两个杂交棉F<sub>1</sub>、F<sub>2</sub>代及亲本冠层结构与物质生产特征

引用本文

冯国艺, 干秀霞, 杨美森, 姚炎帝, 罗宏海, 张亚黎, 张旺锋. 两个杂交棉F₁、F₂代及亲本冠层结构与物质生产特征 . 作物学报, 2013, 39(9): 1635-1643[FENG Guo-Yi, GAN Xiu-Xia, YANG Mei-Sen, YAO Yan-Di, LUO Hong-Hai, ZHANG Ya-Li, ZHANG Wang-Feng. Canopy Structure and Matter Production Characteristics of F₁, F₂, and Their Parents in Two Cotton Hybrids . Acta Agronomica Sinica, 2013, 39(9): 1635-1643] 复制到剪切板

Permissions

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

两个杂交棉F₁、F₂代及亲本冠层结构与物质生产特征

冯国艺^1,², 干秀霞¹, 杨美森¹, 姚炎帝¹, 罗宏海¹, 张亚黎¹, 张旺锋^1,^*

¹石河子大学新疆兵团绿洲生态农业重点实验室 / 农学院, 新疆石河子 832003

²河北省农林科学院棉花研究所 / 农业部黄淮海半干旱区棉花生物学与遗传育种重点实验室, 河北石家庄 050051

^* 通讯作者(Corresponding author):张旺锋, E-mail:zhwf_agr@shzu.edu.cn, Tel: 0993-2057326

基金:本研究由国家自然科学基金项目(31060176)和国家科技支撑计划项目(2007BAD44B07)资助。

摘要

以杂交棉石杂2号和新陆早43的F₁、F₂代及亲本NT2、H2、4-14为试材, 通过测定不同生育时期各材料叶面积指数(LAI)、叶倾角(MTA)、冠层光截获率等指标, 分析了各指标变化对群体光合物质生产的影响。结果表明, 2个杂交棉F₁代LAI具有超亲优势, 冠层光截获率具有中亲优势; LAI和冠层光截获率具有明显的母系遗传特性, 而MTA受到父本的显著影响。F₂代冠层结构主要受F₁代相关指标和衰退率的影响, LAI中亲优势减小了衰退率; 杂交棉F₁代光合物质积累主要受亲本参数和超亲优势的影响, F₂代主要受F₁代参数的影响。杂交棉光合物质积累最大增长速率和直线增长期开始时间较晚, 直线增长期及活跃增长期较长, 最终积累量和最大增长速率较高。杂交棉F₁代具有明显的光合生产和产量优势, F₂代具有一定的产量优势。以选择具有优化冠层结构的亲本为基础, 组配具有较大MTA的父本和较大LAI的母本, 有利于改善杂交棉光合性能, 提高群体光能利用率, 进一步挖掘产量潜力, 为杂交棉高光效组合的选育及提高F₂代应用提供理论依据。

关键词: 杂交棉; 冠层结构; 杂种优势; F₂代

Canopy Structure and Matter Production Characteristics of F₁, F₂, and Their Parents in Two Cotton Hybrids

FENG Guo-Yi^1,², GAN Xiu-Xia¹, YANG Mei-Sen¹, YAO Yan-Di¹, LUO Hong-Hai¹, ZHANG Ya-Li¹, ZHANG Wang-Feng^1,^*

¹The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Group / College of Agriculture, Shihezi University, Shihezi 832003, China

² Key Laboratory of Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, Ministry of Agriculture / Cotton Research Institute, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang 050051, China

Abstract

A field experiment was conducted using the F₁, F₂ of two cotton hybrids of Shiza 2 and Xinluzao 43 and their parents NT2, H2, and 4-14. After measuring the leaf area index (LAI), leaf inclination angle (MTA) and light interception rate (LIR) at different growing periods, it is clear that the matter production of hybrid cotton was affected directly by the parameter changes of the canopy structure and photosynthetic characteristics of two cotton hybrids parents. The results revealed that the over-parent heterosis of F₁ in two cotton hybrids was observed on LAI and mid-parent heterosis of them was provided with LIR. Both LAI and LIR were observed obviously with matrilineal genetic characteristics, while MTA was influenced by paternal inheritance. The canopy structure of F₂in two cotton hybrids was mainly influenced by the related parameters of F₁ in hybrid cotton indexes and their decreasing rate. The decreasing rate was deduced by the over-parent heterosis on LAI. The photosynthate accumulation of F₁ in two cotton hybrids was mainly influenced by the numerical value of their parents and over-parent heterosis, and the photosynthate accumulation of F₂ in two cotton hybrids was mainly influenced by the related parameters of F₁. The initial time of the highest increasing velocity of photosynthate accumulation and the linear increasing period was later, the linear increasing period and the active increasing period of photosynthate accumulation were longer, the total photosynthate accumulation and the highest increasing velocity were larger in two cotton hybrids. The photosynthate and yield were very high in F₁ of hybrid cotton, and there was a high yield only in F₂ of hybrid cotton. Based on choosing the parents with the optimized canopy structure, we should make a well combination between father plant with larger MTA and mother plant with larger LAI, which will be provides used for improving hybrid cotton photosynthetic performance, increasing light use efficiency for enhancing yield potential further. The study provided come theoretical parameters for breeding high photosynthetic efficiency hybrid line and improving utilization of F₂ in hybrid cotton.

Keyword: Hybrid cotton; Canopy structure; Heterosis; F₂

作物光合作用是产量形成的基础, 提高作物光合生产力是农学家长期探索的重要研究内容^[1,2,3,4]。作物冠层结构显著影响群体光合速率^[5]; 改善作物冠层结构是提高光合性能最有效的途径之一^[6]。叶面积指数是衡量作物冠层结构的重要指标, 研究表明, 叶面积指数可估算作物冠层潜在光合生产力及作物干物质积累量^[7]; 叶倾角的变化能显著影响冠层固定CO₂的能力, 进而影响产量^[8]。Stewart等^[9]通过对大量玉米品种的研究表明, 叶面积和叶倾角是影响光合作用的主要因子; 作物群体光截获率对光合作用有重要作用^[10], 改善作物冠层结构特征, 对增强群体光截获率, 提高群体生产力具有重要意义。育种学家已通过遗传改良手段, 选育出具有适宜于光合作用的最佳叶面积和叶片角度的优良品种^[11,12,13]。棉花杂种优势利用是提高产量和改善品质的重要途径。近年来, 中国在棉花杂种优势的研究和利用方面取得了较大进展, 杂交棉F₁代平均增产15%左右^[14], 推动了棉花产量水平的提高^[15]。然而, 如何通过亲本选配, 进一步发挥杂交种的光合生产优势, 挖掘其增产潜力已成为棉花等作物超高产育种和栽培研究关注的热点^{[16,17,18,19]}。

新疆是我国最重要的商品棉生产基地, 自2001年以来, 新疆引进和选育了多个棉花杂交种并在生产上进行示范推广, 使棉花单产水平有了进一步提高^[20,21]。棉花杂交种主要采用人工去雄制种, 成本高且繁殖系数低, 而新疆采用直播, 用种量大, 种植杂交种F₁成本过高, 严重制约了高产杂交棉的大面积推广; 棉花是异源四倍体, F₂代分离并不严重, 仍保持一定的杂种优势^[22,23], 具有较好的增产潜力和广泛的适应性^[24], 有一定的生产应用价值。目前已选配的一些杂交组合F₂在新疆棉区试验示范, 表现出明显的产量优势, 探索推广种植杂交棉F₂已受到棉花科技工作者的重视。因此从遗传角度, 选育能较多保留杂种优势的F₂代是迅速大面积推广杂交棉超高产种植亟待解决的问题之一。本研究探讨亲本对杂交棉F₁、F₂代冠层结构特性的影响, 揭示杂交棉高光效冠层结构形成机制及其与物质生产之间的关系, 以期为超高产杂交棉亲本选配及高产栽培提供理论依据。

1 材料与方法

1.1 供试材料

选用新疆棉区种植面积较大的棉花杂交种石杂2号和新陆早43的F₁、F₂代, 石杂2号父本NT2、母本H2, 新陆早43父本H2, 母本4-14; 同时选取常规棉品种新陆早33为对照(用于计算竞争优势), 共8个材料。

1.2 试验概况

试验于2009—2010年在石河子大学农学试验站进行(45°19′ N, 86°03′ E)。采用宽膜覆盖栽培, 先铺膜后点播, 1膜4行, 行距为(60+20+40+20) cm宽窄行; 小区面积为43.5 m², 随机排列, 重复3次; 留苗密度为每公顷16.5万株。播前深施高效有机肥1500 kg hm^-2, 尿素240 kg hm^-2, 三料磷肥75.3 kg hm^-2作基肥。生育期滴灌12次, 滴水量为3600~4200 m³ hm^-2, 8月底停水, 随水滴施尿素260 kg hm^-2。用缩节胺化调6次, 用量为300~350 g hm^-2。2009年4月19日播种, 4月26日出苗, 7月5日打顶; 2010年5月1日播种, 5月7日出苗, 7月10日打顶。其他管理措施同大田超高产棉花管理。

1.3 测试项目及方法

选择棉花生长发育的关键生育时期, 包括盛蕾期、盛花期、盛铃前期、盛铃后期、吐絮期测定冠层结构、群体光合生产等指标。

1.3.1 冠层结构指标采用LAI-2000冠层仪(Li-Cor, USA), 参照Malone等的方法^[25]测定叶面积指数和叶倾角, 先将探头水平放置于冠层上方, 按下测定按钮, 两声蜂鸣后将探头放入群体内, 仍保持水平, 按下测定按钮, 两声蜂鸣后水平均匀移动探头, 选择冠层内不同位置测量, 重复4次。

