Metabolomics Analysis Reveals the Mechanism of Hydrogen Cyanamide in Promoting Flower Bud Break in Blueberry

Bud dormancy of deciduous fruit trees is a complex process that allows trees to survive long periods in adverse conditions during winter. Dormancy is a major obstacle for both fruit production in mild winter areas and off-season culture of fruit trees in protection facilities. It is very economically advantageous to be able to control the time point of bud break and consequently harvest in crops with high returns and short harvest seasons like blueberry (Vaccinium spp.). Hydrogen cyanamide (H2CN2 (HC)) treatment is an effective method to promote dormancy release and synchronize bud break in perennial deciduous fruit trees, including blueberry. However, there are few systematic studies of the metabolic changes that occur during HC-induced bud breaking. In this study, the metabolome of blueberry buds under forced conditions following HC and water treatment (control) was analyzed using gas chromatography paired with time-of-flight mass spectrometry (GC–TOFMS) technology. A total of 252 metabolites were identified and 16 differential metabolites (VIP > 1, p < 0.05) were detected. The levels of several soluble sugars (fructose, glucose, maltose), organic acids (citric acid, alpha-ketoglutaric, succinic acid), and amino acids (aspartic acid, glutamic acid, phenylalanine) were upregulated, while tyrosine, tryptophan, and asparagine were significantly downregulated in HC-treated buds when compared with control buds. The synthesis and accumulation of phenylpropanoids (salicin, 4-vinylphenol, neohesperidin) were also promoted by HC. These results suggest that alteration of carbohydrate and amino acid metabolism, tricarboxylic acid (TCA) cycle increase, and phenylpropanoid accumulation were crucial in HC-promoted bud breaking in blueberry. This research extends our understanding of the mechanisms involved in dormancy release induced by HC and provides a theoretical basis for applying HC to accelerate bud break.

The sensitivity of herbaceous plants to light Pollution

Plants living near street lights in temperate zones are good examples of the effect of light pollution with a marked shift in leaf fall and bud breaking. Low intensity light (light pollution) is not sufficient for photosynthesis, but can cause changes in many physiological processes, moreover, it can have a disrupting effect on the plant and its connected ecosystem. In this study, physiological effects of light pollution on leaf morphology, leaf anatomy, and photosynthesis were investigated in the herbaceous species Erigeron annuus (L.) Pers. and Fallopia x bohemica (Chrtek et Chrtková) J.P. Bailey under conventional HPS and LED illumination. In our experience, HPS lamps supported the photosynthetic activity of the studied species, the growth of palisade tissue cells. Light pollution of LED lamps reduced net photosynthesis in both species compared to non-light-polluted leaves.

Genome-wide characterization of PEBP family genes in nine Rosaceae tree species and their expression analysis in P. mume

BackgroundPhosphatidylethanolamine-binding proteins (PEBPs) constitute a common gene family found among animals, plants and microbes. Plant PEBP proteins play an important role in regulating flowering time, plant architecture as well as seed dormancy. Though PEBP family genes have been well studied in Arabidopsis and other model species, less is known about these genes in perennial trees. ResultsTo understand the evolution of PEBP genes and their functional role in flowering control, we identified 56 PEBP members belonging to three gene clades (MFT-like, FT-like, and TFL1-like) and five lineages (FT, BFT, CEN, TFL1, and MFT) across nine Rosaceae perennial species. Structural analysis revealed highly conserved gene structure and protein motifs among Rosaceae PEBP proteins. Codon usage analysis showed slightly biased codon usage across five gene lineages. With selection pressure analysis, we detected strong purifying selection constraining divergence within most lineages, while positive selection driving the divergence of FT-like and TFL1-like genes from the MFT-like gene clade. Spatial and temporal expression analyses revealed the essential role of FT in regulating floral bud breaking and blooming in P. mume. By employing a weighted gene co-expression network approach, we inferred a putative FT regulatory module required for dormancy release and blooming in P. mume. ConclusionsWe have characterized the PEBP family genes in nine Rosaceae species and examined their phylogeny, genomic syntenic relationship, duplication pattern, and expression profiles during flowering process. These results revealed the evolutionary history of PEBP genes and their functions in regulating floral bud development and blooming among Rosaceae tree species.

