玉米穗位叶片与果穗碳同化物“半侧分布”

作物果实的形成其物质基础主要来源于穗位叶片碳的同化物.因此,众多学者致力于研究光合产物的运转与分配,在一些基础研究中已经取得了相当的进展.Larson等发现三角叶杨叶片碳同化物供求间有着严格的定向规律.于凤义等在豆科作物中发现叶片间~(14)C-同化物运转分配的“同侧”分布.李小云等在玉米叶片中发现“半叶运转”规律.这些结果无疑对揭示植物碳同化物运转与分配的基本规律做了有益的研究.至于玉米穗位叶碳的同化物在果穗上     

14C-同化物在玉米果穗上的分布与籽粒败育关系

通过^14C-示踪方法，研究了在籽粒发育前期饲喂果穗叶后^14C-同化物在植株及果穗不同部位的分布。结果表明，果穗是灌浆期的主要库器官；^14C-同化物在果穗不同部位的分布不均一，在穗轴中^14C-同化物的分布呈现为基部〉中部〉上部，而在籽粒中则表现为中部〉基部〉上部。顶端穗轴中糖分含量不低于中部穗轴（P〉0．05），而败育粒中还原糖含量高于中部粒（P〈0．05）。因此认为，顶端的败育可能并非源于营养供应不足，而应归因于籽粒库活性不足。     

14C同化物在玉米果穗上的分布与籽粒败育关系

通过¹⁴C示踪方法，研究了在籽粒发育前期饲喂果穗叶后14C-同化物在植株及果穗不同部位的分布。结果表明，果穗是灌浆期的主要库器官；¹⁴C-同化物在果穗不同部位的分布不均一，在穗轴中¹⁴C-同化物的分布呈现为基部＞中部＞上部，而在籽粒中则表现为中部＞基部＞上部。顶端穗轴中糖分含量不低于中部穗轴(P>0.05)，而败育粒中还原糖含量高于中部粒(P<0.05)。因此认为，顶端的败育可能并非源于营养供应不足，而应归因于籽粒库活性不足。     

晚红葡萄着色期光合产物14C的分配规律

本试验以露地栽培的2年生晚红葡萄为试材,通过饲喂果枝上不同节位的叶片以及环割处理,对树体光合产物14C分配进行了研究。研究表明叶片的相对位置影响同化产物向果实的运输和分配,果穗同侧叶片是果实着色期主要源,而异侧叶片尤其是果穗上部的叶片是所在枝条以下的枝蔓的主要源叶,且分配率与器官的重量有关。环割处理后,消除叶片相对位置对果实及其它器官光合产物分配的影响。     

晚播冬小麦各叶位叶片14C同化物的运转分配

采用＾１４ＣＯ２标记方法研究了晚播小麦各叶位叶片同化物质的运转配变化，研究表明，晚播小麦不同叶位叶片的＾１４Ｃ同化物向植株各部位的分配具有明显的分工，据此将晚播小麦主茎叶片分组，基部叶组即晚播小麦冬前及冬季出生的叶片（１－４叶），其同化物主要供给新生叶、根系、部分供给分蘖；中部叶组指返青至拔节期出生的叶片（５－８叶），其同化物主要供给叶片、茎秆和分蘖；拔节后出生的叶片为上部叶组（９－１０叶）。上部     

用~(14)CO_2示踪研究小麦叶片早衰对籽粒产量的影响

研究初步表明,早衰性品系的上部三张叶片绿色面积和叶色消退比正常品种为快,约早4～8天。~(14)C 标记指出,在开花期穗及上部三张叶片的~(14)C 同化物分配为:45%运向茎杆等供继续生长之用;30～35%运向籽粒;20～25%自存。开花后10天约76～81%运向籽粒;11～16%自存;运向茎杆等只占7%。在此期间,早衰性品系分配到籽粒的~(14)C 同化物比正常品系少5%。标记部位留存则多5%。其原因可能由于叶片早衰使同化物输出效率低所致。分析表明,早衰性品系穗及倒二叶、倒三叶~(14)C 同化物输出效率低于正常品系4.0～23.0%。开花后20天内,由于叶片早衰引起的籽粒产量损失率约为5～6％。由于开花后早衰性品系倒二叶、倒三叶比正常品系衰老早5～8天,而此时70%左右的光合产物运向籽粒。因此,在进行早熟小麦育种时,应尽量选育后期叶片不早衰的材料。在栽培上,应重视穗、粒肥的施用,以延长上部叶片功能,增加粒重。     

