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1.
1. The effect of various patterns of flower removal on pod settingwas investigated in Lupinus luteus L. Four-fifths, three-fifths,or two-fifths of the flowers of the main inflorescence wereremoved according to ten different patterns. 2. All flowers could produce pods but later ones were less efficientin doing so. Developing pods had an abscission-inducing effecton later flowers, which became increasingly effective towardsthe apical part of the inflorescence. More pods were retained when flowers on each consecutive whorlwere arranged in a spiral than when the same number was arrangedvertically. Pod setting was incomplete when the number of flowers per inflorescencewas reduced well below the total number of pods normally present. 3. The number of ovules in consecutive flowers gradually decreasedfrom an average of 5.7 at the base to 4.3 at the top of theinflorescence. The ratio of seeds to ovules fluctuated irregularlybetween 65 and 94 per cent, and did not indicate a general trendin embryo abortion. 4. The growth-rate of pods at the top of the inflorescence wasmuch slower than at the bottom. Vascular differentiation wasalmost absent at the top of the inflorescence when the flowerswere fertilized, and further vascular tissue was produced onlywhen flowers produced pods.  相似文献   

2.
Abscission of flowers in Lupinus luteus L. (var. Weiko II) withoutgrowth of ovaries is followed by abscission of small pods (15–20mm. long). Normally flower abscission is much more pronouncedthan pod abscission. Abscission was delayed on plants from which laterals or theirterminal and axifliary buds were removed. Flower abscissionwas not affected, but pod abscission increased as a result ofdefoliation. When flowers at the base of the main inflorescence were replacedby auxins and anti-auxins flower abscission was induced in eitheran auxin pattern in which most of the flowers near the siteof application dropped, and pods developed on the apical whorls,or an anti-auxin pattern in which pods developed on basal whorlsnear the site of application but not higher up. The anti-auxinpattern was similar to the pattern of abscission normally inducedby developing pods on basal whorls. -Naphthylacetic acid (NAA) was much more effective in inducingabscission than ß-indolylacetic acid (IAA). 2:3:5-triiodobenzoicacid (TIBA), NAA, and IAA applied in mixtures at various concentrationsacted mainly antagonistically, i.e. the abscission-inducingeffect of NAA and LAA was depressed in basal whorls, and inapical whorls the effect of TIBA was less prevalent. Consequentlythe effect of the mixtures on the total number of pods was aboutequal to that of the most active component by itself. All growth substances seemed to move much more efficiently inacropetal direction than in basipetal direction in the flowerstalk. Transport in lateral direction was very limited. The effect of growth substances applied on laterals was enhancedby defoliating the main 8tem. The influence of assimilates on flower and pod abscission andtransport of growth substances is discussed.  相似文献   

3.
During the formation and ripening of beans in yellow lupine, their intactness may be increased by treatment of the plants with the microelement molybdenum or the growth factor 24-epibrassinolide. Early stages of the effects of either factor involved activation of various metabolic pathways, which differ in each case; eventually, the supply of fruit elements with free amino acids was improved and the seed productivity of the plants was increased.  相似文献   

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5.
土壤溶液中的砷及其与水稻生长效应的关系   总被引:22,自引:1,他引:22  
陈同斌 《生态学报》1996,16(2):147-153
通过盆栽试验和土壤中砷的吸附试验,探讨了砷在土壤溶液中的氧化-还原行为和溶解行为,并初步揭示了不同价态砷对水稻毒性差异的机理,以及土壤pH对砷的吸附作用和毒害作用的影响。  相似文献   

6.
Wittwer, S. H., and N. E. Tolbert. (Michigan State Univ., E. Lansing.) (2-Chloroethyl) trimethylammonium chloride and related compounds as plant growth substances. III. Effect on growth and flowering of the tomato. Amer. Jour. Bot. 47(7) : 560–565. Illus. 1960.—Application of 10–3 to 10–7 M solutions of (2-chloroethyl) trimethylammonium chloride, (2 bromoethyl)-trimethylammonium bromide, or (2,3-n-propylene) trimethylammonium bromide to the roots of the tomato plant markedly altered growth and promoted earlier flowering. Treated plants developed thicker stems, and dark-green, savoyed leaves. The growth changes were similar to those produced by exposure to high light intensities and low temperatures, and were opposite to, and more persistent than, those induced by gibberellin. A stepwise regulation in the magnitude of growth and dry matter accumulation in tomato plants followed application of chemicals of increasing concentration to cultural solutions. This growth response varied from a stimulation at 10–7 M to a marked suppression at 10–4 M without delay of flowering or visible injury. The control of growth and flowering by the use of these chemicals offers several practical possibilities for their utilization in tomato culture.  相似文献   

