Elevational Gradients in Adult Sex Ratios and Sexual Differentiation in Vegetative Growth Rates of Populus tremuloides Michx

Evolution ◽  
1979 ◽  
Vol 33 (3) ◽  
pp. 914 ◽  
Author(s):  
Michael C. Grant ◽  
Jeffry B. Mitton
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Sexual Differentiation ◽  
Vegetative Growth ◽  
Sex Ratios ◽  
Elevational Gradients

Wounding of aspen roots promotes suckering

2004 ◽  
Vol 82 (3) ◽  
pp. 310-315 ◽  
Author(s):  
Erin C Fraser ◽  
Victor J Lieffers ◽  
Simon M Landhäusser
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Growing Season ◽  
Organic Layer ◽  
Trembling Aspen ◽  
Layer Depth ◽  
Injury Type ◽  
Organic Layers ◽  
Root Injury ◽  
Root Sucker

In early May, 1-m sections of trembling aspen (Populus tremuloides Michx.) roots in a forest cutblock were carefully exposed and examined for damage. Undamaged roots were subjected to one of three wounding treatments (scrape, sever, or uninjured control) and were then reburied to either the full normal organic layer depth or to one third of the normal depth. Following one growing season, the roots were reexposed and assessed for aspen sucker numbers and growth rates. Results indicate that injured roots produced suckers nearly twice as often as uninjured roots. Further, injured roots produced more suckers per root, and these suckers were taller and had greater leaf area. Roots buried under shallow organic layers also generated more suckers, regardless of injury type. The side of injury (distal or proximal) did not affect any of the measured variables. The present study suggests that moderate wounding of aspen roots increases initial sucker numbers and growth rates.Key words: trembling aspen, root sucker, root injury, regeneration.

scholarly journals Growth and Flowering of ‘Alice du Pont’ Mandevilla in Response to Sumagic

1992 ◽  
Vol 10 (1) ◽  
pp. 36-39
Author(s):  
C. Frederick Deneke ◽  
Gary J. Keever ◽  
John A. McGuire
Keyword(s):  
Growth Rates ◽  
Vegetative Growth ◽  
Foliar Application ◽  
Application Rate ◽  
Single Application ◽  
Flower Diameter ◽  
Selection Of

Abstract Vegetative growth of ‘Alice du Pont’ mandevilla can be controlled by selection of an appropriate foliar application rate of Sumagic (uniconazole) and application interval. A single application of 5 to 20 ppm ai Sumagic (uniconazole) controlled vegetative growth for only 3 to 4 weeks; after this time, growth rates were similar to control plants. Multiple applications of 5 to 20 ppm ai Sumagic (uniconazole) effectively restricted vegetative growth; as the concentration of Sumagic (uniconazole) increased, the interval between applications increased from about 4 (5 ppm) to 6 (20 ppm) weeks. A single application of higher rates (30 to 120 ppm) of Sumagic (uniconazole) was phytotoxic. Generally, time to flowering increased and flower diameter decreased when application rate increased.

scholarly journals Jack Pine Regeneration Following Postcut Burning under Seed Trees in Central Saskatchewan

1988 ◽  
Vol 64 (4) ◽  
pp. 315-319 ◽  
Author(s):  
Z. Chrosciewicz
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Pinus Banksiana ◽  
Forest Regeneration ◽  
Black Spruce ◽  
Timber Harvest ◽  
Jack Pine ◽  
Growing Seasons ◽  
Pine Regeneration ◽  
Slash Burning

An experimental burn in conjunction with a seed-tree system was successful in regenerating jack pine (Pinus banksiana Lamb.) on a fresh to somewhat moist upland, loamy till, cutover site in central Saskatchewan. About 20 well-formed, uniformly spaced seed trees per hectare were left standing during timber harvest. The ignition of logging slash was carried out under preselected weather and fuel conditions so that favorable seedbeds and adequate seed dispersal from the seed trees were produced. Four growing seasons after burning, jack pine stocking by 4-m2 quadrats was 90% with 12 195 seedlings/ha. Aspen (Populus tremuloides Michx.), to a lesser degree black spruce (Picea mariana [Mill.] B.S.P.), and other companion tree species also regenerated with the pine. Various seedbed and regeneration characteristics as well as height growth rates are discussed. Key words: Pinus banksiana, slash burning, seed-tree system, forest regeneration, growth rates, central Saskatchewan.

