Ontogeny and histochemistry of the intermediate and reproductive apices of Cosmos bipinnatus var. Sensation in response to gibberellin A3 and photoperiod

1973 ◽  
Vol 51 (3) ◽  
pp. 535-551 ◽  
Author(s):  
Marje Molder ◽  
John N. Owens
Keyword(s):  
Gibberellic Acid ◽  
Response Rate ◽  
Intermediate Stage ◽  
Floral Initiation ◽  
Transitional Stage ◽  
Zonation Pattern ◽  
Short Day ◽  
Cosmos Bipinnatus ◽  
Cytological Features ◽  
Short Days

Plants of Cosmos bipinnatus Cav. ‘Sensation’ (a quantitative short-day plant) were grown under continuous conditions favorable or unfavorable for flowering, and some plants in each group were treated with gibberellic acid (GA3). Floral apices of Cosmos are formed by the transition of previously vegetative apices. The vegetative apex shows a cytohistological zonation pattern superimposed upon a tunica–corpus organization. The vegetative apex passes into an intermediate stage presumed typical of many plants held under non-inductive conditions. This stage is marked by many cytological features characteristic of both reproductive and vegetative apices but leaves continue to be produced. The presence of the intermediate stage accounts for conflicting results obtained in physiological studies since there is great variation in response rate depending on age of plant and the stage of the apex at the start of an experiment. This stage is followed by a typical transitional stage marked by an increase in RNA content, increased mitotic activity, and a change in zonation. Elongation of the apex and internodes occurs followed by initiation of the involucral bracts and floret primordia, marking the beginning of the prefloral and inflorescence stages respectively.GA3 specifically induces Cosmos to flower under non-inductive conditions thereby influencing floral initiation in a facultative short-day plant. Microscopic examination of the rate of apical transition revealed that GA3 substituted effectively for short days but was not as efficient an inducer as were short days.

The effects of gibberellin A3, photoperiod, and age on vegetative growth and flowering in Cosmos bipinnatus var. Sensation

1974 ◽  
Vol 52 (6) ◽  
pp. 1249-1258 ◽  
Author(s):  
Marje Molder ◽  
John N. Owens
Keyword(s):  
Floral Development ◽  
Response Rate ◽  
Developmental Rate ◽  
Intermediate Stage ◽  
Floral Initiation ◽  
Reproductive State ◽  
Apparent Lack ◽  
Cosmos Bipinnatus ◽  
Normal Percentage ◽  
Short Days

Plants of Cosmos bipinnatus Cav. 'Sensation' (a quantitative short-day plant) were grown continuously under conditions favorable or unfavorable for flowering, and some plants in each group were treated with gibberellic acid (GA3). Morphological and anatomical observations revealed that GA3 promoted floral initiation under non-inductive long days but not as efficiently as inductive short days, as judged by the rate of apical transition to the reproductive state. GA3 did not influence the total number of plants that flowered but did increase height growth. Plants treated with GA3 had a normal percentage of initiation, but a much lower developmental rate. Macroscopic recognition of flowering was not possible until the inflorescence stage of the apex.Floral apices of Cosmos are formed by the transition of previously vegetative apices, the apex passing into an intermediate stage typical of most plants held under non-inductive conditions. Transitional, prefloral, and inflorescence stages follow. The formation of an intermediate stage may account for many of the conflicting results observed in physiological studies since there is a great variation in response rate depending on age of plant and stage of the apex at the start of the experiment. Anatomical observations support the findings that although GA3 promotes floral initiation in Cosmos when applied under non-inductive conditions, floral development may not continue, thus resulting in an apparent lack of response. This may also be true of many other plants considered "non-responsive" to GA3 under non-inductive conditions.

