春化及光照对于蒔蘿菜生长与发育的影响

1.蒔蘿菜能在种子萌动时期通过春化阶段。要求春化的条件不严格,不論經过春化或不春化几乎在同一时期現蕾,相差最大者不过4天。 蒔蘿菜种子經20天春化处理,有提早收获期和增加产量的可能。 2.蒔蘿菜形成花蕾与抽苔要求长日照,在8—9小时短日下則发育迟緩。     

温度对叶用莴苣春化的影响

为了探讨温度对叶用莴苣春化的影响,进而明确其春化类型,本试验选用两个易抽薹叶用莴苣品种GB-30和GB-31为试材,分别进行20 d的4、20和25 ℃处理,然后均进行高温胁迫促进抽薹,采用石蜡切片观察茎尖花芽分化进程,并结合后期抽薹开花情况来判断是否进行春化,并确定其春化类型.结果表明:两个品种在前期经过3种温度处理后,在高温胁迫第8天时均有不同程度的抽薹.两个品种不同温度处理下花芽均进行了分化,前期4 ℃处理并没有使其花芽分化明显提前,后期的高温胁迫可以明显促进花芽分化进程.两品种间在不同温度处理下完成各发育阶段所需天数存在差异,两品种各处理从催芽到开花以及从高温到开花的有效积温也存在差异.前期未经低温处理的叶用莴苣也进入花芽分化、抽薹、现蕾及开花阶段,表明叶用莴苣为非低温春化型植物,后期高温处理能明显促进其抽薹开花,而且从催芽开始只有有效积温达到约2500 ℃·d才能开花.     

光照条件对麻类作物发育影响的初步研究

1.从三种洋麻品种对不同光照长度反应的结果,说明洋麻在短日照条件下发育显著加速;“塔什干”在短日照及上海自然日照下植株转向发育均较早,“普通洋麻”“嫁接洋麻”在短日照下发育最快,三个品种在长光照下植株发育均显著延缓。 2.洋麻植株在经过一定短日照的天数处理后,即可显著提早现蕾,亦即完成光照阶段。但是现蕾後如无适当的光照条件仍不能继续开花。植株在开花後如移入不适合的光照条件下,则植株不能继续现蕾开花而上部植株乃继续营养生长,这可能与这种植株自下而上向顶的不断开花习性有关。     

問题解答

问:洋白菜(结球甘蓝)是低温长日照植物,需要在低溫条件下通过春化阶段,伹在河北、山东等地栽培洋白菜通常于11月初在阳哇(冷床)播种,幼苗整个冬季都在低温下度过,为什么不会通过春化阶段? 答:回答这个問题,应当从洋白菜的春化阶段发育的特点談超。洋白菜春化阶段发育的适温較低,而时間較长。曾有人試驗,洋白菜植株若連续处在15℃以上的高温情况下,可以多年不开花。它必須在12℃以下才能进行春化阶段的发育,但很緩慢;而在2—6℃的条件下最为适合,至     

赤霉素影响几种植物开花试验的初步报告

1.在诱导的长日条件下赤霉素可以促进长日性植物雪里蕻、矢车菊植株提早开花,又可诱导要求低温的二年生植物乌塌菜开花。在非诱导的短日条件下赤霉素可以诱导雪里蕻、矢车菊、乌塌菜植株现蕾。但是要求冬性较强的二年生植物乌塌菜开花所需的赤霉素剂量比雪里蕻、矢车菊为高。因此赤霉素可以替代长日性植物的光照条件及要求低温的二年生植物的低温作用,是与Lang用二年生天仙子等以及用金光菊(Rudbeckia bicolor)、冬洋油菜(Brassica napus v.oleifera)等植物所得的结果是一致的。 2.赤霉素可以打破多年生蓿根性植物如芍药、牡丹休眠芽的休眠而提前开花。 3.赤霉素对鳞茎类植物如漳州水仙、风信子植物的开花没有促进作用。     

诸葛菜试管花朵发育的研究

诸葛菜是生产中国的观赏植物。为了探索其花朵发育的特点及其应用的可能性，本文作者首次对诸葛菜试管的花朵发育作了初步研究。本试验将诸葛菜种子消毒后，接种到不含外源植物激素的MS培养基中，取所得试管苗分别进行不同条件的培养试验。低温处理的影响：经过5－7℃低温处理不同天数的试管苗，有的处理可以开花，其中以低温处理7天以上的试管苗的再蕾株率达80％以上，开花株率达70％以上。而未经低温处理的对照则未现苗开花。（Tab.1)外源植物激素GA3的影响：培养基中添加适量的GA3（2mg／L），可以使未经低温处理的诸葛菜试管苗开花。（Tab.2)。硝酸铵含量的影响：适当降低培养基中NH4NO3的含量（半量），可以加速诸葛菜试管苗的现蕾、开花。（Tab.3)。利用诸葛菜外植体具较强再生力容易产生试管苗，以及诸葛菜试管苗经过适当的低温处理较易开花的特点，有可能生产诸葛菜试管花观赏用。     

