scholarly journals Changes in Polyamine Content during Dormancy in Flower Buds of `Anna' Apple

1994 ◽  
Vol 119 (1) ◽  
pp. 70-73 ◽  
Author(s):  
Shiow Y. Wang ◽  
Miklos Faust

Polyamine, putrescine, spermidine, and spermine contents were determined during endodormancy in the buds of low-chilling-requiring `Anna' apples (Malus domestics Borkh.). Putrescine, spermidine, and spermine contents increased greatly in buds when their chilling requirement was satisfied. Polyamine biosynthetic inhibitors α -difluoromethylarginine (DFMA) or α -difluoromethylornithine (DFMO) reduced bud break and bud growth in concert with decreased polyamine titers. DFMO or DFMA did not inhibit bud break when it was applied to buds after they received the full chilling requirement. DFMO was more inhibitory than DFMA. The polyamine requirement was much higher for bud growth and bud development than during differentiation and bud break.

2020 ◽  
Author(s):  
Zhi-Zhen Fang ◽  
Kui Lin-Wang ◽  
He Dai ◽  
Dan-Rong Zhou ◽  
Cui-Cui Jiang ◽  
...  

AbstractChinese plum (Prunus salicina Lindl.) is a stone fruit that belongs to the Prunus genus and plays an important role in the global production of plum. In this study, we report the genome sequence of the Chinese plum ‘Sanyueli’, which is known to have a low-chill requirement for flower bud break. The assembled genome size was 308.06 Mb, with a contig N50 of 815.7 kb. A total of 30,159 protein-coding genes were predicted from the genome and 56.4% (173.39 Mb) of the genome was annotated as repetitive sequence. Bud dormancy is influenced by chilling requirement in plum and partly controlled by DORMANCY ASSOCIATED MADS-box (DAM) genes. Six tandemly arrayed PsDAM genes were identified in the assembled genome. Sequence analysis of PsDAM6 in ‘Sanyueli’revealed the presence of large insertions in the intron and exon regions. Transcriptome analysis indicated that the expression of PsDAM6 in the dormant flower buds of ‘Sanyueli’ was significantly lower than that in the dormant flower buds of the high chill requiring ‘Furongli’ plum. In addition, the expression of PsDAM6 was repressed by chilling treatment. The genome sequence of ‘Sanyueli’ plum provides a valuable resource for elucidating the molecular mechanisms responsible for the regulation of chilling requirements, and is also useful for the identification of the genes involved in the control of other important agronomic traits and molecular breeding in plum.


1999 ◽  
Vol 77 (2) ◽  
pp. 262-268
Author(s):  
Michael J Sumner ◽  
William R Remphrey ◽  
Richard Martin

A relationship was developed between phenological stages of inflorescence expansion and the internal development of pollen within the anther of Amelanchier alnifolia Nutt. flowers. The major microscopic events associated with microsporogenesis and microgametogenesis were correlated with seven stages of external inflorescence development in both natural buds and those forced from dormancy in different concentrations of gibberellin at various times of the year. In fall and early spring, it was found that gibberellin at a concentration of 2.5 mg/L forced buds to produce inflorescences that most resembled those from natural field populations. However, it was not possible to force flower buds to develop all the way to anthesis. Flower bud development stopped when the pollen was at the binucleate stage. Despite this limitation, the ability to force buds increases the time frame for the study of many aspects of the reproductive biology of A. alnifolia.Key words: microsporogenesis, microgametogenesis, gibberellin, GA, flowering.


Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2378
Author(s):  
Ayane Moriyama ◽  
Chiho Yamaguchi ◽  
Shinichi Enoki ◽  
Yoshinao Aoki ◽  
Shunji Suzuki

In grapes, the number of flowers per inflorescence determines the compactness of grape bunches. Grape cultivars with tight bunches and thin-skinned berries easily undergo berry splitting, especially in growing areas with heavy rainfall during the grapevine growing season, such as Japan. We report herein that grape cytokinin oxidase/dehydrogenase 5 (VvCKX5) determines the number of berries per inflorescence in grapes. The number of berries per bunch was inversely proportional to the VvCKX5 expression level in juvenile inflorescences among the cultivars tested. VvCKX5 overexpression drastically decreased the number of flower buds per inflorescence in Arabidopsis plants, suggesting that VvCKX5 might be one of the negative regulators of the number of flowers per inflorescence in grapes. Similarly, the overexpression of grape sister of ramose 3 (VvSRA), which encodes trehalose 6-phosphate phosphatase that catalyzes the conversion of trehalose-6-phosphate into trehalose, upregulated AtCKX7 expression in Arabidopsis plants, leading to a decrease in the number of flower buds per Arabidopsis inflorescence. VvCKX5 gene expression was upregulated in grapevine cultured cells and juvenile grape inflorescences treated with trehalose. Finally, injecting trehalose into swelling buds nearing bud break using a microsyringe decreased the number of berries per bunch by half. VvCKX5 overexpression in Arabidopsis plants had no effect on the number of secondary inflorescences from the main inflorescence, and similarly trehalose did not affect pedicel branching on grapevine inflorescences, suggesting that VvCKX5, as well as VvSRA-mediated trehalose metabolism, regulates flower formation but not inflorescence branching. These findings may provide new information on the crosstalk between VvSRA-mediated trehalose metabolism and VvCKX-mediated cytokinin degradation for determining the number of berries per bunch. Furthermore, this study is expected to contribute to the development of innovative cultivation techniques for loosening tight bunches.


1970 ◽  
Vol 48 (1) ◽  
pp. 133-139 ◽  
Author(s):  
G. S. Hicks ◽  
I. M. Sussex

Young flower primordia of Nicotiana tabacum 'Wisconsin 38' have been successfully cultured on a nutrient medium supplemented with kinetin. The petal, stamen, and carpel primordia form in the normal acropetal sequence during the first week on excised floral apices which initially bore only sepal primordia. Relatively normal morphogenesis of the organs ensues, and on optimal concentrations of kinetin, pedicel length, calyx length and width, corolla width, and ovary length and width after 4 weeks were comparable to those in the normal flower at anthesis. The corolla, filaments, and style were always much shorter than normal. Large quantities of pollen were produced on low kinetin concentrations and normal embryo sacs formed in the numerous ovules. When kinetin was omitted from the medium, similar explants initiated all the organ primordia, but these subsequently remained minute through 4 weeks of culture. The data indicate that organ initiation is independent of exogenously supplied hormones, but that the later phases of bud growth have a marked requirement for kinetin. It is suggested that the sepals or petals may provide some stimulus for the initiation of meiosis in the anthers and ovules. In that flower morphogenesis in culture is independent of specific regulation from the rest of the plant, bud development appears to be relatively autonomous.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 668b-668
Author(s):  
Preston K. Andrews ◽  
Shulin Li ◽  
Margaret L. Collier

The development of sweet cherry (Prunus avium L., `Bing') flower buds from winter through anthesis was examined. Shoots were collected from the top and bottom of the canopy. The weight and size of flower buds and primordia produced on last-season's and 1-year-old wood were measured. As early as mid-December bud and primordia size and weight were greater on last-season's wood than on 1-year-old wood, with the largest and heaviest buds and primordia produced on last-season's wood in the bottom of the canopy. There was a significant negative correlation between the number of primordia per bud and primordium weight. The relationship between flower bud and primordia size during mid-December and ovary size at anthesis suggests a causal relationship, which may be a major source of variation influencing harvested fruit size and quality.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 825B-825
Author(s):  
Donna A. Marshall* ◽  
Stephen J. Stringer ◽  
James M. Spiers