1.3.2 光截获率采用高亮之等^[26]介绍的方法, 在北京时间11:00~14:00, 用LI-250A光量子仪(Li-Cor, USA)测定植株顶部以上30 cm处自然光强I_o (探头面水平向上)、植株反光I_n (探头面水平向下)、入射到冠层底部的光强I。反射率(LRR, %)= I_n/I_o×100, 透射率(LLR, %)=I/I_o×100, 光截获率(LIR, %)=100-LRR-LLR。

1.3.3 光合物质积累与产量在各小区选择代表性植株5株, 从子叶节处剪取地上部分, 分解成叶片、茎和蕾铃等器官, 分别装入纸袋, 105℃下杀青30 min, 80℃下烘干后称重。产量因子及计产方法为: 于收获期各处理在各小区选有代表性植株10株, 考察不同果枝单铃重, 并折算各个处理单铃重; 每处理随机选取3个点, 每个取样点面积2.8 m², 调查各样点全部株数和铃数, 折算出单株结铃数和单位面积总铃数; 以实收籽棉计算产量。

1.4 数据统计及分析

采用中亲优势、超亲优势和衰退率、竞争优势来分析2个杂交棉的杂种优势及遗传表现。中亲优势(%)=(F-P)/P×100, 超亲优势(%)=(F₁-P_H)/P_H×100, 竞争优势(%)=(F-CK)/CK×100, 自交衰退ID₂(%)= (F₁-F₂)/F₁×100; 其中F₁为杂交1代, F₂为杂交2代, P为双亲平均值, P_H为高亲值, CK为推广的标准对照品种新陆早33; 采用CurveExpert 1.3对光合物质积累情况进行Logistic方程拟合, 用Microsoft Excel 2003和SPSS 11.0分析处理试验数据, 用SigmaPlot 10.0作图。

2 结果与分析

2.1 产量及产量构成因子

表1可见, 2年试验中, 2个杂交棉F₁具有明显的超亲优势和竞争优势, F₂代具有较强的竞争优势; 石杂2号F₁代和新陆早43 F₁代皮棉产量均实现3000 kg hm^-2以上的高产水平, F₁代超亲优势达39.1%~46.3%, 竞争优势为26.4%~45.9%, F₂代产量虽然衰退9.2%~12.8%, 但仍具有14.9%~27.4%的竞争优势。分析产量构成因子可以看出, 杂交棉F₁代由于单株铃数、铃重及衣分具有不同程度的超亲优势, 产量大幅度提高, 单株铃数超亲优势为13.4%~ 15.3%, 单铃重8.3%~12.6%, 衣分8.2%~12.8%。可见F₁代杂种优势是各产量构成因子具有超亲优势的综合结果; F₂代单铃重和衣分与F₁无明显差异, 但单株铃数衰退了9.6%~12.1%, 限制了产量水平的提高。

2.2 叶面积指数

叶面积指数(LAI)的大小直接影响作物对光能的截获率, 进而影响群体光合生产。试验表明(图1), 在测定生育时期内, 2个杂交棉F₁代LAI均表现出明显的超亲优势, 以盛蕾期、盛铃后期和吐絮期尤为明显; 新陆早43的F₁代LAI明显高于石杂2号F₁代。回归分析表明, 母本对杂交种F₁代LAI的直接作用更大, 其中石杂2号的直接通径系数为0.7622, 新陆早43为0.5787。F₂代出现一定程度的衰退, 但在盛铃后期和吐絮期表现出中亲优势。在相应生育时期内, 新陆早43亲本较石杂2号亲本平均值高8.9%~37.8%, 石杂2号F₁代超亲优势在盛蕾期为21.2%~23.9%, 盛铃后期和吐絮期为28.0%~36.5%; 新陆早43 F₁代超亲优势盛蕾期为27.4%~33.9%, 盛铃后期和吐絮期为31.1%~64.9%。F₂代盛蕾期到盛花期衰退32.6%~75.9%, 盛铃前期到吐絮期衰退7.7%~19.5%; 进一步分析表明, 盛蕾期到盛铃前期F₂代无明显中亲优势, 盛铃后期和吐絮期中亲优势石杂2号F₂代为18.2%~32.1%, 新陆早43 F₂代为29.0%~60.6%。可见杂交棉F₁代超亲优势和亲本值越大, 叶面积指数越高; F₂代生育后期中亲优势越大, 衰退率越低。

表1 杂交棉亲本及F₁、F₂代产量及产量构成因素(2009-2010)Table 1 Yield and components of hybrid cottons’ parents and their F₁, F₂(2009-2010)

品种(系) Variety (line)	收获株数 Plant No. (×10⁴hm^-2)	单株铃数 Boll No. per plant	总铃数 Total boll No. (×10⁴ hm^-2)	单铃重 Boll weight (g)	衣分 Lint percentage (%)	实收籽棉产量 Seed cotton yield (kg hm^-2)	折合皮棉产量 Lint yield (kg hm^-2)
2009
NT2	16.4±0.78	7.35±0.37 e	120.5±5.62 d	4.69±0.23 e	40.1±2.00 c	5598±252.9 e	2245±100.3 e
H2	16.1±0.80	7.48±0.37 de	120.2±5.70 d	5.07±0.25 d	36.4±1.62 d	6009±290.5 d	2218±90.7 e
4-14	16.3±0.82	7.84±0.35 c	127.8±5.62 c	5.35±0.26 c	39.0±1.75 c	6803±285.2 c	2653±100.3 d
石杂2号F₁Shiza 2 F₁	15.9±0.67	8.55±0.43 b	135.9±6.34 b	5.71±0.29 b	43.4±2.02 b	7571±354.8 b	3285±137.5 b
新陆早43 F₁Xinluzao 43 F₁	16.0±0.70	9.04±0.44 a	144.6±7.12 a	5.84±0.29 a	44.0±2.05 a	8494±401.7 a	3737±157.3 a
石杂2号F₂Shiza 2 F₂	15.9±0.64	7.67±0.20 d	121.9±5.18 d	5.73±0.25 b	43.2±1.76 b	6907±314.3 c	2984±135.5 c
新陆早43 F₂Xinluzao 43 F₂	15.9±0.73	7.95±0.24 c	126.4±5.78 c	5.86±0.27 a	44.1±1.75 a	7387±361.5 b	3257±143.7 b
新陆早33 Xinluzao 33	16.2±0.80	7.55±0.36 d	122.3±5.69 d	4.97±0.23 d	42.9±1.94 b	6055±258.2 d	2598±102.7 d
2010
NT2	16.3±0.77	7.27±0.37 e	118.5±5.62 d	4.82±0.23 d	40.3±2.00 c	5686±252.9 e	2291±100.3 e
H2	16.4±0.81	7.41±0.37 e	121.5±5.70 d	5.16±0.25 c	37.0±1.62 d	6209±290.5 d	2297±90.7 e
4-14	16.2±0.82	7.78±0.35 cd	126.0±5.62 c	5.27±0.26 c	39.2±1.75 c	6603±285.2 c	2588±100.3 d
石杂2号F₁Shiza 2 F₁	16.2±0.41	8.40±0.40 b	136.2±5.63 b	5.59±0.35 b	43.5±1.57 b	7345±350.2 b	3195±135.0 b
新陆早43 F₁Xinluzao 43 F₁	16.1±0.35	8.91±0.34 a	143.6±6.78 a	5.86±0.29 a	44.1±1.03 a	8350±289.4 a	3682±147.5 a
石杂2号F₂Shiza 2 F₂	15.8±0.54	7.59±0.24 d	119.9±5.81 d	5.62±0.25 b	43.4±1.30 b	6687±312.7 c	2902±134.8 c
新陆早43 F₂Xinluzao 43 F₂	15.7±0.57	7.98±0.24 c	125.3±5.99 c	5.85±0.23 a	44.0±1.67 a	7307±352.3 b	3215±131.0 b
新陆早33 Xinluzao 33	16.3±0.71	7.61±0.36 d	119.8±5.69 d	4.93±0.23 d	43.1±1.94 b	5855±258.2 e	2524±102.7 d

同一列标以不同字母的值表示在同年内0.05 水平上差异显著。

Values followed by different letters are significantly different at the 0.05 probability level within a column in the same year.

表1 杂交棉亲本及F₁、F₂代产量及产量构成因素(2009-2010)Table 1 Yield and components of hybrid cottons’ parents and their F₁, F₂(2009-2010)

图1 杂交棉亲本及F₁、F₂代叶面积指数的生育时期变化Fb: 盛蕾期; FF: 盛花期; EFB: 盛铃前期; LFB: 盛铃后期; BO: 吐絮期。Fig. 1 Changes of leaf area index of hybrid cottons’ parents and their F₁, F₂ at different growth stagesFb: full budding; FF: full flowering; EFB: early full bolling; LFB: later full bolling; BO: boll opening．

2.3 叶倾角

作物叶片的空间状态在很大程度上影响光能的利用。试验表明(图2), 在测定生育时期内, 新陆早43 F₁代的叶倾角(MTA)高于石杂2号F₁代, 2个杂交棉F₁、F₂均未表现出超亲优势或中亲优势。回归分析表明, 父本对杂交棉F₁代MTA的大小起主要作用, 其中石杂2号的直接通径系数为0.6091, 新陆早43为0.9051。F₂代衰退率表现为石杂2号8.9%~19.7%, 新陆早43为7.2%~15.2%。父本MTA大小直接影响杂交棉F₁代MTA参数高低, F₁代参数大小及遗传衰退率的高低决定F₂代MTA的高低。

2.4 冠层光截获率

作物光合作用及干物质生产能力与冠层光截获状况密切相关^[27]。研究表明(图3), 在测定生育时期内, 新陆早43 F₁代冠层光截获率高于石杂2号F₁代, 2个杂交棉F₁表现出一定的中亲优势; F₂代仅在盛铃前期表现出一定的中亲优势, 盛蕾期和吐絮期衰退较为明显。回归分析表明, 石杂2号母本对F₁代冠层光截获率直接通径系数为0.6698, 新陆早43为0.7372。杂交棉F₁代在盛蕾期和吐絮期中亲优势为3.6%~10.7%, F₂代在盛铃前期中亲优势为0.7%~ 1.8%。F₂代盛蕾期和吐絮期衰退7.8%~14.6%。可见, 亲本选配主要改善杂交棉F₁代生育早期和后期的冠层光截获率, F₂代在生育前期和后期较高的衰退率直接影响了光合作用以及干物质生产能力。

图2 杂交棉亲本及F₁、F₂代叶倾角的生育时期变化同一生育时期标以不同字母的标值在0.05 水平上差异显著。Fig. 2 Changes of mean foliage tilt angle of hybrid cottons’ parents and their F₁, F₂ at different growth stagesBoxes with superscripts of different letters are significantly different at the 0.05 probability level within a growth stage in the same year.

