH 6.26, 有机质13.7 g kg^-1, 碱解氮103.4 mg kg^-1, Olsen-P 13.0 mg kg^-1, 速效钾93 mg kg^-1。裂区设计, 主处理为不施氮(N30: 0 kg N hm^-2)、适量施氮(N31: 120 kg N hm^-2)和过量施氮(N32: 240 kg N hm^-2) 3个氮肥用量, 副处理选用甘薯品种苏薯16 (半直立株型)和苏薯11 (匍匐株型)。小区面积均为28 m², 4次重复。磷钾田间用量分别为60 kg P₂O₅ hm^-2和180 kg K₂O hm^-2, 肥料品种分别为尿素(含N 46.2%)、过磷酸钙(含P₂O₅ 12%)和硫酸钾(含K₂O 50%), 均在耕翻起垄前基施。垄作规格与栽培密度均同1.2。分别在移栽成活后的30、60、90和120 d挖根取样, 每小区取连续相邻的5株, 调查地下部分膨大根(或块根)数量、叶面积指数和地上/地下部分鲜重。

1.4 测定方法

用根系扫描仪(LA1600+scanner, Canada)扫描获得根系图像后, 用根系分析软件(Winrhizo 2003b, Canada)分析相关根系指标, 包括根长、表面积、体积、根尖数和平均直径, 以及按照直径范围的分布。用Microsoft Excel 2007软件绘图, 用SPSS13.0软件分析数据, 采用Duncan’ s法检验不同处理平均值之间的显著性差异。采用王留梅等^[17]的方法计算叶面积。

2 结果与分析

2.1 氮肥用量对甘薯生长前期源库关系建立的影响

根据苏薯16的品种特性(最终形成的单株有效薯数以4~6个为宜)和本试验中根尖数分布状况, 确定直径大于1.5 mm的根为发生变态增粗的分化根。图1所示, 甘薯的单株总根尖数、分化根根尖数、根平均直径和根系生物量均随施氮量增加呈下降趋势, 而茎叶生物量则随施氮量增加呈上升趋势, 与N10比较, N11处理的总根尖数、根平均直径、分化根根尖数和根系鲜重分别下降20.0% (P> 0.05)、9.4% (P< 0.05)、22.9% (P> 0.05)和57.8% (P< 0.05), N12处理分别下降68.8% (P< 0.05)、15.3% (P< 0.05)、57.1% (P< 0.05)和71.6% (P< 0.05); 与此相反, N11和N12处理的茎叶鲜重则分别比N10增加32.5% (P< 0.05) 和28.5% (P> 0.05)。表明适量施氮就已表现出对甘薯根系前期生长和分化有明显抑制作用, 过量施氮则表现更为显著; 适量和过量施氮对茎叶生长均有明显促进作用。

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图1 甘薯生长前期不同氮用量处理的单株根系形态和生物量
N10、N11和N12表示盆栽试验中3个不同用量氮肥处理, 分别为0、150和300 mg N kg^-1土。相同测定项目标以不同字母的值在P=0.05水平上差异显著。Fig. 1 Individual root morphology and biomass of sweetpotato at early growth stage under different nitrogen rates
N10, N11, and N12 were the three treatments with different nitrogen rates in pot experiment, which were 0, 150, and 300 mg N kg^-1 soil, respectively. Values in the same trait followed by different letters are significantly different atP=0.05.

适量和过量施氮对甘薯根系前期生长和分化的抑制作用在2013年的田间微区试验中也得到了进一步验证。图2所示, 甘薯移栽成活后30 d挖根取样调查, 甘薯的单株薯数在不施氮时为5.3个, 分别比适量施氮时的3.0个和过量施氮时的3.3个增加76.7%和55.9% (P< 0.05); 低量施氮时的单株薯数最高, 为6.3个, 比不施氮处理增加18.9% (P> 0.05)。单株薯重也随着施氮量的增加呈下降趋势, 地上部分茎叶生物量表现相反; 低量、适量和过量施氮处理的单株薯重比不施氮处理分别减少29.3%、36.6%和29.3% (P< 0.05), 茎叶生物量则分别增加-9.4% (P> 0.05)、28.6% (P< 0.05)和41.3% (P< 0.05)。表明适量和过量施氮虽然有利于甘薯生长前期地上部分茎叶生长, 但不利于地下部分根系向块根分化, 不利于库的形成和源库关系的建立; 低量施氮对根系分化有一定促进作用。

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图2 甘薯生长前期不同氮用量处理的单株薯数和生物量N20、N21、N22和N23表示田间微区试验中4个不同用量氮肥处理, 分别为0、60、120和240 mg N kg^-1土。相同测定项目标以不同字母的值在P=0.05水平上差异显著。Fig. 2 Number of tuberous roots and biomass per plant of sweetpotato at early growth stage under different nitrogen ratesN20, N21, N22, and N23 were the four treatments with different nitrogen rates in field mini-plot experiment, which were 0, 60, 120, and 240 mg N kg^-1 soil, respectively. Values followed by different letters in the same trait are significantly different atP=0.05.

为了验证适量和过量施氮对甘薯生长前期根系分化的抑制作用是否会对最终的单株薯数产生影响, 于2013年同时进行了3个氮肥用量和2个甘薯品种的裂区试验。图3所示, 30 d、不施氮处理时, 苏薯16的单株薯数可达到3.5个, 显著高于适量和过量施氮处理的1.8~2.0个(P< 0.05), 苏薯11的单株薯数可达到2.1个, 也显著高于适量和过量施氮处理的1.3~1.6个(P< 0.05)。但60 d后不同施氮处理之间2个甘薯品种的单株薯数并无差异(P> 0.05), 60 d时苏薯16和苏薯11就已分别达到3.9~4.7个和2.9~3.3个, 120 d收获时分别为4.7~4.9个和3.1~3.5个。表明氮肥用量只对单株薯数的稳定时间有较大影响, 而对最终的单株薯数无显著影响, 或者说施氮可延迟单株薯数的稳定时间, 而不利于甘薯源库关系的尽早建立。

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图3 不同氮用量处理的甘薯单株薯数变化趋势
Su16和Su11表示2个不同株型的甘薯品种, 分别为苏薯16 (半直立株型)和苏薯11 (匍匐株型)。N30、N31和N32表示田间裂区试验中3个不同用量氮肥处理, 分别为0、120和240 kg N hm^-2。Fig. 3 Change trends of number of tuberous roots in sweetpotato under different nitrogen rates
Su16 and Su11 were the two sweetpotato varieties with diverse plant type, which were Su16 (with half-erect vine) and Su11 (with creeping vine). N30, N31, and N32 were the three treatments with different nitrogen rates in field split-plot experiment, which were 0, 120, and 240 kg N hm^-2, respectively.