scholarly journals 595 PB 173 `HASS' AVOCADO PHENOLOGY IN CALIFORNIA - PRELIMINARY RESULTS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 517c-517 ◽  
Author(s):  
P. W. Robinson ◽  
M. V. Mickelbart ◽  
M. L. Arpaia
Keyword(s):  
Root Growth ◽  
Growth Rates ◽  
Vegetative Growth ◽  
Growing Season ◽  
Phenological Model ◽  
Preliminary Results ◽  
Hass Avocado

Measurements of flowering, yield, vegetative and root growth were begun in Spring 1992 to establish a phenological model for `Hass' avocado. Although rootstock (Thomas', Topa Topa', Duke 7' and `D9') did not affect the timing or intensity of bloom, differences in yield were observed. Flowering occurred in March - April in both years, although the intensity of bloom in 1993 was drastically reduced due to an extremely heavy 1992-93 crop. Vegetative flushes occurred in April (following bloom) and July in both years. In 1993, however, cumulative growth was ca. 10-fold greater. Rootstock did not affect the timing or intensity of vegetative growth in either year. In both years, vegetative growth preceded root growth. In 1992, there were no differences detected in the timing or intensity of root growth related to rootstock. In 1993, however, the `Topa Topa' rootstock produced more roots throughout the growing season. The timing and intensity of root growth during the spring flush were similar in both years. During Fall 1993, root growth rates, however, were consistently higher than those observed in 1992. Additionally, while root growth ceased in November 1992, roots have continued to grow through January 1994.

scholarly journals Characterization of a rare species of Neurospora isolated from a river water sample in China

2015 ◽  
Vol 67 (2) ◽  
pp. 685-693 ◽  
Author(s):  
Xia Yang ◽  
Siliang Huang ◽  
Yubian Zhang ◽  
Xiaoqiang Zhang
Keyword(s):  
Water Sample ◽  
River Water ◽  
Growth Rates ◽  
Rare Species ◽  
Vegetative Growth ◽  
Carbon Sources ◽  
Morphological Characteristics ◽  
Nitrogen Sources ◽  
Fungal Species ◽  
River Water Sample

A fungal isolate (ZZS4408) was obtained from a river water sample in Henan, China, and identified as a member of Neurospora brevispora, a rare species of Neurospora based on its morphological characteristics and ribosomal DNA internal transcribed spacer (rDNA-ITS) sequence. The temperatures suitable for growth of the isolate were 28-37?C with 31?C as the optimum. The growth rates of hyphal tips were 19.1-42.5 (av. 31.9) ?m min-1 at 32?C. The pH suitable for vegetative growth ranged from 5 to 7, with pH 5.5 as the optimum. The heterodisaccharides (sucrose and lactose) and D-alanine were found to be most favorable for vegetative growth of the isolate, as carbon and nitrogen sources, respectively. The vegetative growth of the isolate was more significantly influenced by nitrogen sources compared to carbon sources. N. brevispora could be considered a desirable fungal species for morphodifferentiation studies due to its rapid growth rates under favorable conditions.

Estimating sex ratios of loggerhead turtles in Brazil from pivotal incubation durations

1997 ◽  
Vol 75 (5) ◽  
pp. 755-770 ◽  
Author(s):  
Maria Ângela Marcovaldi ◽  
Matthew H. Godfrey ◽  
N. Mrosovsky
Keyword(s):  
Sex Ratio ◽  
Sexual Differentiation ◽  
Sex Ratios ◽  
Caretta Caretta ◽  
Temperature Dependent ◽  
Loggerhead Turtles ◽  
Biased Sex Ratio ◽  
Nesting Beaches

A method of estimating natural sex ratios of hatchlings of species with temperature-dependent sexual differentiation from data on incubation durations is described. The method was applied to loggerhead turtles (Caretta caretta) nesting in Brazil. Data on incubation durations were collected from 11 nesting beaches monitored for up to six seasons. It was estimated that 82.5% of the loggerhead hatchlings produced were female. The strongly female-biased sex ratio in Brazil is similar to that found previously for loggerheads using beaches in the eastern U.S.A. This suggests that a female-biased hatchling sex ratio may be a feature of loggerhead populations.

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