图3 杂交棉亲本及F₁、F₂代冠层光截获率的生育时期变化Fig. 3 Changes of canopy light interception rate of hybrid cottons’ parents and their F₁, F₂ at different growth stages

2.5 光合物质积累特征

表2表明, 杂交棉F₁代总光合物质积累量为 23 916.3~30 442.5 kg hm^-2, 超亲优势达47.7%~ 58.9%; F₂代有15.7%~30.9%的衰退率。Logistic方程对杂交棉F₁代及其亲本光合物质积累过程拟合表明, 杂交棉F₁代较亲本光合物质积累增长直线期长6.6~8.8 d, 物质积累活跃期(P)长14.9~20.0 d; 最大增长速率高25.9%~63.2%; F₂代较杂交棉光合物质积累增长直线期和物质积累活跃期(P)衰退9.3%~ 11.4%, 最大增长速率下降5.6%~38.8%。进一步分析表明, 亲本直线增长期开始和结束时间及最大速率出现时间较早, F₂代直线增长期和最大增长速率出现时间明显晚于亲本, 但直线增长期结束时间早于杂交棉F₁代; 新陆早43 F₁代和石杂2号F₁代相比, 直线增长期开始和结束时间及最大增长速率出现时间均较晚, 直线增长期和物质积累活跃期较长, 最大增长速率较大。杂交棉F₂较双亲均值光合物质积累增长直线期长2.2~2.9 d, 物质积累活跃期(P)长5.1~6.5 d; 最大增长速率高7.5%~20.9%; 最大速率出现的时间晚0.6~5.1 d; 总光合物质积累量高14.5%~28.7%。

3 讨论

3.1 杂交棉F₁代冠层结构特性与亲本的关系

通过遗传改良手段, 可选育具有适宜光合作用的冠层结构, 如叶面积和叶片角度等^[11], 在选育良种的过程中, 选取有效光合性能指标早已受到人们的广泛关注^[28]。杂交种性状受其选配的亲本显著影响^{[14,17,19,29]}, 在生长势上表现出非常明显的杂种优势^[30]。本研究表明, 超亲优势显著影响杂交棉F₁代的LAI, 冠层光截获率则受中亲优势影响; MTA并未表现出中亲优势。回归分析表明, LAI和冠层光截获率受母本影响较大, 具有明显的母系遗传特性, 而MTA显著受到父本的影响。杂交种的基因来自双亲, 基因表达方面存在的差异是导致杂种优势的重要原因^[31,32]; 基因差异表达是构成F₁杂种优势性状差异的分子基础^[33,34]; 表型性状的差异可以从基因表达模式上得以反映^[35]。有研究表明亲本基因差异表达与F₁杂种优势呈正相关^{[14,35,36,37,38]}。2个杂交棉F₁代LAI、MTA和冠层光截获率等冠层结构指标杂种优势与亲本差异表达呈正相关。可见, 选择较大MTA和LAI及光合功能较强的父本并配以具有较高光合特性的母本, 能有效改善杂交棉F₁代冠层结构, 提高光合功能。本研究表明, 杂交棉F₁代光合物质积累量没有明显表现出母系或父系遗传, 这可能与本试验选用材料有关, 但也可能说明光合物质积累是一个数量遗传性状, 受到冠层结构各个指标的影响; 但试验结果表明杂交棉F₁代光合物质积累量与亲本平均值和超亲优势呈显著正相关, 因此在选用配合力较好的亲本基础上组配生长势较强的亲本是提高杂交棉F₁代光合物质积累能力的一个有效途径。

表2 杂交棉亲本及F₁、F₂代光合物质积累特征Table 2 Photosynthate accumulation characteristics parents and F₁, F₂ of cotton hybrids

品种 Variety (line)	拟合方程 Fitting equation	r	TPA (kg hm^-2)	T₁ (d)	T₂ (d)	T₃ (d)	V_max (kg hm^-2 d^-1)	T₀ (d)	P (d)
2009
NT2	y=15492.6/(1+90.7e^-0.0672 ^x)	0.9718^**	15163.2 d	47.5	86.7	39.2	260.2	67.1	89.3
H2	y=16890.4/(1+79.2e^-0.0636 ^x)	0.9818^**	16194.6 d	48.0	89.5	41.4	268.5	68.8	94.4
4-14	y=19379.1/(1+72.0e^-0.0625 ^x)	0.9916^**	19170.9 c	47.4	89.5	42.1	302.9	68.4	96.0
石杂2号F₁Shiza 2 F₁	y=24619.7/(1+62.5e^-0.0549 ^x)	0.9988^**	23916.3 b	51.3	99.3	48.0	337.9	75.3	109.3
新陆早43 F₁Xinluzao 43 F₁	y=32710.4/(1+67.6e^-0.0536 ^x)	0.9973^**	30442.5 a	54.1	103.2	49.2	438.2	78.6	112.0
石杂2号F₂Shiza 2 F₂	y=20648.2/(1+92.2e^-0.0619 ^x)	0.9998^**	20172.5 c	51.8	94.3	42.5	319.7	73.0	96.9
新陆早43 F₂Xinluzao 43 F₂	y=21387.3/(1+77.2e^-0.0591 ^x)	0.9909^**	21035.2 bc	51.3	95.9	44.6	315.8	73.6	101.6
2010
NT2	y=16348.0/(1+53.1e^-0.0643 ^x)	0.9994^**	16304.6 d	41.3	82.2	41.0	262.8	61.8	93.3
H2	y=17646.5/(1+51.9e^-0.0652 ^x)	0.9969^**	17413.6 d	40.4	80.8	40.4	287.5	60.6	92.1
4-14	y=18873.5/(1+55.0e^-0.0650 ^x)	0.9999^**	18612.5 cd	41.4	81.9	40.5	306.7	61.7	92.3
石杂2号F₁Shiza 2 F₁	y=27098.9/(1+39.3e^-0.0548 ^x)	0.9971^**	25716.4 b	42.9	91.0	48.1	371.3	67.0	109.5
新陆早43F₁Xinluzao 43 F₁	y=31549.2/(1+43.1e^-0.0542 ^x)	0.9947^**	29555.8 a	45.1	93.7	48.6	427.7	69.4	110.7
石杂2号F₂Shiza 2 F₂	y=19749.6/(1+43.4e^-0.0611 ^x)	0.9986^**	19585.0 c	40.2	83.3	43.1	301.5	61.8	98.3
新陆早43 F₂Xinluzao 43 F₂	y=21032.2/(1+48.4e^-0.0608 ^x)	0.9968^**	20627.7 c	42.2	85.5	43.3	319.5	63.9	98.7

^**表示在0.01水平上差异达显著水平。T₁、T₂为光合物质积累增长直线期起止时间(出苗后天数), T₃为持续天数, T₀为最大增长速率( V_max)出现的时间, P是物质积累活跃期(大约完成总积累量的90%)。

^** means significantly different at P<0.01. T₁, T₂ are the beginning and concluded days to linear increasing stage for photosynthate accumulation, T₃ is the lasting time, T₀ is the days to the highest velocity, P is the active stage of photosynthate accumulation (accomplished about 90% of the total photosynthate accumulation).