2.2 氮肥用量对甘薯生长中期源库关系发展的影响

根据2013年田间裂区试验, 施氮处理的茎叶和总生物量增加均显著高于不施氮处理, 而块根生物量增加两者差异不显著。图4所示, 甘薯生长中期(30~60 d), 适量和过量施氮可使苏薯16和苏薯11的茎叶鲜重增加量比不施氮处理分别显著提高35.5%~ 79.8%和48.9%~73.4% (P< 0.05), 单株薯重增加量则受施氮的影响很小(P> 0.05)。因此, 认为适量和过量施氮均有利于生长中期甘薯源库关系的发展。

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图4 甘薯生长中期不同施氮量处理的生物量增加
N30、N31和N32表示田间裂区试验中3个不同用量氮肥处理, 分别为0、120和240 kg N hm^-2。相同品种和植株部位标以不同字母的值在P=0.05水平上差异显著。Fig. 4 Increments of sweetpotato biomass at middle growth stage under different nitrogen rates
N30, N31, and N32 were the three treatments with different nitrogen rates in field split-plot experiment, which were 0, 120, and 240 kg N hm^-2 respectively. Values followed by different letters in the same cultivar and plant part are significantly different atP=0.05

2.3 氮肥用量对甘薯生长后期源库平衡的影响

根据2013年田间裂区试验, 图5所示, 过量施氮处理时2个甘薯品种的茎叶鲜重均呈持续增加态势, 90 d和120 d时, 苏薯16和苏薯11的茎叶鲜重分别比60 d时增加29.8%~39.7%和30.0%~40.7%; 不施氮处理时甘薯茎叶鲜重呈持续减少态势, 90 d和120 d时, 苏薯16和苏薯11的茎叶鲜重分别比60 d时减少3.8%~35.1%和6.7%~21.8%; 适量施氮处理时甘薯茎叶在块根膨大前期(60~90 d)缓慢增加、块根膨大后期(90~120 d)缓慢下降。与茎叶鲜重变化相对应的是, 不同施氮量之间的单株薯重差异越来越大, 到收获时, 苏薯16和苏薯11在适量施氮时的单株薯重分别为1.02 kg和1.20 kg, 显著高于不施氮时的0.88 kg和0.91 kg以及过量施氮时的0.79 kg和0.87 kg (P< 0.05)。表明氮肥施用过多可导致生长后期甘薯茎叶生长过旺、过少则导致茎叶生长不足, 均不利于维持甘薯生长后期源库平衡和块根产量的形成。

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	图5 不同氮用量处理的甘薯茎叶和块根鲜重变化趋势缩写同图3。Fig. 5 Change trends of fresh weight of shoots and tuberous roots in sweetpotato under different nitrogen rates Abbreviations are the same as those given in Fig. 3

从蔓薯比和叶面积指数的变化趋势(图6)也可看出, 在苏薯16和苏薯11的生长前期、中期和后期, 蔓薯比和叶面积指数均随着施氮量的增加而增加, 到收获时过量施氮处理的蔓薯比和叶面积指数分别达到1.50~1.51和4.9~5.6, 显著高于适量施氮处理时的0.58~0.64 (P< 0.05)和3.3~3.5 (P< 0.05), 不施氮处理的蔓薯比和叶面积指数分别为0.36~0.42和1.6~1.9, 其中叶面积指数也显著低于适量施氮处理(P< 0.05)。进一步表明不施氮使甘薯生长后期源叶生长不足, 而过量施氮则使源叶生长过旺, 两者均不利于维持甘薯生长后期源库平衡。

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	图6 不同氮用量的甘薯蔓薯比和叶面积指数变化趋势缩写同图3。Fig. 6 Change trends of T/R-value and leaf area index (LAI) in sweetpotato under different nitrogen rates Abbreviations are the same as those given in Fig. 3.

2.4 氮肥用量对甘薯产量性状和块根产量的影响

表1所示, 适量施氮(N31)条件下, 苏薯16和苏薯11的单个薯重分别比不施氮(N30)和过量施氮(N32)增加20.4%~36.3%和21.1%~31.7% (P< 0.05), 单株薯重分别增加15.9%~29.1%和31.9%~37.9% (P< 0.05), 而2个甘薯品种最终形成的单株薯数并无显著差异。表明单个薯重是影响块根产量的主要因素, 氮肥不足或过量均使单个薯重降低, 导致块根产量降低。

表1 不同氮用量的甘薯产量性状和块根产量 Table 1 Yield and its traits of sweetpotato tuberous roots under different nitrogen rates

3 讨论

甘薯的“ 源” 与“ 库” 是一对相互作用的矛盾统一体, 它们既相互促进、又相互对立。源叶生长不足可导致光合产物合成减少、生长过旺则导致光合产物向库的分配减少, 影响库容扩大; 库容不足也可产生反馈抑制调节使得光合产物在源端积累, 从而影响源(叶)光合作用, 库(块根)的迅速膨大, 也能加速源(叶)中同化产物转运, 增强植株光合作用^{[12, 13, 14, 15]}。因此, 甘薯块根产量取决于库(贮存光合产物)的能力, 又取决于源(光合作用和光合产物输出)的潜力, 或者说源的潜力和库的能力均是甘薯产量的限制因子^[12]。甘薯自栽插10~20 d发生根系分化、30 d左右“ 单株薯数” 基本稳定之后, 源库关系就开始建立, 随即进入源库关系的发展和平衡阶段, 甘薯源库关系的建立、发展和平衡过程就是块根形成和膨大的过程, 源库关系伴随甘薯形成产量的始终。

甘薯块根产量形成主要取决于单株结薯数和单个薯重, 前者在生长前期就已基本稳定并对最终的块根产量有决定影响^{[3, 18]}, 后者则随着收获期的延长持续增加。氮肥用量过多对作物根系生长的抑制作用在其他作物上已有定论, 在甘薯上的研究也表明施氮过多不仅会抑制生长前期根系生长和分化^{[4, 19, 20]}, 也会使收获时的单株结薯数显著减少^[21]。本文的3个试验结果则表明, 低量施氮对生长前期的根系分化有明显促进作用, 而适量和过量施氮则对根系分化有明显抑制作用, 并使得单株薯数在30 d时显著减少; 但不同施氮量处理之间的单株薯数在生长中期以后又趋于一致, 施氮过多只能延迟单株薯数的稳定时间, 或者说过量施氮延迟了甘薯源库关系的建立时间, 从而使甘薯产量形成的时间缩短; 不同施氮量处理可导致生长后期单个薯重差异越来越大, 甘薯最终块根产量的差异主要与单个薯重有关。

