Effect of Phenological Stages on Plant Dry Matter Partitioning and Seed Production in Berseem (Trifolium alexandrinum L.)

Berseem clover ( Trifolium alexandrinum L.) is an annual forage crop widely grown in Mediterranean environments. Dry matter partitioning in the leaf, stem and root and seed production of three populations of Egyptian as well as Italian origin were evaluated under four cutting regimes. The cutting treatments were applied to the plants at different stages of plant development: at the fourth (A) and eighth nodes elongation (B), at early flowering (C) and physiological maturity of seeds (D), After herbage, harvest plants were utilized for seed yield and evaluation of its seed yield components. Higher dry matter and seed yield was obtained in treatments D and B, respectively. In the other treatments, dry matter content was lower than in treatment D and related to the phenological development of the plant. Dry matter content in the root was higher when the cut was applied at early flowering. Cutting regimes influenced plant mortality, with the number of dead plants increasing from the cut applied in early (A) to that in the final treatment (D). Cuts applied at early stage of development depleted root reserves causing plant death. This peculiarity could be a tool for selecting populations with higher persistence and with a more tolerant physiological response to stress imposed by cuts. The populations of Egyptian origin, in comparison with the Italian ones, were more productive in dry matter in the early stage of growth and in all treatments were higher in seed weight.     

Modelling Biomass Accumulation and Partitioning in Chickpea (Cicer arietinum L.)

Quantitative information regarding biomass accumulation and partitioning in chickpea (Cicer arietinum L.) is limited or inconclusive. The objective of this study was to obtain baseline values for extinction coefficient (K_S), radiation use efficiency (RUE, g MJ^?1) and biomass partitioning coefficients of chickpea crops grown under well‐watered conditions. The stability of these parameters during the crop life cycle and under different environmental and growth conditions, caused by season and sowing date and density, were also evaluated. Two field experiments, each with three sowing dates and four plant densities, were conducted during 2002–2004. Crop leaf area index, light interception and crop biomass were measured between emergence and maturity. A K_S value of 0.5 was obtained. An average RUE of 1 g MJ^?1 was obtained. Plant density had no effect on RUE, but some effects of temperature were detected. There was no effect of solar radiation or vapour pressure deficit on RUE when RUE values were corrected for the effect of temperature. RUE was constant during the whole crop cycle. A biphasic pattern was found for biomass partitioning between leaves and stems before first‐seed stage. At lower levels of total dry matter, 54 % of biomass produced was allocated to leaves, but at higher levels of total dry matter, i.e. under favourable and prolonged conditions for vegetative growth, this portion decreased to 28 %. During the period from first‐pod to first‐seed, 60 % of biomass produced went to stems, 27 % to pods and 13 % to leaves. During the period from first‐seed to maturity, 83 % of biomass was partitioned to pods. It was concluded that using fixed partitioning coefficients after first‐seed are not as effective as they are before this stage. Environmental conditions (temperature and solar radiation) and plant density did not affect partitioning of biomass.     

水分胁迫对夏玉米干物质积累与分配的影响

采用盆栽方法,通过设置不同的水分处理,研究水分胁迫对夏玉米生长发育的影响.从根、茎秆、叶、叶鞘、雌穗等器官水平上考察水分胁迫对夏玉米物质积累、分配等的影响,以及不同水分处理下各器官对夏玉米干物质积累的贡献率.分析发现,不同水分条件下,叶片、茎秆和叶鞘三者是干物质积累的重要来源,在灌浆期以前,叶片是最主要的干物质积累器官.在灌浆前后期,叶片所占的比重分别为22%,21%;茎秆也是夏玉米干物质积累的来源之一,在抽雄初期,T_3茎秆占总重的26%,在抽雄后期T_4茎秆比重为30%.茎秆在吐丝期和灌浆后期的比重分别为24%和23%,而水分胁迫(T_8)的叶鞘比重分别为21%和18%;在生殖生长阶段,植株对水分胁迫非常敏感;水分胁迫下有利于干物质的快速积累,即缩短灌浆期.     