表2 杂交棉亲本及F₁、F₂代光合物质积累特征Table 2 Photosynthate accumulation characteristics parents and F₁, F₂ of cotton hybrids

3.2 杂交棉F₂代冠层结构特性与亲本及杂交棉F₁代的关系

杂交棉F₂代在某些性状上表现出中亲优势^[39], 有可能出现光合速率高于F₁代材料^[40]。本试验结果表明, F₂代个别指标具有中亲优势, 冠层结构指标和光合特性指标较F₁均出现不同程度的衰退。LAI有一定的中亲优势, 减小了F₂代衰退率; 冠层光截获率在盛铃前期表现出中亲优势, 未对衰退率产生影响。研究表明F₂代部分指标具有的中亲优势起到减轻衰退程度的作用, 冠层优化程度主要取决于F₁代的相关指标和遗传衰退率。可见, 亲本对F₂代LAI衰退程度具有明显的影响, 并且通过影响F₁代相关指标间接影响F₂代。杂交棉F₂代生育后期光合物质积累具有较明显的中亲优势, 使光合物质积累量明显高于亲本, 因此产量较双亲均值提高26.5%~ 33.7%, 具有一定的杂种优势。研究表明, F₂代光合物质积累量与衰退率无关, 主要受F₁代相关指标影响。F₂代产量较推广的标准对照品种新陆早33高14.9%~27.4%, 尤其是新陆早43 F₂, 2年试验结果皮棉产量均实现了3000 kg hm^-2以上的高产水平, 2009年较石杂2号F₁低0.9%, 2010年较石杂2号F₁高0.6%, 与石杂2号F₁相差不大, 具有较大的生产应用价值。因此亲本选育很大程度上决定了F₂代的竞争优势, 影响其生产应用价值。

作物产量是一个综合性状, 受植株多个形态、生理以及农艺性状的影响^[41]。作物高产要求具有较高群体光合生产^[40], 通过对冠层结构的改造, 增加光能利用率, 制造更多的光合产物, 增大光合物质积累。杂交棉具有较高的LAI, 能截获更多光能, 光合物质积累增长直线期和活跃期较长、最大速率较大及最终光合物质积累较多, 直线增长期开始和最大速率结束时间及出现时间较晚, 最终光合物质积累较多, 有利于产量提高。因此通过选配亲本优化杂交棉冠层, 提高光合性能, 改善群体光合生产是提高产量的有效途径。冠层形态与结构决定于品种, 要选育冠层结构合理的杂交种, 最大限度地提高光能利用率, 就必须正确选配亲本。在选配亲本过程中不仅要考虑生理功能^[42], 而且要重视亲本冠层特性。超亲优势、中亲优势及F₂代衰退率对挖掘产量潜力具有重要影响, 而如何改变及设计其参数有待进一步研究。

4 结论

杂交棉F₁冠层优化和光合物质生产力的提高是以亲本为基础, F₂代冠层特性主要受杂交棉F₁代相关指标和衰退率的影响, 部分指标的中亲优势影响衰退率; 杂交棉F₁代光合物质积累主要受亲本参数和超亲优势的影响; 杂交棉光合物质积累最大增大速率出现时间和直线增长期开始时间较晚, 最终积累量和最大增大速率较大以及直线增长期和活跃期较长; 杂交棉F₁代具有明显的光合生产和产量优势, F₂代具有一定的产量竞争优势。选择组配具有较大MTA的父本、较大LAI的母本, 有利于杂交棉F₁代提高光能利用率, 进一步挖掘产量潜力以及提高F₂代的应用价值。

参考文献

View Option

[1]	Wang K-R(王克如), Li S-K(李少昆), Song G-J(宋光杰), Chen G(陈刚), Cao S-Z(曹栓柱). Studies on cultivated physiological indexes for high-yielding cotton in Xinjiang. Sci Agric Sin (中国农业科学), 2002, 35(6): 638-644 (in Chinese with English abstract) [本文引用:1]
[2]	Zhao M(赵明), Li J-G(李建国), Zhang B(张宾), Dong Z-Q(董志强), Wang M-Y(王美云). The compensatory mechanism in exploring crop production potential. Acta Agron Sin (作物学报), 2006, 32(10): 1566-1573 (in Chinese with English abstract) [本文引用:1]
[3]	Peng S B, Khush G S, Virk P, Tang Q Y, Zou Y B. Progress in ideotype breeding to increase rice yield potential. Field Crops Res , 2008, 108: 32-38 [本文引用:1]
[4]	Hua S J, Yuan S N, Shamsi I H, Zhao X Q, Zhang X Q, Liu Y X, Wen G J, Wang X D, Zhang H P. A comparison of three isolines of cotton differing in fiber color for yield, quality, and photosynthesis. Crop Sci , 2009, 49: 983-989 [本文引用:1]
[5]	Lü L-H(吕丽华), Tao H-B(陶洪斌), Xia L-K(夏来坤), Zhang Y-J(张雅杰), Zhao M(赵明), Zhao J-R(赵久然), Wang P(王璞). Canopy structure and photosynthesis traits of summer maize under different planting densities. Acta Agron Sin (作物学报), 2008, 34(3): 447-455 (in Chinese with English abstract) [本文引用:1] [CJCR: 1.8267]
[6]	Long S P, Zhu X G, Naidu S L, Ort D R. Can improved photosynthesis increase crop yields?Plant Cell Environ , 2006, 29: 315-330 [本文引用:1]
[7]	Goudriaan J, Monteith J L. A mathematical function for crop growth based on light interception and leaf area expansion. Ann Bot , 1990, 66: 695-701 [本文引用:1]
[8]	Brooks T J, Wall G W, Pinter Jr P J, Kimball B A, LaMorte R L, Leavitt S W, Allan D M, Adamsen F J, Hunsaker D J, Webbeer A N. Acclimation response of spring wheat in a free-air CO₂ enrichment (FACE) atmosphere with variable soil nitrogen regimes. 3: Canopy architecture and gas exchange. Photosynth Res , 2000, 66: 97-108 [本文引用:1] [JCR: 3.243]
[9]	Stewart D W, Costa C, Dwyer L M, Smith D L, Hamilton R L, Ma B L. Canopy structure, light interception, and photosynthesis in maize. Agron J , 2003, 95: 1465-1474 [本文引用:1]
[10]	Hu Y-J(胡延吉), Lan J-H(兰进好), Zhao T-F(赵坦方), Gao F-Z(高法振). Canopy architecture and photosynthetic characteristics in two winter wheat cultivars with different spike type. Acta Agron Sin (作物学报), 2000, 26(6): 905-912 (in Chinese with English abstract) [本文引用:1]
[11]	Joshi A K. Genetic factors afecting photosynthesis. In: Pessarakli M ed. Hand book of Photosynthesis. New York: Marcel Dekker, 1996. pp751-767 [本文引用:2]
[12]	Hao N B, Du W G, Ge Q Y, Zhang G R, Li W H, Man W Q, Peng D Q, Bai K Z, Kuang T Y. Progress in the breeding of soybean for nigh photosynthetic efficiency. Acta Bot Sin , 2002, 44: 253-258 [本文引用:1]
[13]	Ji B H, Tan H H, Zhou R, Jiao D M, Shen Y G. Promotive effect of low concentrations of NaHSO₃ on photophosphorylation and photosynthesis in phosphoenolpyruvate carboxylase transgenic rice leaves. J Integr Plant Biol , 2005, 47: 178-186 [本文引用:1] [JCR: 2.534] [CJCR: 0.7555]
[14]	Xing C-Z(邢朝柱), Yu S-X(喻树迅), Zhao Y-L(赵云雷), Guo L-P(郭立平), Zhang X-L(张献龙), Miao C-D(苗成朵), Wang H-L(王海林). Primary study on gene differential expression of pest resistant cotton hybrids between different heterosis crosses. Acta Agron Sin (作物学报), 2007, 33(3): 507-510 (in Chinese with English abstract) [本文引用:3] [CJCR: 1.8267]
[15]	Wang R-H(汪若海), Li X-L(李秀兰). Progresses on hybrid cotton and its further studies. Sci Agric Sin (中国农业科学), 2000, 33(6): 111-112 (in Chinese with English abstract) [本文引用:1]
[16]	Tollenaar M, Ahmadzadeh A, Lee E A. Physiological basis of heterosis for grain yield in maize. Crop Sci , 2004, 44: 2086-2094 [本文引用:1]
[17]	Guo L-P(郭立平), Xing C-Z(邢朝柱), Miao C-D(苗成朵), Wang H-L(王海林), Song M-Z(宋美珍), Wang H-Q(王海琴). Physiological and biochemical characteristics of hybrid cottons CCRI29, CCRI38, CCRI39 and their parents. Cotton Sci (棉花学报), 2005, 17(5): 314-315 (in Chinese with English abstract) [本文引用:2]
[18]	Ni Z F, Kim E D, Ha M, Lackey E, Liu J X, Zhang Y R, Sun Q X, Chen Z J. Altered circadian rhythms regulate growth vigour in hybrids and allopolyploids. Nature , 2009, 457: 327-331 [本文引用:1]
[19]	Wang X-L(王秀莉), Hu Z-R(胡兆荣), Peng H-R(彭惠茹), Du J-K(杜金昆), Sun Q-X(孙其信), Wang M(王敏), Ni Z-F(倪中福). Relationship of photosynthetic carbon assimilation related traits of flag leaves with yield heterosis in a wheat diallel cross. Acta Agron Sin (作物学报), 2010, 36(6): 1003-1010 (in Chinese with English abstract) [本文引用:2]
[20]	Hu Z-Z(胡兆璋). Review of the five agriculture science and technology leaps in Xinjiang construction group. State Farms Technol Xinjiang (新疆农垦科技), 2009, (1): 3-6 (in Chinese) [本文引用:1]
[21]	Du M-W(杜明伟), Luo H-H(罗宏海), Zhang Y-L(张亚黎), Yao Y-D(姚炎帝), Zhang W-F(张旺锋), Xia D-L(夏东利), Ma L(马丽), Zhu B(朱波). Photosynthesis characteristics of super-high- yield hybrid cotton in Xinjiang. Sci Agric Sin (中国农业科学), 2009, 42(6): 1952-1962 (in Chinese with English abstract) [本文引用:1] [CJCR: 1.4522]
[22]	Tang B, Johnie N, Jenkins J C, McCarty J C, Watson C E. F₂ hybrids of host plant germplasm and cotton cultivars: I. Heterosis and combining ability for lint yield and yield component. Crop Sci , 1993, 33: 700-705 [本文引用:1]
[23]	Zhang Z-H(张正圣), Li X-B(李先碧), Liu D-J(刘大军), Xiao Y-H(肖月华), Luo M(罗明), Huang S-L(黄顺礼), Zhang F-X(张凤鑫). Study on combining ability and heterosis between high strength lines and Bt (Bacillus thuringiensis) bollworm-resistant lines in upland cotton (Gossypium hirsutum L. ). Sci Agric Sin (中国农业科学), 2002, 35(12): 1450-1455 (in Chinese with English abstract) [本文引用:1]
[24]	May O L, Jividen G M. Genetic modification of cotton fiber properties as measured by single- and high-volume instruments. Crop Sci , 1999, 39: 328-333 [本文引用:1]
[25]	Malone S, Herbert Jr D A, Holshouser D L. Evaluation of the LAI-2000 plant canopy analyzer to estimate leaf area in manually defoliated soybean. Agron J , 2002, 94: 1012-1019 [本文引用:1]
[26]	Gao L-Z(高亮之), Li L(李林). Rice Meteoric Ecology (水稻气象生态学) . Beijing: Agriculture Press, 1992. pp121-123(in Chinese) [本文引用:1]
[27]	Maddonni G A, Otegui M E. Leaf area, light interception and crop development in maize. Field Crops Res , 1996, 48: 81-87 [本文引用:1]
[28]	Sheeky J E, Mitchell P L, Hardy B C. Redesigning Rice Photosynthesis to Increase Yield. Netherland : IRRI & Elsevier Science, 2000. pp101-102 [本文引用:1]
[29]	Cheng J-F(程建峰), Ma W-M(马为民), Chen G-Y(陈根云), Hu M-J(胡美君), Shen Y-G(沈允钢), Li Z-S(李振声), Tong Y-P(童依平), Li B(李滨), Li H-W(李宏伟). Dynamic changes of photosynthetic characteristics in Xiaoyan 54, Jing 411, and the stable selected superior strains of their hybrid progenies. Acta Agron Sin (作物学报), 2009, 35(6): 1051-1058 (in Chinese with English abstract) [本文引用:1]
[30]	Zhang H-G(张宏根), Kong X-W(孔宪旺), Zhu Z-B(朱正斌), Tang S-Z(汤述翥), Yi C-D(裔传灯), Gu M-H(顾铭洪). Analysis of characteristics and heterosis of three-line parents in hybrid japonica rice. Acta Agron Sin (作物学报), 2010, 36(5): 801-809 (in Chinese with English abstract) [本文引用:1]
[31]	Sun Q X, Wu L M, Ni Z F, Meng F R, Wang Z K, Lin Z. Differential gene expression patterns in leaves between hybrids and their parental inbreds are correlated with heterosis in a wheat diallel cross. Plant Sci , 2004, 166: 651-657 [本文引用:1]
[32]	Adams K L. Evolution of duplicate gene expression in polyploidy and hybrid plants. J Hered , 2007, 98: 136-141 [本文引用:1]
[33]	Bao J Y, Lee S, Chen C, Zhang X Q, Zhang Y, Liu S Q, Clark T, Wang J, Cao M L, Yang H M, Wang S M, Yu Y J. Serial analysis of gene expression study of a hybrid rice strain (LYP9) and its parental cultivars. Plant Physiol , 2005, 138: 1216-1231 [本文引用:1]
[34]	Huang Y(黄毅), Li L-H(李利华), Chen Y(陈莹), Li X-H(李香花), Xu C-G(徐才国), Wang S-P(王石平), Zhang Q-F(张启发). Comparison analysis of hybrid rice hybrid LYP9 and parents at seedling stag. Sci China: Ser C (中国科学·C辑): 2006, 36(4): 302-311 (in Chinese with English abstract) [本文引用:1]
[35]	Zhang X-M(张小蒙), Xiao N(肖宁), Zhang H-X(张洪熙), Feng Y-X(冯彦侠), Liu Z-X(刘知晓), Gao Y(高勇), Dai Z-Y(戴正元), Chen J-M(陈建民). Analysis of the relationship between differential expression of rice gene and heterosis. Sci Agric Sin (中国农业科学), 2012, 45(7): 1235-1245 (in Chinese with English abstract) [本文引用:2] [CJCR: 1.4522]
[36]	Xiong L Z, Yang G P, Zhang Q F, Maroof M A S. Relationships of differential gene expression in leaves with heterosis and heterozgosity in a rice diallel cross. Mol Breed , 1998, 4: 129-136 [本文引用:1]
[37]	Wang Z-K(王章奎), Ni Z-F(倪中福), Meng F-R(孟凡荣), Wu L-M(吴利民), Xie X-D(谢晓东), Sun Q-X(孙其信). Primary study on the relationship between differential gene expression patterns in roots at jointing stage and heterosis in agronomic traits in a wheat dialle cross. Sci Agric Sin (中国农业科学), 2003, 36(5): 473-479 (in Chinese with English abstract) [本文引用:1]
[38]	Xing C Z, Zhao Y L, Yu S X, Zhang X L, Guo L P, Wang H L. Relationship between gene differential expression of leaves in full opening flower stages of hybrids & their parents and heterosis in pest-resistant cotton. Acta Genet Sin , 2006, 33: 948-956 [本文引用:1]
[39]	Wang X-D(王学德), Pan J-J(潘家驹). Genetic analysis of heterosis and inbreeding depression in upland cotton. Acta Agron Sin (作物学报), 1991, 17(1): 18-23 (in Chinese with English abstract) [本文引用:1] [CJCR: 1.8267]
[40]	Jiang H(江华), Wang H-W(王宏炜), Su J-H(苏吉虎), Shi X-B(石晓冰), Shen Y-G(沈允钢), Li Z-S(李振声), Wei Q-K(魏其克), Zhang X-M(张锡梅), Li B(李滨), Li M(李鸣), Zhang J-J(张吉军). Photosynthesis in offspring of hybridization between two wheat cultivars. Acta Agron Sin (作物学报), 2002, 28(4): 451-454 (in Chinese with English abstract) [本文引用:2] [CJCR: 1.8267]
[41]	Boerma H R, Specht J E. Soybeans: Improvement, Production and Uses, 3rd edn. Madison, Wisconsin, USA: SSSA Publishers, 2004. pp303-396 [本文引用:1]
[42]	Kindred D R, Gooding M J. Heterosis for yield and its physiological determinants in wheat. Euphytica , 2005, 142: 149-159 [本文引用:1] [JCR: 1.554]