单个薯重与地上部分源叶光合作用和光合产物的分配密切相关^[3], 如何使源叶尽早长时间地发挥最大光合效率, 且使源叶合成的光合产物尽可能多地向块根分配是单个薯块质量持续增加的2个必要条件。氮肥施用是影响它们的最重要因素, 增施氮肥虽然可显著提高甘薯生长中后期的叶面积指数和光合速率, 但单个薯块质量却显著下降^{[21, 22]}, 因此, 甘薯的施氮效果往往不稳定^{[23, 24, 25]}。本研究中, 甘薯的叶面积指数随着施氮量的增加而提高, 60 d时适量和过量施氮处理的叶面积指数就已达到4以上(甘薯发挥源叶最大光合效率的叶面积指数为4左右), 而不施氮处理的叶面积指数在整个生长期内都不到3, 与此同时, 收获时过量施氮处理的蔓薯比仍然达到1.5, 显著高于不施氮和适量施氮处理的0.5左右; 60 d后适量施氮处理的单个薯重增长速度显著高于不施氮和过量施氮处理(图7)。表明过量施氮虽然有利于促进生长中期甘薯源库关系规模和总量的发展, 从而可尽早使源叶发挥高效率光合作用以合成更多的光合产物, 但同时也为生长后期茎叶旺长创造了条件, 使得光合产物向块根的分配显著减少, 而不施氮则反之, 2种情形均可造成生长后期源库失衡, 致使单个薯重差异越来越大, 最终导致减产。值得注意的是, 即使在适量施氮条件下也很难使叶面积指数较长时间维持在4左右, 收获时的蔓薯比也达到0.58~ 0.64, 表明生长后期甘薯源库平衡对氮非常敏感。

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	图7 不同氮用量的甘薯单个薯重变化趋势缩写同图3。Fig. 7 Change trends of fresh weight per tuberous root in sweetpotato under different nitrogen rates Abbreviations are the same as those given in Fig. 3

在甘薯的生产实际中, 氮肥主要以基施为主而施用效果一直不稳定, 其原因一般认为与甘薯根系发达、耐瘠薄以及生长后期源库失衡有关^{[23, 24, 25]}。本文研究结果除进一步证实了施氮对甘薯生长后期源库平衡的敏感影响之外, 还初步得到以下两点启示, 一是氮肥的施用效果不稳还可能与施用方式有关, 适量和过量施氮条件下基施均使甘薯生长前期源库关系建立的时间(即单株薯数稳定的时间)推迟, 甘薯块根产量形成的时间缩短(据此建议氮肥的施用时间适当后移)。二是不同施氮量产生的甘薯最终块根产量差异主要来自单个薯重, 但单个薯重的差异是否与单株薯数稳定时间推迟有关尚需进一步研究。

4 结论

氮肥施用对甘薯源库关系建立、发展和平衡均有显著影响。生长前期适量施氮即可延迟源库关系建立时间, 使甘薯块根膨大时间缩短; 生长中期适量和过量施氮均可促进甘薯源库规模发展, 提前使源叶达到高效率光合作用的生长规模; 生长后期甘薯源库平衡对氮较敏感, 不施氮与过量施氮可分别使源叶生长不足和过旺从而使源库失衡导致减产。

The authors have declared that no competing interests exist.

作者已声明无竞争性利益关系。

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[25]	Hill W A, Dodo H, Hahn S K, Mulongoy K. Adeyeye S O. Sweet potato root and biomass production with and without nitrogen fertilization. Agron J, 1990, 82: 1120-1122 [本文引用:2] [JCR: 1.518]

2003

0.862

0.0

Hai M

, Kubota

The effects of drought stress and leaf ageing on leaf photosynthesis and electron transport in photosystem 2 in sweet potato (Ipomoea batatas Lam. ) cultivars.

Photosynthetica, 2003, 41: 253-258

Of the four tested sweet potato cultivars having different features in growth and yield, cv. Koganesengan (KOG) was sustainable in photosynthetic activity through young to aged leaves under drought. One of the causes for this phenomenon may be stomatal conductance ( g s ) of this cultivar that was relatively high in both aged and drought-imposed leaves. In these leaves the non-photochemical quenching (NPQ) was low and the quantum yield of photosystem 2 (Φ e ) was high, compared to those of the other cultivars. This helps to prevent excessive accumulation of chemical energy in leaves and a decrease in photoinhibition damage to the photosynthetic function, by which KOG sustains a relatively high photosynthetic activity under the drought and alleviates functional deterioration caused by leaf age.

1.Kyushu University Graduate School of Bioresource and Bioenvironmental Science Hakozaki, Higashi-ku, Fukuoka 812-8581 Japan 2.Kyushu University Faculty of Agriculture Hakozaki, Higashi-ku, Fukuoka 812-8581 Japan

... 源和库是作物形成经济产量的2个重要方面, 对大多数作物而言, 其源库关系都有一个建立、发展和平衡的过程, 甘薯具有典型的源库关系, 其协调发展是甘薯高产的保障^[1,2] ...

2010

0.0

1982

0.0

... 甘薯库建立的时间远比一般作物早, 如水稻、小麦和玉米等均在穗分化之后, 而甘薯则在移栽后4周左右, 因此甘薯形成产量的时间远比一般作物长、产量也远比一般作物高^[3] ...

... 甘薯的生长分为前期(发根分枝结薯期)、中期(薯蔓并长期)和后期(薯块盛长期)^[3], 在长江中下游和南方薯区的夏秋薯, 前、中和后期一般可界定为移栽成活后30 d、30~60 d和60~120 d ...

... 甘薯块根产量形成主要取决于单株结薯数和单个薯重, 前者在生长前期就已基本稳定并对最终的块根产量有决定影响^[3,18], 后者则随着收获期的延长持续增加 ...

... 单个薯重与地上部分源叶光合作用和光合产物的分配密切相关^[3], 如何使源叶尽早长时间地发挥最大光合效率, 且使源叶合成的光合产物尽可能多地向块根分配是单个薯块质量持续增加的2个必要条件 ...

2002

1.67

0.0

Kim S

, Mizuno

, Sawada

, Fujimura

Regulation of tuber formation and ADP-glucose pyrophosphorylase (AGPase) in sweet potato (Ipomoea batatas (L. ) Lam. ) by nitrate.

