大豆开花后光周期反应的研究

利用中国大豆主要生态区的生育期不同的代表品种研究了大豆（Ｇｌｙｃｉｎｅ ｍ ａｘ （Ｌ．）Ｍｅｒｒ．）开花后对光照长度的反应． 结果表明,不同成熟期的大豆品种开花后普遍存在着对光照长度的反应．这种反应属于典型的光周期现象,而不是由温度的替代作用、光合时间的改变或前期短日后效应引起的．开花后光周期反应不仅存在于大豆的花荚期,而且存在于鼓粒期．研究认为∶大豆开花结实对光周期的需求是一个连续过程;光周期对大豆生育期的调控作用存在于出苗至成熟的全过程;光周期诱导开花和促进成熟的作用有一定的共同性;光周期诱导效果具有持效性和可逆性     

Studies on the Photoperiodic Responses in Short-Day Plant Helianthus tubevotus

Plants of Helianthus tuberosus, variety white tuber, were treated with various daylengths of 4, 6, 8, 10, 11, 12, 13, 14, 15, 18 h. for 25 days as soon as six leaves on a plant appeard Irradiation for 6–13 h per day induced the plants to form flower buds and flowering, daylength with 14 h or longer kept the plants in vegetative growth. The experiments showed that this variety of Helianthus tuberosus required short days for flowering and the critical daylength was about 13 h. The plants were treated with short days for different durations. At least 17 days were required, Formation of flower buds and flowering had positive correlation with the number of short days over 17 days. After short-day induction, the shorter the daylength is, the more the flower buds inverted. Long-day treatment after an appropriate period of short days wouid reduce the number of flower and induce new vegetative branches from flowering granehes.     

光周期对穗花狐尾藻生长、开花与种子形成的影响

通过人工补光和遮光处理,初步研究了光周期对狐尾藻生长和开花的影响。研究发现:8h短日照条件不利于狐尾藻的生长和花序形成,导致狐尾藻不能正常开花和结实;与自然日照长度(平均日照14h)条件下相比,16h长光照条件可以增加植株的高度和分枝数,形成更大的生物量;但24h全光照条件对生长有抑制作用。长光照条件下,狐尾藻花序形成时间和开花时间均比自然条件下延迟,形成花序的数目也显著较自然条件下的少,但长光照条件下形成的种子比自然条件下形成的种子具有更高的萌发率。     

Studies on Flowering Responses of Urena lobata

Urena lobata L. is a qualitative short-day plant with a critical dark period of about 12 hr. A minimum of 12 short days are required for floral initiation. Gibberellic acid (GA₃) sprayed onto the leaves promoted flowering. The growth retardant, (2-chloroethyl)-trimethylammonium chloride (CCC) markedly inhibited flowering and stem elongation. This inhibition was reversed by subsequent application of GA₃.     

Functional and Evolutionary Characterization of the CONSTANS Gene Family in Short-Day Photoperiodic Flowering in Soybean

CONSTANS (CO) plays a central role in photoperiodic flowering control of plants. However, much remains unknown about the function of the CO gene family in soybean and the molecular mechanisms underlying short-day photoperiodic flowering of soybean. We identified 26 CO homologs (GmCOLs) in the soybean genome, many of them previously unreported. Phylogenic analysis classified GmCOLs into three clades conserved among flowering plants. Two homeologous pairs in Clade I, GmCOL1a/GmCOL1b and GmCOL2a/GmCOL2b, showed the highest sequence similarity to Arabidopsis CO. The mRNA abundance of GmCOL1a and GmCOL1b exhibited a strong diurnal rhythm under flowering-inductive short days and peaked at dawn, which coincided with the rise of GmFT5a expression. In contrast, the mRNA abundance of GmCOL2a and GmCOL2b was extremely low. Our transgenic study demonstrated that GmCOL1a, GmCOL1b, GmCOL2a and GmCOL2b fully complemented the late flowering effect of the co-1 mutant in Arabidopsis. Together, these results indicate that GmCOL1a and GmCOL1b are potential inducers of flowering in soybean. Our data also indicate rapid regulatory divergence between GmCOL1a/GmCOL1b and GmCOL2a/GmCOL2b but conservation of their protein function. Dynamic evolution of GmCOL regulatory mechanisms may underlie the evolution of photoperiodic signaling in soybean.     