芹菜中玉米赤霉烯酮的分离与鉴定

芹菜属于冬性长日植物,它需要经过低温春化阶段才能开花结实,但低温仅是外界条件,还必需通过植物体内部的生理生化变化才能起作用。关于春化作用机理的研究,自 Melchers(1939)提出低温诱导植物形成春化素(vernalin)的假说以后,Purvis等(1953),Highkin(1955)和Tomita(1959,1964)曾自不同植物中分离出能代替低温或促进开花的物质,但都     

冬小麦春化过程中可溶性蛋白质组成的变化与形态发生的关系

冬小麦“农大139”经40天左右的春化处理才能迅速而整齐地抽穗,但经14—21天低温处理,已经具有在夏季抽穗的可能性,虽然抽穗推迟且极不整齐;再将春化时间延长,则抽穗百分比增加,且从播种到抽穗的时间缩短。这表明,春化过程中低温对发育的作用有两种效应:前期低温是诱发生理状态的转变,后期低温则只具有加速发育的作用,两个时期的转变是在春化的中期。蛋白质合成抑制剂乙基硫氨酸和对-氟苯丙氨酸能抑制冬小麦的春化,抑制时期也是在春化过程的中期。不同时间低温处理后冬小麦幼芽中可溶性蛋白质含量及组成发生了变化,春化过程中期(低温处理14天之后)不仅含量比对照增加了一倍,而且有新的蛋白质谱带出现。春麦中无类似现象,未经低温处理的春麦已含有冬麦中新出现的谱带。说明冬小麦春化过程的第14—21天左右是与春化过程有关的蛋白质合成的关键时期,该时期新合成的蛋白质与植株的发育状态之间存在着密切的相关关系。     

油菜中内源赤霉素嫁接转移研究

在温室条件下,将未春化的油菜接穗分别嫁接在已春化和未春化油菜砧木上,结果已春化油菜砧木上的接穗植株很快开花,而未春化砧木上的接穗植株不能开花,其主要原因是与已春化油菜砧木内源赤霉素含量高,并传递到接穗有关。     

水稻春化阶段及光照阶段分析方法

(一)春化阶段分析方法1.种子春化处理的条件(1)春化温度分为15°,20°,25°,30℃等四种。(如条件不够,可采用15°及25℃两种温度采用3、6、9、12、15等五种处理日数。)     

FLOWER-PROMOTING EFFECT OF GIBBERELLIN IN WINTER WHEAT AND BARLEY

1. Vernalized and unvernalized seeds of barley were sown in greenhouseunder short day or long day condition. At the second leaf stage,a half of the plants in each plot was sprayed with gibberellin.Plants grown from vernalized seeds headed at about the sametime under long day condition, whether they were treated withgibberellin or not. Under short day condition, however, gibberellinpromoted heading. With plants grown from the unvernalized seeds,gibberellin promoted heading under long day condition whereasit delayed heading under short day condition. Thus the substitutionof gibberellin for long day effect and for vernalization effectwas shown.
2. Immature embryos growing on developing ear of wheatand barleywere vernalized with low temperature combined withor withoutgibberellin application. Plants grown from the seedstreatedat their early ripening stage with low temperature combinedwith gibberellin gave earlier heading, associated with the decreasedleaf number, than the plants from seeds treated with low temperaturealone. This effect of gibberellin lasted for a half-year ofseed storage.
3. Gibberellin was applied to germinating seedsunder vernalizationtreatment. Gibberellin promoted floweringin varieties whichpossess high requirement for chilling vernalization,when thechilling was insufficient to satisfy the high requirement.However,the effect of gibberellin was obscure with varietiespossessingrelatively low requirement for vernalization.

(Received September 15, 1964; )     

Factors controlling Flowering in the Chrysanthemum: III. FAVOURABLE EFFECTS OF LIMITED PERIODS OF LONG DAY ON INFLORESCENCE INITIATION

Experiments are described which indicate that Chrysanthemumcuttings derived from unvernalized long-day stock plants flowersooner and with lower leaf numbers after vernalization thansimilarly treated cuttings from short-day stock. Long-day treatmentof young cuttings also hastens inflorescence initiation providedthe period of such treatment is limited and given before orimmediately after vernalization. The effect of long day appearsto be maximal when vernalization is complete. Long-day treatmentcannot substitute for vernalization.     