Plant Growth Regulation, 2002, 37: 207-213

The relationship between nitrate fertilization and tuber-bulking inroots from single-leaf explants was examined to clarify the mechanism of tuberformation. Cuttings of sweet potato leaves were grown on a medium containing 1,10, 30, and 50 mM nitrate and analyzed with regard tomorphologicaland biochemical traits. The cuttings grown on higher concentrations ( 10mM) showed inhibited root growth, with no apparent effect on leafgrowth or root length. The roots accumulated starch in a medium containing alower nitrate concentration ( 10 mM). Under this culturecondition, both the ADP-glucose pyrophosphorylase (AGPase) transcript level andthe starch content in the root decreased, while there was no decrease in thestarch content in the leaf. The greater AGPase transcript level in rootsgrowingwith a higher nitrate concentration ( 10 mM) might be caused bynitrogen-mediated signalling and/or changes in the levels of starch metabolism.Starch synthesis via AGPase and cell proliferation may work together for tuberformation in sweet potato root.

1.University of Tsukuba 2.Hirosaki University

... 甘薯移栽后很快在茎基部长出4~10对相邻的不定根, 之后不定根分化增粗并逐渐膨大成为膨大根(库)^[4,5,6], 因此在生长前期甘薯的#cod#x0201c ...

... 氮肥用量过多对作物根系生长的抑制作用在其他作物上已有定论, 在甘薯上的研究也表明施氮过多不仅会抑制生长前期根系生长和分化^[4,19,20], 也会使收获时的单株结薯数显著减少^[21] ...

2002

0.0

... 甘薯移栽后很快在茎基部长出4~10对相邻的不定根, 之后不定根分化增粗并逐渐膨大成为膨大根(库)^[4,5,6], 因此在生长前期甘薯的#cod#x0201c ...

2009

0.0

... 甘薯移栽后很快在茎基部长出4~10对相邻的不定根, 之后不定根分化增粗并逐渐膨大成为膨大根(库)^[4,5,6], 因此在生长前期甘薯的#cod#x0201c ...

2011

0.0

1.889

戴明宏, 赵久然, 杨国航, 王荣焕, 陈国平. 不同生态区和不同品种玉米的源库关系及碳氮代谢. 中国农业科学, 2011, 44: 1585-1595

Dai M

, Zhao J

, Yang G

, Wang R

, Chen G

Source-sink relationship and carbon-nitrogen metabolism of maize in different ecological regions and varieties.

Sci Agric Sin, 2011, 44: 1585-1595(in Chinese with English abstract)

【Objective】A field experiment was conducted to illustrate different performances of source-sink relationship and carbon-nitrogen metabolism of maize in different ecological regions and varieties in 2009.【Method】Three experimental sites (Nong’an, Changping and Xunxian) which were located in Northeast, Jingjintang and Huanghuaihai regions, respectively, and six representative varieties were selected.【Result】Grain yields under different sites performed as: Nong’an＞Xunxian＞Changping; XY335 got the highest while JD28 got the lowest grain yield among six varieties, and the differences among other four varieties were not significant. Under different ecological conditions, grain yield of varieties was more related to kernels number per ear than kernel weight; and grain yield was positively related to grain-leaf ratio while not to the maximum LAI at silking stage; grain yield also had a high positive correlation with dry matter amount accumulated after silking. Besides, uncoordinated source-sink relationship under low-yielding ecological condition was performed by high soluble sugar content in stem during key growing stages. C/N value showed a negative correlation with grain yield under different ecological regions. Different varieties could be divided into three types according to source of grain nitrogen: 1. nitrogen uptake during late-phase (61.0%-68.4%) was higher than transported nitrogen (39.7%-46.0%); 2. nitrogen uptake during late-phase was equal to transported nitrogen; 3. and nitrogen uptake during late-phase (42.5%-45.3%) was lower than transported nitrogen (57.2%-61.7%).【Conclusion】Coordinated source-sink relationship under high yielding ecological condition was highlighted by high grain-leaf ratio, high HI value (including NHI), high amount of dry matter and nitrogen accumulated during grain filling period, suitable soluble sugar content in stem, and relatively low C/N value. High-yielding variety also showed a high grain-leaf ratio and high amount of dry matter and nitrogen accumulated during grain filling period.

北京市农林科学院玉米研究中心

【目的】阐明不同生态区及品种条件下玉米源库协调性、碳氮代谢的差异表现及其与产量的关系。【方法】在东北（吉林省农安）、京津唐（北京昌平）和黄淮海（河南省浚县）3个生态区各设一个试验点，以6个高产、稳产的优良品种为试验材料，在稀植条件下（密度45 000 株/hm2）比较不同生态区和不同品种玉米的产量和产量构成、叶面积指数（LAI）和粒叶比、干物质和氮素分配转运、可溶性糖和C/N等指标。【结果】3个试验点的产量表现为农安＞浚县＞昌平；6个品种中产量最高的是先玉335，最低的是京单28，其它品种间差异不显著。在不同生态区和品种条件下，玉米产量与穗粒数的相关性明显大于千粒重；吐丝期最大LAI与产量的相关性不显著，而粒叶比则与产量成正相关；吐丝后干物质生产量与籽粒产量呈极显著正相关。低产生态条件下，茎鞘内富集了大量的可溶性糖，反映了源-库-流的不协调。在不同生态条件下，C/N与产量呈负相关。根据籽粒氮素的来源可将不同品种归为3类：（1）对后期吸氮（61.0%—68.4%）的依赖高于器官转运氮（39.7%—46.0%）；（2）后期吸氮量与器官转运氮量相当；（3）后期吸氮（42.5%—45.3%）低于器官转运氮（57.2%—61.7%）。【结论】适宜生态条件下，玉米源库关系更加协调，表现在粒叶比高、收获指数（包括氮素收获指数）大、灌浆期干物质积累量和氮素吸收量大、茎鞘可溶性糖含量适宜、C/N值相对较低。而粒叶比高、籽粒灌浆期干物质积累量和氮素吸收量大也是高产品种的重要特点。

... 氮素养分通过影响源库关系而影响作物产量在水稻、小麦和玉米等作物上已有许多研究报道, 根据作物源库特性对氮素养分的响应来调节氮素养分管理措施, 提出施氮建议也不乏有益的探索^{[7,8,9,10,11]} ...

2006

0.0

1.883

易镇邪, 王璞, 张红芳, 申丽霞, 刘明, 戴明宏. 氮肥类型与施用量对华北平原夏玉米源库关系的影响. 植物营养与肥料学报, 2006, 12: 294-300

Yi Z

, Wang

, Zhang H

, Shen L

, Liu

, Dai M

Effects of type and application rate of nitrogen fertilizer on source-sink relationship in summer maize in North China Plain.