2002

0.0

... 作物光合作用是产量形成的基础, 提高作物光合生产力是农学家长期探索的重要研究内容^[1,2,3,4] ...

2006

0.0

... 作物光合作用是产量形成的基础, 提高作物光合生产力是农学家长期探索的重要研究内容^[1,2,3,4] ...

2008

0.0

... 作物光合作用是产量形成的基础, 提高作物光合生产力是农学家长期探索的重要研究内容^[1,2,3,4] ...

2009

0.0

... 作物光合作用是产量形成的基础, 提高作物光合生产力是农学家长期探索的重要研究内容^[1,2,3,4] ...

2008

0.0

1.8267

Acta Agronomica Sinica. 2008, 34(3):447 - 455 DOI:10.3724/SP.J.1006.2008.00447

Canopy Structure and Photosynthesis Traits of Summer Maize under Different Planting Densities

不同种植密度下的夏玉米冠层结构及光合特性

LÜ Li-Hua¹,TAO Hong-Bin¹,XIA Lai-Kun¹, HANG Ya-Jie¹,ZHAO Ming²,ZHAO Jiu-Ran³,WANG Pu^1,*

吕丽华¹;陶洪斌¹;夏来坤¹; 张雅杰¹; 赵明²; 赵久然³;王璞^1,*

1 Key Laboratory of Crop Cultivation and Farming System, Ministry of Agriculture / College of Agronomy and Biotechnology, China Agricultural University, Beijing 100094; 2 Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081; 3 Maize Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100089, China

Canopy structure has strong effects on photosynthesis and grain yield in maize (Zea mays L.). Planting density is one of the most important factors that can regulate canopy structure. Many researches have shown that leaf area index (LAI) and leaf area duration (LAD) increase accordantly with the proper increase of planting density, but the percent transmission decreases sharply under excessive high density, resulting in uneven light distribution within canopy and photosynthesis reduction. We need to know which proper planting densities for cultivars lead to little influence on photosynthesis and higher grain yield in summer maize. However, so far few reports on this topic have been found and no quantitative criteria can be used in evaluating canopy structure of different maize cultivars. Therefore, we conducted an experiment with three cultivars and three planting densities in the field having medium soil fertility and application of 180 kg N ha^-1 in Wuqiao Experimental Station (37°41′02″N，116°37′23″E) of China Agricultural University in 2006 to establish such quantitative criteria for high yielding cultivars in North China Plain. The split plot design was employed with main plot of plant density (low, medium, and high respectively), sub-plot of cultivar (CF008, Zhengdan 958, and Jinhai 5 respectively), and three replicates in each sup-plot. According to plant type, the densities of three cultivars were 9.75×104 (low), 11.25×104 (medium), and 12.45×104 (high) plants ha-1 for CF008; 8.25×104 (low), 9.75×104 (medium), and 11.25×104 (high) plants ha-1 for Zhengdan 958; and 6.75×104 (low), 8.25×104 (medium), and 9.75×104 (high) plants ha-1 for Jinhai 5. The high-yielding canopy structure and photosynthesis were obtained under both low and medium densities of the three cultivars. Percent transmission, leaf angle, and stem diameter decreased with the increase of plant density. The chlorophyll relative content (SPAD) and the rate of net photosynthesis rate (Pn) were the smallest under high density because of the uneven light distribution within canopy. For CF008, SPAD value of ear leaf and the third leaf under ear decreased sharply in later growth stages. LAD and LAI values before mid-filling stage were greater under medium or high densities, while different tendency occurred in the maturity stages. Moreover, the proportion of after-silking LAD was greater under low or medium densities, showing that canopy structure was unsuitable under high density due to early senescence. For Zhengdan 958 and Jinhai 5, LAD after silking was greater than that before silking, which was benefit for high grain yield. Our results confirmed that proper planting density can establish high-yielding canopy structure and improve population photosynthesis and yield in maize. We also obtained a series quantitative criteria for high-yielding canopy structure based on the data from Wuqiao area: percent transmission of 13.4%–19.45% in silking stage and 16.19%–21.48% in mid-filling stage under low or medium densities; LAI of 5.59–6.75 in silking stage and 2.24–3.68 in maturity stage, especially highen in middle and upper leaf layers in maturity stage under low or medium densities; Pn of 33.6–43.8 μmol CO2 m-2 s-1 in middle and upper layer leaves in silking stage under low or medium densities; higher LAD after silking under low or medium densities, with 172.01–235.91 m2 d m-2 under medium density.

