Gibberellins and sorghum development

1988 ◽  
Vol 66 (6) ◽  
pp. 1101-1106 ◽  
Author(s):  
Stewart B. Rood ◽  
Darla M. Bruns ◽  
Susan J. Smienk
Keyword(s):  
Vegetative Growth ◽  
High Performance ◽  
Shoot Growth ◽  
Developmental Stages ◽  
Shoot Elongation ◽  
Field Trials ◽  
Reversed Phase ◽  
Height Growth ◽  
Forage Production ◽  
Sorghum Bicolor L

Sorghum (Sorghum bicolor (L.) Moench) hybrids adapted for grain (cv. Northrup King X8102) or forage production (cv. Pride PF70) were grown in field trials at Lethbridge, Alta., Canada, and shoot cylinders containing the apical meristems were harvested at various developmental stages for analyses of endogenous gibberellin-like (GA-like) substances. Extracts were purified and chromatographed on sequential SiO2 partition columns and C18 reversed-phase high-performance liquid chromatography, and GA-like substances were detected and quantified by the cv. Tan-ginbozu dwarf rice microdroop assay. Concentrations of GA-like substances in the shoots were higher during vegetative growth than during shoot elongation or panicle elongation and the pattern of declining concentration of GA-like substances was observed for both hybrids over both field seasons. The qualitative distribution of GA-like substances was generally similar across hybrids and developmental stages, with a GA19-like substance accounting for about 60% of the total GA-like activity (GA19 is a native GA of sorghum). The exogenous application of GA3 promoted height growth and inhibited tillering, with maximal effects occurring when application was early, during rapid vegetative growth. Applications of GA3 subsequent to panicle initiation promoted panicle elongation but did not alter the time of anthesis. These results on endogenous GA concentration and response to exogenous GA3 application suggest a role for endogenous GAs in the control of shoot growth and development in sorghum.

scholarly journals Controlling dietary cation-anion differences in forages by chloride fertilisation

2020 ◽  
Vol 29 (1) ◽  
Author(s):  
Lars Nesheim ◽  
Olav Martin Synnes ◽  
Arvid Steen ◽  
Anne Langerud ◽  
Anne Kjersti Bakken
Keyword(s):  
Dairy Cows ◽  
Developmental Stages ◽  
Field Trials ◽  
Reed Canary Grass ◽  
Forage Production ◽  
Meadow Fescue ◽  
Milk Fever ◽  
Western Norway ◽  
Canary Grass ◽  
The Ideal

Rations with low to negative dietary cation-anion difference (DCAD) given to dairy cows before calving reduce the risk of hypocalcaemia (milk fever). Different strategies for increasing forage DCAD were investigated in field trials in Central and Western Norway. Fertilisation with 70, 140 or 210 kg Cl per hectare as calcium chloride and low supply rates of K reduced DCAD in forage harvested at late developmental stages in spring growth of timothy and meadow fescue. The ideal negative DCAD was only attained on soils very low in plant available K. Timing (spring versus late spring) and source of Cl (CaCl2 versus MgCl2) were of no importance for the result. When pure stands of seven grasses were fertilised in spring either without chloride or with 140 kg chloride per hectare, the lowest values of DCAD after chloride fertilisation were found in perennial ryegrass and reed canary grass. By comparison, cocksfoot had equally high or higher Cl concentrations in its tissues, but accumulated more K, and seemed to be poorly suited for low DCAD forage production. It was concluded that Cl fertilisation is a more efficient means of controlling DCAD than sward species composition.

Response of yellow poplar (Liriodendrontulipifera L.) seedling shoot growth to low concentrations of O3, SO2, and NO2

1984 ◽  
Vol 14 (1) ◽  
pp. 150-153 ◽  
Author(s):  
M. J. Mahoney ◽  
J. M. Skelly ◽  
B. I. Chevone ◽  
L. D. Moore
Keyword(s):  
Shoot Growth ◽  
Dry Weight ◽  
Shoot Elongation ◽  
Height Growth ◽  
Yellow Poplar ◽  
Shoot Height ◽  
Low Concentrations ◽  
Highly Correlated

Six-week-old yellow poplar (Liriodendrontulipifera L.) seedlings from one half-sib family were exposed to various combinations of 0.07 ppm O3, 0.06 ppm SO2, and 0.10 ppm NO2 6 h daily for 35 consecutive days. Ozone and SO2 alone did not suppress total shoot elongation compared with control seedlings after the 5-week fumigation period, whereas the combinations of O3 + SO2, SO2 + NO2, or O3 + SO2 + NO2 significantly reduced total shoot height 51, 64, and 51%, respectively. Of the pollutant combinations, SO2 + NO2 most severely inhibited the rate of height growth with this effect initially occurring after only 2 weeks of fumigation. The dry weight of seedlings exposed to O3 + SO2, SO2 + NO2, or O3 + SO2 + NO2 were significantly less than plants exposed to no pollutants, O3, or SO2. Total shoot height growth was highly correlated with seedling dry weight (r = 0.97)

SOME EFFECTS OF ARTIFICIAL DEFOLIATION ON THE GROWTH OF JACK PINE (PINUS BANKSIANA LAMB.)

