scholarly journals The Role of Leaves and Carbohydrates in Flowering of Protea cv. Lady Di

HortScience ◽  
2001 ◽  
Vol 36 (5) ◽  
pp. 905-908
Author(s):  
Audrey I. Gerber ◽  
Karen I. Theron ◽  
Gerard Jacobs

Inflorescence initiation in Protea cv. Lady Di (P. magnifica Link × P. compacta R. Br.) occurs predominantly on the spring growth flush when it is subtended by one or more previous growth flushes. Mature, over-wintering leaves are essential for induction of flowering in `Lady Di', and are also crucial to the early stages of inflorescence initiation and differentiation. Defoliation before elongation of the spring growth flush was complete prevented flowering, and shoots either remained vegetative or produced inflorescences that aborted. Levels of carbohydrates in the stem and leaves of overwintering shoots were low, and early growth and development of both the spring flush and inflorescence were, therefore, supported by current photosynthates from the mature leaves on the overwintering shoot. Likewise, reserve carbohydrates available in the flowering shoot were insufficient to account for the rapid increase in dry weight during the major portion of growth of the spring flush and inflorescence. This increase occurred after elongation of the spring flush was complete and was supported by current photosynthates from the leaves of the spring flush. Defoliation treatments that did not prevent inflorescence initiation had no effect on inflorescence development or on flowering time.

1975 ◽  
Vol 49 (4) ◽  
pp. 446-472 ◽  
Author(s):  
Carlos Manuel Peláez

This study analyzes the Brazilian experience as a case study in the role of banking in the early stages of economic growth and development.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1159g-1159
Author(s):  
Abdulrhman I. Al-hemaid ◽  
David S. Koranski

Petunia `Red Flash', Vinca `Little Blanch', Pansy `Magestic Giant Purple', and Impatien `Super Elfin Red' plugs were held in the greenhouse after they reached the saleable size in 200, 406, 512, and 800 for 1 to 3 weeks Pansy plugs were held in coolers at 40, 50, or 60F under fluorescent light for 16 hrs photoperiod for 1 to 3 weeks in 200, 406, 512, or 800 plug trays. All plants ware transplanted weekly and were grown in the greenhouse until flowering and data were collected. For plants bald in the greenhouse, plants were affected by transplanting time. As the holding time increased the final height, diameter, flower number, and fresh and dry weight of plants decreased. The flowering time was delayed by increase the holding time, regardless of plant variety, As cell size decreased, plant height, diameter, flower number, and fresh and dry weight decreased. For plants held in the coolers, the flowering time was delayed by the transplant time, regardless of cooler temperatures Plant quality was not affected by the treatment. The height, diameter, flowers number, and fresh and dry weight of plants showed a little effects by temperatures, cell size, and transplanting time.


1969 ◽  
Vol 58 (4) ◽  
pp. 393-405
Author(s):  
Teh-ling Chu ◽  
J. L. Serapión

The role played by leaves in the perception and inhibition of the flowering stimulus was studied through defoliation treatment in three sugarcane varieties. It was found that the expanding leaves (0 and —1) in the variety P.R. 980 appear to be most effective in producing a flowering stimulus. The mature leaves (+3 and +4) in the variety Cl 41-223 appear to produce a transmissible flowering inhibitor. Absence of the young leaves within the leaf spindle during a period critical to initiation of inflorescence primordia resulted in a significant reduction of flowering intensity in varieties N.Co. 310 and Cl 41-223, and a marked delay in the flowering time in N.Co. 310. Removal of these leaves during subsequent stages of inflorescence caused a somewhat depressive flowering response and a considerable delay in the flowering time of N.Co. 310. A late-initiating variety, Cl 41-223 appears to begin producing a floral stimulus around August 20, about 2 to 3 weeks later than that of the early-initiating variety N.Co. 310.