研究了种植密度对夏播玉米(CF008、郑单958和金海5号）冠层结构及光合特性的影响，目的是通过密度调控，构建高效冠层，发挥品种潜力，同时确立不同夏玉米品种高产高效冠层的定量化技术指标。结果表明，3个夏玉米品种均在中或低密度下（CF008为9.75和11.25万株 hm-2，郑单958为8.25和9.75万株 hm^-2，金海5号为6.75和8.25万株 hm^-2）构建的冠层较合理，冠层光合性能较高。冠层内透光率、叶夹角、茎粗、叶绿素相对含量（SPAD值）和净光合速率（Pn）均随着密度的增加而降低，说明高密度易造成群体内光分布不合理，导致光合性能的降低。灌浆中期前群体光合势（LAD）和叶面积指数（LAI）均表现为中或高密度条件下较高，而后为中或低密度下较高，并且吐丝后LAD所占比率为中或低密度处理显著高于高密度处理，说明高密度条件下冠层结构不合理，造成生育后期叶片提早衰老。在中或低密度下，群体穗位层透光率较大，吐丝期和灌浆中期分别为13.4%~19.45%和16.19%~21.48%；叶面积发展动态较为合理，吐丝期LAI达5.59~6.75，成熟期仍然保持在2.24~3.68，尤其中上层叶片LAI高值持续期较长；吐丝期中上层叶片Pn达到33.6~43.8 μmol CO2 m^-2 s^-1；吐丝后的群体LAD较高，特别是中密度下LAD达172.01~235.91 m2 d m-2，后期光合面积持续时间较长，更有利于玉米产量的提高。

... 作物冠层结构显著影响群体光合速率^[5] ...

2006

0.0

... 改善作物冠层结构是提高光合性能最有效的途径之一^[6] ...

1990

0.0

... 叶面积指数是衡量作物冠层结构的重要指标, 研究表明, 叶面积指数可估算作物冠层潜在光合生产力及作物干物质积累量^[7] ...

2000

3.243

0.0

PHOTOSYNTH RES. 2000, 66(1-2):97 - 108 DOI:10.1023/A:1010634521467

Acclimation response of spring wheat in a free-air CO2 enrichment (FACE) atmosphere with variable soil nitrogen regimes. 3. Canopy architecture and gas exchange

Talbot J. Brooks(12) Gerard W. Wall(1) Paul J. Pinter(1) Bruce A. Kimball(1) Robert L. LaMorte(1) Steven W. Leavitt(3) Allan D. Matthias(3) Floyd J. Adamsen(1) Douglas J. Hunsaker(1) Andrew N. Webber(4)

1.USDA-ARS, US Water Conservation Laboratory, Phoenix, AZ 85040, USA
2.Department of Geography, Arizona State University, Tempe, AZ 85287-0104, USA
3.University of Arizona, Tucson, Arizona USA
4.Department of Plant Biology, Arizona State University, Tempe, Arizona

The response of whole-canopy net CO₂ exchange rate (CER) and canopy architecture to CO₂ enrichment and N stress during 1996 and 1997 for open-field-grown wheat ecosystem (Triticum aestivum L. cv. Yecora Rojo) are described. Every Control (C) and FACE (F) CO₂ treatment (defined as ambient and ambient +200 μmol mol⁻¹, respectively) contained a Low- and High-N treatment. Low-N treatments constituted initial soil content amended with supplemental nitrogen applied at a rate of 70 kg N ha⁻¹ (1996) and 15 kg N ha⁻¹ (1997), whereas High-N treatments were supplemented with 350 kg N ha⁻¹ (1996 and 1997). Elevated CO₂ enhanced season-long carbon accumulation by 8% and 16% under Low-N and High-N, respectively. N-stress reduced season-long carbon accumulation 14% under ambient CO₂, but by as much as 22% under CO₂ enrichment. Averaging both years, green plant area index (GPAI) peaked approximately 76 days after planting at 7.13 for FH, 6.00 for CH, 3.89 for FL, and 3.89 for CL treatments. Leaf tip angle distribution (LTA) indicated that Low-N canopies were more erectophile than those of High-N canopies: 48° for FH, 52° for CH, and 58° for both FL and CL treatments. Temporal trends in canopy greenness indicated a decrease in leaf chlorophyll content from the flag to flag-2 leaves of 25% for FH, 28% for CH, 17% for CL, and 33% for FL during 1997. These results indicate that significant modifications of canopy architecture occurs in response to both CO₂ and N-stress. Optimization of canopy architecture may serve as a mechanism to diminish CO₂ and N-stress effects on CER.

... 叶倾角的变化能显著影响冠层固定CO₂的能力, 进而影响产量^[8] ...

2003

0.0

... Stewart等^[9]通过对大量玉米品种的研究表明, 叶面积和叶倾角是影响光合作用的主要因子 ...

2000

0.0

... 作物群体光截获率对光合作用有重要作用^[10], 改善作物冠层结构特征, 对增强群体光截获率, 提高群体生产力具有重要意义 ...

1996

0.0

... 育种学家已通过遗传改良手段, 选育出具有适宜于光合作用的最佳叶面积和叶片角度的优良品种^[11,12,13] ...

... 1 杂交棉F₁代冠层结构特性与亲本的关系通过遗传改良手段, 可选育具有适宜光合作用的冠层结构, 如叶面积和叶片角度等^[11], 在选育良种的过程中, 选取有效光合性能指标早已受到人们的广泛关注^[28] ...

2002

0.0

... 育种学家已通过遗传改良手段, 选育出具有适宜于光合作用的最佳叶面积和叶片角度的优良品种^[11,12,13] ...

2005

2.534

0.7555

J INTEGR PLANT BIOL. 2005, (2):178 - 186

Promotive Effect of Low Concentrations of NaHSO3 on Photophosphorylation and Photosynthesis in Phosphoenolpyruvate Carboxylase Transgenic Rice Leaves

... 育种学家已通过遗传改良手段, 选育出具有适宜于光合作用的最佳叶面积和叶片角度的优良品种^[11,12,13] ...

2007

0.0

1.8267

Acta Agronomica Sinica. 2007, 33(3):507 - 510

Primary Study on Gene Differential Expression of Pest-resistant Cotton Hybrids between Different Heterosis Crosses

不同优势抗虫棉杂交组合不同生育期基因表达差异初探

XING Chao-Zhu¹;YU Shu-Xun^1,*; ZHAO Yun-Lei²; GUO Li-Ping¹;ZHANG Xian-Long²; MIAO Cheng-Duo¹; WANG Hai-Lin¹

邢朝柱¹ ; 喻树迅^1,* ; 赵云雷²; 郭立平¹ ; 张献龙²; 苗成朵¹ ; 王海林¹

¹ Cotton Research Institute, Chinese Academy of Agricultural Sciences, Anyang 455004, Henan;² Huazhong Agricultural University, Wuhan 430070, Hubei, China

Leaf cDNA of 3 pest-resistant cotton crosses with remarkable different yield heterosis and their parents in 4 growth stages were amplified by DDRT-PCR (The mRNA Differential Display) with 45 primers combinations. The results were as follows: The proportions of genes differential expression between F1 and their parents were degressive tendency from square stage to boll stage in these crosses. The percentages of genes differential expression in the high heterotic cross were higher than those in the low heterotic crosses in four growth stages, which showing a closely relationship between gene differential expression and heterosis occurrence. The percentages of M3 (bands expressed only F₁) in the high heterotic crosses surpassed those in middle or low heterotic crosses at three earlier growing stages, which suggested M3 played an important role in yield heterosis occurrence. M4 (bands expressed in one parent and F1) was the main expression pattern in gene differential expression, but varied within narrow range in four growing stages, which indicated no remarkable correlation between yield heterosis and M4.

采用DDRT-PCR技术对3个产量优势差异较大的杂交棉组合及其亲本在4个生育期叶片cDNA进行扩增和差显，结果表明，产量高、中、低优势组合与其亲本基因差异表达比例从蕾期到花铃期总体上呈递减趋势；杂种特异表达在前3个生育期高优势组合高于中或低优势组合，特异表达可能对杂种优势的产生起一定作用；单亲表达一致是基因差异表达中最主要表达模式，但在各生育期高、中、低优势组合之间变化幅度较小，表明此模式可能与杂种优势发挥无明显关系。

... 近年来, 中国在棉花杂种优势的研究和利用方面取得了较大进展, 杂交棉F₁代平均增产15%左右^[14], 推动了棉花产量水平的提高^[15] ...

... 杂交种性状受其选配的亲本显著影响^{[14,17,19,29]}, 在生长势上表现出非常明显的杂种优势^[30] ...

