scholarly journals Effect of Light Period Longer than Critical Day Length after Heading on the Growth and Development of Rice under a Controlled Environment

2010 ◽  
Vol 22 (2) ◽  
pp. 114-117
Author(s):  
Shinichi MARUYAMA ◽  
Yasuhiro ISHIGAMI ◽  
Eiji GOTO
Author(s):  
T.A. Mironova ◽  
◽  
M.V. Vlasov

The article discusses the technology of growing young mulard hybrid for subsequent fattening of fatty liver. They are given main production characteristics of growing — temperature conditions, illumination, and the duration of the light period. Data on the dynamics of live weight during cultivation from day old to 28 days, growth and development indicators of young mullards are given.


2014 ◽  
Vol 49 (4) ◽  
pp. 397-407 ◽  
Author(s):  
Janusz Maszewski

During long-term axenic culture of Chara continuous illumination (L=24) increases mitotic activity of almost all types of cells. In such conditions only initiation of oogonia is inhibited, leading into a strong predomination of male generative organs. Prolonged darkness (L:D=1:23) exerts a mitodepressing effect. Oogonia and antheridia are especially susceptible to the reduction of the light period. Modifications of the elongating growth in various photoperiods are different in the polyploid regions of the vegetative thallus and in haploid cells of the antheridial filaments. Segments of both axial internodes and lateral pleuridia increase their dimensions at L:D=1:23, whereas at L=24 their growth is significantly inhibited. Different reaction is noted in the cells of antheridial filaments: at L=24 they are about 10% longer than in the control (L:D=14:10). The duration of the antheridium aevelopment, from the stage of unicellular filaments to the moment of antheridium opening, is 1.5 days shorter at L=24 as compared with the control. This shortening includes proportionally both the period of divisions within antheridial filaments and the period of spermatozoid differentiation.


1978 ◽  
Vol 26 (1) ◽  
pp. 119-127
Author(s):  
D.P. de Vries ◽  
L. Smeets

As a basis for breeding cvs adapted to flowering in winter light conditions, the growth of hybrid tea rose seedlings under controlled conditions was studied. Irradiance varied from 4-24 W/m2, day length was 8 h, temperature 21 deg C. Like cvs, the seedlings sometimes aborted the flower bud at low light intensity. With increasing irradiances, the following phenomena were observed: the juvenile period of the seedlings shortened; plants were longer at bud formation, at first flowering and at flower bud abortion; leaf area and the number of petals increased. Leaf number was constant at all irradiances. Flowering seedlings were smaller at bud formation, but taller at actual flowering than blind ones. Blind seedlings had fewer leaves with a smaller area. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2016 ◽  
Author(s):  
He Huang ◽  
Dmitri A. Nusinow

AbstractIn Arabidopsis thaliana, an assembly of proteins named the evening complex (EC) has been established as an essential component of the circadian clock with conserved functions in regulating plant growth and development. Recent studies identifying EC-regulated genes and EC-interacting proteins have expanded our understanding of EC function. In this review, we focus on new progress uncovering how the EC contributes to the circadian network through the integration of environmental inputs and the direct regulation of key clock genes. We also summarize new findings of how the EC directly regulates clock outputs, such as day-length dependent and thermoresponsive growth, and provide new perspectives on future experiments to address unsolved questions related to the EC.


2000 ◽  
Vol 41 (1) ◽  
pp. 101-106 ◽  
Author(s):  
S. Yahav ◽  
S. Hurwitz ◽  
I. Rozenboim

1999 ◽  
Vol 133 (2) ◽  
pp. 159-166 ◽  
Author(s):  
M. BRINK

A semi-controlled environment study was conducted from May to September 1996 in Wageningen, The Netherlands, to investigate the interaction between growth and development in bambara groundnut (Vigna subterranea) and the influence of photoperiod on dry matter partitioning. The experimental design was a split-plot with four photoperiods (10·5, 11·8, 13·2 and 14·5 h/d) and two light treatments: unshaded and shaded (42% light reduction). The selection used was ‘DipC94’ from Botswana. The dates of 50% flowering and 50% podding were determined, and samples of plants were harvested at 22, 36, 50, 64, 78, 92, 106 and 120 days after sowing. Total dry matter production was 41% lower in the shaded treatment than in the unshaded treatment, but the rates of progress from sowing to flowering and flowering to podding decreased by only 3 and 12% respectively. This suggests that growth and development in bambara groundnut are largely independent. Photoperiod influenced dry matter partitioning indirectly, through its influence on the onset of podding. There were, however, no strong direct photoperiod effects on dry matter partitioning, either before or after the onset of podding.


1988 ◽  
Vol 66 (9) ◽  
pp. 1834-1840 ◽  
Author(s):  
L. Combe ◽  
Ph. Quetin ◽  
G. Decoux

Radish tuberization was studied with plants grown in a controlled-environment room at 19 °C day and night, with a daily light duration (radiant flux density, 600 μmol m−2 s−1 photosynthetically active radiations (PAR)) varying from 4 to 24 h at 2 h intervals. Day length did not seem to play a role in the initiation of tuberization: tuber thickening began after about 50 h of cumulative light exposure for all treatments. Moreover, two light treatments with the same daily photosynthetic balance, 8 h a day at high saturating irradiance (600 μmol m−2 s−1 PAR) and 16 h a day at low irradiance (200 μmol m−2 s−1 PAR), resulted in the same growth and tuberization regardless of day length. When the photoperiod is shorter than 7 h, it can modify leaf area, but for longer photoperiods, age is the main criterion determining foliage area. Cumulative light exposure determines the tuber dry matter to foliage dry matter ratio (tuberization index) if the day length is shorter than 16 h; if it is not, plant age alone determines the tuberization index. Day length has an effect on radish tuberization essentially because of its trophic action by photo-synthetic assimilate allocation to tuber thickening.


1973 ◽  
Vol 51 (5) ◽  
pp. 941-956 ◽  
Author(s):  
David P. Holmes

A comparative study was made of the growth and development of the shoot apex/inflorescence in two contrasting spring wheat (Triticum aestivum L.) cultivars: Marquis—a standard height, day-length-sensitive type; and Pitic 62—a semidwarf, Norin 10 derivative with relatively low day-length sensitivity. The effects of 8-, 12-, 16-, 20-, and 24-h photoperiods and of two nitrogen levels in 12 and 20 h on both cultivars were determined, as well as those of two phosphorus levels on Marquis in 20 h.Apical primordium production continued for a longer duration in Pitic than in Marquis, and the initiation of spikelet primordia was delayed. Spikelet development was more synchronous in Pitic than in Marquis in all treatments. Apical spikelet formation always coincided in both cultivars with the initiation of rachis internode extension. Inflorescence development after termination of spikelet primordia formation was as fast in Pitic as in Marquis (or faster in short photoperiods).In general, increasing N increased the rate and duration of primordium production (apical spikelet formation occurring later at high N), and delayed inflorescence development and extension. These effects were more pronounced in Pitic, resulting in much greater N responses for spikelet and grain numbers per spike, and for grain yields per spike. Effects of high P were similar to those of high N. Increasing photoperiod increased the rate, but decreased the duration of primordium production, and accelerated the development and the extension growth of the inflorescence.The results are discussed in relation to a postulated involvement of endogenous gibberellins and inhibitors in the regulation of inflorescence growth and development.


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