Effects of photoperiod, temperature and vernalization on the phenology and spikelet numbers of spring wheats

Fourteen cultivars of north temperate, Australian, Mexican and Rhodesian origins, were grown in eight treatments: 2-day-lengths (10 h and 14h) × two temperature regimes (18/13 °C and 25/20 °C) × two seed vernalization treatments (unvernalized and 28 days at 1–2 °C). Numbers of days to 50 % ear emergence, leaf numbers and spikelet numbers of the main shoots were recorded. The north temperate cultivars were the most sensitive to daylength: in long days their mean spikelet number was 15 and they headed in 40–50 days, while in short days they had a mean of 24 spikelets and failed to head in 100 days. The Rhodesian cultivars were the least sensitive, but nevertheless headed 20–30 days earlier and had three to five fewer spikelets per ear in long days. The effects of vernalization on the tropical cultivars were related to maturity class: they ranged from negligible in early cultivars such as Sonora 64 and Devuli to decreases of 20 days to heading and seven spikelets in late cultivars such as Mexico 120 and Cajeme 71 in long days. The effects of temperature varied with cultivar and with vernalization treatment. Early cultivars and vernalized late cultivars headed earlier and had fewer spikelets in the warmer regimes while unvernalized late cultivars tended to have more spikelets and headed later. It is suggested that some vernalization of these late cultivars took place in the cooler regime. The significance of the results for the understanding of the physiological basis of the adaptation of wheat cultivars to different climatic zones is discussed.     

Operant supplementary heating in groups of growing pigs in relation to air velocity

The aim of the experiments was to investigate the effect of air velocity on the temperature preferred by growing pigs 12–14 weeks old. Pigs displayed a temperature preference by means of operant supplemental heating. They pushed a button connected to heating lamps. Six experiments of three weeks each and with two treatments with a group of 8 pigs each were made. Animals were housed in groups and weighed 14–20 kg at the start of the experiments. Air velocity was 0.08, 0.25 and 0.40 m/s. At each air velocity four replicates were made. Mean temperatures preferred were 17.9°C at 0.08 m/s, 20.5°C at 0.25 m/s and 21.7°C at 0.40 m/s. Within a day temperature preference fluctuated with 5.7 K at 0.08 m/s, 4.3 K at 0.25 m/s and 4.2 K at 0.4 m/s. Temperatures preferred were highest during day time.     

Effect of Vernalization and Red Light Illumination of Seedlings of Bread Wheat (Triticum aestivum L.) on the Temperature Profile of cAMP Phosphodiesterase Activity

Phenotypic manifestations of Vrn(vernalization) and Ppd (photoperiod) genes responsible for transition of bread wheat Triticum aestivumL. to generative growth (flowering) are mutually related. Since the mechanism of phytochrome-induced photoperiodism involves the enzymes of cyclic adenosine monophosphate metabolism, and phosphodiesterase in particular, we tested involvement of phosphodiesterase in the process of winter wheat vernalization and formation of flowering competence in alternate wheat requiring a long photoperiod but no vernalization for its transition to flowering. We studied temperature dependence of phosphodiesterase activity in vernalized and unvernalized winter wheat on the one hand and in etiolated and red light illuminated seedlings of alternate wheat on the other hand. Short-term experiments demonstrated that red light illumination is similar to long photoperiod by the effect on the long-day plants. Both influences induced a pronounced inversion of the temperature profile of phosphodiesterase activity in the 28–45°C range. We propose that phosphodiesterase is involved in vernalization and can serve as a receptor of low temperature in winter wheat. Changed temperature profile is a radical control mechanism of phosphodiesterase activity in response to the influences (red light and vernalizing temperatures) responsible for competence of various bread wheat forms for generative growth.     