1962 ◽  
Vol 40 (2) ◽  
pp. 273-280 ◽  
Author(s):  
L. C. O'Neil
Keyword(s):  
Relative Efficiency ◽  
Pinus Banksiana ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Jack Pine ◽  
Height Growth ◽  
Appreciable Effect ◽  
Normal Height ◽  
Pine Sawfly ◽  
Reduced Height

Young jack pine (Pinus banksiana Lamb.) were defoliated manually to measure the effects of defoliation on growth of this species, and to determine the relative efficiency of foliage of different ages with respect to growth. The removal of 2-year-old or 3-year-old foliage had no appreciable effect on tree growth, but their joint removal reduced height growth. Height growth was also reduced by the removal of 1-year-old foliage. Current foliage was found essential for the maintenance of normal height, diameter, and shoot growth; in addition, its removal induced high bud mortality, the production of profuse adventitious growth, and a reduction in the rate of shoot elongation. Trees deprived of all but current foliage showed marked reductions in height, diameter, and shoot growth. Complete defoliation resulted in tree death shortly thereafter. Growth reductions resulting from some of the treatments approximated that following defoliation by the Swaine jack-pine sawfly (Neodiprion swainei Midd.). Also, the present results are compared with those obtained by several other workers in this field.

Interaction between gibberellin A4/7 and root-pruning on the reproductive and vegetative process in Douglas-fir. II. Effects on shoot elongation and its relationship to flowering

1985 ◽  
Vol 15 (2) ◽  
pp. 348-353 ◽  
Author(s):  
J. E. Webber ◽  
S. D. Ross ◽  
R. P. Pharis ◽  
J. N. Owens
Keyword(s):  
Synergistic Effect ◽  
Vegetative Growth ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Douglas Fir ◽  
Threshold Concentration ◽  
Root Pruning ◽  
Flowering Response ◽  
Seed Cone ◽  
Female Flowering

Shoot elongation and female flowering response were assessed for gibberellin A4/7 (GA4/7) and root-pruning (RP) treatments in 9- and 10-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings of families with good- and poor-flowering histories. In families with a poor-flowering history, stem injections of GA4/7 significantly enhanced elongation of third-whorl terminal shoots but produced no flowering response. In families with a good-flowering history, GA4/7 treatment had no effect on shoot elongation but did result in a significant increase in seed-cone buds. In contrast, root-pruning significantly retarded shoot growth in families with both good- and poor-flowering histories and was also the single most effective treatment for enhancing flowering. Combined, GA4/7 plus RP had a synergistic effect on flowering and GA4/7 partially overcame the inhibition of shoot growth caused by RP alone. These results are consistent with a hypothesis that exogenous and endogenous gibberellins are used preferentially for vegetative growth processes, with increased flowering occurring only after a threshold concentration of effector gibberellins is reached.

Effects of chilling and photoperiod on dormancy release of container-grown loblolly pine seedlings

1983 ◽  
Vol 13 (6) ◽  
pp. 1265-1270 ◽  
Author(s):  
Melvin P. Garber
Keyword(s):  
Loblolly Pine ◽  
Vegetative Growth ◽  
Shoot Growth ◽  
Height Growth ◽  
Broad Temperature Range ◽  
Dormancy Release ◽  
Chilling Requirement ◽  
Seedling Mortality ◽  
Pine Seedlings ◽  
Chilling Temperatures

Loblolly pine (Pinustaeda L.) seedlings, which set bud in fall, required exposure to chilling temperatures before growth could resume under a 10- or 12-h photoperiod; whereas a 14-h photoperiod partially substituted for the chilling requirement. A 10- to 14-h photoperiod, however, did not affect the rate of budbreak once the chilling requirement was satisfied. A broad temperature range (0 – 12 °C) was equally effective in satisfying the chilling requirement. In situations where subfreezing temperatures were sufficient to decrease the extent of shoot growth or result in seedling mortality, the rate of budbreak for surviving seedlings was not affected. Exposure to low but above freezing temperatures beyond that necessary to satisfy the chilling requirement for budbreak resulted in increased height growth. Chilling temperatures apparently were involved both in ameliorating bud dormancy and promoting vegetative growth.

scholarly journals 225 Prohexadione-Ca: Reduction in Vegetative Growth and Pruning of Apple Trees

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 481A-481 ◽  
Author(s):  
J.R. Evans ◽  
J.A. Balles ◽  
B.A. Brinkman ◽  
V.E. Harris ◽  
J.D. Helm ◽  
...  
Keyword(s):  
Vegetative Growth ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Application Rate ◽  
Growth Reduction ◽  
Apple Trees ◽  
Positive Effects ◽  
Enhanced Resistance ◽  
Prohexadione Calcium ◽  
Made In

