Photosynthate allocation in Pinustaeda. II. Seasonal aspects of photosynthate allocation to different biochemical fractions in shoots

1980 ◽  
Vol 10 (3) ◽  
pp. 338-347 ◽  
Author(s):  
Hsu-Ho Chung ◽  
Robert L. Barnes

Research was conducted to study (1) seasonal changes in tissue composition and (2) dynamic allocation of photosynthate to different biochemical fractions in growing shoots of the current and previous years of 15-year-old loblolly pine (Pinustaeda L.). As the growing season progressed, the shoots increased rapidly in total biomass; however, old needles formed in the previous year lost dry weight. The most striking biochemical change was a rapid decrease in starch content of old needles early in the growing season. Soluble sugars and organic acids in old needles also decreased slightly. Contents of biochemical constituents generally increased in current axes and needles as the organs grew and increased in weight, although there were decreases in organic acid contents of current axes early in the growing season. Formation of nonlabile major constituents (cellulose, hemicelluloses, lignin, and protein) in current-year shoots proceeded at different rates. These rates were interpreted in terms of aspects of shoot growth and development. Seasonal allocation of photosynthates into biochemical constituent fractions in current year growth flushes was calculated. Results suggested that photosynthates were allocated to constituents of different functional categories (metabolism, storage, structure, and protection) at different times of the growing season in such a way that structural growth was of first priority. Thus, allocation of photosynthates to structural growth early in the season enables branches to compete for favorable growing conditions.

HortScience ◽  
1999 ◽  
Vol 34 (7) ◽  
pp. 1279-1285 ◽  
Author(s):  
D. Bradley Rowe ◽  
Frank A. Blazich ◽  
Robert J. Weir

Hedged stock plants of four full-sib families [27-2 × 27-5, 27-3 × 27-1, 27-2 × 27-1, and 27-6 × 27-1 (designated B, G, R, and W)] of loblolly pine (Pinus taeda L.) were fertilized daily with a complete nutrient solution containing N at 10, 25, 40, 55, or 70 mg·L–1. In May, terminal softwood stem cuttings were taken and placed under intermittent mist. Families were combined to form composite poor-rooting (BR) and good-rooting (GW) families. At 0, 3, 6, 9, and 12 weeks after sticking, cuttings were evaluated for rooting and analyzed for mineral nutrient and carbohydrate content. Percent rooting by week 12 for cuttings from stock plants receiving N between 25 to 70 mg·L–1 was 28% to 33%, whereas significantly fewer (17%) cuttings from plants receiving 10 mg·L–1 had rooted. By week 12, 98% of cuttings taken from stock plants receiving N at 10 mg·L–1 were alive, while significantly fewer (81% and 82%) of the more succulent cuttings receiving 55 and 70 mg·L–1, respectively, had survived. Nearly all increases in cutting height occurred within the first 3 weeks. In contrast, top dry weight increased steadily throughout the experiment. There were no significant differences in rooting between the two composite families until week 12, when 32% of cuttings from family GW had rooted compared with 24% for family BR. Survival of cuttings was greater for the poor-rooting family (BR) (94%) than for the good-rooting family (GW) (82%) after 12 weeks. Levels of total nonstructural carbohydrates (TNC) and individual soluble sugars were initially higher in cuttings taken from stock plants that received higher rates of N, whereas the reverse was true for starch content. With the exception of sucrose, content of TNC and soluble carbohydrates generally increased over time. Starch was nearly depleted by week 3, but had increased by weeks 6 and 9. No correlation was found between TNC: N ratios and rooting percentage. Family GW contained greater quantities of myo-inositol, glucose, fructose, sucrose, total soluble carbohydrates (TSC), and TNC than did family BR. Mineral nutrient content was generally greater in cuttings taken from stock plants that received higher rates of N; these cuttings also maintained higher levels throughout the 12-week rooting period. As with the soluble carbohydrates, the good-rooting composite family (GW) contained greater amounts of all mineral nutrients than did the poor-rooting family BR.


Author(s):  
N.S. Kozhushko ◽  
M.M. Sakhoshko ◽  
M.G. Bashtovyi ◽  
D.V. Smilyk ◽  
V.I. Avramenko ◽  
...  