Photoperiodic alteration of postpartum reproductive function in suckled cows

Three experiments were conducted using a total of 41 cows to determine if photoperiod modulates the establishment of postpartum estrous cycles and conception. Cows calving in the autumn and winter were exposed to either 18 hr light/day (18L:6D) or natural photoperiods. In Exp. 1, cows receiving 18L:6D had shorter (P<0.025) intervals from calving to estrus (61 +/- 3.8 days) than cows not receiving supplemental light (154 +/- 23.9 days). The same was true for primiparous cows in Exp. 2 (76 +/- 5.5 days vs 153 +/- 38.0 days; P<0.06) but not for the multiparous cows in Exp. 2 (56 +/- 5.2 days vs 40 +/- 7.4 days) or for all cows in Exp. 3 (60 +/- 10.1 days vs 70 +/- 13.5 days). Because conception rate was higher for cows exposed to 18L:6D for the multiparous cows in Exp. 2 and all cows in Exp. 3, interval to conception was significantly shorter for animals exposed to 18L:6D in all experiments. Generally, interval from calving to uterine involution was also reduced by exposure to 18L:6D. No effects of photoperiod were observed on body weight changes, serum levels of luteinizing hormone (LH), follicle stimulating hormone (FSH) or estradiol or on estradiol-induced release of gonadotropins. It was concluded that in certain situations day length can hasten estrus and conception in postpartum cows. The effect of photoperiod interacts with other conditions, one of which is parity. The endocrine basis for these effects are not known.     

Photoperiodic regulation of FGF21 production in the Siberian hamster

This article is part of a Special Issue "Energy Balance".     

光照因子对鹿茸生长发育的影响作用

控制光照周期中的光照强度(I)和光照／黑暗比率(L／D)对鹿茸的生长发育影响的作用明显,其中,在I=300lx和L/D=1.00-3.00时,鹿茸的生长发育最好。此外,鹿体内的性腺激素对鹿茸的生长发育有明显的作用。     

A Set of Three Genes Regulates Photoperiodic Responses of Flowering in Rice (Oryza sativa)

Differentiation in photoperiodic response of flowering has been key to the evolution and wide geographic distribution of rice, an essentially short-day plant. Crosses were made such that the hybrid F1 plants flower later than the late-flowering parents to investigate the genetic basis underlying this differentiation. From initial experiments, three major genes for flowering time were identified from four naturally occurring variants under natural long-day conditions. An F2-derived trigenic mutant line bred-true for a day-neutral response was selected and used as the recipient to synchronize the genetic background for the major genes. Experiments conducted under various daylengths indicated that these genes are responsible for photoperiodic sensitivity and the trihybrid has a critical daylength between 13.5 and 14 h. The three genes regulate photoperiodic responses qualitatively and quantitatively through complementary and other epistatic effects, respectively. The complementation suggests that the three genes act in a linear manner to repress the transition from the vegetative to reproductive phases under long daylengths. This set of genes also provides a model to understand the genetic mechanism underlying the elongated vegetative growth period in the F1 generation, which is usually an obstacle to the use of heterosis, and the selection for early maturation in rice breeding.     

