scholarly journals Ontogeny in terminal buds of Abies nordmanniana (Pinaceae) characterized by ubiquitin

2008 ◽  
Vol 95 (6) ◽  
pp. 766-771 ◽  
Author(s):  
B. Veierskov ◽  
H. N. Rasmussen ◽  
B. Eriksen
1997 ◽  
Vol 99 (1) ◽  
pp. 185-189
Author(s):  
Wen-Shaw Chen ◽  
Kuang-Liang Huang ◽  
Hsiao-Ching Yu

2016 ◽  
Vol 72 (8) ◽  
Author(s):  
Kiarash Afshar Pour Rezaeieh ◽  
Bunyamin Yildirim ◽  
Ahmet Metin Kumlay

Horticulturae ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 82
Author(s):  
Amandeep Kaur ◽  
Louise Ferguson ◽  
Niels Maness ◽  
Becky Carroll ◽  
William Reid ◽  
...  

Pecan is native to the United States. The US is the world’s largest pecan producer with an average yearly production of 250 to 300 million pounds; 80 percent of the world’s supply. Georgia, New Mexico, Texas, Arizona, Oklahoma, California, Louisiana, and Florida are the major US pecan producing states. Pecan trees frequently suffer from spring freeze at bud break and bloom as the buds are quite sensitive to freeze damage. This leads to poor flower and nut production. This review focuses on the impact of spring freeze during bud differentiation and flower development. Spring freeze kills the primary terminal buds, the pecan tree has a second chance for growth and flowering through secondary buds. Unfortunately, secondary buds have less bloom potential than primary buds and nut yield is reduced. Spring freeze damage depends on severity of the freeze, bud growth stage, cultivar type and tree age, tree height and tree vigor. This review discusses the impact of temperature on structure and function of male and female reproductive organs. It also summarizes carbohydrate relations as another factor that may play an important role in spring growth and transition of primary and secondary buds to flowers.


1973 ◽  
Vol 51 (6) ◽  
pp. 1137-1145 ◽  
Author(s):  
Kyu-Byung Yun ◽  
J. M. Naylor

The mitotic cycle can be arrested in the apical summit of vegetative terminal buds of Tradescantia paludosa by restricting the level of nitrogen or light available to the plant. Cells in this portion of the bud are much more sensitive to these stress conditions than those in the subjacent portion of the meristem. This differential response induced the establishment of a quiescent "central zone" which is distinguished from the rest of the meristem by the apparent absence of mitosis and DNA synthesis, larger nuclear volume, and a lower histone content of chromatin. These features are identical with those imposed by apical dominance in apices of inhibited lateral buds.The results support the view that competition for nutrients is an important causal factor in apical dominance. They suggest also that competition for nutrients within the terminal bud meristem is important in the regulation of growth in vegetative shoots in respones to conditions of the environment.


2006 ◽  
Vol 36 (4) ◽  
pp. 1054-1058 ◽  
Author(s):  
O K Hansen ◽  
E D Kjær

A paternity analysis using five microsatellite markers was conducted in a Danish clonal seed orchard with 13 Abies nordmanniana (Stev.) Spach clones. The purpose was to investigate potential seed-orchard dysfunctions, with special emphasis on nonequal pollen contributions and selfing. Male paternity was found for 232 seedlings germinated from seeds collected on three ramets, each of eight clones, and the relative contribution of each clone to the gene pool of male gametes was calculated. Furthermore, 49 ramets were genotyped to check for erroneous grafting. The effect of an unbalanced male contribution was quantified by means of two measures: (1) the status number (NS), which reflects buildup of coancestry in the seed-orchard crop as a result of a low number of clones and an unequal male contribution, and (2) the asymptotic variance effective population number (Ne(v)). The contributions by pollen donors from the 13 clones were highly skewed. Three clones were fathers to more than 75% of the progenies, while making up only 24% of the ramets in the seed orchard. Four clones sired no progenies at all. The unequal contribution on the male side corresponded to NS = 4.2 and Ne(v) = 5.8. Some selfing was observed, which may give rise to concern if clonal seed orchards with few clones are established. The estimated maximum pollen contamination from outside the seed orchard was 4.3%. No grafting–labelling errors were identified.


Author(s):  
S. M. Khairi

Abstract A description is provided for Podosphaera clandestina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Crataegus monogyna, C. pentagyna, C. punctata, Mespilus germanica, Cratoegomespilus grandiflora, C. dardari, Pyrus communis, Cydonia vulgaris, Pyrocydonia winkleri and P. danieli. DISEASE: Hawthorn mildew. Severe attacks cause defoliation and death of terminal buds on young seedlings and on soft shoots on hedges and trees. The disease has been recorded on hawthorn fruits. The host plant can be grown only from seeds. GEOGRAPHICAL DISTRIBUTION: Worldwide (Salmon, 1900; 45, 3081). Cleistothecia play no part in the disease in England. The overwintering mycelium, inside infected buds, survives until the following spring. These infected buds are the primary infections found each year. Secondary infection is by air-borne conidia.


