Growth and reproductive development of alfalfa as influenced by 2,3,5-triiodobenzoic acid

1981 ◽  
Vol 59 (3) ◽  
pp. 373-376 ◽  
Author(s):  
J. C. Phillips ◽  
D. O. Chilcote
Keyword(s):  
Branch Length ◽  
Reproductive Development ◽  
Day Length ◽  
Leaf Axil ◽  
Floral Initiation ◽  
Triiodobenzoic Acid ◽  
Total Branch Length ◽  
Alfalfa Leaf ◽  
Primary Stem ◽  
Axillary Branches

The plant regulator 2,3,5-triiodobenzoic acid (TIBA) at concentrations of 0, 10,50, 100, or200 ppm(0, 2 × 10−5, 1 × 10−4, 2 × 10−4,or4 × 10−4 M, respectively) was applied to leaves of alfalfa grown at 14-h day length, 12 000 μW cm−2, 20 °C day–16 °C night. The number of racemes per primary stem and on axillary branches was recorded daily for 34 days after TIBA application. Length of primary stems and branches and number of nodes and branches were determined 34 days after TIBA application.TIBA did not affect number of nodes or branches per primary stem, but at a concentration of 10 ppm it promoted the elongation of both primary stems and axillary branches and also raceme formation on both stems and branches. This resulted in a fivefold increase in total branch length per primary stem and a highly significant increase in total raceme production. These results may explain in part reported effects of TIBA on seed production of alfalfa and are also consistent with reported effects of TIBA on flowering and axillary bud development in several other legumes.The observation that two structures (branches and (or) racemes) may typically arise from an alfalfa leaf axil may be useful in understanding the phenomena of branching and floral initiation in this crop.

Day-length influence on reproductive development and tillering in ‘Fergus’ barley

1975 ◽  
Vol 53 (23) ◽  
pp. 2770-2775 ◽  
Author(s):  
D. T. Fairey ◽  
L. A. Hunt ◽  
N. C. Stoskopf
Keyword(s):  
Hordeum Vulgare ◽  
Reproductive Development ◽  
Tiller Number ◽  
Day Length ◽  
Floral Initiation ◽  
Internode Elongation ◽  
Spikelet Number ◽  
Hordeum Vulgare L ◽  
Initial Formation ◽  
Double Ridge

Effects of variation in day length on spikelet and tiller development were studied in a two-rowed barley, Hordeum vulgare L. cultivar ‘Fergus.’ Spikelet number and the length of the spikelet-forming phase increased with progressive reductions in day length from 24 to 12 h. However, increases in spikelet number were offset by abortion of spikelet primordia during spikelet differentiation and elongation of the stem internodes. Floral initiation occurred at all day lengths, but intemode elongation and heading were markedly delayed at 12 h. The cessation of spikelet initial formation and the beginning of internode elongation did not occur simultaneously in any day length. The latter began just before or at double ridge formation.Tiller numbers were highest at 12 h and progressively decreased in longer day lengths. Each plant produced four primary tillers at all day lengths, and differences in tiller number were accounted for by secondary and tertiary tiller production.

Environmental and Genetic Control of Reproduction in Danthonia caespitosa Populations

1978 ◽  
Vol 26 (3) ◽  
pp. 351 ◽  
Author(s):  
KC Hodgkinson ◽  
JA Quinn
Keyword(s):  
Floral Induction ◽  
Flag Leaf ◽  
Day Length ◽  
Herbarium Specimens ◽  
Floral Initiation ◽  
Inflorescence Development ◽  
Southern Limit ◽  
The North ◽  
Eastern Australia ◽  
Controlled Environments

Seedlings and older plants of five populations of Danthonia caespitosa from south-eastern Australia were grown in controlled environments and in a transplant garden to determine the effect of day length, temperature, and vernalization of floral initiation and inflorescence development. The populations were selected from widely separated sites which spanned the latitudinal range (31-42°S.) for the species and extended from a hot, semiarid environment in the north to a relatively cool and moist temperature environment in the south. Examination of herbarium specimens indicated that seed set could occur as early as mid September at the northern limit for the species and not before mid January at the southern limit (Tasmania). In a uniform transplant garden located at Deniliquin (latitude 35° 23′S.) plants from the northern site reached anthesis 4 weeks earlier than plants from southern sites. Controlled environment experiments revealed that D. caespitosa is a long-day plant. Northern populations required a 9 . 5 hr day length or longer for floral induction compared with 11 hr or longer for southern populations. The number of days in inductive conditions (outside, day length 13.5 hr) required for floral initiation was 5-7 for the three most northern populations and 21-25 days for the two southern populations. Inflorescence development (initiation to flag leaf stage) was considerably slower in southern populations. All but the most northern population responded to vernalization. Flowering was earlier in temperatures that were optimal for plant growth. At high temperatures (36/31°C day/night) flowering was not significantly delayed for the three most northern populations, but was for the two southern populations, and florets contained caryopses in only the three northern populations. These results suggest that in cool and moist temperate habitats reproduction of this species is programmed by day length and temperature effects on floral initiation and development to coincide with a predictable growing season, whereas in hot semiarid habitats this control is relaxed, which permits opportunistic reproduction whenever soil moisture and temperature permit growth.