不同时期断根对花生植株生长的影响

为了探明断根时期对花生植株生长的影响,为确定适宜的断根时期提供依据。在大田覆膜栽培条件下,研究了不同时期断根对花生植株生长的影响。研究结果表明,断根可降低花生株高,减少主茎叶片数、分枝数、单株开花数和果针数,且随断根时间的提前而影响明显;适期断根有利于延缓花生叶片衰老,使适宜叶面积系数维持较长时间,增加有效分枝数和有效果针数,并可较少干物质的无益消耗、减少过多的冗余生长,有利于荚果形成;断根过晚基本不影响植株生长。本试验以开花后15~20天进行断根处理对植株生长的综合效果较好。     

Cold Stress Injury during the Pod-Filling Phase in Chickpea (Cicer arietinum L.): Effects on Quantitative and Qualitative Components of Seeds

Chilling stress (<10 °C) is detrimental for chickpea, especially at the reproductive phase and leads to abortion of flowers, pods and impaired seed filling, causing severe reduction in yield. The information on the effects of low temperature during different pod-filling stages on quality and quantity of developing seeds is lacking in chickpea and hence this study. In this study, chickpea plants growing under warm conditions of the glasshouse were subjected to cold conditions of the field at the two stages, (a) early pod-filling and (b) late pod-filling, and subsequently analysed for stress injury in terms of electrolyte leakage (EL), 2,3,5-triphenyl tetrazolium chloride reduction, relative leaf water content and total chlorophyll content in the leaves of control and cold-stressed plants. Cold stress caused elevation of EL but reduced all the other parameters. Sucrose content decreased significantly in the leaves of cold-stressed plants. The differences between the effects of stress at two stages on the total plant dry weight were small and insignificant. The seed growth rate, seed fill duration, seed number, and average seed weight and size decreased greatly in the plants cold-stressed at the late pod-filling stage than those stressed at the early pod-filling stage. Greater reduction was observed in starch, proteins, soluble sugars, fat, crude fibre and storage protein fractions in the seeds of the plants cold-stressed at the late pod-filling stage. This coincided with a larger decrease in sucrose content, the activities of sucrose synthase, invertase and starch synthase observed at this stage. The germination and growth potential were, however, inhibited to a greater extent in seeds of plants stressed at the early pod-filling stage.     

Relationship Between Digestibility of Bromus inermis Plant Parts

The change in leaf to stem ratio with advancing maturity is perhaps the greatest contributing factor in forages to decreased nutritive value. However, the relationship between the digestibility of plant parts has not been determined in most forage grasses. The objective of this study was to investigate the relationship between digestibility of smooth bromegrass ( Bromus inermis Leyss.) plant parts and that between them and whole plant digestibility. Thirty genotypes grown as solid stands and spaced plants were used for the study. The leaves, stems, panicles, and whole plants were evaluated for digestibility using the acid-pepsin dry matter disappearance (APDMD) technique. Genotypes were significantly different in leaf, stem, and panicle APDMD in each cutting under the two planting patterns. Significant differences were also found among APDMD of the first cutting (APDMD-1) of leaves, stems, panicles, and whole plants, respectively, over the two-year period. The APDMD of leaves, stems, panicles, and whole plants were less variable in the second and third cuttings than in the first cutting. Among the plant parts, the APDMD of leaves correlated best with whole plant APDMD. Furthermore, leaf APDMD also correlated better with stem APDMD than with panicle APDMD. Useful regression equations for the prediction of whole plant APDMD from leaf APDMD were obtained.     

Assimilation and Partitioning of Photosynthate and Nitrogen in Isogenic Tall, Semidwarf, and Doubledwarf Winter Wheats

Patterns of assimilation and partitioning of photosynthate and nitrogen in isogenic tall, semidwarf, and doubledwarf (Norin 10/5/Pawnee) 'Pawnee' hard red winter wheats ( Triticum aestivum L.) were studied under controlled environmental conditions and field conditions. The objective of the investigations was to determine reasons for the advantageous harvest index associated with dwarf genes. Plants were sampled at four growth stages and separated into plant parts as they developed. Ribulose bisphosphate carboxylase (RuBPC) and nitrate reductase (NR) activities in leaves differed among growth stages but not among isogenic lines. Fructosan in sheaths, stems, and roots increased from the soft dough stage to maturity, but differed little among the lines. Nitrogen concentrations decreased in leaf blades, stems, and roots as plants developed to the soft dough stage and then stayed nearly constant until maturity. Nitrogen in all plant parts frequently varied directly with the complement of dwarfing genes, being lowest in the tall line and highest in the doubledwarf line. The tall and semidwarf lines had significantly higher grain yield, test weight, total dry matter, spike number, and 1000-kernel weight than the doubledwarf line under either or both experimental conditions. The dwarf lines, however, had significantly higher kernel number per spike than the tall line. Harvest index was higher for the doubledwarf line (0.58) than for the two other lines (0.54).     