Flowering of Stylosanthes guianensis in controlled temperatures under natural photoperiod

1984 ◽  
Vol 35 (2) ◽  
pp. 219 ◽  
Author(s):  
RL Ison ◽  
LR Humphreys
Keyword(s):  
Floral Initiation ◽  
Minimum Duration ◽  
Stylosanthes Guianensis ◽  
Short Day ◽  
Long Day ◽  
Natural Photoperiod ◽  
Low Levels ◽  
Short Days

Seedlings of Stylosanthes guianensis var. guianensis cv. Cook and cv. Endeavour were grown in naturally lit glasshouses at Brisbane (lat. 27� 30' S.) at 35/30, 30/25 and 25/20�C (day/night), and were sown so as to emerge at 18-day intervals from 18 January to 11 June. Cook behaved as a long day-short day plant, with seedlings emerging after 5 February flowering incompletely or remaining vegetative until the experiment was terminated in mid-October. In the 25/20�C regimen flowering was incomplete in Cook; in Endeavour flowering was delayed but a conventional short-day response was observed. At 35/30�C Endeavour flowering was inhibited in the shortest days of mid-winter, suggesting a stenophotoperiodic response, but short days were confounded with low levels of irradiance. Minimum duration of the phase from emergence to floral initiation was c. 66-70 days in Cook and c. 40-45 days in Endeavour; the duration of the phase floral initiation to flower appearance was linearly and negatively related to temperature.

scholarly journals Effects of Short-Day and Gibberellic Acid Treatments on Summer Vegetative Propagation of Napier Grass (Pennisetum purpureumSchumach)

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yasuyuki Ishii ◽  
Asuka Yamano ◽  
Sachiko Idota
Keyword(s):  
Gibberellic Acid ◽  
Vegetative Propagation ◽  
Napier Grass ◽  
Pennisetum Purpureum ◽  
Normal Variety ◽  
Early Maturation ◽  
Short Day ◽  
Positive Effect ◽  
Short Days ◽  
Dwarf Variety

The effects of short-day (SD) and gibberellic acid (GA3) treatments on promoting vegetative propagation during the summer were examined in Napier grass (Pennisetum purpureumSchumach). A dwarf variety of late heading type (DL) Napier grass was exposed to three SD treatments (5, 10, and 20 short days plus a spray of 400 ppm GA3solution following each SD treatment, GASD) or no treatment (control). Additionally, then, a dwarf variety of early heading (DE) and the normal variety of Merkeron (ME) were exposed to 10 days of GA-SD treatment together with nontreated controls. For DL and DE, GA-SD treatments showed the following effects: 10-day GA-SD treatment increased significantly (P<0.05) the length of lateral tiller buds, maintained a high rooting percentage, and increased the diameter of the tiller buds. This resulted in a taller plant, one with enhanced tiller numbers, and thus a greater number of established nursery plants for the two dwarf varieties. In contrast, there was only a limited positive effect of the GA-SD treatments on the normal variety, ME. Thus, 10 days of GA-SD treatment was judged to be the most effective treatment for promoting lateral tiller bud elongation and early maturation in tiller buds for the two dwarf varieties of Napier grass.

Ontogeny and histochemistry of the vegetative apex of Cosmos bipinnatus "Sensation"

1972 ◽  
Vol 50 (6) ◽  
pp. 1171-1184 ◽  
Author(s):  
Marje Molder ◽  
John N. Owens
Keyword(s):  
Mitotic Activity ◽  
Mitotic Index ◽  
Vegetative State ◽  
Zonation Pattern ◽  
Short Day ◽  
Rna Content ◽  
Cosmos Bipinnatus ◽  
Leaf Arrangement ◽  
Nucleolar Volume ◽  
Initial Present

Plants of Cosmos bipinnatus Cav. "Sensation" (a quantitative short-day plant) were grown under continuous conditions of long days to maintain the vegetative state. The vegetative apex shows a cytohistological zonation pattern superimposed upon a tunica–corpus organization. The biseriate tunica is separated into two zones: axial and lateral; while the corpus is separated into three zones: the peripheral, central, and rib meristem. Based on mitotic activity (both frequency and index) there is neither a "méristème d'attente" nor an "anneau initial" present. A double plastochron cycle is present because of the decussate leaf arrangement and the presence of prominent leaf bases. Cytohistological zonation, nucleolar volume, RNA content, and mitotic index vary in a cyclic manner with the phase of plastochron. Although the degree of zonation decreases just after leaf buttress initiation, zonation does not disappear at any time during a plastochron.