Photoperiodic modulation of circadian rhythms in the cricket Gryllus bimaculatus

The waveform and the free-running period of circadian rhythms in constant conditions are often modulated by preceding lighting conditions. We have examined the modulatory effect of variable length of light phase of a 24h light cycle on the ratio of activity (alpha) and rest phase (rho) as well as on the free-running period of the locomotor rhythm in the cricket Gryllus bimaculatus. When experienced the longer light phases, the alpha/rho-ratio was smaller and the free-running period was shorter. The magnitude of changes in alpha/rho-ratio was dependent on the number of cycles exposed, while the free-running period was changed by a single exposure, suggesting that there are separate regulatory mechanisms for the waveform and the free-running period. The neuronal activity of the optic lobe showed the alpha/rho-ratio changing with the preceding photoperiod. When different photoperiodic conditions were given to each of the two optic lobe pacemakers, the alpha/rho-ratio of a single pacemaker was rather intermediate between those of animals treated with either of the two conditions. These results suggest that the storage of the photoperiodic information occurs at least in part in the optic lobe pacemaker, and that the mutual interaction between the bilateral optic lobe pacemakers is involved in the photoperiodic modulation.     

Photoperiodic history determines the reproductive response of rainbow trout to changes in daylength

The mechanisms underlying the photoperiodic entrainment of the endogenous circannual rhythm of maturation in the rainbow trout were investigated by subjecting December-spawning fish to abrupt changes in daylength which varied in their timing or magnitude. These protocols advanced spawning by up to 4 months. Maturation occurred in sequence in fish maintained on 18L:6D from January and February, and in fish exposed to 18L:6D from December, January and February, followed by 6L:18D in May, indicating that the abrupt increases in daylength were effective entraining cues. `Long' photoperiods of between 12 and 22 h applied in January, followed by shorter photoperiods of between 3.5 and 13.5 h from May, were equally effective in advancing maturation. Maturation was also advanced, though to a lesser extent, in fish maintained on photoperiods of 8.5 or 10 h from January, followed by a photoperiod of 1.5 h from May. In contrast, maturation was delayed in fish maintained under a constant 8.5-h photoperiod from January, and these fish also exhibited a desynchronization of spawning times characteristic of endogenous circannual rhythms in free-run. Collectively, these results indicate that photoperiodic history determines the reproductive response of rainbow trout to changes in daylength. Accepted: 7 August 1998     

Intermittent Illumination and the Photoperiodic Control of Flowering in Carnation

Plants of glasshouse carnation, a facultative long-day plant,were grown in photoperiodic cycles comprising 8 h natural daylightfollowed by 16-h ‘nights’. Throughout the nightseither continuous or intermittent lighting was given from tungsten-filamentlamps. Intermittent lighting comprised 15-min cycles of 5 or 6 minof light followed by 10 or 9 min of dark. This was as effectiveas continuous lighting in promoting flower initiation providinglight intensities were adjusted to give the same total lightenergy per night. If the same light intensity was used for bothcontinuous and intermittent lighting their relative effectivenessdepended on a number of factors. Superiority of the continuous-lightingtreatment in promoting flower initiation was apparent when theintensity of light was very low, when the treatments were givenfor relatively few nights or where shoots were illuminated atan early stage of growth. The use of intermittent lighting did not offer any obvious practicaladvantages as a means of controlling flowering in carnation.     

Serine Involvement in the Flowering of Lemna during Photoperiodic Induction

The levels of the endogenous free amino acid serine in Lemnaperpusilla are found to fluctuate during the course of shortdays. Serine levels do not change in plants receiving long daysor continuous light. The levels of serine decrease graduallyin the dark reaction of short days reaching their lowest aboutthe middle of the dark period, indicating a utilization of serineduring the dark reaction. In the second half of the dark periodthe serine level rises. The decline and rise of serine duringthe dark period is observed in successive short-day cycles.During the light period the serine level increases, reachinga maximum after 6 h from the beginning of the light exposure.When the light period is eliminated and a continuous dark periodis given the serine level remains unchanged. It is suggestedthat serine is involved in the floral initiation as a precursorto a flowering substance.     