Plant Nutr Fert Sci, 2006, 12: 294-300 (in Chinese with English abstract)

Source-sink relationship is a crucial problem to understand the physiological course of yield formation of crop,so does to maize.It's well known that source-sink relationship of maize was affected by many facts,such as cultivars,plant density and ecological conditions,and it had been classified into three types: source-limited,sink-limited and source-sink interacted.But the research related to effect of nitrogen fertilizer(NF),especially the different types of NF,on source-sink was seldom.In this study,two summer maize cultivars,Zhengdan 958(ZD958) and Nongda 108(ND108),were used as the material to study the effects of different N application rates(0,90 and 180 kg/ha) of three types of NFs,i.e.common urea(U),coated urea(CU) and compound fertilizer(CF),on source-sink relationship for yield formation of summer maize.The main results were as follows: 1) N application significantly increased the yield of summer maize,and the effect compound fertilizer was the highest.Grain number per ear of two cultivars increased along with the increment of N application rate,and the heightening value of Nongda 108 was bigger.The change of 1000grain weight showed difference according to cultivars and types of NF.2) LAI,chlorophyll content in filling stage and amount of dry matter accumulation of two cultivars increased with the increment of N application rates,and the heightening value of coated urea and compound fertilizer were bigger than that of common urea.3) Output percent of stem-sheath store matter can be used to reflect the harmonious degree between source and sink.In this study,it declined evidently with the increment of N application for two cultivars.The ratio of grain number to leaf area of Zhengdan 958 descended clearly after N application,especially application of compound fertilizer,but that of Nongda108 showed no evident trend.4) In a(general) way,positive correlation at 0.05 level existed between LAI,chlorophyll content and yield and grain number per ear (respectively,) but negative correlation existed between output percent of stem-sheath store matter and yield and its components.Negative correlation at 0.05 level existed between the ratio of grain number to leaf area and yield for Zhengdan 958, but this correlation for Nongda108 was weak.In conclusion,under conditions of this experiment,compound fertilizer and coated urea were more advantageous to heighten sink volume and source productivity than common urea,and as for type of source-sink relationship,Zhengdan 958 belonged to the source-limited and Nongda108 belonged to source-sink interacted.

College of Agronomy and Biotechnology;China Agricultural University;Beijing 100094;China

以郑单958和农大108为材料,研究了3种类型氮肥(普通尿素、包膜尿素和复合肥)不同施用量(N.0、90和180.kg/hm 2 )对华北平原夏玉米产量形成的源库关系的影响。主要结果如下:1)施氮使夏玉米极显著增产,增产效应以复合肥最好。两品种穗粒数随施氮量增加而增加,农大108增幅较大,千粒重因品种与氮肥类型不同表现有异;2)两品种LAI、灌浆期叶片叶绿素含量、干物质积累量均随施氮量增大而增大,复合肥与包膜尿素处理增幅较普通尿素处理大;3)茎鞘物质输出率随施氮量增大而显著降低。施氮使郑单958粒叶比显著降低,以复合肥处理降幅最大,而农大108表现不明显;4)一般情况下,LAI、灌浆期叶绿素含量与产量、穗粒数呈显著正相关,茎鞘物质输出率与产量及其构成因素呈负相关。郑单958粒叶比与产量呈显著负相关,农大108两者间关系不大。本试验条件下,与普通尿素相比,复合肥与包膜尿素更有利于源生产能力及库容的增大;在源库关系上,郑单958属增源增产型,而农大108属源库互作型。

2007

0.0

吉春容, 赵琳, 李世清, 李生秀. 施氮和栽培模式对半湿润农田生态系统冬小麦源特征的影响. 西北农林科技大学学报(自然科学版), 2007, 35(11): 53-59

Ji C

, Zhao

, Li S

Effect of nitrogen fertilizer and planting modes on the source characteristic of winter wheat in sub-humid farmland ecosystem.

J Northwest A&F Univ (Nat Sci Edn), 2007, 35(11): 53-59 (in Chinese with English abstract)

It is of great importance to study the difference of source characteristic of winter wheat under different nitrogen fertilizations and planting modes for optimizing fertilization and planting strategies of dry-land farming on Loess Plateau.The field experiment was conducted at the south part of Loess Plateau with about 632 mm precipitation each year.Xiaoyan 22 was used as indicating crop to study the effect of nitrogenous fertilizations(no nitrogen application and nitrogen application 120 kg/hm 2 ) and planting modes(check-CK,plastic sheet-mulching-PSM,ridge-furrow tillage-RFT and plastic sheet-mulching on ridge-PSMR) on the source characteristic of winter wheat.The main results showed that nitrogen fertilizations were able to increase the nitrogen content of flag leaf significantly,especially at jointing stage.The effect of planting modes was less than nitrogen fertilizations.The flag leaf nitrogen content of PSMR and PSM were higher than the other two planting modes during the filling stage and maturing stage,especially the effect of PSM was more obvious during the filling stage.The chlorophyll of nierogen application was higher than no nitrogen appliction during the different growth scage.The chlorophyll content of RFT was the highest of all the planting modes,while that of CK was the lowest.The area of green leaf per plant under the condition of nitrogen fertilization was increased by 23.4%,20.7%,15.3% and 8.9% compared with no-nitrogen fertilization.The effect of nitrogen fertilization on the area of green leaf per plant was the largest at the reviving stage.Green leaf areas of PSM,RFT and PSMR were higher than CK significantly,and green leaf area of PSMR was the largest.Nitrogen fertilization could significantly increase photosynthetic rate(Pn) of flag leaf.There was a significant difference of Pn between different planting modes,and Pn of PSMR was the largest.However,there was no significant difference between PSM and PSMR.According to the analysis of correlation between different targets and grain yield,it was important for grain yield to increase the nitrogen content of flag leaf,especially during the terminal growth stage.Therefore it was beneficial to increase the nitrogen content of flag leaf and Pn with applying nitrogen,so as to increase grain yield.PSM and PSMR were the first planting modes according to the result of this research.

为了探讨不同施氮水平及不同栽培模式下小麦源特征的变化,在黄土高原南部年降水量632 mm左右的半湿润区,以小偃22为供试品种,研究不同施氮水平(不施氮和施纯氮120 kg/hm 2 )及不同栽培模式(常规栽培、地膜覆盖、垄沟栽培、垄播覆膜)对小麦源特征的影响.结果表明,施氮能够极显著地增加小麦各生育期旗叶氮含量,其中以拔节期的影响效果最为明显;不同栽培模式对旗叶氮含量的影响效果较小;在灌浆期和成熟期,垄播覆膜和地膜覆盖两种栽培模式下旗叶氮含量均高于其他处理,其中以垄播覆膜效果较为明显,分别较常规栽培增加12%和29%.施氮条件下,冬小麦各生育期旗叶叶绿素含量均高于不施氮处理;不同栽培模式下以垄沟栽培模式下旗叶叶绿素含量最高,常规栽培最低.返青期、拔节期、开花期和灌浆期,施氮处理单株绿叶面积较不施氮处理分别增加23.4%,20.7%,15.3%和8.9%,施氮对单株绿叶面积的影响以返青期最为显著;地膜覆盖、垄沟栽培和垄播覆膜栽培模式下,单株绿叶面积明显高于常规栽培,以垄播覆膜栽培模式下单株绿叶面积最大.施氮能够显著增加开花期、灌浆旗和成熟期旗叶净光合速率( P ＜0.05),各栽培模式间旗叶净光合速率存在极显著差异( P ＜0.01),其中以垄播覆膜栽培条件下旗叶净光合速率最大.相关分析发现,增加功能叶氮含量,特别是生育后期氮含量,对籽粒产量具有重要作用.说明施氮有利于增加功能叶氮含量,提高净光合速率,进而有利于提高籽粒产量,从这一角度出发,地膜覆盖和垄播覆膜栽培应为首选栽培模式.