烤烟漂浮育苗中烟苗的基本生长规律

2000-2001年,以NC89为供试品种,采用商品基质和育苗专用肥,进行烤烟漂浮育苗基本生长规律的研究。结果表明:在苗床期内,烟苗的茎高、单株根鲜重和茎鲜重在生育期内呈现持续增加趋势;茎围、单株根干重和茎干重在生育期内呈现先缓慢增加后迅速增加趋势;螺旋根发生率在苗床期内的变化是大十字期迅速增加而后基本趋于稳定。烟苗的根、茎、叶、全株中干物质积累均呈S型曲线,且相关性达到极显著水平。在小十字期和大十字期,烟苗各器官的干物质分配规律是叶>根>茎;在七叶一心期和成苗期,烟苗各器官的干物质分配规律是叶>茎>根。叶片内叶绿素含量、NR酶活性、SOD酶活性、根系活力均呈递增趋势;烟苗叶片中INV酶活性在整个苗床期内基本处于一个相对稳定的状态。与烤后烟叶中主要化学元素含量相比,烟苗体内的N,K,Ca,Mg特别丰富,尤其是小十字期。     

两系杂交稻干物质积累与运转特性研究

根据湘西山区生态环境特点,分析比较了4个两系杂交中稻与2个三系杂交中稻的干物质积累与运转情况,结果表明：两系杂交组合前中期叶片、茎鞘养分积累较多,后期向穗部转移亦比较充分,供试组合剑叶展开期平均干重为39.7g/蔸,齐穗期茎鞘叶平均干重为41.0g/蔸,分别比三系杂交组合高14.41%和23.88%;茎鞘叶干物质向穗部的平均运转量为16.4 g/蔸,比三系杂交组合高18.84%;平均运转率为40.00%,与三系杂交组合平均值40.18%相近;对产量的贡献率为43.27%,比三系杂交组合平均值高近5个百分点。     

水稻甬优12产量13.5t hm~(–2)以上超高产群体的生育特征

以籼粳交超级稻甬优12为试材、四叶一心期带蘖小苗移栽,超稀植(12.45×104穴hm–2)栽培,对高产(10.5~12.0 t hm–2)、更高产(12.0~13.5 t hm–2)、超高产(13.5 t hm–2)3个产量群体的产量及其结构、茎蘖动态、叶面积动态及干物质的积累与运转等进行了系统比较研究。结果表明,产量由高产(10.5~12.0 t hm–2)到更高产(12.0~13.5 t hm–2)再到超高产(13.5 t hm–2),群体的颖花量不断提高,结实率和千粒重略微下降。与高产和更高产群体相比,超高产群体茎蘖数起点较高,在有效分蘖临界叶龄期及时够苗,至拔节期群体茎蘖数稳步增长,达高峰苗,此后群体茎蘖数平缓下降,成穗率近60%;群体叶面积指数生育前期较小,最大值出现在孕穗期,为9.17,此后平缓下降,成熟期在4.0以上;群体干物质积累量在拔节期略低,此后各生育时期均升高,抽穗期为14.38 t hm–2,抽穗至成熟期为9.73 t hm–2,成熟期为24.11 t hm–2;群体根系干重、根冠比及单茎伤流强度在后期(抽穗至成熟期)均较高。     

不同水稻产量形成过程的干物质积累与分配特征

2003年在福建农林大学教学农场以晚季稻汕优63（三系杂交稻）、两优2186（二系杂交稻）和IR64（常规稻）为材料,研究了3种晚季水稻产量形成过程的干物质积累与分配特征。结果表明,汕优63、两优2186和IR64的干物质积累量在各生育期的变化趋势相似,干物质积累量间亦无显著差异。汕优63、两优2186和IR64的干物质积累量均在黄熟期最高,依次达到2074.13 g/m2、1976.10 g/m2和1924.14 g/m2,完熟期时依次降低到1926.38 g/m2、1933.80 g/m2和1842.30 g/m2,完熟过程中损耗的干物质分别占其干物质积累量的7.12%、2.63%和4.25%,这与呼吸消耗增强,稻株自然衰老有关。汕优63和IR64的群体生长率均以孕穗初期最大,分别为52.13 g/(m2·d)和44.26 g/(m2·d),两优2186的CGR以齐穗期最大（45.15 g/),3种水稻各生育期CGR的大小依次为：孕穗初期（齐穗期）>灌浆期>黄熟期>分蘖盛期>分蘖初期。3种水稻的干物质在各器官中的分配比例均以籽粒的最大,汕优63、两优2186和IR64的干物质分配在籽粒中的比例分别为47.94%,41.14% 和45.69%。灌浆过程中,汕优63、两优2186和IR64总干物质的表观转化率依次为46.87%、24.98%和34.41%。汕优63（三系杂交稻）在物质转化和分配方面比两优2186（二系杂交稻）和IR64 （常规稻）更优。采用三次曲线模型和Logistic模型对3种水稻产量形成过程干物质积累变化进行拟合的结果表明,三次曲线模型拟合的精度均比Logistic模型高,R2均大于0.99。     