小麦幼苗阶段体内同化物的运输和分配

用~(14)C 示踪法研究了冬小麦在冬前分蘗期主茎和2个一级分蘗各叶同化物的输出方向和供应范围。主茎和分蘖最顶部1片展开叶(O 叶)主要供应主茎和该分藥本身的生长部位,随叶位下移,逐渐减少,增加对下一级分蘖的供应。主茎和分蘖顶部3片展开叶的同化物均主要供应正在出现的下一级分蘗和其下节位的只有1片展开叶的分蘖,对其他分     

源库调节对新疆高产棉花产量形成期光合产物生产与分配的影响

 以不同基因型棉花品种（常规棉新陆早13号、杂交棉标杂A₁）为材料,在皮棉产量2500 kg以上的膜下滴灌高产条件下,于花铃期分别进行剪叶、疏蕾处理,研究了源库关系改变对叶片光合速率、¹⁴C同化物运转分配及产量的影响。结果表明,去1/4叶后,新陆早13号剩余叶片光合速率（Pn）显著增加,¹⁴C同化物输出率及在棉铃中的分配率提高,产量和纤维品质与对照（CK）无明显差异;疏1/4蕾铃后,标杂A₁叶片Pn和棉株光合物质累积未受到影响,但加速了同化物向棉铃的运转速率,增强了棉铃对茎叶和根系中同化物的再调运能力,产量高于CK。因此,依据不同品种对源库关系改变的响应,通过协调关键栽培技术调控源库关系,进而调节光合产物运转及分配的方向和速率,对实现新疆棉花超高产、稳产具有重要意义。     

水稻移栽后苗期茎叶光合产物运转与分配特性研究

采用³H核素示踪方法,研究了水稻移栽后苗期茎叶光合产物的运转分配特性。结果表明,栽后4 d标记的茎鞘3H同化物在标记后10 d,有7.6%~9.8%运往新根,6.7%~15.6%运往主茎新叶,6.9%~9.9%运往分蘖茎叶;标记后30 d,约12%分配至新根,10%~14%分配至分蘖茎叶。标记后10~30 d参与再分配的同化物主要来自主茎茎鞘,输入器官主要为分蘖和新根。移栽后20 d标记叶片的3H同化物在标记后10 d,19%~28%分配至主茎新叶,4.6%~13.4%分配至分蘖,3%~5%运往新根。3个品种中,冈优22茎、叶光合产物分配到主茎中的比例较高,K优047分配到分蘖的比例较高,Ⅱ优162输送到新叶中的比例最大。     

土壤通气性对马铃薯产量的影响及其生理机制

选用克新10号和克新11号马铃薯品种为材料，研究了土壤通气性对马铃薯某些生理特性和块茎产量形成的影响。结果证明，改善土壤通气性，可以增加功能叶片ATP含量，提高功能叶片ATP酶活性；增加块茎中ATP含量和脱落酸（ABA）含量,提高块茎中ATP酶活性。促进14C同化物由叶片向块茎的运输和分配，提高干物质在块茎中的分配率；极     

Reproductive response of two morphologically different pea cultivars to drought

Water use by semi-leafless peas (Pisum sativum L.) is usually less than that of conventional peas because of their reduced surface leaf area, suggesting that semi-leafless peas would be less sensitive to drought because drought develops later. This work aimed to study the reproductive response of peas cv. Solara (semi-leafless) and cv. Frilene (conventional) subjected to similar controlled soil drought during the critical period occurring between flowering and initial seed filling. Plants were subjected to drought by watering with a fraction of water used in the evapotranspiration of control plants. Soil, pod and seed water contents, leaf water status parameters, dry matter (DM) partitioning, seed yield, yield components and water use efficiency (WUE) were measured. Although soil water content decreased in a similar way in both cultivars, leaf Ψ_w and RWC only decreased significantly in Solara. Well-watered Frilene plants produced higher shoot and pod DM, but lower seed DM. Well-watered Solara plants produced lower pod DM and higher seed DM than Frilene. Under drought, Frilene increased partitioning of total plant DM to vegetative organs, particularly roots, and decreased DM allocation to pods and seeds increasing flower abortion. By contrast, droughted Solara interrupted vegetative growth and increased leaf senescence but maintained similar partitioning of total plant DM to pods and seeds as in well-watered conditions. For both cultivars there was a close relationship between the percentage of total DM partitioned into seeds and WUE_y (water use efficiency on seed yield basis). Results demonstrate that when plants suffered the same level of drought in the soil, the reproductive response of the two cultivars was linked to differences in their WUE.     

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.     