2013

0.0

0.951

莫钊文, 李武, 段美洋, 潘圣刚, 田华, 唐湘如. 减氮对华南早晚兼用型水稻源库特性的影响及其机理. 华北农学报, 2013, 28(5): 206-212

Mo Z

, Li

, Duan M

, Pan S

, Tian

, Tang X

Effects of reduced nitrogen fertilizer on source and sink characteristics of early/ late season rice in Sourth China and their mechanism.

Acta Agric Boreali-Sin, 2013, 28: 206-212 (in Chinese with English abstract)

Effects of N fertilizer (Conventional N (187.5 kg/ha),reduction of N by 28%(135.0 kg/ha) and without N(0 kg/ha)) on rice sink and source characteristics were studied using four varieties (Yuejingsimiao 2, Guixiangzhan,Huayou 8305 and Tianyou 998 ) in field experiment. Compared by conventional N,reduction of N by 28%would maintain or promote the rice source and sink coordination,which resulted in no significant decrease in yield.Reduction of N by 28%increased grain yield by 11.99%,5.51%and 6.46%for Yuejingsimiao 2,Guixian-gzhan and Huayou 8305, rexpectively, due to enhancement of photosynthetic or the transfer ability of sheath and stem. Reduction of N by 28%improved sink capacity and ratio of spikelets No. and leaf area in Yuejingsimiao 2 and Guixiangzhan,improved available filled ratio of sink in Huayou 8305, while there was no significant difference in Tianyou 998.

1 College of Agronomy, South China Agricultural University, Guangzhou 510642, China; 2 Scientific Observing and Experimental Station of Crop Cultivation in South China, Ministry of Agriculture, Guangzhou 510642, China; 3 Crops Research Institute, Guangdong Academy of Agricultural Science, Guangzhou 510642, China

研究了大田条件下氮肥水平(常规施氮肥(187.5 kg/hm 2 )、减氮28%(135.0 kg/hm 2 )和不施氮肥(0 kg/hm 2 )对不同基因型水稻(粤晶丝苗2号、桂香占、华优8305和天优998)的源库特性的影响。结果表明,减氮不会导致华南早晚兼用型水稻产量显著降低在于其能维持或促进水稻的源库协调性。与常规施氮比较,减氮28%有利于提高粤晶丝苗2号、桂香占及华优8305的产量,增幅分别为11.99%,5.51%,6.46%,主要归因于减氮28%能增强后期叶片光合或茎鞘转运而有利于稳定高产形成。减氮28%有利于提高粤晶丝苗2号和桂香占库容和粒叶比,提高华优8305库容有效充实度,而对天优998无显著影响。

2010

0.0

1989

0.0

... 对甘薯的类似研究较少且主要针对生长后期的源库平衡, 提出的施氮建议也多为甘薯生长后期的氮素管理^{[12,13,14,15,16]}, 对于甘薯生长前期和中期源库关系建立和发展过程中氮素养分的响应则鲜有研究报道 ...

... 库容不足也可产生反馈抑制调节使得光合产物在源端积累, 从而影响源(叶)光合作用, 库(块根)的迅速膨大, 也能加速源(叶)中同化产物转运, 增强植株光合作用^{[12,13,14,15]} ...

... 因此, 甘薯块根产量取决于库(贮存光合产物)的能力, 又取决于源(光合作用和光合产物输出)的潜力, 或者说源的潜力和库的能力均是甘薯产量的限制因子^[12] ...

1990

1.643

0.0

1977

1.513

0.0

1990

0.0

1989

0.0

0.895

2001

0.0

... 采用王留梅等^[17]的方法计算叶面积 ...

2005

0.0

1.889

王庆美, 张立明, 王振林. 甘薯内源激素变化与块根形成膨大的关系. 中国农业科学, 2005, 38: 2414-2420

Wang Q

, Zhang L

, Wang Z

Formation and thickening of tuberous roots in relation to the endogenous hormone concentrations in sweetpotato.

Sci Agric Sin, 2005, 38: 2414-2420 (in Chinese with English abstract)

A field trial was conducted to investigate the changes of endogenous hormone concentration during formation and thickening of tuberous roots in sweetpotato (Ipomoea batatas L.) of different genotypes (Xushu 18, Minamiyutaka and I .trifida-K123). The present results suggested that the concentrations of zeatin riboside (ZR), dihydro-zeatin riboside (DHZR), abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl-adenine (IPA) of Xushu 18 and Minamiyutaka were significantly higher than those of I.trifida-K123. Dry tuberous root yields were positively correlated with the concentrations of ABA, ZR and DHZR at 1% or 5% significant level, but not correlated with the concentrations of IAA, IPA and GA4. The concentrations of ABA, ZR and DHZR played very important roles for the tuberous roots formation and thickening in sweetpotato. The concentrations of ZR, DHZR, ABA and IAA in the top or inner parts of tuberous roots were significantly higher than those of in the end or outer parts. Meanwhile, endogenous hormone concentrations of big tuberous roots were significantly higher than that of middle or small ones at early thickening period. In fast thickening period of tuberous roots, endogenous hormone concentrations of middle tubers were the highest. However, at late thickening period, endogenous hormone concentrations of small tubers ranked the highest.