Prohexadione-Ca (BAS 12511W or Apogee™ Plant Growth Regulator) acts within a plant by blocking the biosynthesis of growth-active gibberellin. The result is decreased cell and shoot elongation; thus, vegetative growth in apple trees can be reduced. Air blast applications of prohexadione calcium were made in the Spring 1998 in commercial orchards. Application rate was 125 ppm a.i. applied twice beginning at 5 to 12 cm of new shoot growth. Reduction of shoot growth averaged 45% across locations. As a result of reduced vegetative growth, dormant pruning was reduced. In total, significant benefits to the grower included reduced pruning costs in addition to other positive effects such as improved light penetration and enhanced resistance to some pathogens. Research will continue with the effect of prohexadione-Ca on pruning in multiple year studies.

scholarly journals ‘D’Anjou’ Pear Shoot Growth and Return Bloom, but Not Fruit Size, Are Reduced by Prohexadione-Calcium

HortScience ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 180-187 ◽  
Author(s):  
Todd C. Einhorn ◽  
Mateus S. Pasa ◽  
Janet Turner
Keyword(s):  
Vegetative Growth ◽  
Shoot Growth ◽  
Fruit Size ◽  
Growth Control ◽  
Shoot Elongation ◽  
Early Spring ◽  
Internodal Length ◽  
Fruit Number ◽  
Return Bloom ◽  
Prohexadione Calcium

Prohexadione-calcium (P-Ca) was applied to ‘Anjou’ pear (Pyrus communis L.) trees in the lower and upper Hood River Valley (HRV), Oregon, to determine its effectiveness for managing the excessive vigor of ‘Anjou’ under different growing climates. Vegetative growth and development (weekly shoot growth rate, total annual extension growth, number of initiated shoots, internodal length, and number of nodes), yield (fruit number and fruit size), and return bloom dynamics were evaluated between 2010 and 2013. P-Ca consistently reduced shoot elongation by ≈40% in all years and at both sites when doses of 250 ppm were applied in early spring (i.e., ≈5 cm of annual shoot extension) compared with untreated trees. Shorter shoots were the result of both reduced internodal growth and fewer nodes. In the cooler, upper HRV, a single P-Ca application controlled shoot elongation for the entire season, but in the warmer, lower HRV, a second flush of growth was generally observed ≈60 days after the first application. A subsequent P-Ca application (250 ppm) provided added growth control in some instances. Yield was unaffected by P-Ca the season of application; however, in one year, an increase in fruit number indirectly led to reduced fruit size; otherwise, fruit size was unaffected by P-Ca. Postharvest fruit quality was not influenced substantially by P-Ca. Return bloom, however, was consistently reduced by P-Ca. Return yield, the year after P-Ca application (recorded in 2013 only), was reduced in proportion to the decrease in return bloom relative to untreated trees. In 2012, ethephon was also evaluated, alone or in combination with P-Ca. When applied on its own either once (150 ppm, 5-cm growth), or twice [150 ppm, 5-cm growth; 300 ppm, 57 days after full bloom (DAFB)], ethephon did not affect vegetative growth or yield components but did improve return bloom and return yield relative to other treatments; however, when combined with P-Ca, ethephon did not reverse reductions in return bloom or return yield induced by P-Ca. The most effective ethephon treatment for promoting flowering and return yield (300 ppm, 57 DAFB) was not tested in combination with P-Ca. We conclude that P-Ca is an effective tool for controlling vigor of ‘Anjou’ trees, but the decrease in return bloom requires additional investigation. Further work testing combinations of ethephon and P-Ca are warranted to optimize growth and productivity of ‘Anjou’ trees.

Development and Validation of A Reversed Phase-High Performance Liquid Chromatography Method for the Quantitative Estimation of Ramipril Drug Content from Formulated Dosage Form

2016 ◽  
Vol 6 (3) ◽  
Author(s):  
Raju Chandra ◽  
Manisha Pant ◽  
Harchan Singh ◽  
Deepak Kumar ◽  
Ashwani Sanghi
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Active Ingredient ◽  
High Performance ◽  
Limit Of Detection ◽  
Quantitative Estimation ◽  
Reversed Phase ◽  
Uv Detector ◽  
Chromatography Method ◽  
Drug Content

A reliable and reproducible reversed-phase high performance liquid chromatography (RP-HPLC) was developed for the quantitative determination of Remipril drug content from marketed bulk tablets. The active ingredient of Remipril separation achieved with C18 column using the methanol water mobile phase in the ratio of 40:60 (v/v). The active ingredient of the drug content quantify with UV detector at 215 nm. The retention time of Remipril is 5.63 min. A good linearity relation (R2=0.999) was obtained between drug concentration and average peak areas. The limit of detection and limit of quantification of the instrument were calculated 0.03 and 0.09 µg/mL, respectively. The accuracy of the method validation was determined 102.72% by recoveries method.

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