Chilling requirement evaluation of the Abjosh cultivar (Vitis vinifera) in Afghanistan

This study was conducted to determine the chilling requirement of the Abjosh grape (local cultivar). The experiment was carried out based on randomized complete block design with three replications. The grape cuttings were treated at 5°C for (0, 100, 200, 250, 300, 350, 400, and 500 hrs) as chilling treatments at Samangan Higher Education Institute in the autumn of 2018. The traits such as the percentage of bud breaking, number of days to the first bud breakage, number of days to 50% of bud breaking, and number of days to the last bud breaking were measured. The results showed that the percentage of bud breaking increased significantly, as the chilling hrs (hours) increased. By the increasing of cold duration, the percentage of bud breaking in 500 hrs increased to 80% whereas, number of days to the first bud breaking, 50% of bud breaking and the number of days to the last bud breaking were decreased to 13, 14, and 16 days, respectively. Though, there were no significant differences between the 400 and 500 cold hrs in all indicators. The findings revealed that at least 300 hrs of cold duration is essential to reach an acceptable percentage of bud breaks, but further elaboration is needed.

Chemical and mechanical methods on fruit setting and pomological traits of Chinese jujube (Ziziphus jujuba Mill.) under Czech agro climatic condition

The aim of this research was conducted to improve fruit set using different types of treatments and to find out the best treatment on the basis of number of fruits and pomological traits. For the research, ten years old 12 Lang cultivar of jujube trees and 3 seedlings from open pollinated of Ukraine genotypes were used. The tree spacing was 3.50×1.26 m. Spraying of Borax showed that average numbers of fruits were higher than the other treatments, average values of height, weight, width and thickness were also higher than the other treatments. On the other hand Urea and Girdling gave poor results in both years. In case of seedlings, different treatments for fruit setting have not given good results. Spraying with different treatments did not affect fruit-setting and pomological characteristics as well, in a larger scale. In 2006, bud breaking started in jujube cultivars on 28th April and in seedlings on 6th May. In 2007, bud breaking started in jujube cultivars 11 days earlier and 10 days earlier on 26th April in seedling. In jujube cultivars, there were some variations in the dates of flowering during 2006; the average date of flowering was 26th June in 2006 for all cultivars of jujube. In seedlings, flowering started on 6th July 2006. During 2007 flowering started in jujube cultivar jujube cultivars started flowering 12 days earlier and seedlings 22 days earlier. During 2006, fruit set started in jujube cultivars and seedlings, on 12th July and 14th July respectively. During 2007, fruit set started in jujube cultivars and seedlings on 1st July and 10th July respectively. In 2007 fruit set in jujube cultivars started 11 days earlier and in seedlings 4 days earlier. During 2006, ripening started in jujube cultivars and seedlings on 26th Sept. During 2007 ripening started in jujube cultivars and seedlings on 2nd and 10th Sep. respectively. In 2007, ripening started in jujube cultivars 24 days earlier and seedlings 16 days earlier. Statistical evaluations of the data showed the differences between 2006 and 2007.

Genetic diversity detection of seed-propagated walnut (Juglans regia L.) germplasm from Eastern Anatolia using SSR markers

Continuous seed propagation in Turkey has given rise to a great number of seedling walnut trees which represents valuable walnut genetic resources. The number of native walnut trees is estimated to be over 5 million in Turkey and they possess large phenotypic variability in yield, nut and kernel characteristics, late bud breaking, late flowering, winter hardiness and tolerance to diseases. Progress in walnut breeding requires the exploitation of genetic variation among cultivars and landraces. In this study, we used 32 local diverse walnut genotypes obtained from seeds and 2 standard cultivars (‘Sebin’ and ‘Bilecik’). This study implemented 21 previously used simple sequence repeats (SSR) markers to determine genetic diversity. The analysis revealed 135 alleles with an average of 6.43 alleles per locus. Genetic similarity ranged from 0.23 (for samples KW22 and KW29) to 0.87 (for samples KW27 and KW28). The highest number of alleles per locus was obtained from WGA276 locus (11 alleles), followed by WGA054 (9 alleles), WGA202 and WGA321 (8 alleles) while the lowest number was detected in WGA027. According to the morphological and molecular data, the genotypes differed from each other and the cvs. Sebin and Bilecik. The majority of the genotypes had higher fruit weight and some of the genotypes had higher kernel ratio than cvs. Sebin and Bilecik implying the importance of registering genotypes as cultivars. This research provides information on the genetic relationship of walnut genotypes and cultivars and emphasises the importance of protection and utilisation of seed-propagated walnut genetic resources.