According to statistic evaluation of the manifestation of signs of the economic suitability of state sort resources of 2019 registration potatoes when growing it in different agro-climatic conditions, a significant advantage of influence of the forest-steppe conditions was determined. Compared to Polesia the increase of yield rose for 4.1 t/ha or 18 % (НІР05 = 2.18, Ffact= 12.65 > F05 = 4.22) and the amount of trade potato for 22.72 ha or 20 % (Ffact = 58.87). There is also a tendency to increase the number of starch from unit of area for – 17 % and the total consumer properties for – 8 %.  However, there is a significant difference in the reduction of storability of products by 45 % and the lack of it’s resistance to macrosporiosis and late blight. It was proved that the yield of varieties for cultivation in the polesia zone by 25.7 % depended on the duration of the growing season (Ffact = 4.14 > F05  = 0.06). The relationship between yield and starch of potatoes in Polesia zone varieties  was determined – 23.6 % and in forest-steppe – 17.3 % and starch collection, respectively, 33.6 % and 28.0 %. The dependence of storability of potato which grew in the polesia zone and in forest-steppe from the amount of starch for 15 % was mathematically proved (Ffact = 2.11 > F05 = 0.17) і 11.3 % (Ffact = 1.52 > F05 = 0.24); the dependence of storability on the duration of the growing season in the Forest-Steppe conditions was confirmed(Ffact = 0.66 > F05  = 0.43). In addition, the 12 % of tasting grade of the Forest-Steppe varieties depended on the starch content amount (Ffact = 1.65 > F05 = 0.22). According to the results of the regression analysis, mathematical models have been developed to predict yields, culinary and consumer properties, and the storability of new potato varieties under different growing conditions. The project of a conveyor for the consumption of fresh product in summer  period with the involvement of varieties of early ripeness in the Forest-Steppe was presented: 80 days after planting – Sanibel, 90 days after planting – Medison, Paroli, 95 days after planting – Bazalia, Bernina, 100 days after planting – Donata, in the Polesia zone ‒ 80 days after planting – Sanibel, 90 days after planting – Paroli, 95 days after planting –Bazalia, 100 days after planting – Medison, Bernina, Donata. By distribution of varieties by predicted high content of phytonutrients there were bred varieties with red skin and creamy flesh – Bazalia and Sanibel, by high content with yellow flesh – Baltic Rosa and moderate content with white flesh – Oleksandrit, Fotynia, Ricarda. Introduction of new varieties with certain high adaptive potential of storability and content of bioactive compounds in potatoes will provide growth of potato production in the conditions of the northeast forest-steppe and increase its competitiveness in the domestic and foreign markets and will solve the problem of year-round consumption of fresh quality products.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 454c-454
Author(s):  
Anil P. Ranwala ◽  
Beth Hardin ◽  
William B. Miller

The energy and carbon needs for early shoot growth in tulips are mainly provided by reserve carbohydrates in bulbs. The cold-treatment of bulbs before greenhouse forcing enhances the breakdown and remobilization of reserve carbohydrates in bulb scales, and is necessary for proper shoot growth and flowering in tulips. Tulip bulbs are known to contain both starch and fructans as reserve carbohydrates. We evaluated several extraction solvents, including ethanol and distilled water, and several extraction temperatures to accurately determine the amounts of different types of non-structural carbohydrates in tulip bulb scales. Extraction with distilled water resulted in excessive solubilization of starch. For example, extraction at 70 °C solubilized more than 80% of starch to glucan polymers. On the other hand, 80% ethanol at 70 °C extracted all soluble sugars including fructans with no apparent solubilization of starch. The changes in non-structural carbohydrates in the outermost bulb scale of tulip (Tulipa gesneriana L. `Frankfurt') during 12 weeks of cooling at 8.8 °C followed by 5 weeks of greenhouse forcing were determined. Starch was the major carbohydrate in bulb scales consisting of ≈70% of the dry weight at the beginning of cold treatment. Starch content per scale decreased slightly during cold treatment, but rapidly after transferring to greenhouse. Sucrose and soluble fructan content per scale increased during cold treatment, then decreased after transferring to greenhouse. Glucose content per scale remained fairly constant during cooling and greenhouse forcing, while fructose content increased in the greenhouse.