2000 ◽  
Vol 51 (1) ◽  
pp. 113 ◽  
Author(s):  
A. Liu ◽  
T. J. Ridsdill-Smith ◽  
D. C. Nicholas

Redlegged earth mite (Halotydeus destructor) causes feeding damage to some pulse species at the seedling stage. To quantify the effect of this damage on subsequent plant growth and development, an experiment was conducted in the glasshouse using yellow lupin, Lupinus luteus cv. Motiv, which is highly susceptible to the mites. After emergence, plants were infested with 0, 100, 150, and 250 mites/plant, collected from the field. Fourteen days after application, mites were removed. Damage to plants was estimated at seedling stage, flowering time, and maturity. At seedling stage (on Day 14), feeding damage scores to cotyledons and true leaves were greater at higher mite densities. Damaged plants produced fewer nodules, fewer lateral roots, and less dry weight than the control. On Day 35, severely damaged plants failed to recover and on the surviving plants, cotyledons and true leaves died earlier than on the plants without damage. On Day 78, when plants were flowering, the surviving plants produced fewer nodules and branches, and less dry weight per plant than the control. The flowering time of plants with the mite treatments was delayed by up to 6 days compared with the controls. The final shoot dry weight, pod number, seed number, and seed yield per pot were significantly reduced by the mite treatments. Feeding by H. destructor on seedlings of yellow lupin caused a reduction in seed yield of 58% at the highest mite density treatment. This significant economic loss needs to be confirmed under field conditions, but it signifies the need to develop appropriate control measures for this pest.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Annamalai Anandan ◽  
Chidambaranathan Parameswaran ◽  
Anumalla Mahender ◽  
Amaresh Kumar Nayak ◽  
Sampthamprajan Vellaikumar ◽  
...  

AbstractTo better understand the early response of genotypes to limited-phosphorus (P) conditions and the role of the phosphate transporter OsPHT1 gene family in the presence of PSTOL1, it is essential to characterize the level of tolerance in rice under limited-P conditions. In the present experiment, six rice genotypes were studied in three-way interactions [genotype (G) × phosphorus (P) × duration (D)] by comparing them at two instances (14 d and 28 d) under seven different concentrations of P (0.5‒10.0 ppm) in a hydroponic system. Trait differences and interactions of these traits were clearly distinguished among the various P rates. However, aboveground trait expression registered increased growth from 6.0 to 10.0 ppm of P. The major root-attributed traits in 0.5 ppm of P are significantly increased vis-à-vis 10 ppm of P. Analysis of variance displayed a significant difference between the genotypes for PSTOL1 and PHT1 expression. In low P, maximum root length with a shoot and root dry weight was observed in a new indigenous accession, IC459373, with higher expression of PSTOL1 than in Dular and IR64-Pup1 in 0.5 ppm of P at 14 d. Among the 13 PHT1 genes, OsPT1, OsPT2, OsPT6, and OsPT13 showed significant upregulation in IC459373, Dular, and IR64-Pup1. These results indicated that studying the expression levels of the PSTOL1 and PHT1 gene family at the early growth stages would be helpful in identifying superior donors to improve low-P tolerance and P-use efficiency in rice breeding programs.


1969 ◽  
Vol 22 (3) ◽  
pp. 523 ◽  
Author(s):  
D Bouma

In the early stages, boron deficiency had little effect on dry matter accumula-tion by the plant as a whole. Root growth, however, declined significantly and this was accompanied by an accumulation of dry matter in the leaves. At progressive stages of boron deficiency distribution of dry matter to new leaf tissue also became restricted. When plants already deficient in boron were transferred to solutions without boron, increases in dry weight of existing leaves were greater than for the corresponding plants transferred to complete solutions. However, the dry weight of leaves formed after the transfer increased at a much slower rate in the no-boron than in the complete solutions_


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1159G-1159 ◽  
Author(s):  
Abdulrhman I. Al-hemaid ◽  
David S. Koranski