Plant Growth Regulators Influence 14CO2 Assimilation and Translocation of Assimilates in Indian Mustard

Effect of plant growth regulators Naphthalene acetic acid (NAA), Gibberellic acid (GA₃) and Kinetin on ¹⁴CO₂ assimilation, partitioning of ¹⁴C into major biochemical fractions and translocation of assimilates was studied in different parts of Indian Mustard ( Brassica juncea ) at late ripening stage. Leaves, stem and pod walls are photosynthetically active and are important sources for seed filling. NAA and kinetin increased the ¹⁴CO₂ assimilation rate in all the three photosynthetically active parts. All the three growth regulators increased the export of ¹⁴assimilates out of source organs and increased the movement of assimilates into the reproductive parts (pods). The increased movement of photoassimilates into the developing pods may be due to the stimulation of sink activity by the growth regulators which resulted in the higher demand for photoassimilates. It was suggested that growth regulators may increase yield by altering distribution of assimilates in the mustard plants.     

冬小麦叶片氮含量时空分布及其与植株氮营养状况的关系

以低蛋白小麦品种宁麦9号和高蛋白小麦品种淮麦20为材料,研究了冬小麦不同生育时期冠层叶片氮素时空分布特征及其与植株氮含量的关系。结果表明,叶片氮含量在不同叶位间的分布因生育时期而异,拔节期、抽穗期和开花期叶片氮含量都呈现顶1>顶2>顶3>顶4的趋势,而在药隔期及孕穗期,两品种顶2叶氮含量均大于顶1叶。     

不同冻水和起身水组配下的冬小麦物质积累与分配

研究表明，随着冻、起总水量的增加或减少，小麦单株干物质积累量呈明显增加或减少趋势。叶片随着冻、起总水量的降低，在孕穗期前，向茎秆的物质转移比例增大，孕穗期后，其自身干物质积累比例下降幅度越大，相应地向穗部的物质转移比例也越大；当处理总水量超过９００ｍ＾３／ｈｍ＾２时，叶鞘干物质积累比例在春５叶时最大，而不足９００ｍ＾３／ｈｍ＾２时则在春４叶时最大；茎和穗子的干物质积累比例始终保持上升趋势。不同冻、     

The Influence of the Pea Plant Ideotype on Seed Protein Content and Seed Yield

The assimilation and translocation pattern of radioactive 14-C-assimilates and how it may affect nitrogen fixation was studied in conventional and semi-leafless pot grown field peas ( Pisum sativum L.). Leaf areas, plant development patterns and yield components and their influence on protein content, protein yield and seed yield were studied by using simple regression, multiple regression and factor analyses over a period of two years of field grown material.
It was shown that roots and nodules received most of the carbon assimilate from the lower leaves at the beginning of flowering. Four weeks later most of the assimilates came from the upper leaves. Furthermore, it was discovered that stipules were more important than leaflets in supplying the roots and nodules. Field studies supported the results obtained in pot grown material. They also showed that in order to achieve high seed and protein yield it is more important to have many generative nodes instead of a few with several pods on each. In semi-leafless types, vegetative upper nodes and late flowering are also important factors. An ideotype suited for both high seed yield, high seed protein yield and high protein content is discussed.     

Non-destructive Limits to Seed Growth and Leaf Protease Activities in Nodulating and Non-nodulating Soybean Isolines

Leaf senescence leads to a progressive decline in the photosynthetic competence of the leaf. This paper describes some effects of source:sink imbalance on leaf protein catabolism and senescence in soybean. We manipulated pod growth by restricting 100 or 50 % (PR-100 or PR-50, respectively) of young pods at the R4 stage in plastic drinking straws. This effectively reduces final seed mass without interrupting the vascular connections of pods. Nodulating (NOD+) and non-nodulating (NOD−) isolines of the 'Clay' soybean were grown in drainage lysimeters and three pod-restriction (PR) treatments were compared. Pod restriction decreased seed biomass per plant as a result of lower individual seed mass, which was only partially balanced by the increase in seed number. The nitrogen concentration in seeds remained unchanged in NOD+ plants, while it increased with the degree of sink restriction in seeds of NOD− plants. Leaf soluble protein, CO₂ exchange rate and seed nitrogen content were consistently lower in NOD− plants; the leaf protein level remained stable with time in PR-100 plants, decreased for PR-50 and dropped for controls. Endoprotease (HBase) and carboxypeptidase (CPase) activities were significantly lower in leaves from PR-100 plants, while aminopeptidase activity was enhanced, indicating a de novo synthesis of leaf protein. This is consistent with the reported accumulation of vegetative storage proteins (VSPs) in soybean and other legumes after moderate or severe sink reduction. Thus, small modifications of the source:sink ratio such as those obtained by the non-destructive PR technique have an impact on leaf protein catabolism. Nodulating and non-nodulating soybean isolines showed similar responses to PR in terms of leaf senescence initiation and progression, but the rate of the processes appear to be largely influenced by plant N status.