7.
Mechanical stimulation of dorsal mouse skin by skin massage or removal of the horny layer results in a mutually comparable increase in DNA-labelling and mitotic activity. However, only after injury such as removal of the horny layer hyperplasia develops. This phenomenon, called ‘hyperplastic transformation’ is characterized by a transient abolition of the epidermal G1 chalone responsiveness. There is some indication that the susceptibility to a heat labile factor, probably the epidermal G2 chalone, is not affected. Skin massage neither interferes with the responsiveness to epidermal G1 chalone nor induces ‘hyperplastic transformation’. Mouse tail epidermis shows a ‘functional hyperplasia’ and responds to the G1 chalone. To explain these observations, it is assumed that the epidermal stem cell population is heterogeneous consisting of G1 chalone-sensitive and G1 chalone-insensitive cells.  相似文献   

8.
The response of Chamaenerion angustifolium (fireweed) plants to different patterns of artificial leaf and flower herbivory was examined to determine if the effects of localized herbivory were confined within vertical sectors of the plant. The effect of leaf and flower removal on fruit development was compared for removals within sectors and distributed among sectors. Fruit development did not differ in plants subjected to different patterns of leaf and flower removal. These results suggest that in disturbed plants carbohydrate movement is not confined within vertical sectors.  相似文献   

9.
油菜叶片及其脱分化和再分化中质体的电镜观察   总被引:1,自引:0,他引:1  
我们用电镜观察了油菜叶片植株再生中质体的超微结构变化。在油菜叶肉细胞中,叶绿体的基粒,基质片层发育良好,偶尔有淀粉粒。在来自叶片的愈伤组织细胞中,质体体积变小,类囊体已经消失或部分消失,有的质体含有淀粉粒,但很少有质体小球。经培养分化后的愈伤组织,特别是在表层细胞中,质体数量急剧增多,形态变化很大,贮藏淀粉明显减少。基质内已有泡状或管状结构。有的质体已出现长的基质片层,但未见到基粒;质体中常有质体球。由此可见,质体是一个十分敏感的细胞器,它的变化与细胞分化有关,变化最大的部分是片层系统,贮藏淀粉,质体小球。片层系统中尤以基粒片层变化最为显著。  相似文献   

10.
甲基茉莉酸酯对花生种子萌发和贮藏物质降解的影响   总被引:7,自引:0,他引:7  
甲基茉莉酸酯(Me-Ja)对花生种子萌发基本没有影响,但对下胚轴和根的生长有抑制作用,且与浓度正相关.低浓度Meja促进子叶淀粉酶活性和淀粉降解,高浓度作用相反。Me-Ja部分抑制脂肪降解、贮藏蛋白降解和内肽酶活性,明显抑制脂肪酶活性.文中还讨论了Me-a抑制种子萌发与ABA作用的异同。  相似文献   

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12.
Callose accumulated in the tissues of boron deficient bean and cotton plants, the extent and distribution of which depended on the species. Sieve plates in the phloem of boron deficient bean were characterized by heavy plugs of callose, while the sieve plates of boron deficient cotton were essentially unaffected. Translocation of 14C was, however, drastically reduced in both plants. It is suggested that callose deposition in boron deficient plants is a secondary effect of cellular damage.  相似文献   

13.
In a sand-culture experiment lasting 21 weeks plants of timothy grown from seed were maintained at all combinations of three levels of nitrogen, phosphorus and potassium. The number and weight of tillers, leaves and ears, and the weight of roots, were determined at the end of the experiment, and for some of the treatments at intervals of 4 weeks. All three nutrients had significant effects, especially N which at its lowest level of supply tended to mask the effect of the other two elements. Potassium influenced tiller numbers least, especially those of primary tillers, but in the presence of high concentrations of N and P it had a large effect on leaf area and dry weight. Relative growth and net assimilation rates responded to varying nutrient supply only in the early stages of growth, so that in general variations in dry weight were associated with nutrient effects on leaf area.  相似文献   