Petunia `Red Flash', Vinca `Little Blanch', Pansy `Magestic Giant Purple', and Impatien `Super Elfin Red' plugs were held in the greenhouse after they reached the saleable size in 200, 406, 512, and 800 for 1 to 3 weeks Pansy plugs were held in coolers at 40, 50, or 60F under fluorescent light for 16 hrs photoperiod for 1 to 3 weeks in 200, 406, 512, or 800 plug trays. All plants ware transplanted weekly and were grown in the greenhouse until flowering and data were collected. For plants bald in the greenhouse, plants were affected by transplanting time. As the holding time increased the final height, diameter, flower number, and fresh and dry weight of plants decreased. The flowering time was delayed by increase the holding time, regardless of plant variety, As cell size decreased, plant height, diameter, flower number, and fresh and dry weight decreased. For plants held in the coolers, the flowering time was delayed by the transplant time, regardless of cooler temperatures Plant quality was not affected by the treatment. The height, diameter, flowers number, and fresh and dry weight of plants showed a little effects by temperatures, cell size, and transplanting time.


2016 ◽  
Vol 3 (2) ◽  
pp. 56-62
Author(s):  
R. Iskra ◽  
V. Vlizlo ◽  
R. Fedoruk

The results of our studies and the data of modern literature regarding the biological role of Cr(III) compounds in conditions of their application in the nutrition for pigs and cattle are discussed. The metabolic impact of Cr(III), coming from different sources – mineral and organic compounds, obtained by chemical synthesis or a nanotechnological method (chromium citrate), as well as in the form of biocomplexes from the cultural medium of Saccharomyces cerevisiae yeasts was analyzed. The metabolic connection between the impact of Cr(III) and the biosynthesis of some hormones – insulin, cortisol – as well as the sensitivity of some tissues and organs to the effect of chromium compounds was studied. A considerable part of the review material was dedicated to the metabolic effect of Cr(III) compounds on the reproductive function of pigs and cattle and their impact on the viability of the offspring and gametes of animals. The data about the stimulating effect of Cr(III) on the growth and development of the organism of piglets and calves, meat and milk performance of these species of animals are discussed. The relevance of dosing Cr(III) in the nutrition of pigs and cattle is highlighted.


2017 ◽  
Vol 7 (4) ◽  
pp. 30-34 ◽  
Author(s):  
O. A. Didur ◽  
Yu. L. Kulbachko ◽  
V. Y. Gasso

<p>The problem of transformation of natural landscapes resulted from the negative technogenic impact is highlighted. It is shown that mining enterprises are powerful anthropo-technical sources of organic and inorganic toxicants entering the environment. Their wastes pollute all components of the ecosystems and negatively influence human health by increasing a risk of disease. The nature of the accumulation of trace elements (Fe, Cu, Zn, Ni, Cd, and Pb) by invertebrate animals of various functional groups under conditions of anthropo-technogenic pressure was studied. The sample plots were located on self-overgrowing sites with ruderal vegetation located in the immediate vicinity of the Mangan ore-dressing and processing enterprise (Dnipropetrovsk region). It is quite naturally that among the studied biogenic microelements (Fe, Cu, Zn and Ni), the phyto-, zoo-, and saprophages in the investigated zone of technogenic pollution most actively accumulate Fe:<em> </em>22758, 17516 and 18884 mg/kg dry weight on average, respectively. There are significant differences (p ≤ 0.05) in the content of studied microelements between saprophages and phytophages. The saprophages accumulate such trace metals as Mn, Cu, Zn and Cd in high quantities, but Ni and Pb – in smaller ones. The saprophagous functional group of invertebrates is an active agent of detritogenesis, in the conditions of modern nature management it acts as a powerful element of ecosystem engineering (habitat transformation), the main ecological role of which is to modify the habitat of other soil biota. In addition, the saprophages fulfil their concentrating geochemical function. They actively participate in the most important soil biochemical process: the formation of humus, the migration of microelements along trophic chains, the biological cycle in general, and provide such supporting ecosystem services as increasing soil fertility and nutrient cycling.</p>


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