山东农业大学农学院

研究了不同基因型甘薯块根内源激素含量变化对块根形成和膨大的影响。结果表明，块根形成前后和膨大高峰期，甘薯栽培种徐薯18和Minamiyutaka的ZR、DHZR、ABA、IAA和IPA含量均显著高于近缘野生种I.trifida(K123)，差异达极显著水平。块根日鲜重增长速率与ZR、DHZR和ABA的含量变化动态高度一致。块根形成前后及块根膨大中期和高峰期，块根干重与块根ABA、ZR和DHZR含量间呈显著（或极显著）正相关, 与IAA、iPA和GA4间无明显相关性。ZR、DHZR和ABA含量的高低，在不定根能否转化形成块根和块根膨大的速率方面起关键的作用。块根不同部位（顶部、中部和尾部以及外部、中部和内部）各种激素含量差异显著，块根的顶部激素含量最高、生理活性最强,内部和中部（ABA除外）也是各种激素含量高的部位。膨大前期大块根的ZR、DHZR、ABA及IAA含量显著高于小块根，膨大中期中等大小块根激素含量最高，膨大后期小块根的激素含量显著高于中等大小的块根和大块根。

2013

0.0

1.889

宁运旺, 马洪波, 许仙菊, 汪吉东, 张辉, 许建平, 陈杰, 张永春. 氮磷钾缺乏对甘薯前期生长和养分吸收的影响. 中国农业科学, 2013, 46: 486-495

Ning Y

, Ma H

, Xu X

, Wang J

, Zhang

, Xu J

, Chen

, Zhang Y

Effects of deficiency of N, P, or K on growth traits and nutrient uptakes of sweetpotato in early growing stage.

Sci Agric Sin, 2013, 46: 486-495 (in Chinese with English abstract)

【Objective】The objective of the study is to accumulate the information for sweetpotato diagonosis of deficiency of nitrogen(N), phosphorus(P), or potassium(K) nutrients.【Method】A pot experiment with two sweetpotato cultivars (Sushu11 with stolons and Sushu14 with half-erect stem), four treatments (CK, -N, -P, -K) and four duplicates was conducted. A sweetpotato seedling was planted in a pot which was filled with sand, and four pots from the same treatment were placed in a plastic turnover box which was filled with solution medium. The seedlings were precultured in distilled water for three days and 1/2Hogland solution for a week, and treatment began after three new leaves had germinated. Four weeks later, the apparent deficiency symptoms appeared and the whole plant was sampled. Growth traits, photosynthetic characters, biomass accumulation and allocation, contents of N, P, and K in various plant parts of sweetpotato were investigated. 【Result】N, P, or K deficiency significantly reduced the sweetpotato shoots and total biomass (P＜0.01) compared with the CK treatment, where the greatest reduction occurred at the -N treatment (P＜0.01), the following was the -K treatment and the third was the -P treatment (P＜0.01). N, or K deficiency significantly reduced the sweetpotato roots biomass (P＜0.01 or P＜0.05), however there wasn’t changes in the -P treatment (P＞0.05). N or P deficiency significantly reduced the sweetpotato dry weight ratio of shoot to root (P＜0.01 or P＜0.05), while there wasn’t changes in the -K treatment(P＞0.05). Leaf area, leaf and branch number of a single plant significantly decreased under deficiency of N, P, or K (P＜0.01), the largest decrement of that occurred at the -N treatment, which were significantly lower than that of the -P and -K treatment (P＜0.01). Length of main stem of the two cultivars had a significant decrement in the -N treatment (P＜0.01), however, that of the -P or the -K treatment were concerned with the sweetpotato varieties, which significantly decreased for Sushu11 (P＜0.01) and had no changes for Sushu14 (P＞0.05). SPADs value of the 6th-8th function leaves was significantly decreased under deficiency of N or K(P＜0.01), however it was significantly increased under deficiency of P(P＜0.01). Deficiency of N, P, or K could significantly decrease net photosynthetic rate(P＜0.01), but had no effects on transpiration rate and intercellular CO2 concentration(P＞0.05). Stomatal conductance significantly decreased under deficiency of N or K(P＜0.05), however there weren’t changes under deficiency of P(P＞0.05). Contents of corresponding N, P, or K in various parts of sweetpotato significantly decreased under the condition of the -N, -P, or -K treatments. N deficiency could significantly decrease K contents of aboveground plant(leaf, petiole, and stem)(P＜0.01) and increase P content of roots (P＜0.01). P deficiency could significantly decrease N contents of leaf and petiole, K contents of petiole and stem (P＜0.01), however increase K content of roots (P＜0.05). Under the condition of K deficiency, N and P contents of petiole significantly decreased(P＜0.01), P content of leaves and roots significantly increased (P＜0.01). According to the results of this experiment, contents of N, P, and K in leaves under the condition of normal growth were 25.0-44.8 mg•kg-1(average 34.9 mg•kg-1), 2.7-6.3 mg•kg-1 (average 4.2 mg•kg-1), and 17.4-32.7 mg•kg-1 (average 25.2 mg•kg-1 ), respectively. When contents of N, P, and K in leaves were 10.0 mg•kg-1, 1.3 mg•kg-1, and 5.1 mg•kg-1 respectively, the apparent deficiency symptoms occurred. 【Conclusion】The results could provide references for the sweetpotato diagnosis under deficiency of N, P, or K in early growing stage.

Institute of Agricultural Resource and Environment, Jiangsu Academy of Agricultural Science/Scientific Observing and Experimental Station of Arable Land Conservation of Jiangsu Province, Ministry of Agriculture, Nanjing 210014

【目的】为甘薯生长前期氮磷钾缺素诊断积累资料。【方法】选取生长性状差异较大的2个甘薯品种，通过营养液砂培盆栽试验，设置4个处理（CK, -N, -P, -K）和4次重复，薯苗移栽后在蒸馏水和1/2 Hogland营养液中分别预培养3 d和7 d，至3片新叶后开始处理，4周后甘薯出现明显缺素症状，取全株样研究氮磷钾缺乏条件下的生长性状、光合特性、生物量积累分配和植株各部位养分含量的变化。【结果】（1）氮磷钾缺乏可显著降低甘薯茎叶和总生物量（P＜0.01），其中以缺氮影响最大，缺钾次之，缺磷影响最小。氮钾缺乏可显著降低根系生物量（P＜0.05 或P＜0.01），缺磷对根系生物量无影响（P＞0.05）。氮磷缺乏可显著降低甘薯的冠根比（P＜0.05 或P＜0.01），缺钾对冠根比没有影响。（2）氮磷钾缺乏均可显著降低甘薯的单株分枝数、单株叶片数和单株叶面积（P＜0.01），但以缺氮的影响最大，并显著低于缺磷和缺钾处理（P＜0.01）。对主蔓长度的影响各不相同，缺氮可显著降低主蔓长度（P＜0.01），磷钾缺乏对甘薯主蔓长度的影响与品种有关。磷钾缺乏条件下，匍匐株型品种苏薯11的主蔓长度显著降低（P＜0.01），而半直立株型品种苏薯14的主蔓长度无显著变化（P＞0.05）。（3）甘薯第6—8功能叶片的SPAD值在氮钾缺乏时显著减少、磷缺乏时显著提高（P＜0.01），净光合速率在氮磷钾缺乏时均可显著减少（P＜0.01），气孔导度只在氮钾缺乏时显著减少（P＜0.05）、不受缺磷影响（P＞0.05），蒸腾速率和胞间二氧化碳浓度均不受氮磷钾缺乏影响（P＞0.05）。（4）氮磷钾缺乏可显著减少植株各部位相应养分含量（P＜0.01），并对其它养分吸收产生影响。缺氮可显著降低地上部分叶片、叶柄和茎蔓的钾含量（P＜0.01），促进磷在根系中的积累（P＜0.01）。缺磷可显著减少叶片（P＜0.01）和叶柄（P＜0.05）的氮素含量以及叶柄和茎蔓的钾含量（P＜0.01），增加钾素在根系中的积累（P＜0.05）。缺钾可显著减少叶柄的氮磷含量（P＜0.01），促进叶片和根系对磷的吸收（P＜0.01）。（5）根据本试验结果，正常生长的甘薯叶片含氮量为25.0—44.8 mg•kg-1（平均为（34.9±9.1）mg•kg-1），含磷量为2.7—6.3 mg•kg-1（平均为（4.2±1.3）mg•kg-1），含钾量为17.4—32.7 mg•kg-1（平均为（25.2±6.3）mg•kg-1），当叶片中氮磷钾含量分别为10.0、1.3和5.1 mg•kg-1时甘薯会出现明显的氮磷钾缺乏症状。【结论】研究结果可为甘薯氮磷钾营养的前期诊断提供借鉴。