Expression of Vernalization Genes in Near-isogenic Wheat Lines: Effects of Night Temperature

Four near-isogenic lines of wheat (Triticum aestivum L.em Thell)were used to compare selected night temperatures for their effectivenessas vernalizing temperatures. All treatments (conducted withina phytotron) had a common day temperature of 20 °C for 12h and night temperatures were 4, 7, 10, 13 and 20 °C. Interpretationof results for reproductive development was confounded by threeinteracting factors, their relative importance varying withgenotype. Firstly, development rate was generally slower atlower night temperatures. Secondly, in contrast, there was atendency for lower night temperatures to hasten developmentrate if vernalization requirements were satisfied. Thirdly,the lower night temperatures provided a more favourable environmentfor leaf production such that for some genotypes, vernalizedplants had higher final leaf numbers than unvernalized plants.Only for the genotype with the strongest vernalization response(vrn1 vrn2) did hastening of development due to vernalizationoverride any delaying effects. For this genotype, 4, 7 and 10°C were vernalizing temperatures. For the other three genotypes,any hastening of development due to vernalization was outweighedby delaying effects of lower night temperatures. Spikelet numberand days to anthesis were positively correlated in three ofthe four genotypes. It appeared that differences in spikeletnumber were a direct result of night temperature influencingthe duration of the spikelet phase and/or rate of spikelet initiation.Plant size at flowering was determined by the differential effectsof night temperature on growth and development rates. Triticum aestivum L., wheat, vernalization, night temperature, isogenic lines     

Pericarp anatomy and hormone profiles of cypselas in dormant and non‐dormant inbred sunflower lines

The pericarp anatomy and the effects of storage after harvest, storage temperature and early cypsela imbibition on phytohormone profiles were studied in inbred sunflower lines B123 and B91. On day 0, germination of B123 cypselas was near 0%, indicating dormancy, whereas that of B91 cypselas was near 100%, indicating non‐dormancy. The germination of B123 and B91 on day 33 at room temperature (25 °C) storage was similar. Cell wall thickness and sclerification of the pericarp were higher in B123 than B91, suggesting that structural characteristics may contribute to physical dormancy in B123. Jasmonates (JAs), salicylic acid (SA) and abscisic acid (ABA) were measured in dry and imbibed pericarps. SA content of dry pericarp was higher on day 33 than day 0. SA content during imbibition on day 33 was similar for room and low (?20 °C) storage temperatures. ABA content after 12 h imbibition was similar on days 0 and 33 at low temperature, but it increased on day 33 at room temperature for B123. 12‐Oxo‐phytodienoic acid (OPDA) was maximal on day 0 for B123, but peaked at day 33 at low temperature for B91. JA was higher on days 0 and 33 at room temperature as compared with low temperature. Our findings indicate that pericarp hormone profiles are affected in the two lines with different dormancy degree depending on storage conditions and imbibition processes.     

Quantitative-genetic analysis of reciprocal crosses between a winter and a spring cultivar of common wheat (Triticum aestivum L.)

The winter wheat cultivar Sakhalin (parent A) and the spring wheat cultivar Khush-hal (parent B), assumed to be both nuclear-genetically and plasmotypically different, were reciprocally crossed and the F₁ generation of the reciprocals backcrossed to either parent. The populations (AxB)F₁, (AxB)F₂, [(AxB)F₁xA]F₁ and [(AxB)F₁xB]F₁, and their reciprocals (BxA)F₁, (BxA)F₂, [(BxA)F₁xA]F₁ and [(BxA)F₁xB]F₁, assumed to have the plasmotypes of the parents A and B respectively, were spring sown in the same field from unvernalized (experiment #1) and vernalized (experiment #2) seeds. The results of the analyses of variance of the data recorded in the two experiments are fairly similar. In both the experiments the plasmotypically A populations have produced more heads and higher grain yields per plant than their plasmotypically B reciprocals. The components of the family means and of half the differences between the reciprocals within the families show that vernalization has not affected the efficiency of the nuclear genes of parent A but has reduced the efficiency of the nuclear genes of parent B in both the homozygous and the heterozygous states. This in turn has affected the components of family mean squares and those of the family x reciprocals interaction mean squares in the analysis of variance tables.     

Using short-term growth of enclosed 0-group European flounder, Platichthys flesus, to assess habitat quality in a Danish bay

Instantaneous growth rates of 0‐group European flounder, Platichthys flesus, obtained from two 9‐day enclosure experiments were used to assess the relative quality of three eelgrass and three bare sand habitats in the Bay of Aarhus, Denmark. Measurements of temperature, dissolved oxygen, salinity, sediment structure and biomass of benthic macrofauna were made during the experiments. Gut content analysis was performed after retrieval of the fish. Growth rates of flounder at two bare sand sites were higher or equal to growth rates at the three eelgrass sites, and at a muddy bare sand site in both experiments. The variation in gut fullness of flounder between vegetated and bare sand sites followed the pattern observed in growth rates, but diverged from the spatial variation in prey abundance, which indicates that there were differences in the feeding efficiency between sites. Overall, habitat complexity, i.e. the presence or absence of vegetation seems to be the most important factor determining the growth rates and, by corollary, habitat quality for juvenile European flounder in the Bay of Aarhus.