Auswirkungen unterschiedlicher physiologischer Alter und Pflanzknollengrößen auf die oberirdischen Pflanzenorgane von Kartoffeln (Sorte Granola)

In a two-year field trial, the influence of the physiological age and the size of seed tubers on various growth parameters was determined
Emergence and senescence occurred earlier in plants of older physiological age. On the other hand the physiological age did not influence the number of stems, the stem dry weight, the leaf number, the leaf dry weight, the leaf area, and the specific leaf area. There was a positive correlation between seed tuber size and number of stems but a negative correlation to the stem dry weight. Bigger seed tubers and consequently a higher number of stems had initially a positive effect on the number of leaves, leaf area and leaf dry weight per plant but this was reversed in the course of the vegetation period. The specific leaf area was only influenced by the weather conditions. There was a strong, highly significant negative correlation between number of stems and branching. The correlation between number of stems and leaf area as well as leaf area duration was positive.     

减库对大豆叶片碳代谢的影响

植物的碳代谢过程与植株生长和产量形成密切相关,是受源库关系影响最明显的生理过程之一。研究减库对大豆叶片碳代谢的影响,可为明确源库关系失衡导致的减产机理研究提供理论依据。以早熟大豆品种苏豆13为材料,于2019年和2020年在江苏省农业科学院大豆试验站进行池栽试验,在大豆R4期设置减库处理(去除全部豆荚、去掉1/2豆荚和全部种子损伤处理),以正常植株为对照,研究减库对大豆碳代谢的影响。结果表明,减库处理延缓了叶片衰老和脱落,导致叶片持绿。减库处理显著抑制了短期内的净光合速率(Pn),但是未影响初始羧化速率(a)。Pn降低主要受气孔限制,随时间延长,光合抑制作用逐渐减弱并转为促进作用,在生育后期,减库处理的叶片仍能保持相对较高的a、蔗糖磷酸合成酶(SPS)、蔗糖合成酶(SuSy)和酸性转化酶(SAI)活性及光合色素、可溶性糖、淀粉、蔗糖和果糖含量,利于维持相对较高的光合性能。减库处理导致更多的光合产物向营养器官分配,茎、叶片和叶柄在一定程度上成为新的库器官,利于生育后期的叶片光合产物输出并保持相对较高的碳代谢水平。去除全部豆荚和种子损伤处理延缓叶片衰老和脱落、光合性能和碳代谢水平降低的作用...     

有机水溶肥对水稻干物质、氮素积累和转运的影响

采用大田小区试验,研究了有机水溶肥对水稻各器官干物质和氮素积累、转运和分配的影响及其与水稻产量的关系。结果表明,常规施氮条件下,根施肥能显著提高水稻产量,产量达8 288.3kg/hm ²,且根施肥效果优于叶面肥;减氮15%条件下根施肥和叶面肥配合施用能有效缓解减氮对水稻产量的降低作用,较减氮15%处理显著增产3.2%。根施肥和叶面肥均能显著提高水稻抽穗前营养器官干物质、茎鞘和叶片氮素积累量;同时,增加抽穗后叶片向穗的氮转运量,进而提高其氮回收利用率和氮生理利用率。水稻产量与抽穗期茎鞘、叶片（除分蘖期茎鞘外）干物质积累量以及抽穗后茎鞘和叶氮素转运量显著正相关。研究表明,施用有机水溶肥能维持水稻营养生长期较高的干物质和氮素积累量,增强抽穗-成熟期氮素向穗转运能力,促进水稻高产和氮高效利用。     

