光生态膜的发光强度对作物产量的影响

采用在高分子树脂中分散进荧光助剂、着色剂来模拟栽培作物的作用光谱并制成农膜。用这种光生态膜苫盖日光温室进行番茄生产,产量提高了53.7％。研究了光生态膜的光稳定性,观察到作物的产量与光生态膜的发光强度呈正相关。     

莴苣的光生态研究

通过叶片的反射光谱测量来研究莴苣的光生态,采用在高分子树脂中分散进荧光助剂、着色剂来模拟栽培作物的光合作用之作用光谱。用这种光生态膜苫盖温室大棚进行蔬菜生产,产量提高了４４．６％ 。     

遮荫对月季光合特性及生长发育的影响

采用人工遮荫法研究不同程度遮荫(75%、50%和25%全光照,以全光照为对照)处理对月季的生长发育、光合特性及叶绿素荧光参数的影响。结果表明:(1)随着遮荫程度的增加,月季的叶片厚度、花径、成花率均呈降低趋势,叶绿素含量呈增加趋势;净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)降低,气孔限制值(Ls)升高,Pn下降的主要原因可能为气孔限制。(2)月季在遮荫条件下的光饱和点和光补偿点、暗呼吸速率下降,表现出其对光照降低的生理适应机制;其光饱和点在600~1 200μmol·m-2·s-1,光补偿点在29.89~62.95μmol·m-2·s-1,CO2补偿点在78.16~89.41μmol·mol-1,CO2饱和点在1 100μmol·mol-1左右,潜在光合能力13.06~25.63μmol·m-2·s-1,其对光的适应范围较宽,光照和CO2浓度对其光合能力的影响较大。(3)各处理条件下叶绿素荧光参数显示,月季在自然光和低光下(50%和25%全光照)叶片PSⅡ受到了明显伤害,光合作用原初反应过程受到抑制,光合电子传递受到影响。研究发现,月季虽是阳生植物,但光照生态幅较宽,轻度遮荫(75%全光照)能促进其光合作用效率,减少光抑制,植株长势好,成花率高。     

光生态膜对黄瓜生态的影响

通过叶片的反射光谱测量来研究黄瓜的光合作用之作用光谱,采用在高分子树脂中分散进荧光助剂、着色剂来模拟栽培作物的作用光谱。用这种光生态膜苫盖日光温室进行黄瓜生产,产量提高了２１．４％。     

调光生态膜对蔬菜品质的影响

调光生态膜能将太阳辐射中不能被植物光合作用利用的光谱成分通过其中的荧光转光剂转换为光合作用有效光谱,其功效不仅是在低温寡照季节促进植物生长,提高产量,也会对植物中各种营养成分的含量产生影响。本文通过用国标法对光生态膜和对照膜苫盖下的番茄、黄瓜、甜椒中可溶性总糖、维生素C、可滴定酸度、粗蛋白等营养成分的定量测定和对比分析,得出了调光生态膜对这些蔬菜营养成分的改善提高比。     

西红柿的光生态研究

采用叶片的反射光谱测量来研究西红柿的光生态。西红柿叶片在４５０ｎｍ处、６８０ｎｍ处各有一条带宽为１２０ｎｍ的吸收带,这说明蓝、红光能够促进西红柿的生长。往聚乙烯树脂中添加荧光助剂、着色剂模拟西红柿作用光谱制成农膜。用这种农膜苫盖温室大棚进行西红柿生产。通过产量调查来进一步认证西红柿的光生态。     

植物油的荧光光谱法研究

荧光光谱技术具有灵敏度高,选择性好等优点。植物油中含有各种荧光成分,对食用油中菜籽油、玉米油、芝麻油、葵花仁油、花生油的同步荧光光谱和三维荧光光图谱进行了分析研究,结果表明：利用同步荧光光谱和三维荧光图谱的特征,可以区分植物油的品种,可用于植物油的鉴别和质量监控,该法提供了一种油定性分析的方法,同时也扩展了荧光法在食用油鉴别中的应用。     