1980 ◽  
Vol 10 (3) ◽  
pp. 348-356 ◽  
Author(s):  
Hsu-Ho Chung ◽  
Robert L. Barnes

Using data on CO2 exchange, growth, and biochemical composition, an approach was developed to calculate the seasonal production, consumption, and surplus of photosynthate in shoots of loblolly pine (Pinustaeda L.). The amounts of CO2 released and of glucose substrate required in biosynthesis of shoot biomass over the growing season were also calculated. Individual growth flushes of different age-classes, as well as of an entire 1-year-old branch unit, ofPinustaeda were used as bases for calculations.Substrate requirements and CO2 production were relatively constant throughout the growing season. Within the whole 1-year-old branch unit, 63% of the photosynthate production was supplied by the two growth flushes of the previous year. Growth of the current year's shoot represented the major consumption of photosynthate, and this made up 66% of the total photosynthate consumed in the branch unit. Surplus of photosynthate, which would be available for translocation from the branch, was about 38% of the total photosynthate produced. Most of the photosynthate surplus was derived from the growth flushes of the previous year. Source and sink relationships, with regard to photosynthate partitioning in the 1-year-old branch unit over the growing season, were clarified and described.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 648d-648
Author(s):  
Jack W. Buxton ◽  
Donna Switzer ◽  
Guoqiang Hou

Marigold seedlings, 3 weeks old, were grown in natural light growth chambers at 3 day/night temperature regimes, 8°N/16°D, 13°N/20°D and 18°N/24°D, in a factorial combination with ambient and 1000-1500 ppm CO2. Seedlings were harvested at regular intervals during a 24 hr period and were analyzed for soluble sugars (reducing sugars and sucrose) and starch. Neither temperature nor CO2 concentration affected the accumulation of soluble sugars or starch during the day or night. The soluble sugar concentration ranged from 3% of dry weight at sunrise to 6% at mid-day; the concentration changed little during the night. Light intensity was different during replications of the experiment. Increased light intensity appeared to cause a slight increase in the soluble sugars maintained by the seedling during the day. Accumulated starch increased 6% to 8% from sunrise to late afternoon. Preliminary results indicate that light intensity greatly affected the concentration of starch. On the higher light intensity day, starch accumulated to a maximum of 18% of dry weight; whereas on the lower light intensity day the maximum concentration was 10%. During the night following the lower light intensity day, the starch concentration decreased to approximately 3% by the end of the night; following a brighter day the starch content was 13% at the end of the night.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 435B-435
Author(s):  
Jenny Heringer Vires ◽  
Robert Geneve ◽  
Robert Anderson

Purple coneflower, Echinacea sp. (Asteraceae), is a herbaceous perennial native to North America. Within the past decade, extensive research has been conducted to confirm echinacea's immunostimulatory, antiviral, and antibacterial benefits to humans. E. angustifolia, E. purpurea, and E. pallida are the primary species grown and studied for the herbal industry. However, there are other species and cultivars that may produce higher yields in biomass and chemical quality. The objective for this study is to evaluate the differences in biomass and phenolic content of five cultivars of E. purpurea and five species of Echinacea under Kentucky growing conditions. Differences in biomass (dry weight) of Echinacea species and cultivars harvested after the first year of growth was determined. There was a significant difference in total dry weight between E. purpurea cultivars. E. purpurea `Bright Star' and `Clio' produced significantly greater total dry weight compared to all other cultivars. There was no significant difference in root or flower biomass between cultivars. Biomass production differed between Echinacea species for root, vegetative, and flower parts. The total biomass of E. purpurea and E. tennesseensis was significantly higher compared to other species. E. pallida and E. paradoxa were not significantly different from E. purpurea in root biomass, even though both species produced less above-ground growth. E. tennesseensis produced 45% to 105% more flowers compared to other species. Differences in phenolic content between species and cultivars will also be presented.


Biologia ◽  
2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Nada Elloumi ◽  
Mohamed Zouari ◽  
Leila Chaari ◽  
Chiraz Jomni ◽  
Bechir Ben Rouina ◽  
...  

AbstractAlmond (Prunus dulcis L.) seedlings were exposed to 0, 25, 50, 100 and 150 μM of CdCl2 in a solution culture under controlled conditions. The effects of cadmium (Cd) exposure on almond seedlings growth, stomatal architecture, gas exchange and physiological parameters were investigated.Under cadmium stress conditions, significant decrease in fresh and dry weight, length of shoot and chlorophyll content were observed. Stomatal conductance, transpiration and net photosynthetic rates were generally depressed by Cd stress, despite stomatal frequency values and stomatal pore size remained unchanged. Exposure to Cd severely restricted the starch content and increased soluble sugars.