Distribution of epicormic branches and foliage on Douglas-fir as influenced by adjacent canopy gaps

2018 ◽  
Vol 48 (11) ◽  
pp. 1320-1330
Author(s):  
John W. Punches ◽  
Klaus J. Puettmann
Keyword(s):  
Branch Length ◽  
Canopy Gaps ◽  
Douglas Fir ◽  
Canopy Gap ◽  
Tree Age ◽  
Gap Size ◽  
Terminal Bud ◽  
Total Branch Length ◽  
A Minor ◽  
Epicormic Branches

The influence of adjacent canopy gaps on spatial distribution of epicormic branches and delayed foliage (originating from dormant buds) was investigated in 65-year-old coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco). Sample trees were selected across a broad range of local densities (adjacent canopy gap sizes) from a repeatedly thinned stand in which gaps had been created 12 years prior to our study. Lengths and stem locations of original and epicormic branches were measured within the south-facing crown quadrant, along with extents to which branches were occupied by sequential (produced in association with terminal bud elongation) and (or) delayed foliage. Epicormic branches, while prevalent throughout crowns, contributed only 10% of total branch length and 2% of total foliage mass. In contrast, delayed foliage occupied over 75% of total branch length, accounted for nearly 39% of total foliage mass, and often overlapped with sequential foliage. Canopy gap size did not influence original or epicormic branch length or location. On original branches, larger gaps may have modestly negatively influenced the relative extent of sequential foliage on branches and (or) slightly positively influenced delayed foliage mass. Delayed foliage appears to contribute substantially to Douglas-fir crown maintenance at this tree age, but canopy gap size had a minor influence, at least in the short term.

Chondrilla juncea L. in Australia. I. Some factors affecting flowering

1966 ◽  
Vol 17 (4) ◽  
pp. 457 ◽  
Author(s):  
EG Cuthbertson
Keyword(s):  
Dark Period ◽  
Critical Factor ◽  
Photoperiodic Response ◽  
Day Length ◽  
Floral Initiation ◽  
Factors Affecting ◽  
Two Stages ◽  
Relationship Of ◽  
The Relationship ◽  
Chondrilla Juncea

The interaction between day length and vernalization, and the influence of growth temperature on flowering, in Chondrilla juncea L. (skeleton weed) have been studied. Bolting and floral initiation in unvernalized plants were suppressed in a 9-hr photoperiod. Increasing the photoperiod beyond 12 hr resulted in progressively earlier bolting and floral initiation, the critical day length being slightly less than 12 hr. Interrupting a 16-hr dark period by 1 hr of low-intensity light near its centre caused some plants to flower. Prior vernalization further accelerated bolting and flowering and reduced the dependence on day length. Vernalization, however, was not an obligate requirement. Post-bolting development was favoured by high temperatures. It was concluded that flowering in skeleton weed occurred in two stages. The first or photo-inductive phase was controlled by at least two partial processes. These were vernalization and a photoperiodic response in which the length of the dark period was the critical factor. The relationship of the flowering processes to the distribution of skeleton weed in Australia is discussed briefly.