A study was initiated in November, 2002 to determine the effects of exposing two Southern Highbush blueberries (Vaccinium corybosum L) to artificial chilling hours on initiation of bud break and advancement of floral and vegetative bud maturity. Plants of `Jubilee' and `Misty' were divided into 2 groups in which one was left outdoors, allowing chilling to occur and accumulate naturally, while the other group was placed in a growth chamber set at a constant artificial temperature of 4 °C. Five plants of each cultivar were then placed into a heated greenhouse after 0, 200, 400, 600, or 800 hours of chilling (total hours of exposure to <5 °C) had accumulated for forcing of flower bud development. The progression of floral bud development of the terminal three buds on five tagged stems was observed at 7-10 day intervals for 30 days. At the end of the forcing period observations were also made on total percent vegetative and floral bud break. Prior to accumulating sufficient chilling requirements, chilling delivery method did not appear to influence the rate of floral bud development since none advanced past stage 3 regardless of chilling regime used. However after chilling requirements were met, flower buds of plants that were allowed to chill naturally developed more quickly than did those chilled by artificial means.


Author(s):  
Silvia Carpenedo ◽  
Maria do Carmo Bassols Raseira ◽  
Rodrigo Cezar Franzon

As the climate change takes place, the cultivation of temperate climate crops in subtropical areas has become a challenge. The success of fruit crops, such as blackberry, in certain areas depends basically on its chilling requirement and the chilling accumulation in those areas. Usually the models used to predict those accumulations presents widely variable results being necessary to test the models in the location where the species is cultivated. The objective of this work was to estimate the chilling requirement for bud break of   blackberry cultivars Caingangue, BRS Cainguá, Guarani, Tupy, BRS Xavante, BRS Xingu, Brazos, Cherokee and Choctaw, using the models of Utah, Positive Utah, Low Chill, Taiwan, Chilling Hours ≤7.2°C, Chilling Hours ≤11°C, and Dynamic and both temperature and phenological data from 2010 to 2019. The results showed a high variability in cold accumulation for all studied cultivars in all tested models. None of the models performed perfectly to estimate chilling requirement however, the Taiwan and the Utah Positive models can be used to provide a rough estimate of this requirement. On the other hand, Utah and Low Chill      models are clearly not suitable for estimating blackberry chilling requirement. The estimated    chilling requirement showed that all the studied cultivars are well adapted to the climatic       conditions of the southern Rio Grande do Sul, which is emphasized by their good productivity in most of the years.


Author(s):  
H. Ramírez ◽  
A. I. Melendres- Alvarez ◽  
A. Zermeño- González ◽  
D. Jasso- Cantú ◽  
J. A. Villarreal- Quintanilla

Aims: The apricot (Prunus armeniaca L.), is a drought-sensitive deciduous fruit. This concept arises from the fact that soil moisture stress can: Decrease the number and quality of flower buds differentiated; delay the time of flower differentiation and decrease the number of flower buds per shoot. The objectives of this investigation were to determine: The extent to which drought influences water status in the leaves; its effect on flower buds development and on bloom in apricot cv. “Royal”. Study Design: Trees were divided into 6 groups of six replicate each under a random block design. Results were analyzed using the statistical program 'RStudio' for Windows version 10 and data obtained subjected to a comparison of means with the Tukey (P≤0.05) test. Place and Duration of Study: The experiment was conducted at the Department of Horticulture in Universidad Autónoma Agraria Antonio Narro, Saltillo, Mexico, during 2018-2019. Methodology: Seven-year-old apricot trees growing in containers were subjected to a 4 to 5week period of water stress at different times during the growing season. Leaf water potential was periodically measured and flower bud development was followed from early differentiation up to full bloom. Results: Leaf water potential in water stressed trees was constantly low. Water stress early in the season induced a delay in bud development during late summer and fall. Water stress late in the season did not appreciably affect the rate of bud development. Full bloom was delayed when water stress was applied in late summer and fall. Water stress at flower bud initiation and differentiation, together with high temperatures, may have induced flowers with double pistils. Water stress from April through October did not induce flower drop. Conclusion: Soil water stress severely affect leaf water potential; delays flower bud development and may induce flowers with double pistils without flower drop.


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