Growth Analysis in Relation to Pigeonpea Improvement

An attempt was made to assess possible constraints to higher production, with respect to partitioning of total dry matter to reproductive sinks in early pigeonpea. Growth, dry matter accumulation and yield components were determined in four diverse genotypes under four dates of sowing and different plant densities. Data on growth characteristics, dry matter accumulation (vegetative and reproductive) were obtained for three sowings, while the data on yield components were obtained for two dates of sowing. Growth analysis showed that the total dry matter was low upto 30 days after sowing and increased linearly upto 120 days. Coversely, LAD was high for the first 30 days and reduced at later stages of growth. The mean LAI of genotypes did not very much at initial stage of growth. However, it has given interesting picture during 70 to 90 days of growth. The higher biological yield and seed yield were attributable to high LAI and LAD coupled with thick stem, more effective branches, more pods per plant and larger raceme length. Harvest index was the maximum with increased plant populations in all sowings. Indeterminate varieties under high plant density and narrow row spacing (50 cm) developed a large leaf area and were presumably able to make better use of light. Growth and branching of individual plants were reduced at the higher plant population, but on per unit basis more dry matter was produced. It is suggested that breeding should be concentrated to improve an inability to accumulate adequate vegetative dry matter for the maintenance and filling of pods, may force the plant to continue vegetative production into the reproductive dry matter to support production of ultimate seed yield.     

新疆不同刈割期对春性大麦干草产量和青贮品质影响的研究

为了探明春性大麦在新疆地区作为青贮饲料的最佳刈割时间,以垦啤麦13、P13-3和甘啤4号为研究对象,分析不同刈割期（抽穗期、灌浆期、灌浆10d和蜡熟期）干物质产量、营养品质和青贮品质。结果表明,随着刈割期的推迟,垦啤麦13和P13-3干物质含量和干草产量显著增加,P13-3蜡熟期干草产量显著高于其他时期,参试的3个品种（系）中P13-3在蜡熟期干草产量最大,达到14 731.46kg/hm ²。随着刈割期的推后,3个春性大麦品种（系）干草中粗蛋白和粗脂肪含量呈下降趋势,垦啤麦13和P13-3的中性洗涤纤维含量逐渐上升。随着刈割时间的推迟,大麦青贮后乳酸、乙酸和丁酸含量呈下降趋势,垦啤麦13和P13-3在灌浆10d后青贮其发酵品质显著高于抽穗期和灌浆期。因此,从产量和品质两方面综合考虑,新疆地区春性大麦最佳青贮刈割时间为灌浆10d。     

黄秋葵作为禽用着色剂的品种比较试验

通过14个作为禽用着色剂的黄秋葵品系比较试验,分析其种子发芽率、产量（叶片、茎杆、种子）、营养成分（叶片、茎杆）。结果表明：14个品系的种子发芽率差异极显著,其中021和007-1发芽率最高,达到92.5%;叶片和茎杆平均干物质产量差异均亦极显著,004-2叶片干物质产量最高,达到4948kg/hm2,018茎秆干物质产量最高,达到7103.4kg/hm2;008的营养价值最高;种子产量007-1最高,公顷产量大于3000kg。综合评价,018品系作为禽用着色剂较适合推广种植。     

Effects of harvest management on growth dynamics, forage and seed yield in berseem clover

Berseem clover (Trifolium alexandrinum L.) is an annual forage crop widely grown in Mediterranean environments. However, there is little information available on the patterns of accumulation and partitioning of assimilate in berseem and how this varies with harvest management, plant ontogeny or is influenced by genotype. Field experiments were conducted in Foggia (Italy) during three growing seasons (1991–92, 1992–93 and 1993–94), with the aim of evaluating the effects of different harvest managements on growth dynamics, forage yield and seed yield of one population of Egyptian (cv. ‘Giza 10’) as well as Italian (cv. ‘Sacromonte’) origin. Cutting treatments were applied at three different plant ages: sixth internode elongation (A), early flowering (B), and uncut control (C). The growth and development of the shoot and root systems were followed by destructive harvests made at about 5-day intervals during 9 weeks in spring in all treatments. Seasonal growth pattern, determined as dry matter accumulation, forage yield and seed production were greatly influenced by harvest management. The maximum value (20.5 g per plant on average) of dry weight was reached at about 250 days after sowing for treatment C. Defoliation induced a decrease of crown and root dry matter, however, as shown by the allometric relationships, the growth of roots and shoots was closely correlated and in most cases, shoot growth was higher than root growth and stem relative growth rate (RGR) was higher than leaf RGR. Berseem clover is a defoliation-tolerant species because after cutting, regrowth was accompanied by higher values of leaf-stem ratio (LSR), RGR and stem elongation rate (SER) than in control plants. The highest value for total forage yield (1.6 Kg m⁻²) and seed yield (60.5 g m⁻²) were obtained in treatment B and A, respectively. Plants cut at the sixth internode elongation showed a good seed yield and a small decrease (15%) in total forage yield as regards treatment B. Therefore, treatment A appeared the most favourable for obtaining double utilization (forage and seed yield) in a berseem crop. Berseem plants were greatly influenced by harvest treatments applied, but the response did not vary according to the genetic characteristics of the two cultivars examined.     