2014 ◽  
pp. 125-136
Author(s):  
Marija Markovic ◽  
Mihailo Grbic ◽  
Dragana Skocajic ◽  
Matilda Djukic

The effect of the concentration of MS salts and explant type on D. serotinus rooting and acclimatization was investigated in order to optimize a protocol for the micropropagation of this species. The obtained results showed that explant type as well as the concentration of MS salts had a significant effect on rooting, and the highest rooting rate (85-86,7%) was achieved when culturing single-node cuttings and terminal buds on a half-strength MS medium supplemented with 0,5 mgL-1 NAA. Nevertheless, mean number of roots per explant was higher on the MS media (15,3-18,6) than on the half-strength MS media (11,8-13,4). The best acclimatization rate was obtained in a 4:1 mixture of peat and sand (83,3-86,7%). The explant type from which in vitro plantlets developed had no effect on the acclimatization rate.


2020 ◽  
Vol 13 (10) ◽  
pp. 102
Author(s):  
A. V. Silva ◽  
J. F. Silva Filho ◽  
M. C. T. Silva ◽  
N. C. A. Vaz ◽  
M. L. G. Silva

Common Bean (Phaseolusvulgaris L) is one of the main food sources in Brazil, hás cultural and nutricional values. Its cultivation can be found mosthy by small producers with small production áreas and some technological types, and extends throughout the national territory. The objective of this research was to elaborate a review about the edaphoclimatic adaptability and agricultural production environments of the bean crop. Since, beans can be sown at three times of the year, in which edaphoclimatic characteristics are defined as: 1 st crop (Sowing performed between August and October); 2nd crop (Sowing performed from January to April); and autumn crop winter crop, in which sowing occurs from May and, characterized as annual crop. In the 3rd harvest the use of irrigatin system, made by sprinkler system. However, sowing in different harvest may be influenced by the type of culivar used, as it hás Type I characterization because it hás a determined growth habit with reproductive terminal buds in the main stem and branches, while the second (types II, III and IV) have indeterminate growth habit with vegetative terminal buds on the main stem and branches. However there is a difference between the three types in the plant, the type III prostrate sinze and type IV plant that hás large climbing capacity. Although it demonstrates these attributes, the bean also hás during its biological cycle the vegetative and reproductive phases, which are divided into tem stages. The vegetative phase (V) consists of stages V0, V1, V2, V3 and V4 and the reproductive phase (R), of stages R5, R6, R 7, R8 and R9 being crucial for the development of the crop. Despite these stages of bean development, it hás wide adaptation and geographical distribuion, the bean  is very little tolerant to extreme environmental factors, being a relatively demanding crop with reagard to most edaphoclimatic conditions. Thus, the agroclimatic characteristics of the region and the requirements and limitations of common bean are of fundamental importance for the choice of an environment where the crop can grow and develop well, in order to obtain optimum yield, taking full advantage of the cultivar. and other practices or technologies employed in order to provide positive effects on the crop.Common Bean (Phaseolusvulgaris L) is one of the main food sources in Brazil, hás cultural and nutricional values. Its cultivation can be found mosthy by small producers with small production áreas and some technological types, and extends throughout the national territory. The objective of this research was to elaborate a review about the edaphoclimatic adaptability and agricultural production environments of the bean crop. Since, beans can be sown at three times of the year, in which edaphoclimatic characteristics are defined as: 1 st crop (Sowing performed between August and October); 2nd crop (Sowing performed from January to April); and autumn crop winter crop, in which sowing occurs from May and, characterized as annual crop. In the 3rd harvest the use of irrigatin system, made by sprinkler system. However, sowing in different harvest may be influenced by the type of culivar used, as it hás Type I characterization because it hás a determined growth habit with reproductive terminal buds in the main stem and branches, while the second (types II, III and IV) have indeterminate growth habit with vegetative terminal buds on the main stem and branches. However there is a difference between the three types in the plant, the type III prostrate sinze and type IV plant that hás large climbing capacity. Although it demonstrates these attributes, the bean also hás during its biological cycle the vegetative and reproductive phases, which are divided into tem stages. The vegetative phase (V) consists of stages V0, V1, V2, V3 and V4 and the reproductive phase (R), of stages R5, R6, R 7, R8 and R9 being crucial for the development of the crop. Despite these stages of bean development, it hás wide adaptation and geographical distribuion, the bean  is very little tolerant to extreme environmental factors, being a relatively demanding crop with reagard to most edaphoclimatic conditions. Thus, the agroclimatic characteristics of the region and the requirements and limitations of common bean are of fundamental importance for the choice of an environment where the crop can grow and develop well, in order to obtain optimum yield, taking full advantage of the cultivar. and other practices or technologies employed in order to provide positive effects on the crop.


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