Pruning and dormancy breaking make two sustainable grape-cropping productions in a protected environment possible without overlap in a single year

In table grape production, protected cultivation in a vineyard in different regions and climates is currently a commonly used practice. The aims of this study were to provide key approaches to sustainably produce two crops of grape without overlap under protected environment in a single year. Spraying the degreening chemicals 400 mg/L ethephon +0.4% sulfur at 4 weeks of vine nutrient restoration after the harvest of the summer crop resulted in the highest percentage of sprouting inflorescence. The retention of 7–10 buds in the base shoot results in the high percentage of sprouting inflorescence. Bud breaking chemicals with 2.5% hydrogen cyanamide+2.0% Baoguoliang +0.02% Shenzhonggen significantly led to sprout inflorescence more efficiently. Cluster and fruit weights of the winter crop weighed significantly less than those of the summer crop. However, the contents of total soluble sugar and titratable acidity were higher than those of the summer crop. The anthocyanin content in the peel of the winter fruit was significantly higher than that in the summer fruit. The yield of the winter crop is controlled by the yield of the summer fruit. To maintain the stability of the two crops for one year, the ratio of yield in the winter to the summer should be controlled from 2:5 to 3:5 to ensure the sustainable production of two crops without overlap for ‘Summer Black’ grape. These results may help grape growers to overcome the impacts of rainy and hot climates with the help of protected facilities, and it could enable the use of solar radiation and heat resources in subtropical and tropical areas.

Sources of resistance to the erineum strain of Colomerus vitis (Acari: Eriophyidae) in grapevine cultivars

The erineum strain of Colomerus vitis (GEM) is the most destructive pest of vineyards in western Iran and sometimes causes considerable damages to the grapevine. Little information is available on the susceptibility of the grapevine to this pest and its knowledge can be useful for a sustainable management of GEM. The present study was aimed at evaluating the responses of the plants to the infestation of GEM in order to compare the resistance/susceptibility of some native cultivars to this pest. Also, the profiling of JA, SA and IAA in leaves of infested plants of Sezdang was studied. The experiment was carried out on eighteen native cultivars and the non-native Muscat Gordo which were selected amongst the most common in southern and western Iran. Potted plants were cultivated under greenhouse conditions at a temperature of 32 ± 3.8°C, 75 ± 5% R.H. and a photoperiod of L16: D8 h. The impact of GEM was evaluated on the basis of the leaf area and weight, number and size of the erinea, and percentage of leaves with erinea three months after the infestation. The cane length was measured, too. Mite density on galled leaves (three months after the infestation) and in buds (at the bud breaking) was assessed. Cluster analysis based on the leaf damage index induced by GEM allowed to distinguish highly affected (Sezdang, Khalili, Ghalati and Rishbaba), moderately affected (Neyshaboori, Gazne, Muscat, Lale, Shahani Sefid, Ahmad, Monagha and Sia) and scarcely affected (Yaghuti, Rotabi, White Thompson, Atabaki, Koladari and Sahebi and Shahani Gerd) cultivars. The mite density into the buds and on the galled leaves was higher in the medium-late (Rishbaba and Khalili) and late ripening (Sezdang and Ghalati) cultivars rather than in the early (Sahebi and Shahani Gerd) and early-medium (Atabaki) ripening ones. The leaf damaged area, the leaf weight, the shoot length and the erineum development were correlated to the mite density and were the highest on Sezdang, Khalili, Ghalati and Rishbaba and the lowest on Atabaki, Koladari, Sahebi and Shahani Gerd. The highest density of the overwintering population was detected in proximal buds of all treated cultivars. The plant responses and the mite density were investigated also in the second and third year after the first mite infestation on highly affected (Sezdang, Khalili, Ghalati, Rishbaba), a few of the moderately affected (Neyshaboori, Gazne, Muscat) and the scarcely affected cultivars (White Thompson, Atabaki, Koladari, Sahebi, Shahani Gerd). The leaf damaged area, the percentage of galled leaves, the percentage of cane length reduction and the mite density strongly decreased during all three years of observations on the highly affected Sezdang, Khalili and Gazne. On the contrary, Ghalati and Rishbaba displayed an increase of the leaf damaged area, leaf damaged index and mite density on galled leaves during the same period in comparison to the first year of observation. The percentage of the leaves with erinea, the leaf damaged area and the mite density of Sezdang were highly and positively correlated with IAA while a negative correlation was found between the leaf damaged area and the mite density with SA and JA in the assayed years. Almost all data currently collected allowed a recognition of White Thompson, Atabaki, Koladari, Sahebi and Shahani Gerd as the least affected cultivars.