水葫芦及菠菜光合作用原初光反应的超快光谱研究

采用相同的分离技术,从水葫芦（Ｅｉｃｈｈｏｒｎｉａ ｃｒａｓｓｉｐｅｓ （Ｍａｒｔ）Ｓｏｌｍｓ．）和菠菜（Ｓｐｉｎａｃｉａ ｏｌｅｒａｃｅａ Ｌ．）叶片中提取叶绿体。利用吸收光谱和低温荧光光谱及皮秒荧光单光子计数技术对它们的光谱性质和光系统Ⅱ荧光寿命进行了研究。这两种叶绿体吸收光谱相似,暗示着它们都能高效吸收不同波长的光子。低温荧光光谱显示,水葫芦叶绿体两个光系统之间激发能分配平衡状态差,表明不利     

光系统II核心复合物的稳态荧光光谱(英文)

在 83K 和 160K 两个温度下,通过激发波长对荧光发射谱的影响研究了光系统II中核心复合物的荧光光谱特性。用不同波长的光激发,核心复合物的发射谱的最大发射峰值不变,用 480、489、495 和 507nm 的光分别激发核心复合物,其光谱最大峰值处的荧光强度随不同激发波长下β-胡萝卜素分子的吸收强度的增大而降低,在长波长区域光谱的变化依赖于首先被激发的色素分子。所以,激发波长的不同影响着核心复合物中能量传递的途径。通过高斯解析,分析出核心复合物中至少存在有 7组叶绿素a组分,它们是Chla660,Chla670,Chla680,Chla682,Chla684,Chla687和Chla690。     

口腔常见致龋菌荧光光谱特征的初步研究

目的采用三维荧光光谱分析技术对口腔常见致龋菌荧光光谱特征进行初步分析。方法选择口腔常见致龋菌变形链球菌及远缘链球菌,对其进行复苏和培养,运用三维荧光光谱分析技术对其菌液进行荧光学光谱检测。结果变形链球菌及远缘链球菌的三维荧光光谱图相似,均出现2个荧光峰,最佳激发波长分别位于230nm和280nm,最佳发射波长相同,均为340nm。结论成功获得口腔常见致龋菌(变形链球菌及远缘链球菌)的固有荧光三维光谱图,为致龋菌荧光评价技术的应用提供参考。     

γ射线紫外线镰刀菌产生玉米赤霉烯酮毒素的影响

锭刀菌(Fusarium)经γ射线、紫外线辐射诱变后,接种于大米培养基中.经10℃低温产毒培养.采用薄层层析方法定性定量分析培养物中的镀刀菌毒素—玉米赤霉烯酮(zearalenone简称ZEA).结果表明:不同菌株对诱变剂的反应不同.产毒菌株NF5232、NF5946在较大剂量γ射线处理后,ZEA产量显著增加,但其产生的色素量下降.或者用紫外线处理,仍然产生ZEA.不产毒菌株NF6127、NF6123、NP6138和HD—002,经γ射线或紫外线处理后仍不产生ZEA.由此可知镰刀菌产生ZEA毒素的能力是相对稳定的,其产毒机制是由菌株本身的遗传特性决定的,一定剂量的γ射线可使低产毒菌株变为高产毒菌株.     

乙烯利诱导网纹甜瓜主蔓两性花花芽分化的形态和解剖学研究

以网纹甜瓜(Cucumis melo L.var. reticulatus Naud.)品种’西域1号’为试验材料,于幼苗3叶1心期喷施浓度为150 mg·L^-1的乙烯利溶液进行处理,诱导主蔓形成两性花,以清水为对照,分别对处理和对照植株不同时期的主蔓和侧蔓花芽分化过程进行形态和解剖学观察。结果表明：经乙烯利处理后,幼苗植株主蔓花原基持续向两性花分化,最终发育形成两性花。未经处理植株的主蔓花原基在分化早期与两性花发育过程相同,但在雌蕊出现后,不再继续发育,最终发育形成雄花。处理植株主蔓两性花发育过程与侧蔓两性花发育过程相同。     

Contribution of sepals and gibberellin treatments to growth and development of rose (Rosa hybrida) flowers