1988 ◽  
Vol 12 (1) ◽  
pp. 5-7 ◽  
Author(s):  
J. C. Adams ◽  
B. G. Lockaby

Abstract Understory sweetgum (Liquidambar styraciflua L.) in three 40-50-yr-old stands of loblolly pine was sampled to estimate the total and component biomass encompassed by this species. Individual tree sweetgum equations (based on D²H) were developed for total tree and tree component biomass for each stand. Total stand estimates of 9.79, 8.38, 1.09, and 0 32 tons/ac were determined for total, stem, branch, and foliage dry weight, respectively. There were no statistical differences among stands for total tree and stem biomass equations, but differences were found among stands for foliage and branch equations. The differences among crown component equations are probably reflective of the understory growing conditions in the different stands. South. J. Appl. For. 12(1):5-7.


1977 ◽  
Vol 89 (3) ◽  
pp. 589-597 ◽  
Author(s):  
A. B. McAllan ◽  
R. H. Phipps

SummaryThe (early maturing) maize hybrid, Anjou 210, was sown on 1 May (1975) and 50000 (LD) and 150000 (HD) plants/ha established. Leaf, stem, ear and husk components of the shoots, and whole shoots were separately examined for changes in dry weight, soluble sugars, starch, hemicellulose and cellulose at regular intervals from 104 to 154 days after planting together with whole shoots after ensiling.Throughout the sampling period whole shoot and ear dry weights increased steadily whereas those of leaf and stem decreased in plants from both treatments.Total soluble sugar contents for plants grown at LD were at a maximum 104 days after planting compared with 125 days after planting for the HD crop. Immediately prior to ensiling whole shoot soluble sugar content was 74 and 93 g/kg D.M. for LD and HD treatments respectively.Small amounts of starch (g/kg D.M.) were found in stems (10–25), husks (40–80) and leaves (17–35) of plants grown at both densities. The starch content of the ear increased from 57 to 390 g/kg D.M. and 168 to 376 g/kg D.M. in plants grown at LD and HD respectively.For plants from both treatments hemicellulose contents of husks, leaves and whole shoots increased with age whereas those of stems decreased. Cellulose contents did not vary greatly over the growing season.On ensiling plants from both densities, total soluble sugars had virtually disappeared after only 3 days. Apparent losses (approximately 0·3 g/g), over a longer period of time, were observed in hemicellulose sugars and starch. Apparent increases were observed in cellulose contents of approximately 0·15 g/g.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Gerong Wang ◽  
Yue Sun ◽  
Mo Zhou ◽  
Naiqian Guan ◽  
Yuwen Wang ◽  
...  

Abstract Background Herbs are an important part of the forest ecosystem, and their diversity and biomass can reflect the restoration of vegetation after forest thinning disturbances. Based on the near-mature secondary coniferous and broad-leaved mixed forest in Jilin Province Forestry Experimental Zone, this study analyzed seasonal changes of species diversity and biomass of the understory herb layer after different intensities of thinning. Results The results showed that although the composition of herbaceous species and the ranking of importance values were affected by thinning intensity, they were mainly determined by seasonal changes. Across the entire growing season, the species with the highest importance values in thinning treatments included Carex pilosa, Aegopodium alpestre, Meehania urticifolia, and Filipendula palmata, which dominated the herb layer of the coniferous and broad-leaved mixed forest. The number of species, Margalef index, Shannon-Wiener index and Simpson index all had their highest values in May, and gradually decreased with months. Pielou index was roughly inverted “N” throughout the growing season. Thinning did not increase the species diversity. Thinning can promote the total biomass, above- and below-ground biomass. The number of plants per unit area and coverage were related to the total biomass, above- and below-ground biomass. The average height had a significantly positive correlation with herb biomass in May but not in July. However, it exerted a significantly negative correlation with herb biomass in September. The biomass in the same month increased with increasing thinning intensity. Total herb biomass, above- and below-ground biomass showed positive correlations with Shannon-Winner index, Simpson index and Pielou evenness index in May. Conclusions Thinning mainly changed the light environment in the forest, which would improve the plant diversity and biomass of herb layer in a short time. And different thinning intensity had different effects on the diversity of understory herb layer. The findings provide theoretical basis and reference for reasonable thinning and tending in coniferous and broad-leaved mixed forests.


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