小麦是世界第一大口粮作物,是人类生活所依赖的重要食物来源,全球约35%~40%的人口以小麦为主要粮食。2016年世界小麦种植面积约22 010.76万hm2,约占全球谷物种植面积的30.7%,远超过玉米、水稻、大豆,居世界谷物种植面积之首。本文论述了世界小麦生产概况,包括小麦的种类、分布及主要生产国的基本情况,重点论述了中国小麦的生产和发展情况。随着社会的发展和科学技术的进步,中国的小麦生产能力逐步发展,主要体现在3个方面:一是种植面积起伏变化大,二是单产稳步提升,三是总产持续增长。无论是冬小麦还是春小麦,高产高效栽培技术和优良品种对产量的提升都起到了重要作用,我国小麦生产水平有了很大提高。

Content of wheat flour proteins affects the quality of wheat flour. Zinc nutrition in wheat can change the protein content of the flour. The inconsistency and instability of wheat grain quality during grain filling while under high temperature stress (HTS) are major problems in the production of high quality wheat. At present, there is a lack of studies on zinc fertilizer and HTS effects on wheat flour protein and the content of its components. For this study, treatment combinations of four levels of zinc fertilizers and exposure to a short-term HTS, at 20 d after flowering (D20), were tested on two wheat cultivars with different gluten levels. Individuals of a strong gluten wheat, Gaoyou 2018 (GY2018), and a medium gluten wheat, Zhongmai 8 (ZM8), were grown in pots at the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing in 2015 2017. We measured grain yield and weight and the activities of two enzymes (nitrate reductase and glutamine synthetase) from the flag leaves, collected at D10 and D20. Total protein content, protein yield, and content of four protein components (albumin, gliadin, glutenin, and globulin) were measured from flour produced from the pot-grown plants. HTS significantly increased the contents of total protein, albumin, gliadin, and glutenin in wheat grains, and reduced the grain yield, grain weight, protein yield, globulin content, and flag leaf nitrate reductase (NR) and glutamine synthetase (GS) activities. The results showed that HTS and zinc fertilizer had greater impacts on the strong gluten cultivar compared to the medium gluten cultivar. Under HTS, grain yield decreased by 13 and 8% in GY2018 and ZM8, respectively; protein yield decreased by 7 and 8% in GY2018 and ZM8, respectively. Zinc fertilizer increased: grain and protein yields; grain weight; total protein, albumin, gliadin, and glutenin contents; protein yield; and NR and GS activities. In contrast, zinc fertilizer reduced the content of globulin. The addition of 15 mg Zn kg 1 soil had the strongest effect on grain yield and quality as compared to the other three treatments (additions of 0, 30, and 45 mg Zn kg 1 soil). Zinc fertilizer also reduced the negative effects of HTS on protein yield, content, and components' content. Therefore, wheat grown with additional zinc in the soil can improve the quality of the flour.

Improving radiation use efficiency （RUE） of the canopy is necessary to increase wheat （Triticum aesfivum） production. Tridimensional uniform sowing （U） technology has previously been used to construct a uniformly distributed population structure that increases RUE. In this study, we used tridimensional uniform sowing to create a wheat canopy within which light was spread evenly to increase RUE. This study was done during 2014-2016 in the Shunyi District, Beijing, China. The soil type was sandy loam. Wheat was grown in two sowing patterns： （1） tridimensional uniform sowing （U）; （2） conventional drilling （D）. Four planting densities were used： 1.8, 2.7, 3.6, and 4.5 million plants ha-1. Several indices were measured to compare the wheat canopies： photosynthetic active radiation intercepted by the canopy （IPAR）, leaf area index （LAI）, leaf mass per unit area （LMA）, canopy extinction coefficient （K）, and RUE. In two sowing patterns, the K values decreased with increasing planting density, but the K values of U were lower than that of D. LMA and IPAR were higher for U than for D, whereas LAI was nearly the same for both sowing patterns. IPAR and LAI increased with increasing density under the same sowing pattern. However, the difference in IPAR and LAI between the 3.6 and 4.5 million plants ha-1 treatments was not significant for both sowing patterns. Therefore, LAI within the same planting density was not affected by sowing pattern. RUE was the largest for the U mode with a planting density of 3.6 million plants ha-1 treatment. For the D sowing pattern, the lowest planting density （1.8 million plants ha-1） resulted in the highest yield. Light radiation interception was minimal for the D mode with a planting density of 1.8 million plants ha-1 treatment, but the highest RUE and highest yield were observed under this condition. For the U sowing pattern, IPAR increased with increasing planting density, but yield and RUE were the highest with a planting density of 3.6