Photoperiodic control of reproduction in the milkweed leaf beetle, Labidomera clivicollis

ABSTRACT. Photoperiod significantly affected reproduction in a central Texas population of the milkweed leaf beetle Labidomera clivicollis (Kirby) (Chrysomelidae). Laboratory reared beetles responded to a critical photoperiod of LD 12.5: 11.5; longer photoperiods induced reproduction, while shorter photoperiods induced diapause. Both larval and adult stages exhibited sensitivity to photoperiod. Beetles exposed to long days as adults reproduced regardless of photoperiod experienced as larvae. However, exposure to long days, as larvae but short days as adults also induced reproduction in an intermediate portion of the population. No larval instar appeared to be more sensitive than the others, and the proportion of the population responding did not increase with cumulative larval exposure to long days. Larval sensitivity to photoperiod may be ecologically significant to central Texas populations because it permits a substantial portion of the autumn generation to initiate a third generation in favourable years.     

大豆抗种粒斑驳基因效应的研究

３个在成株与种粒抗生不同的品种（系）东农７９－９、东农８１－４３、铁６９１５（东农）与３个都感的品种合丰２５、丰收１２、天北白目配制品个杂交组合。１９９１与１９９２年在网室与田间同时种植杂交组合物６个世代,人工接种ＳＷＶ,鉴定实验结果认为,抗种粒斑驳的行为是由基因控制的。抗生基因因为显性。抗生基因的数目与抗生亲本的抗生强度有关。抗性基因的遗传方式在抗生强的亲本中表现为单基因的简单遗传,而在抗生弱的     

Effect of Photoperiodic Induction on the Protein Synthesis of Cotyledons and the Morphology of Apical Meristem of Pharbitis nil Plant

After photoperiodic induction of Pharbits nil seedlings with two expanded cotyledons byshort day, the changes of protein in cotyledons or in shoot apex were investigated by polyacrylamide gel electrophoresis technique and electron, microscopy respectively Electron microscopicobservation shows that a kind of spherical electron-dense bodies appears in vacuoles of the apical meristem. Change of protein patterns also observed in the cotyledons. The number of basicprotein bands increased from eight in the untreated control to ten in the induced cotyledons, andthe number of, buffer-soluble protein bands increased from ten in the untreated control totwelve in the induced cotyledons. Authors suggest that the appearence of new protein bandsand electron-dense bodies is probably related to gene expression in the induction process ofphotoperiod of Pharbitis.     

Identification of Soybean Genes Involved in Circadian Clock Mechanism and Photoperiodic Control of Flowering Time by In Silico Analyses

Glycine max is a photoperiodic short-day plant and the practical consequence of the response is latitude and sowing period limitations to commercial crops. Genetic and physiological studies using the model plants Arabidopsis thaliana and rice （Oryza sativa） have uncovered several genes and genetic pathways controlling the process, however information about the corresponding pathways in legumes is scarce. Data mining prediction methodologies, including multiple sequence alignment, phylogeneUc analysis, bioinformaUcs expression and sequence motif pattern identification, were used to identify soybean genes involved in day length perception and photoperiodic flowering induction. We have investigated approximately 330 000 sequences from open-access databases and have identified all bona fide central oscillator genes and circadian photoreceptors from A. thaliana in soybean sequence databases. We propose a working model for the photoperiodic control of flowering time in G. max, based on the identified key components. These results demonstrate the power of comparative genomics between model systems and crop species to elucidate the several aspects of plant physiology and metabolism.     

抽提大豆各组织总DNA方法的比较研究

 抽提大豆各组织总ＤＮＡ方法的比较研究忻骅袁卫明顾其敏（上海复旦大学生物化学系,上海２００４３３）十六烷基三甲基溴化铵（ＣＴＡＢ）选择性沉淀ＤＮＡ的方法被广泛用于抽提生物组织,特别是植物组织的总ＤＮＡ,它简便快速,所得ＤＮＡ的纯度好,适用于进一步的酶切...