The long-short day requirement for flowering in Stylosanthes guianensis

1988 ◽  
Vol 39 (2) ◽  
pp. 199 ◽  
Author(s):  
K Trongkongsin ◽  
LR Humphreys
Keyword(s):  
Early Summer ◽  
Controlled Environment ◽  
Floral Initiation ◽  
Previous Exposure ◽  
Spike Density ◽  
Stylosanthes Guianensis ◽  
Short Day ◽  
Seed Crops ◽  
Incandescent Lamps ◽  
Short Days

Five 'tardio' selections of Stylosanthes guianensis ssp. guiunensis var. pauciflora and S. guiunensis var. guianensis cv. Cook were grown in a glasshouse where natural daylength was shortencd, or extended by incandescent lamps. They did not flower or flowered weakly in 152 cycles of 10 h short days (SD), but flowered more rapidly and prolifically if exposed to 30, 60 or 90 16 h long days (LD) followed by 30 10 h cycles than under natural daylength conditions at 27' 30' S. Increasing the previous exposure to LD reduced the number of 10 h cycles to floral initiation. Similar behaviour was exhibited by cv. Bandeirante which did not flower in 131 cycles of 11 h, but which flowered when SD induction followed 45 to 65 cycles of 14 h. Spike density was positively related to number of LD, which favoured first flower appearance on the terminal apices of lateral rather than of main shoots. CIAT 1283 and cv. Cook grown in controlled environment cabinets at 30�/23� (day/night) did not flower in 140 cycles of 10 h SD, but flowered if LD were interposed before SD induction. Cook had a greater LD requirement of 50 cycles of 14 or 15.5 h for floral initiation, whilst CIAT 1283 had a lesser LD requirement and flowered after 20 cycles of 14 or 15.5 h or after 50 cycles of 12.5 h. These data indicate a qualitative long-short day flowering response. This has implications which favour the higher latitudes for seed production and the early summer sowing of seed crops when plants would receive maximum LD exposure before SD induction occurs.

scholarly journals Floral Initiation and Development in Sisyrinchium bermudiana

HortScience ◽  
1992 ◽  
Vol 27 (1) ◽  
pp. 73-74
Author(s):  
G.L. Roberts ◽  
M.J. Tsujita ◽  
J. Gerrath
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Floral Initiation ◽  
Shoot Apices ◽  
Short Day ◽  
Growth Chambers ◽  
Short Days ◽  
Scanning Electron

Sisyrinchium bemudiana L. plants were grown in growth chambers under lo-hour short-day regimes. Scanning electron microscopy of shoot apices collected at biweekly intervals showed that the transition from vegetative to floral status occurs after 10 weeks of short days. Stamens and tepals develop first as common stamentepal primordia that then bifurcate to form outer tepals with stamens opposite. Subsequently, the inner tepals are initiated in an alternate pattern.

scholarly journals Identifying new variation at the J locus, previously identified as e6, in long juvenile ‘Paranagoiana’ soybean

2021 ◽  
Author(s):  
Nour Nissan ◽  
Elroy R. Cober ◽  
Michael Sadowski ◽  
Martin Charette ◽  
Ashkan Golshani ◽  
...  
Keyword(s):  
Single Gene ◽  
Pcr Amplification ◽  
Gene Control ◽  
Grain Yields ◽  
Short Day ◽  
Exon 4 ◽  
Short Days ◽  
Kasp Markers

Abstract Key message A previously identified soybean maturity locus, E6, is discovered to be J, with the long juvenile allele in Paranagoiana now deemed j−x. Abstract Soybean grown at latitudes of ~20° or lower can produce lower grain yields due to the short days. This limitation can be overcome by using the long juvenile trait (LJ) which delays flowering under short day conditions. Two LJ loci have been mapped to the same location on Gm04, J and E6. The objective of this research was to investigate the e6 allele in ‘Paranagoiana’ and determine if E6 and J are the same locus or linked loci. KASP markers showed that e6 lines did not have the j−1 allele of LJ PI 159925. A population fixed for E1 but segregating for E6, with e6 introgressed from Paranagoiana, showed single gene control for flowering and maturity under short days. Sequencing Glyma.04G050200, the J gene, with long amplification Taq found that the e6 line ‘Paranagoiana’ contains a Ty1-copia retrotransposon of ~10,000 bp, inserted within exon 4. PCR amplification of the cDNA of Glyma.04G050200 also showed differences between the mRNA sequences (presence of insertion in j−x). Hence, we conclude that the loci E6 and J are one locus and deem this new variation found in Paranagoiana as j−x.