研究了冬小麦主茎及分蘖的植株性状,分析了单茎主要性状的相关关系,并结合不同群体的产量分析,探讨高产小麦分蘖的合理利用范围。研究结果表明,冬小麦主茎及分蘖的单茎性状均优于高位蘖。因此认为主茎、1N、2N和3N为优势蘖组,1N-1及其以后出生的分蘖为劣势蘖组。在高产栽培中,以每亩12～15万基本苗为宜,即利用优势蘖组成穗以获得高产。

小麦立体匀播就是使小麦种子均匀合理地分布在土壤中的立体空间内,出苗后无行无垄,均匀分布.立体匀播是基于小麦生长发育特性,充分发挥小麦个体均匀健壮和群体充足合理的协调机制,关键技术是使小麦株距均匀,改常规条播小麦田间分布的"一维行距"为立体匀播的"二维株距".使小麦在合理群体范围内,单株独立占有地下和地上相对均匀的营养空间,均衡占有农田土地资源和自然光热资源,使常规条播麦苗集中的一条"线",变为麦苗相对分布均匀的一个"面",促使麦苗单株充分健壮发育,地下形成相对强大的根系,地上形成相对健壮的优势蘖,根多苗壮,从而建立高质量的群体结构,促使形成产量因素的穗、粒、重协调发展,实现高产高效.

<p>在我国内蒙古自治区赤峰市农牧交错区研究了不同耕作方式及不同施氮量对小麦氮肥吸收利用和产量的影响.结果表明：长期实施保护性耕作使小麦对氮素的利用率提高3%～4%，减轻氮肥对农田环境的污染；保护性耕作有利于促进小麦对氮素的吸收，提高小麦产量.当施氮量由120 kg&middot;hm^-2增加到360 kg&middot;hm^-2时，小麦对氮素的吸收利用由36.5%降低为26%；氮素损失增加约5%，对应的氮素损失量则从60 kg&middot;hm^-2增加到约200 kg&middot;hm^-2，对环境的污染明显增加.小麦对上季残留氮素的利用受耕作方式影响较小，受上季施氮量影响较大，总体趋势为施氮量越高，小麦利用率越低，损失越多.经过两季小麦种植后，小麦-土壤系统回收的总氮素比例约为44%～50%，其中土壤残留氮素约占施氮量的13%～18%.</p>

为探明小麦分蘖的发生、成穗与先合产物分配及部分品质指标的关系，以三个不同类型小麦品种为试验材料，通过^14C示踪研究了三个分蘖力与成穗率不同的小麦品种在分蘖期、拔节期与抽穗期三个主要生育期的^14C光合产物分配特点。结果表明，在整个生育期中，分蘖力较低的9559的^14C光合产物分配均保持显著的主茎优势，而分蘖力中等的扬麦12和分蘖力较高的徐州26的主茎与单个分蘖之间^14C光合产物分配比例差异较小，但徐州26的分蘖^14C光合产物占整株的比例极显著高于9559，显著高于扬麦12。分蘖^14C光合产物分配比例高的品种，分蘖成穗率及淀粉含量亦高。