14.
以1龄性腺发育中期鲤鱼为材料,采用腹腔(i.p)注射的方法,研究不同的下丘脑肽和神经递质对鲤鱼促性腺激素(GtH)和生长激素(GH)分泌的影响。结果表明:促甲状腺激素释放激素(TRH)、L-多巴(L-DOPA)、甲基睾酮(MT)、γ-氨基丁酸(GABA)、促黄体素释放激素类似物(LHRH-A)和三碘甲状腺原氨酸(T3)都能显著刺激GtH的分泌,但最大效应时间各不相同。TRH和LHRH-A能促进GH的分泌,L-DOPA、MT、GABA对血清GH水平没有明显影响;T3则对GH分泌有一定的抑制作用。这说明鲤鱼GtH和GH的分泌除了受各自的下丘脑释放因子和释放抑制因子的双重神经内分泌调控外,还受多种其它相同和不同调节因子的影响,也反映了鲤鱼GtH和GH分泌的神经内分泌调控的复杂性。  相似文献   

15.
摄食水平和食物种类对金鱼生长及氮、磷排泄的影响   总被引:14,自引:2,他引:14  
本文报道了金鱼的生长率、氨排泄率及磷酸盐排泄率的两个实验的结果。实验A用牛肉作饵料,实验B用配合饲料作饵料。每一实验分6个摄食水平。特定生长率(SGR)与摄食率(R)的关系为:SGR=a十bln(R+1)。实验中两种食物对上式的系数无显著影响。氨排泄率NE与氮摄取率NI的关系为:NE=a+bNI。实验中两种食物对上式的‘b’值无显著影响,但两个实验得出的‘a’值有显著差异。磷酸盐排泄率(PE)与磷摄取率(PI)的关系为:PE=a+bPI。实验中两种食物对上式中的‘b’值无显著影响,但得出的‘a’值有显著差异。若不考虑食物种类的影响,而将两实验数据合并,氮、磷摄取率可分别解释氮、磷排泄率变异的98%和75.7%。  相似文献   

16.
17.
The effect of sodium, chloride on the growth of a halophyte,Suaeda maritima (L.) Dum., was compared with its effect on Pisumsativum L. cv. Alaska under controlled environmental conditions.The salt stimulated the growth of Suaeda maximally at concentrationsof 170 to 340 mM while the growth of Pisum was inhibited evenby 100 mM. Both species accumulated ions in the tops and themaximum concentrations of Na+ and Cl rose in Suaeda to860 mM (based on the water content) and 730 mM and in Pisumto 170 mM and 300 mM respectively. Respiration in both specieswas inhibited as the NaCl level in the culture solution wasraised. Four supernatant enzymes (malic dehydrogenase, glucose-6-phosphatedehydrogenase, peroxidase, and acid phosphatase) prepared fromPisum and from Suaeda (grown either in the absence of addedNaCl or in the presence of 340 mM NaCl) were assayed in variouslevels of sodium chloride. The dehydrogenases were markedlyinhibited by increasing salt concentrations while there wasa smaller effect on the peroxidase and acid phosphatase. Therewas no difference in the effect of salt on the enzymes preparedfrom the two species although one is halophilic and the otherhalophobic.  相似文献   

18.
19.
官厅水库几年前曾受到工业废水的轻发污染。1973年以后,污染得到控制,水质有所改善。1973—1975年间我们调查研究了该水库鲤鱼的生长特征,并与清洁的密云水库进行了比较。主要结果摘要于后: 1.官厅水库鲤鱼平均肥满度2.32±0.10,密云水库鲤鱼平均肥满度2.80±0.40。两地20厘米以上鲤鱼肥满度与体长的关系分别为K=8.976 L~(-0.3801)和K=9.936 L~(-0.3757)。官厅水库各种大小鲤鱼均比密云水库相应大小的鲤鱼为瘦。 2.官厅、密云两个水库鲤鱼长重关系式分别为W=0.0368 L~(2.8571)和W=0.1054 L~(2.6081)。 3.官厅水库鲤鱼的体长增长速度亦慢于密云水库鲤鱼,但从1973年以后生长速度加快,这与水质变化情况是一致的。 4.密云水库鲤鱼生长型式比较正常,可用von Bertalanffy生长方程式表示,公式如下:l_l=84[1-e~(-0.15)(t 0.15)]。官厅水库鲤鱼生长一度出现异常现象,不能用上述方程式表示。 5.分析官厅水库鲤鱼生长一度变慢的原因,认为污染是主要的影响因素。因此,鲤鱼的生长状况可作为监测水污染的生物学指标之一。  相似文献   

20.
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.  相似文献   

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