Responses of Some Turkish Wheat Cultivars to Vernalization and Photoperiod

1988 ◽  
Vol 24 (2) ◽  
pp. 237-245
Author(s):  
Serpil Terzioğlu
Keyword(s):  
Bread Wheat ◽  
Normal Development ◽  
Photoperiodic Response ◽  
Reliable Information ◽  
Floral Initiation ◽  
Wheat Cultivars ◽  
Primary Shoot ◽  
Time Of Year ◽  
Short Days

SUMMARYThe vernalization and photoperiodic response of six locally adapted bread wheat cultivars grown under natural daylength conditions during the summer or winter months was examined in glasshouse experiments. The wheat was vernalized by chilling imbibed grains at 2 ± 1°C for 0, 15 or 45 days. Vernalization for 45 days followed by long summer days led to floral initiation in all cultivars within 28 days but vernalization for 0 or 15 days only led to floral initiation in one cultivar. Vernalization followed by long days reduced the time from transplanting to anthesis, resulting in early ear emergence. Vernalization followed by short days accelerated the development of all the cultivars, but normal development could also occur without vernalization at this time of year. Apical differentiation of the primary shoot and its length and development gave the most reliable information on the period of vernalization required.

scholarly journals Influence of daylength on vernalization of winter rye. 2. Continued experiments with short-day vernalization in winter rye.

1966 ◽  
Vol 14 (2) ◽  
pp. 89-102
Author(s):  
T.A. Hartman
Keyword(s):  
Day Treatment ◽  
Cold Treatment ◽  
Winter Rye ◽  
Optimum Duration ◽  
Short Day ◽  
Accelerate Development ◽  
Short Days

In vernalization trials with winter rye, short-day treatment prior to cold treatment was capable of inducing accelerated development and early ear emergence even when the temperature during the former treatment was 25 degrees C. Short days imposed during protracted cold treatments could also accelerate development provided that the optimum duration of short-day vernalization (about 14 days) was not exceeded. Results confirmed the assumption that cold vernalization and short-day vernalization were different processes. [See also F.C.A. 18: 1236].-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Floral Induction in the Short-Day Plant Chrysanthemum Under Blue and Red Extended Long-Days

2021 ◽  
Vol 11 ◽  
Author(s):  
Malleshaiah SharathKumar ◽  
Ep Heuvelink ◽  
Leo F. M. Marcelis ◽  
Wim van Ieperen
Keyword(s):  
Blue Light ◽  
Floral Induction ◽  
Sole Source ◽  
Solar Light ◽  
Growth Chamber ◽  
Flower Initiation ◽  
Dependent Manner ◽  
Led Light ◽  
Short Day ◽  
Short Days

Shorter photoperiod and lower daily light integral (DLI) limit the winter greenhouse production. Extending the photoperiod by supplemental light increases biomass production but inhibits flowering in short-day plants such as Chrysanthemum morifolium. Previously, we reported that flowering in growth-chamber grown chrysanthemum with red (R) and blue (B) LED-light could also be induced in long photoperiods by applying only blue light during the last 4h of 15h long-days. This study investigates the possibility to induce flowering by extending short-days in greenhouses with 4h of blue light. Furthermore, flower induction after 4h of red light extension was tested after short-days RB-LED light in a growth-chamber and after natural solar light in a greenhouse. Plants were grown at 11h of sole source RB light (60:40) in a growth-chamber or solar light in the greenhouse (short-days). Additionally, plants were grown under long-days, which either consisted of short-days as described above extended with 4h of B or R light to long-days or of 15h continuous RB light or natural solar light. Flower initiation and normal capitulum development occurred in the blue-extended long-days in the growth-chamber after 11h of sole source RB, similarly as in short-days. However, when the blue extension was applied after 11h of full-spectrum solar light in a greenhouse, no flower initiation occurred. With red-extended long-days after 11h RB (growth-chamber) flower initiation occurred, but capitulum development was hindered. No flower initiation occurred in red-extended long-days in the greenhouse. These results indicate that multiple components of the daylight spectrum influence different phases in photoperiodic flowering in chrysanthemum in a time-dependent manner. This research shows that smart use of LED-light can open avenues for a more efficient year-round cultivation of chrysanthemum by circumventing the short-day requirement for flowering when applied in emerging vertical farm or plant factories that operate without natural solar light. In current year-round greenhouses’ production, however, extension of the natural solar light during the first 11 h of the photoperiod with either red or blue sole LED light, did inhibit flowering.

Sign in / Sign up

Export Citation Format

Share Document