The quality or structure of a wheat population is significantly affected by the compositions of tillers. Little has been known about the physiological basis for the differences of productive capacity among tillers. Two winter wheat cultivars, Shannong 15 (SN15) and Shannong 8355 (SN8355), were used to investigate the differences of productive capacity among tillers and analyze the physiological mechanisms that determine the superior tiller group. Low-position tillers (early initiated tillers) had a higher yield per spike than high-position tillers (late initiated tillers) in both cultivars, which was due to their more grain number per spike, more fertile spikelet per spike, less sterile spikelet per spike and higher grain weight. According to cluster analysis, tillers of SN15 were classified into 2 groups: superior tiller group including main stem (0), the first primary tiller (I) and the second primary tiller (II); and inferior tiller group including the third primary tiller (III) and the first secondary tiller (I-p). Tillers of SN8355 were classified into 3 groups: superior tiller group (0 and I), intermediate tiller group (II and III) and inferior tiller group (I-p). In comparison with other tiller groups, the superior tiller group had higher photosynthetic rate of flag leaves, higher antioxidant enzyme (SOD, POD and CAT) activities and lower levels of lipid peroxidation in leaves, higher grain filling rate in both superior and inferior grains during grain filling, higher single-stem biological yield and larger single-stem economic coefficient. Correlation analysis showed that yield per spike was positively and significantly correlated with the flag leaf photosynthetic rate, grain filling rate, the antioxidant enzyme activities and soluble protein content (except for SN15 at 5 days post-anthesis (DPA)) of flag leaf, the single-stem biological yield, and the single-stem economic coefficient. Remarkable negative correlation was also found between yield per spike and MDA content of flag leaf. These results suggested that superior tiller group had stronger leaf photosynthetic capacity, more predominance in terms of grain filling, slower senescence rate, higher biological yield and larger economic coefficient, and therefore, showed greater productive capacity than other tiller groups.

选用分蘖成穗率不同的2种穗型 冬小麦品种,通过3个密度水平大田试验研究了分蘖期主茎和不同蘖位分蘖间的干物质积累与光合特性的差异,以探讨2种穗型品种分蘖成穗的生理机制.结果显 示:(1)在冬小麦分蘖期间,分蘖成穗率低的大穗型品种兰考矮早八高位分蘖干物质积累速率较慢,分蘖与主茎的差距较大;而分蘖成穗率高的多穗型品种豫麦 49-198分蘖与主茎的干物质积累速率差距较小.(2)2品种分蘖与主茎干物重比值(蘖/茎)均随着种植密度增加而降低,成穗分蘖的蘖/茎值拔节期均大 于0.5,而同期未成穗分蘖均低于0.5.(3)在分蘖期间,兰考矮早八分蘖的净光合速率随生育进程增长比主茎缓慢,且随密度增加分蘖与主茎的差距进一步 加大;豫麦49-198分蘖与主茎的光合速率差异较小,且种植密度对其影响也较小.(4)拔节中前期种植密度对2品种的荧光参数影响较小,拔节后期2品种 分蘖的初始荧光(F0)均显著大于主茎,而PSⅡ最大光化学效率(Fv/Fm)却显著低于主茎;随种植密度增加,2品种主茎与分蘖的F0和Fv/Fm差异 增大,且这种趋势随蘖位上升表现得更加明显.研究表明,大穗型品种兰考矮早八拔节期主茎与分蘖间干物质积累和光合性能的差异过大是其分蘖成穗率低的主要原 因.

Increased yields in winter wheat cultivars have been found to be largely attributable to improved partitioning of biomass to the grain, i.e., higher harvest index. However, there is a biological upper limit to harvest index and therefore breeders need to exploit increased biomass production as the mechanism by which yields are increased. Evidence for improved biomass was sought in experiments conducted over three years (1994 to 1996), at the Plant Testing Station, Crossnacreevy, near Belfast, with 10 varieties of winter wheat introduced over the period 1977 to 1991. Variation in grain yield was more strongly associated with variation in biomass (an increase of 0.78 t/ha in grain yield at 85% dry matter (DM) per 1 t/ha increase in biomass at 100% DM; R05 = 0.71) than in harvest index (an increase of 0.1 t/ha at 85% DM per percentage point increase in harvest index; R05 = 0.36). When age (= year of first harvest in UK National List trials) of the varieties was taken into account, yield (0.037 tha6301y6301; R05 = 0.42) and biomass (0.034 tha6301y6301; R05 = 0.31), but not harvest index (0.34%/year; R05 = 0.001), increased as year increased. Genetic gain in yield was smaller without fertiliser N (0.021 tha6301y6301; R05 = 0.21) and at 40 kg ha N (0.025 tha6301y6301; R05 = 0.25) than at 215-250 kg/ha N (0.065 tha6301y6301; R05 = 0.39). Theoretically, if the maximum biomass (18.60 t/ha for Rialto), could have been combined with the maximum harvest index (55.3%) in Riband, yield would potentially have been increased by 2.5 t/ha compared with yields for either variety.