... 有研究表明亲本基因差异表达与F₁杂种优势呈正相关^{[14,35,36,37,38]} ...

2000

0.0

... 近年来, 中国在棉花杂种优势的研究和利用方面取得了较大进展, 杂交棉F₁代平均增产15%左右^[14], 推动了棉花产量水平的提高^[15] ...

2004

0.0

... 然而, 如何通过亲本选配, 进一步发挥杂交种的光合生产优势, 挖掘其增产潜力已成为棉花等作物超高产育种和栽培研究关注的热点^{[16,17,18,19]} ...

2005

0.0

... 然而, 如何通过亲本选配, 进一步发挥杂交种的光合生产优势, 挖掘其增产潜力已成为棉花等作物超高产育种和栽培研究关注的热点^{[16,17,18,19]} ...

... 杂交种性状受其选配的亲本显著影响^{[14,17,19,29]}, 在生长势上表现出非常明显的杂种优势^[30] ...

2009

0.0

... 然而, 如何通过亲本选配, 进一步发挥杂交种的光合生产优势, 挖掘其增产潜力已成为棉花等作物超高产育种和栽培研究关注的热点^{[16,17,18,19]} ...

2010

0.0

Acta Agronomica Sinica. 2010, 36(6):1003-1010

Relationship of photosynthetic carbon assimilation related traits of flag leaves with yield heterosis in a wheat diallel cross.

Wang X-L , 王秀莉), Hu Z-R , 胡兆荣), Peng H-R , 彭惠茹), Du J-K , 杜金昆), Sun Q-X , 孙其信), Wang M , 王敏), Ni Z-F

以按照NCII遗传交配设计配制的20个普通小麦杂交种及其亲本为材料，系统测定灌浆初期、中期和后期旗叶的6个光合碳同化相关性状，包括光合速率、气孔导度、胞间CO₂浓度、蒸腾速率、水分利用效率和原初光能转化效率，并与产量性状杂种优势进行相关分析。结果显示，杂种优势值因组合、性状和发育时期不同而差异很大。偏相关分析表明，光合碳同化性状与穗长和有效穗数杂种优势之间没有相关性，但与其他产量性状杂种优势之间存在显著的相关关系，特别是在作物籽粒产量形成最为关键的灌浆中期，光合速率、胞间CO₂浓度、水分利用效率和原初光能转化效率与穗粒数、千粒重、单株产量和主茎穗产量等性状的杂种优势呈显著或极显著正相关，说明较高的光合能力及水分利用效率可能是小麦产量杂种优势形成的重要生理基础之一

... 然而, 如何通过亲本选配, 进一步发挥杂交种的光合生产优势, 挖掘其增产潜力已成为棉花等作物超高产育种和栽培研究关注的热点^{[16,17,18,19]} ...

... 杂交种性状受其选配的亲本显著影响^{[14,17,19,29]}, 在生长势上表现出非常明显的杂种优势^[30] ...

2009

0.0

... 新疆是我国最重要的商品棉生产基地, 自2001年以来, 新疆引进和选育了多个棉花杂交种并在生产上进行示范推广, 使棉花单产水平有了进一步提高^[20,21] ...

2009

0.0

1.4522

Scientia Agricultura Sinica. 2009, 42(6):1952 - 1962

Photosynthesis Characteristics of Super-High-Yield Hybrid Cotton in Xinjiang

新疆超高产杂交棉的光合生产特征研究

DU Ming-wei, LUO Hong-hai, ZHANG Ya-li, YAO Yan-di, ZHANG Wang-feng,XIA Dong-li, MA Li, ZHU Bo

杜明伟,罗宏海,张亚黎,姚炎帝,张旺锋,夏东利,马丽,朱波

石河子大学农学院/新疆兵团绿洲生态农业重点实验室

【Objective】 To explore photosynthesis characteristics, summarize the principle of yield formation, and propose yield components and photosynthetic physiological indexes, experiments were conducted with super-high-yield cotton in field. It was of great significance to excavate yield potential and construct super-high-yield cultivation technique system. 【Method】 One hybrid cotton cultivar Biaoza A1 and four traditional cultivars including Xinluzao 13, Xinluzao 26, Wanshi 217 and Wanshi 315 were selected as the experimental materials. Leaf area index, chlorophyll SPAD value, photosynthetic rate, photosynthate accumulation and distribution were measured at different growth stages. 【Result】 Compared to high yield traditional cultivar, super-high-yield hybrid cultivar (lint 3 500 kg?hm-2) had higher leaf area index, chlorophyll SPAD value and photosynthetic rate, all of which had longer duration during growth stage. Furthermore, the ratio of canopy respiration rate to total canopy apparent photosynthesis rate which maintained at a low level at the middle and late growth stage, was significantly lower than that of high yield traditional cultivar especially at early boll opening stage. Biaoza A1 had longer and earlier linear increase stage of vegetative organs photosynthate accumulation, which led to greater photosynthate accumulation. However, the linear increase stage of reproductive organs and total photosynthate accumulation and the peak of accumulation appeared comparatively later than those of high yield traditional cultivar. 【Conclusion】 The indexes of yield components and photosynthetic physiology of super-high-yield Biaoza A1 (lint 3 500 kg?hm-2) were proposed, i.e., total number of bolls＞150×104?hm-2, boll weight ＞5.5 g, lint percentage ＞44%; leaf area index at early full bolling stage 4.9-5.2, at early boll opening stage above 3.3; chlorophyll SPAD value at full bolling stage 65.4-66.5, at early boll opening stage above 64.8; net photosynthetic rate at flowering and boll forming stage 32.2-36.5 μmol?m-2?s-1, at early boll opening stage above 22.2 μmol?m-2?s-1; canopy apparent photosynthesis rate at early full bolling stage approximately 43.4 μmol?m-2?s-1, at early boll opening stage above 16.3 μmol?m-2?s-1; total photosynthate accumulation approximately 26 345.4 kg?hm-2, economic coefficient no less than 31%.

【目的】研究超高产条件下棉花的光合生产特征,总结超高产形成规律,提出超高产的产量结构和光合生理指标,对挖掘品种产量潜力,构建超高产栽培技术体系具有重要意义。【方法】以杂交棉标杂A1为研究对象,采取定向培育超高产试验示范田,以一般产量水平条件下常规棉品种（系）为对照,研究超高产条件下标杂A1产量形成过程中叶面积指数、叶绿素相对含量（SPAD值）、光合速率和光合物质积累与分配等变化。【结果】与常规高产棉田相比,标杂A1皮棉单产达到3 500 kg?hm-2时,叶面积指数高且持续期长,叶绿素SPAD值、单叶光合速率在盛铃期至初絮期显著高于对照;群体光合速率峰值高且持续时间长,群体呼吸速率占群体总光合的比例在生育中后期保持在较低水平,初絮期显著低于常规高产棉田;营养器官光合物质积累直线增长期起始时间早、积累持续时间长、物质积累量大,群体总光合物质和生殖器官光合物质积累直线增长期及积累速率峰值出现较晚,积累活跃期较长,物质积累强度大。【结论】杂交棉标杂A1皮棉单产达到3 500 kg?hm-2的产量结构和生育期主要光合生理指标：总铃数每公顷应大于150万个,单铃重大于5.5 g,衣分不低于44%;叶面积指数在盛铃前期应达4.9～5.2,初絮期应维持在3.3以上;叶绿素SPAD值在盛铃期达到65.4～66.5,初絮期仍在64.8以上;单叶光合速率在盛蕾期至盛铃期保持在32.2～36.5μmol?m-2?s-1,初絮期应高于22.2μmol?m-2?s-1;群体光合速率盛铃前期达43.4μmol?m-2?s-1,初絮期在16.3μmol?m-2?s-1以上;总光合物质积累量达26 345.4 kg?hm-2,经济系数不低于31%。

1993

0.0

... 棉花是异源四倍体, F₂代分离并不严重, 仍保持一定的杂种优势^[22,23], 具有较好的增产潜力和广泛的适应性^[24], 有一定的生产应用价值 ...

2002

0.0

... 棉花是异源四倍体, F₂代分离并不严重, 仍保持一定的杂种优势^[22,23], 具有较好的增产潜力和广泛的适应性^[24], 有一定的生产应用价值 ...

1999

0.0

... 棉花是异源四倍体, F₂代分离并不严重, 仍保持一定的杂种优势^[22,23], 具有较好的增产潜力和广泛的适应性^[24], 有一定的生产应用价值 ...

2002

0.0

... 1 冠层结构指标采用LAI-2000冠层仪(Li-Cor, USA), 参照Malone等的方法^[25]测定叶面积指数和叶倾角, 先将探头水平放置于冠层上方, 按下测定按钮, 两声蜂鸣后将探头放入群体内, 仍保持水平, 按下测定按钮, 两声蜂鸣后水平均匀移动探头, 选择冠层内不同位置测量, 重复4次 ...

1992

0.0

... 2 光截获率采用高亮之等^[26]介绍的方法, 在北京时间11:00~14:00, 用LI-250A光量子仪(Li-Cor, USA)测定植株顶部以上30 cm处自然光强I_o (探头面水平向上)、植株反光I_n (探头面水平向下)、入射到冠层底部的光强I ...

1996

0.0

... 4 冠层光截获率作物光合作用及干物质生产能力与冠层光截获状况密切相关^[27] ...

2000

0.0

2009

0.0

... 杂交种性状受其选配的亲本显著影响^{[14,17,19,29]}, 在生长势上表现出非常明显的杂种优势^[30] ...

2010

0.0

... 杂交种性状受其选配的亲本显著影响^{[14,17,19,29]}, 在生长势上表现出非常明显的杂种优势^[30] ...