1973

1.643

0.0

2012

0.0

1.667

陈晓光, 李洪民, 张爱君, 史新敏, 唐忠厚, 魏猛, 史春余. 不同氮水平下多效对食用型甘薯光合和淀粉积累的影响. 作物学报, 2012, 38: 1728-1733

Chen X

, Li H

, Zhang A

, Shi X

, Tang Z

, Wei

, Shi C

Effect of paclobutrazol under different N-application rates on photosynthesis and starch accumulation in edible sweet potato.

Acta Agron Sin, 2012, 38: 1728-1733 (in Chinese with English abstract)

A field experiment was conducted to study the effects on leaf photosynthesis, root tuber starch accumulation and yield in edible sweetpotato ( Ipomoea batatas L. Lam cv. Beijing 553) with two nitrogen treatments (120 and 240 kg ha –1 ) and three paclobutrazol (PP 333 ) spraying levels (0, 100, and 200 mg ha –1 ). The result showed that increasing nitrogen application boosted P n and chlorophyll content, reduced dry matter allocation in root tuber and starch accumulation rate, and significantly reduced the fresh weight per lump of root tuber(by 8.0%) and the starch yield and root tuber yield (by 30.7% and 20.5%). Spraying PP 333 improved P n and chlorophyll content, accelerated the transportation of carbohydrate from leaf to root tuber and enhanced its allocation in root tuber, the starch accumulation rate, significantly the fresh weight per lump of root tuber (by 18.6%) and the yield of starch and fresh weight of root tuber(by 46.1% and 32.5%). It was indicated that both starch accumulation and yield could be regulated by PP 333 under high nitrogen application rate.

1 Key Laboratory of sweetpotato biology and genetic breeding, Sweetpotato Research Institute, Chinese Academy of Agricultural Sciences, Xuzhou 221121, China; 2 National Key Laboratory of Biology, Agronomy College, Shandong Agricultural University, Tai’an 271018, China

在大田条件下，以北京553为试验材料，设置施低氮(N 120 kg hm – 2 )和施高氮(N 240 kg hm –2 ) 2个处理，每个处理下设置3个多效唑喷施浓度，研究不同施氮水平下喷施多效唑对食用甘薯光合特性和块根淀粉积累的影响。结果表明, 增施氮肥能够提高叶片叶绿素含量和光合速率，但减少干物质在块根中的分配率，降低块根淀粉积累速率，显著降低了单薯重、淀粉产量和鲜薯产量，降幅分别为8.0%、30.7%和20.5%；喷施多效唑可以提高叶片叶绿素含量和光合速率，促进碳水化合物向块根的运转，提高干物质在块根中的分配，提高淀粉积累速率，显著增加单薯重、淀粉产量和鲜薯产量，平均增幅分别为18.6%、32.5%和46.1%。说明在高氮条件下喷施多效唑对甘薯块根淀粉积累和产量的提高具有明显的调节作用。

... 氮肥施用是影响它们的最重要因素, 增施氮肥虽然可显著提高甘薯生长中后期的叶面积指数和光合速率, 但单个薯块质量却显著下降^[21,22], 因此, 甘薯的施氮效果往往不稳定^[23,24,25] ...

2013

0.0

1995

0.889

0.0

... 在甘薯的生产实际中, 氮肥主要以基施为主而施用效果一直不稳定, 其原因一般认为与甘薯根系发达、耐瘠薄以及生长后期源库失衡有关^[23,24,25] ...

2003

0.0

Ankumah R

, Khan

, Mwamba

, Kpomblekou

The influence of source and timing of nitrogen fertilizers on yield and nitrogen use efficiency of four sweet potato cultivars.

Agric, Ecosyst & Environ, 2003, 100: 201-207

Abstract Nitrogen (N) availability is a very important determinant of crop yield. It is also one of the most expensive inputs in crop production. Thus, the efficient management of N by farmers with limited resource is a very important part of successful soil and crop management system. A field study was conducted on a Norfolk sandy loam soil at the George Washington Carver Agricultural Experiment Station, Tuskegee, AL, to evaluate the influence of fertilizer source and timing on the yield of four sweet potato [ Ipomoea batatas (L.)] cultivars. Two N sources (urea, CO(NH 2 ) 2 and ammonium nitrate, NH 4 NO 3 ), four sweet potato cultivars (‘Georgia Jet’, GA-Jet; ‘TU-82-155’, TU-155; ‘TU-1892’; and ‘Rojo Blanco’, Rojo-Bl) and three times (zero, single, and split applications) were used in a factorial designed experiment. Plants were harvested after 80 and 120 days and total and marketable yields determined. Nitrogen recovery efficiency, yield efficiency and physiological efficiency were also determined. Total and marketable yields of early maturing cultivars were significantly higher than of late maturing cultivars ( P P

... 在甘薯的生产实际中, 氮肥主要以基施为主而施用效果一直不稳定, 其原因一般认为与甘薯根系发达、耐瘠薄以及生长后期源库失衡有关^[23,24,25] ...

1990

1.518

0.0

... 在甘薯的生产实际中, 氮肥主要以基施为主而施用效果一直不稳定, 其原因一般认为与甘薯根系发达、耐瘠薄以及生长后期源库失衡有关^[23,24,25] ...