The fresh weight of sepals during the development of the rose flowerbuds from 4 mm to 22 mm in diameter increased fromabout 30 mg to ca. 350 mg. However, due to a morerapid gain in the total fresh weight of the flower, the sepal fresh weight as aproportion of the total weight of the buds decreased from about 55% to only 8%at the end of the measurement period. The net photosynthesis of sepals,measuredclose to the flower harvest, was approximately 60% of that in the youngest,uppermost leaves whereas no photosynthesis occured in the petals. Theconcentration of sucrose in petals of almost fully developed, desepalledflowerswas 15% lower in comparison with the control flowers with intact sepals. On theother hand, the concentration of sucrose in petals of control and desepalledflowers that were kept for 10 days in complete darkness was equal, reachingabout 50% of the concentration in petals of flowers grown in the light.Periodicmeasurements of reducing sugars in the petals did not show differences in theirconcentration between the control and desepalled flowers during the first 8daysafter sepal removal. After an additional four days the concentration ofreducingsugars in petals of the desepalled flowers was only 50% in comparison to thatinpetals of control flowers. Excising the sepals reduced fresh and dry weights,aswell as the length of buds and the peduncles, indicating that sepals may be asource of gibberellins during flower development. Treatment with50mg GA₃ in lanolin paste, completely restored thelength of the peduncles, but only partially restored the other measuredparameters of the flowers. Formation of 'star-shape' abnormality indesepalled flowers, which is a common phenomenon in rose flowers exposed toexternal ethylene was completelly prevented by applying GA₃ afterthesepals were excisied. This supported the previously suggested hypothesis aboutthe flinction of gibberellins in reducing the sensitivity of rose flower organsto ethylene.     

溴代十六烷基吡啶对香石竹切花的保鲜效应

研究切花瓶插液中加入0．3g．L^-1季铵盐化合物溴代十六烷基吡啶（CPB）后,瓶插液中微生物密度和切花茎杆基部病原菌分离频率下降,切花后期的水分平衡和鲜重能较好地维持,花冠直径增大,观赏寿命延长。     

采前喷钙对芍药切花生理生化的影响

以芍药切花品种'杨妃出浴'为试验材料,于采前不同时期喷施4%的CaCl2溶液,以不喷钙切花为对照,观察、测定芍药切花瓶插寿命、花径以及瓶插期间生理生化的变化,已探讨采前喷钙及喷钙时期对芍药切花衰老的影响.结果显示,采前喷钙处理有利于芍药切花保持水分平衡,增加切花花径和鲜重,降低切花体内可溶性蛋白质的降解速度,减缓膜透性的增大,延长切花寿命.研究表明,以采前21 d喷钙为最佳处理,可以延长芍药切花瓶插寿命2.3 d.     

Reproductive ecology of dioecious Siparuna (Monimiaceae) in Ecuador–a case of gall midge pollination

The reproductive ecology of the dioecious genus Siparuna , belonging to the primitive family Monimiaceae, was investigated in Ecuador. Thirteen species were studied, and species growing at high altitudes (above 500 m) were compared with species growing at lower altitudes. The genus has specialized flowers pollinated by Cecidomyiidae (Asynapta sp. and other genera) that lay eggs chiefly in male flowers since these are more easily accessible than female flowers due to their morphology. Several traits ensure that pollen transfer is accomplished: 1. long flowering of individuals and single flowers; 2. specific floral morphology (unisexuality, landing platform, restricted pore) allowing the flowers to be visited by Cecidomyiidae seeking egg-laying sites, and 3. a low number of ovules that have to be pollinated in each flower. The low number of ovules per flower results in a high pollen-ovule (P/O) ratio even though pollen production in male flowers is only moderate.
High altitude species had larger flowers, higher pollen-ovule ratios, fewer ovules per female flower, and longer periods of anthesis. Gender differences were seen in the longer functionality of female flowers; the larger numbers of male flowers produced; and the average diameter at breast height (DBH) biased for one of the two sexes depending on the species investigated, with no clear trend in the size distributions of individuals of both sexes. Sex ratios departed significantly from unity both to male and female bias but usually were in favour of males. There were no general differences in the ratio of functional male to female flowers at the time of observation nor in the sizes of male and female flowers. The evolution of unisexual flowers in Siparuna can be explained as a result of the differential predation by larvae: unimportant in male flowers, destructive if occurring in female flowers.     

Fruit Abscission in Cowpea, Vigna unguiculata (L.) Walp.: II. QUANTITATIVE ESTIMATIONS OF TOTAL NUCLEIC ACIDS IN OVARIES OF PERSISTING AND ABSCISSING FLOWERS

The fresh weights and quantities of total nucleic acids (RNAand DNA) in the ovaries of abscissing flowers and persistingflowers were estimated at intervals. Starting from 48 h prior to anthesis, particularly during the24 h immediately preceding it, large differences were observed:ovaries of abscissing flowers were much lighter and accumulatedmuch less nucleic acid than those of persisting flowers. Forinstance, at anthesis the ovaries of persisting flowers (atraceme 1, in acropetal order) were twice as heavy, and containedtwice as much DNA and one-and-a-half times as much RNA as theovaries of abscissing flowers (at raceme 3). These differenceswere further maintained from after the flowers had opened untileventual shedding of the raceme 3 flowers. The results provided clear evidence of the very basic retardationexperienced by the abscissing flower before and after opening.     