2004

0.0

... 杂交种的基因来自双亲, 基因表达方面存在的差异是导致杂种优势的重要原因^[31,32] ...

2007

0.0

... 杂交种的基因来自双亲, 基因表达方面存在的差异是导致杂种优势的重要原因^[31,32] ...

2005

0.0

... 基因差异表达是构成F₁杂种优势性状差异的分子基础^[33,34] ...

2006

0.0

... 基因差异表达是构成F₁杂种优势性状差异的分子基础^[33,34] ...

2012

0.0

1.4522

Scientia Agricultura Sinica. 2012, 45(7):1235 - 1245 DOI:10.3864/j.issn.0578-1752.2012.07.001

Analysis of the Relationship Between Differential Expression of Rice Gene and Heterosis

水稻基因差异表达与杂种优势的关系分析

ZHANG Xiao-Meng, XIAO Ning, ZHANG Hong-Xi, FENG Yan-Xia, LIU Zhi-Xiao, GAO Yong, DAI Zheng-Yuan, CHEN Jian-Min

张小蒙, 肖宁, 张洪熙, 冯彦侠, 刘知晓, 高勇, 戴正元, 陈建民

1.扬州大学生物科学与技术学院江苏扬州 225009
2.江苏里下河地区农业科学研究所/国家水稻改良中心南京分中心，江苏扬州225007

【Objective】The strong and weak heterosis groups in rice were analyzed for investigating the relationship between differential expression patterns of gene and heterosis. 【Method】The differential display-PCR (DD-PCR) technology was used to analyze gene differentially expressed patterns for the nine F1 of Yangdao 6, Minghui 63 and Teqing varieties as male parent in tillering leaves, booting panicles and heading flag leaf. 【Result】At the same growth stage, four kinds of gene differentially expressed patterns, UNP1 (genes specifically expressed in female parent), UNP2 (genes specifically expressed in male parent), UNF1(genes specifically expressed in F1), ABF1 (genes specifically silenced in F1), were presented obvious difference between strong heterosis group G1(Yangdao 6 as male parent) and weak heterosis group G2 (Minghui 63 as male parent). Correlation analysis showed that UNP2 of tillering leaves was significantly positive corelated to yield per plant, and the expressed genes from the paternal were benefit to heterosis. The differentially expressed gene patterns existed obvious difference among three growth stages in the same heterosis group, which indicates that gene expression is spatial and temporal characteristic. Total nineteen differentially expressed gene fragments between G1 and G2 groups were acquired and distributed along one to eleven chromosomes except the twelfth chromosome. The function analysis result showed that they were mainly involved in material synthesis and transport, energy, carbohydrate metabolism pathways and so on. 【Conclusion】 The gene differential expression patterns in strong and weak heterosis group exist significant difference at different growth stages. The phenotypic differences could be reflected by gene differential expression patterns.

【目的】分析水稻强、弱优势组合的基因差异表达模式特征，探讨其与杂种优势之间的关系。【方法】以扬稻6号、明恢63、特青配置的9个杂种F1为材料，利用差异显示PCR技术（differential display polymerase chain reaction，DD-PCR）分别分析分蘖期（叶片）、孕穗期（幼穗）、抽穗期（剑叶）的基因差异表达模式。【结果】同一时期内强优势组G1（父本扬稻6号）、中优势组G3（父本特青）以及弱优势组G2（父本明恢63）在母本特异表达（UNP1）、父本特异表达（UNP2）、F1特异表达（UNF1）、F1特异缺失表达（ABF1）4个基因差异表达模式上存在明显差异；相关分析表明分蘖期叶片UNP2与单株产量呈极显著正相关，来自父本的基因特异表达有利于提高杂种优势；同一优势组在不同时期的表达模式也存在明显差异，反映了基因的时空表达特征；获得19个G1、G2间特异性差异表达的基因片段，分布在除第12染色体以外的其余11条染色体上，主要涉及物质合成与运输、能量代谢、糖类代谢等重要途径。【结论】水稻强、弱优势组合F1在不同生育期基因表达模式存在显著差异，表型性状的差异可以从基因表达模式上得以反映。

... 表型性状的差异可以从基因表达模式上得以反映^[35] ...

... 有研究表明亲本基因差异表达与F₁杂种优势呈正相关^{[14,35,36,37,38]} ...

1998

0.0

... 有研究表明亲本基因差异表达与F₁杂种优势呈正相关^{[14,35,36,37,38]} ...

2003

0.0

... 有研究表明亲本基因差异表达与F₁杂种优势呈正相关^{[14,35,36,37,38]} ...

2006

0.0

Acta Genetica Sinica. , :

... 有研究表明亲本基因差异表达与F₁杂种优势呈正相关^{[14,35,36,37,38]} ...

1991

0.0

1.8267

Acta Agronomica Sinica. 1991, 17(1):18 - 23

Genetic Analysis of Heterosis and Inbreeding Depression in Upland Cotton

陆地棉杂种优势及自交衰退的遗传分析

Wang Xuede;Pan Jiaju

王学德;潘家驹

Zhejiang Academy of Agricultural Sciences

The basic genetic parameters for lint yield,yield components and fiber propertiesof upland cotton were estimated through variance anlysis with 56 F1 populations es-tablished by NCII mating,design.The mean heterosis percentages of 56 F1 and 30F2 populations were also calculated respectively.Experimen

采用 NCⅡ交配设计,估计了陆地棉产量、产量构成因子和纤维品质性状的遗传参数,以及计算了56个组合的杂种一代平均优势和30个组合的杂种二代平均优势。通过不同世代间的比较,对7个性状杂种优势及自交衰退进行遗传分析,结果表明:产量、铃重和纤维长度不但有极显著的 F_1杂种优势,而且也有显著的 F_2杂种优势,这些性状的优势主

... 2 杂交棉F₂代冠层结构特性与亲本及杂交棉F₁代的关系杂交棉F₂代在某些性状上表现出中亲优势^[39], 有可能出现光合速率高于F₁代材料^[40] ...

2002

0.0

1.8267

Acta Agronomica Sinica. 2002, 28(4):451 - 454

Photosynthesis in Offspring of Hybridization between Two Wheat Cultivars

小麦杂交后代的光合作用

Jiang Hua;Wang Hongwei;Su Jihu;Shi Xiaobing;Shen Yungang;Li Zhensheng;Wei Qike;Zhang Ximei;Li Bin;Li Ming;Zhang Jijun

江华;王宏炜;苏吉虎;石晓冰;沈允钢;李振声;魏其克;张锡梅;李滨;李鸣;张吉军

对小麦品种京411(J411)和小偃54(X54)及杂交后代植株于灌浆期对旗叶进行光合速率的比较测定, 在优选F3代的一个株系1-15中观测到测定的多数植株的光合速率比亲本高10%以上, 并且此结果在对它的F4代植株的测定中得到确证. 通过这个初步实验, 对选择具有高光合能力的植株作为培育优良小麦品种的重要指标的可能性以及在实际应用

... 2 杂交棉F₂代冠层结构特性与亲本及杂交棉F₁代的关系杂交棉F₂代在某些性状上表现出中亲优势^[39], 有可能出现光合速率高于F₁代材料^[40] ...

... 作物高产要求具有较高群体光合生产^[40], 通过对冠层结构的改造, 增加光能利用率, 制造更多的光合产物, 增大光合物质积累 ...

2004

0.0

... 作物产量是一个综合性状, 受植株多个形态、生理以及农艺性状的影响^[41] ...

2005

1.554

0.0

EUPHYTICA. 2005, 142(1-2):149 - 159 DOI:10.1007/s10681-005-1250-y

Heterosis for yield and its physiological determinants in wheat

D. R. Kindred(12) M. J. Gooding(1)

1.Crops Research Unit, Department of Agriculture, The University of Reading, Earley Gate, PO BOX 237, Reading, RG6 6AR U.K.
2.ADAS Centre for Sustainable Crop Management, Boxworth, Cambridge, CB3 8NN U.K.

Heterosis in hybrid wheat varieties produced using a chemical hybridising agent was assessed in field experiments. Hyno Esta and its parents were compared in factorial combinations of four-seed rates (25–300 seeds m^–2) and two nitrogen fertilizer rates (0 and 200 kg N ha^–1) in 2001/02 and again in 2002/03. Hyno Rista and Hyno Renta and their parents were compared at two-seed rates in 2001/02. Hyno Rista and its parents were added factorially to the Hyno Esta experiment in 2002/03, while Hyno Renta and Hybred and their parents were compared at two seed rates in 2002/03. Mid parent heterosis for grain yield was found in three hybrids and two of these showed high parent heterosis. High parent heterosis in Hyno Esta over a range of sowing densities was mostly exhibited in total biomass but also, in one of two years, in harvest index. High parent heterosis in Hyno Renta was associated more with harvest index than with biomass. The heterosis for biomass in Hyno Esta resulted from greater interception of photosynthetically active radiation (PAR) than the male parent, with better radiation use efficiency than the female parent. In both seasons Hyno Esta achieved grain numbers per ear at least as high as the high parent for this trait (Audace), and combined this with mean grain weights at least as heavy as the high parent for mean grain weight (Estica). Much of the increased biomass and grain yield in the hybrid came late in the season as high parent heterosis was expressed for both maximum grain filling rate and grain filling duration. Heterosis was higher when nitrogen was applied than when withheld; only greater at lower seed rates when expressed in proportionate terms (e.g. as a percentage of the parents), rather than in absolute terms (e.g. t ha^–1); and greater in the year with the cooler and wetter summer.

... 在选配亲本过程中不仅要考虑生理功能^[42], 而且要重视亲本冠层特性 ...