膜下滴灌追肥种类对花生结荚期茎叶干物重、矿质养分吸收和产量的影响

为明确不同肥料种类及其相互配合追施提高花生产量的效应,确定适宜的追施肥料种类和相互配施,为花生科学施肥提供理论依据和技术指导。本研究在大田覆膜滴灌条件下,于花针期设置追施氮、钙、硼肥及其相互配施处理,研究了膜下滴灌追肥种类对花生结荚期茎叶干物重、矿质养分吸收和产量的影响。结果表明,花针期追施氮、硼、钙肥及其相互配施均可不同程度地提高花生茎叶干物重、含氮量和积累量、含钙量和积累量、荚果产量,但单独追施氮、硼、钙肥效果不如氮、硼、钙肥配合施用,其中以追施氮硼钙或氮钙提高茎叶干物重、含氮量和积累量、含钙量和积累量、荚果产量的效果好。追施硼肥可提高花生茎秆、叶片含硼量和积累量,而与氮、钙肥配施则可促进花生对硼素的吸收积累。花生产量与茎叶干物重、氮积累量、钙积累量和叶片硼积累量均呈显著正相关关系,茎叶干物重与茎叶氮积累量、茎叶钙积累量均呈显著正相关关系,茎叶氮积累量与茎叶含氮量呈显著正相关关系,茎叶钙积累量与茎叶含钙量呈显著正相关关系,茎叶硼积累量与茎叶含硼量呈显著正相关关系。说明氮硼钙配施促进了花生对氮、硼、钙的吸收积累,增加了干物质量,进而提高了产量。     

限水减氮对豫北冬小麦产量和植株不同层次器官干物质运转的影响

采用节水栽培并减少氮肥用量是实现豫北冬小麦生产的高产、高效和环境友好发展的必然选择,探明限水减氮对冬小麦产量和植株各层次器官干物质运转的影响,可为该地区冬小麦节水栽培和合理施用氮肥提供科学依据。2009—2010和2010—2011年连续2年在河南浚县钜桥进行小麦田间裂区试验,主区设置2个灌溉水平[拔节水(W1)和拔节水+开花水(W2)],副区设置5个氮肥水平[330 kg hm~(–2) (N4,豫北地区小麦生产中常规施氮量)、270 kg hm~(–2) (N3)、210 kg hm~(–2) (N2)、120 kg hm~(–2) (N1)、0 kg hm~(–2) (N0)],测定了籽粒产量和植株各层次器官干物质运转量、运转率和对籽粒贡献率。减量施氮与N4相比,各营养器官向籽粒运转的干物质量均有增加,其中,穗轴+颖壳的干物质运转量增加了323.2%,增幅远高于茎节的24.5%和叶片的4.6%,且穗轴+颖壳的干物质运转率和对籽粒贡献率增幅也远高于茎节和叶片。减量施氮处理的叶片干物质运转量的增加主要源于倒三叶和倒四叶,分别增加28.7%和201.1%,而茎节干物质运转量的增加主要源于除穗位节外的其他茎节,分别增加21.7%(倒二节)、71.8%(倒三节)、44.5%(倒四节)和31.1%(余节)。与W2相比, W1干物质运转量无显著差异,但干物质运转率略高(24.6%vs. 23.8%),对籽粒贡献率较高(35.1%vs. 30.0%),籽粒产量降低11.2%,水分供应量减少750 m3 hm~(–2)。可见,减量施氮促进了营养器官,尤其是穗轴+颖壳和下层器官(倒三叶、倒四叶、倒三节、倒四节和余节)的干物质向籽粒的运转,提高了对籽粒贡献率,有利于提高籽粒产量。