Role of Aminocyclopropane-1-carboxylic Acid (ACC) in Control of Ethylene Production in Fresh and Cold-stored Rose Flowers

The relationships between ethylene production, aminocyclopropane-1-carboxylicacid (ACC) content and ethylene-forming-enzyme (EFE) activityduring ageing and cold storage of rose flower petals (Rose hybridaL. cv. Gabriella) were investigated. During flower ageing at20 °C there was a climacteric rise in petal ethylene production,a parallel increase in ACC content, but a continuous decreasein EFE activity. Applied ACC increased petal ethylene productionc. 200-fold. During cold storage of flowers at 1 °C therewere parallel increases in petal ethylene production and ACCcontent, to levels greater than those reached in fresh flowersheld at 20 °C. EFE activity decreased during storage. Immediatelyafter cold-stored flowers were transferred to 20 °C ethyleneproduction and ACC levels were c. four times greater than infreshly cut flowers. These levels increased to maximum valuesof two to four times the maximum values reached during ageingof fresh, unstored, flowers. It was concluded that in rose petalsethylene synthesis is probably regulated by ACC levels and thatcold storage stimulates ethylene synthesis because it increasesthe levels of ACC in the petals. Key words: Rose flower, senescence, ethylene     

Fruit Abscission in Cowpea, Vigna unguiculata (L.) Walp: I. DISTRIBUTION OF 14C-ASSIMILATES IN THE INFLORESCENCE, AND COMPARATIVE GROWTH OF OVARIES FROM PERSISTING AND ABSCISING OPEN FLOWERS

One of the hypotheses proposed for the abscission of flowersand fruits from the cowpea was that the oldest fruits at raceme1 on the peduncle monopolize the mobile nutrients availableto the whole inflorescence. Consequently, the distal young fruitsand flowers starve, abort, and are shed. This hypothesis wastested through autoradiographic studies of the distributionof ¹⁴C-assimilates on the cowpea inflorescence and the comparativegrowth of ovaries from persisting and abscising open flowersand young fruits. ¹⁴C-asaimilates were distributed to the fruits at raceme 1 andto flower buds, open flowers, and young fruits distal to raceme1. Therefore, the hypothesis that the fruits at raceme 1 monopolizethe mobile assimilates cannot be maintained. At the time of opening the persisting flowers of raceme 1 hadheavier ovaries than the aborting flowers of raceme 3 althoughboth types of flowers were visually alike. During the initial12 h following opening, the difference in ovary size was maintainedand often accentuated. The ovary of the persisting flower increasedin both fresh and dry weights. The growth of the ovary of theaborting flower was variable; the fresh weight often decreased,although it also increased in some experiments; the dry weightremained unchanged or decreased or increased remarkably. The availability of nutrients was considered to be of secondaryimportance in the chain of events leading to fruit abscission.Other internal factors which may control vital processes relatedto embryo development appear to be of primary, underlying importance.     

The role of genes influencing the corolla in pollination of Antirrhinum majus

Studies of pollination ecology have been hindered by an absence of biochemical information about the basis of polymorphism. Using model plants and mutant lines described by molecular genetics may circumvent this difficulty. Mutation of genes controlling petal colour and petal epidermal cell shape in Antirrhinum majus was previously shown to influence fruit set. White flowers set less fruit than magenta flowers and mutants with flat petal epidermal cells set less fruit than flowers with conical cells. Here we analyse the causal pathway underlying this phenomenon through a study of floral characteristics and bee behaviour. Results indicate that bees recognized plants with magenta conical‐celled flowers at a distance and did not approach white flowers or magenta flat‐celled flowers so frequently. Petal cell shape interacted with colour in determining whether an approaching bee landed on a flower within a plot and whether a bee landing on a flower would probe it. The intrafloral temperature of flowers with conical petal cells was shown to increase with solar irradiance, unlike the intrafloral temperature of flowers with flat petal cells. The difference in fruit set may reflect pollinator discrimination between genotypes as a consequence of the effect of intrafloral temperature on nectar quality and quantity.