Selection of flood-resistant and susceptible seedlings of Populustrichocarpa Torr. & Gray

1988 ◽  
Vol 18 (2) ◽  
pp. 271-275 ◽  
Author(s):  
Barbara A. Smit
Keyword(s):  
Leaf Area ◽  
Marked Reduction ◽  
Branch Length ◽  
Stomatal Resistance ◽  
Growth And Survival ◽  
Seed Collection ◽  
Individual Leaf ◽  
Total Branch Length ◽  
Collection Sites ◽  
Selection Of

To identify Populustrichocarpa plants with contrasting levels of resistance to flooding, seedlings from five diverse riparian sites were evaluated for growth and survival under flooding conditions. All seedlings survived 6 or 8 weeks of flooding. Total branch length and leaf number were reduced in all flooded plants relative to nonflooded controls. There was also a marked reduction in individual leaf area and increased stomatal resistance of flooded plants compared with nonflooded controls. Growth of flooded and nonflooded plants was highly variable within populations and no significant trends were found among populations. Therefore differential responses to flooding can be selected for within any of the seed collection sites. Plants that were rated as particularly resistant or susceptible fo flooding were selected for further study.

OVERWINTERING SPRUCE BUDWORM ON BLACK SPRUCE: SAMPLE-UNIT SIZE AND POPULATION DISTRIBUTION

1985 ◽  
Vol 117 (4) ◽  
pp. 395-399 ◽  
Author(s):  
Daniel J. Robison ◽  
Lawrence P. Abrahamson ◽  
Miroslaw M. Czapowskyj ◽  
Edwin H. White ◽  
Douglas C. Allen
Keyword(s):  
Population Distribution ◽  
Black Spruce ◽  
Branch Length ◽  
Spruce Budworm ◽  
Unit Size ◽  
Optimum Size ◽  
Sample Unit ◽  
Larval Distribution ◽  
Total Branch Length ◽  
Branch Distribution

AbstractOptimum size of a sample unit and within-branch distribution of overwintering spruce budworm were determined for black spruce in northern Maine. No significant differences in sample reliability were found between whole-branch and 45-cm branch-tip samples. Larval distribution on branches varied with total branch length and a model was developed to estimate the whole-branch population from a 45-cm branch tip. Use of a 45-cm branch-tip sample unit is recommended because it is biologically and statistically valid and reduces sampling costs.

scholarly journals Impact of Different Phytohormones on Morphology, Yield and Cannabinoid Content of Cannabis sativa L.

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 725 ◽  
Author(s):  
Lisa Burgel ◽  
Jens Hartung ◽  
Daniele Schibano ◽  
Simone Graeff-Hönninger
Keyword(s):  
Plant Height ◽  
Plant Architecture ◽  
Biomass Yield ◽  
Cannabis Sativa ◽  
Unit Area ◽  
Branch Length ◽  
Specific Level ◽  
Total Plant ◽  
The Impact ◽  
Axillary Branches

The impact of exogenously applied plant growth regulators (PGR), 1-naphthalenaecetic acid (NAA), 6-benzylaminopurine (BAP), and a mixture of both (NAA/BAP-mix), was investigated in regard to plant height, length of axillary branches, number of internodes, biomass yield and cannabinoid content of three different phytocannabinoid-rich (PCR) Cannabis genotypes. The results showed that total plant height was significantly reduced under the application of NAA (28%), BAP (18%), and NAA/BAP-mix treated plants (15%). Axillary branch length was also significantly reduced by 58% (NAA) and 30% (NAA/BAP-mix). BAP did not significantly reduce the length of axillary branches. The number of internodes was reduced by NAA (19%), BAP (10%), and the NAA/BAP-mix (14%) compared to the untreated control. NAA application influenced the plant architecture of the tested cv. KANADA beneficially, resulting in a more compact growth habitus, while inflorescence yield (23.51 g plant−1) remained similar compared to the control (24.31 g plant−1). Inflorescence yield of v. 0.2x and cv. FED was reduced due to PGR application while cannabinoid content remained stable. Overall, the application of PGR could be used on a genotype-specific level to beneficially influence plant architecture and optimize inflorescence yield per unit area and thus cannabinoid yield, especially in the presence of space limitations under indoor cultivation.

scholarly journals On Asymptotics of the Beta Coalescents

2014 ◽  
Vol 46 (2) ◽  
pp. 496-515 ◽  
Author(s):  
Alexander Gnedin ◽  
Alexander Iksanov ◽  
Alexander Marynych ◽  
Martin Möhle
Keyword(s):  
Asymptotic Expansions ◽  
Branch Length ◽  
Wasserstein Distance ◽  
Stable Limit ◽  
Initial Number ◽  
Stable Law ◽  
Total Branch Length ◽  
Coalescent Tree ◽  
Number Of Particles

We show that the total number of collisions in the exchangeable coalescent process driven by the beta (1, b) measure converges in distribution to a 1-stable law, as the initial number of particles goes to ∞. The stable limit law is also shown for the total branch length of the coalescent tree. These results were known previously for the instance b = 1, which corresponds to the Bolthausen-Sznitman coalescent. The approach we take is based on estimating the quality of a renewal approximation to the coalescent in terms of a suitable Wasserstein distance. Application of the method to beta (a, b)-coalescents with 0 < a < 1 leads to a simplified derivation of the known (2 - a)-stable limit. We furthermore derive asymptotic expansions for the moments of the number of collisions and of the total branch length for the beta (1, b)-coalescent by exploiting the method of sequential approximations.

