scholarly journals ELEVATIONAL GRADIENTS IN ADULT SEX RATIOS AND SEXUAL DIFFERENTIATION IN VEGETATIVE GROWTH RATES OFPOPULUS TREMULOIDESMICHX.

Evolution ◽  
1979 ◽  
Vol 33 (3) ◽  
pp. 914-918 ◽  
Author(s):  
Michael C. Grant ◽  
Jeffry B. Mitton
1992 ◽  
Vol 10 (1) ◽  
pp. 36-39
Author(s):  
C. Frederick Deneke ◽  
Gary J. Keever ◽  
John A. McGuire

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.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 517c-517 ◽  
Author(s):  
P. W. Robinson ◽  
M. V. Mickelbart ◽  
M. L. Arpaia

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.


2015 ◽  
Vol 67 (2) ◽  
pp. 685-693 ◽  
Author(s):  
Xia Yang ◽  
Siliang Huang ◽  
Yubian Zhang ◽  
Xiaoqiang Zhang

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.


1997 ◽  
Vol 75 (5) ◽  
pp. 755-770 ◽  
Author(s):  
Maria Ângela Marcovaldi ◽  
Matthew H. Godfrey ◽  
N. Mrosovsky

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.


2020 ◽  
pp. 1616-1622
Author(s):  
Madlles Queiroz Martins ◽  
Fábio Luiz Partelli ◽  
Adelmo Golynski ◽  
Adésio Ferreira ◽  
Weverton Pereira Rorigues ◽  
...  

Coffea canephora plants grown at low or elevated temperatures undergo changes in photosynthetic processes, which have a direct impact on vegetative growth. This species shows plants with distinct stress tolerance mechanisms and a great genetic diversity; however, there are no studies concerning the study of altitude on plant growth for these genotypes. The objective of this study was to evaluate the growth rates of orthotropic and plagiotropic branches from 28 Coffea canephora genotypes, ca. 3 years of age, cultivated at 850 m of altitude. The experimental design was a randomized complete block design with four repetitions. Each repetition was compounded by five plants. The period of the experimental evaluation was from 01/23/2013 to 07/07/2013. We selected and identified the orthotropic and plagiotropic branches, which were evaluated bimonthly according to their length (mm), assessing the growth rates. The results were associated with climatic factors that occurred during the experimental period. The genetic material of Coffea canephora evaluated in the study shows genetic diversity to the characteristics growth rate of orthotropic and plagiotropic branches, thus, it is possible to select genotypes with potential for cultivation at 850 m of altitude. In general, genotypes of Coffea canephora exhibited variations in growth rates, mainly in response to changes in temperature, with a sharp and constant drop in growth rates between the period from 05/05/2013 to 05/ 23/2013, when the recorded temperatures were always below 13 °C. Genotypes A1, NV2 and NV1 can be pointed as the ones which showed the best vegetative growth results at 850 meters of altitude.


1969 ◽  
Vol 26 (8) ◽  
pp. 1969-1983 ◽  
Author(s):  
S. Apollonio

About 1450 specimens of the decapod crustacean Pasiphaea multidentata were collected in deep waters of the Gulf of Maine in 1966–69, and were examined for size, sex, weight, breeding, fecundity, and feeding. The sizes and sex ratios of the catches vary with the egg-bearing seasons, suggesting that ovigerous females are susceptible to greater predation. The data do not permit estimates of growth rates or age of maturity. The ratios of carapace length to total length differ in males and females. Two egg clutches per female per year were produced, the second clutch being smaller in numbers, probably because of "reproductive fatigue" in the female. In each clutch the number of eggs produced is a linear function of carapace length. About 50% of the stomachs were empty. Eighteen per cent contained crustacean remains of which about half could be identified as remains of the copepods Metridia longa, M. lucens, and Euchaeta norvegica. Epizoic suctorians were found on a few shrimps.


Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1417
Author(s):  
Congping Xu ◽  
Ying Zhang ◽  
Qiang Han ◽  
Xiangyang Kang

Tetraploid plants often have altered rates of vegetative growth relative to their diploid progenitors. However, the molecular basis for altered growth rates remains a mystery. This study reports microRNA (miRNA) and gene expression differences in Populus tetraploids and counterpart diploids using RNA and miRNA sequencing. The results showed that there was no significant difference between young leaves in the expression of vegetative growth-related miRNAs. However, as leaves aged, the expression of auxin- and gibberellin-related miRNAs was significantly upregulated, while the expression of senescence-related miRNAs was significantly downregulated. The dose effect enhanced the negative regulation of the target genes with ARFs, GA20ox, GA3ox, and GAMYB being downregulated, and TCP and NAC being upregulated. As a result, the chloroplast degradation of tetraploid leaves was accelerated, the photosynthetic rate was decreased, and the synthesis and decomposition ability of carbohydrate was decreased.


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