An upper limit for spikelet number per ear in wheat as controlled by photoperiod

1971 ◽  
Vol 22 (4) ◽  
pp. 537 ◽  
Author(s):  
HM Rawson
Keyword(s):  
Day Length ◽  
Floral Initiation ◽  
Wheat Cultivars ◽  
Spikelet Number ◽  
Upper Limit ◽  
Long Duration ◽  
Concurrent Development ◽  
Double Ridge

In seven diverse wheat cultivars, spikelet number per main ear as influenced by day length was approaching a maximum at 30. Differences in final spikelet number between treatments and cultivars arose from differences in double ridge number at floral initiation (range from 3 to 12), in the rate of production of spikelet primordia (from 0.60 to 1.78 spikelets per day), and in the duration of production. In cultivars with a high final spikelet number, fertility towards the tip of the ear was linked with the establishment of many spikelet primordia before the appearance of glume initials and with the concurrent development of spikelets. Development of the ear of Triticale was also sensitive to day length, with the formation of up to 50 spikelets under an 8 hr photoperiod. The large number of spikelets was achieved by long duration and high rates of production, which were in excess of those for wheat under corresponding photoperiods. Suggestions are made regarding the production of more spikelets per ear in wheat.

scholarly journals Photoperiodic Flowering Response of Essential Oil, Grain, and Fiber Hemp (Cannabis sativa L.) Cultivars

2021 ◽  
Vol 12 ◽  
Author(s):  
Mengzi Zhang ◽  
Steven L. Anderson ◽  
Zachary T. Brym ◽  
Brian J. Pearson
Keyword(s):  
Essential Oil ◽  
Environmental Conditions ◽  
Cannabis Sativa ◽  
Day Length ◽  
Tropical Region ◽  
Floral Initiation ◽  
Flowering Response ◽  
Photoperiodic Flowering ◽  
Critical Photoperiod ◽  
Different Sources

Cultivation of hemp (Cannabis sativa L.) in tropical and subtropical regions can be challenging if the flowering behavior of a given cultivar is unknown, poorly understood, or not accurately selected for the photoperiod. Identifying cultivars adapted to local environmental conditions is key to optimizing hemp vegetative and flowering performance. We investigated the effects of varying light cycles in regulating extension growth and flowering response of 15 essential oil and 12 fiber/grain hemp cultivars both indoors and outdoors. Plants were subjected to 11 photoperiods in the controlled rooms ranging from 12 to 18 h, and natural day length in the field. The critical photoperiod threshold was identified for seven essential oil cultivars and two fiber/grain cultivars. “Cherry Wine-CC,” “PUMA-3,” and “PUMA-4” had the shortest critical day length between 13 h 45 min and 14 h. The flowering of essential oil cultivars was generally delayed by 1–2 days when the photoperiod exceeded 13 h compared with 12 h, and flowering was further delayed by 7–8 days when the photoperiod exceeded 14 h. In fiber/grain cultivars, flowering was generally delayed by 1–3 days when the day length exceeded 14 h. Flowering for most essential oil cultivars was delayed by 5–13 days under a 14-h photoperiod compared with 13 h 45 min, suggesting a photoperiod difference as little as 15 min can significantly influence the floral initiation of some essential oil cultivars. Cultivars represented by the same name but acquired from different sources can perform differently under the same environmental conditions, suggesting genetic variation among cultivars with the same name. Average days to flower of fiber/grain cultivars was correlated with reported cultivar origin, with faster flowering occurring among northern cultivars when compared with southern cultivars. Plant height generally increased as the day length increased in essential oil cultivars but was not affected in fiber/grain cultivars. In addition, civil twilight of ~2 μmol·m−2·s−1 was discovered to be biologically effective in regulating hemp flowering. Collectively, we conclude that most of the essential oil cultivars and some southern fiber/grain cultivars tested express suitable photoperiods for tropical and sub-tropical region cultivation.

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