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Cell production and cell expansion in ‘Gala’ and ‘Grand Gala’ fruits. (A) Cell number in ‘Gala’ (n=4) and ‘Grand Gala’ (n=3) fruit cortex was measured during fruit development. Cell number was determined as the number of cell layers between the petal vascular trace and the peel. Inset presents a magnified view of cell number during early fruit growth. (B) Radial cell diameter in ‘Gala’ (n=4) and ‘Grand Gala’ (n=3) fruit cortex was determined during fruit development. Inset presents a magnified view of cell diameter during early fruit growth. Error bars represent standard error of the means. Asterisk indicates significant difference between means (P ≤0.05).
Source publication
Fruit size regulation was studied in the apple cultivar 'Gala' and a large fruit size spontaneous mutant of 'Gala', 'Grand Gala' (GG). GG fruits were 15% larger in diameter and 38% heavier than 'Gala' fruits, largely due to an increase in size of the fruit cortex. The mutation in GG altered growth prior to fruit set and during fruit development. Pr...
Contexts in source publication
Context 1
... number (cell layers) in the floral-tube tissue was not significantly different between 'Gala' and GG at 6 d before bloom but was higher by five cell layers at bloom and at 4 DAFB ( Fig. 2A, inset). The absolute and relative cell production rates were significantly higher in GG at bloom (P <0.05). In apple flowers, pollination and fertilization occur several days after bloom resulting in the stimulation of cell production and fruit growth. Such an increase in cell production was observed in 'Gala' and GG fruits between 4-9 DAFB. ...Context 2
... <0.05). In apple flowers, pollination and fertilization occur several days after bloom resulting in the stimulation of cell production and fruit growth. Such an increase in cell production was observed in 'Gala' and GG fruits between 4-9 DAFB. Cell number in the GG fruit cortex was higher than that in 'Gala' during early fruit growth (9-28 DAFB; Fig. 2A). However, cell number was not significantly different between 'Gala' and GG during the later stages of fruit growth (43 DAFB-harvest; Fig. 2A). The absolute and relative cell production rates were not significantly different between 'Gala' and GG during fruit growth. The majority of cell production in 'Gala' fruits occurred between ...Context 3
... growth. Such an increase in cell production was observed in 'Gala' and GG fruits between 4-9 DAFB. Cell number in the GG fruit cortex was higher than that in 'Gala' during early fruit growth (9-28 DAFB; Fig. 2A). However, cell number was not significantly different between 'Gala' and GG during the later stages of fruit growth (43 DAFB-harvest; Fig. 2A). The absolute and relative cell production rates were not significantly different between 'Gala' and GG during fruit growth. The majority of cell production in 'Gala' fruits occurred between 4-24 DAFB after which cell production occurred at a lower rate ( Fig. 2A, inset). In GG fruits, cell production was initiated at the same time as ...Context 4
... between 'Gala' and GG during the later stages of fruit growth (43 DAFB-harvest; Fig. 2A). The absolute and relative cell production rates were not significantly different between 'Gala' and GG during fruit growth. The majority of cell production in 'Gala' fruits occurred between 4-24 DAFB after which cell production occurred at a lower rate ( Fig. 2A, inset). In GG fruits, cell production was initiated at the same time as in 'Gala' but continued only until 20 DAFB after which cell production occurred at a lower rate ( Fig. 2A, inset). These data indicate that GG fruit cortex cells exited the cell production phase earlier than those in ...Context 5
... 'Gala' and GG during fruit growth. The majority of cell production in 'Gala' fruits occurred between 4-24 DAFB after which cell production occurred at a lower rate ( Fig. 2A, inset). In GG fruits, cell production was initiated at the same time as in 'Gala' but continued only until 20 DAFB after which cell production occurred at a lower rate ( Fig. 2A, inset). These data indicate that GG fruit cortex cells exited the cell production phase earlier than those in ...Context 6
... in the floral-tube tissue of GG had larger radial cell diameter prior to bloom, at bloom, and at 4 DAFB (Fig. 2B, inset). Between 4-9 DAFB, cells in GG fruits had a lower relative rate of cell expansion (P¼0.04). Radial cell diameter in GG fruits was not significantly different from that of 'Gala' from 9-16 DAFB (Fig. 2B). Between 16-20 DAFB, GG fruit cells had a higher relative cell expansion rate (P¼0.02) resulting in 24% higher cell diameter at 20 ...Context 7
... in the floral-tube tissue of GG had larger radial cell diameter prior to bloom, at bloom, and at 4 DAFB (Fig. 2B, inset). Between 4-9 DAFB, cells in GG fruits had a lower relative rate of cell expansion (P¼0.04). Radial cell diameter in GG fruits was not significantly different from that of 'Gala' from 9-16 DAFB (Fig. 2B). Between 16-20 DAFB, GG fruit cells had a higher relative cell expansion rate (P¼0.02) resulting in 24% higher cell diameter at 20 DAFB (Fig. 2B, inset). Thereafter, cell diameter in GG continued to be significantly higher than that in 'Gala'. At harvest, radial cell diameter in GG fruits was 15% greater than that in 'Gala' (Fig. 2B), ...Context 8
... inset). Between 4-9 DAFB, cells in GG fruits had a lower relative rate of cell expansion (P¼0.04). Radial cell diameter in GG fruits was not significantly different from that of 'Gala' from 9-16 DAFB (Fig. 2B). Between 16-20 DAFB, GG fruit cells had a higher relative cell expansion rate (P¼0.02) resulting in 24% higher cell diameter at 20 DAFB (Fig. 2B, inset). Thereafter, cell diameter in GG continued to be significantly higher than that in 'Gala'. At harvest, radial cell diameter in GG fruits was 15% greater than that in 'Gala' (Fig. 2B), in spite of a lower relative cell expansion rate between 71 DAFB and harvest (P¼0.001). Change in cell size was further characterized through an analysis ...Context 9
... 9-16 DAFB (Fig. 2B). Between 16-20 DAFB, GG fruit cells had a higher relative cell expansion rate (P¼0.02) resulting in 24% higher cell diameter at 20 DAFB (Fig. 2B, inset). Thereafter, cell diameter in GG continued to be significantly higher than that in 'Gala'. At harvest, radial cell diameter in GG fruits was 15% greater than that in 'Gala' (Fig. 2B), in spite of a lower relative cell expansion rate between 71 DAFB and harvest (P¼0.001). Change in cell size was further characterized through an analysis of the distribution of cell area during fruit growth. In comparison to 'Gala,' a higher proportion of cells in GG had a larger cell area at full bloom (FB), 28 DAFB, and 127 DAFB ...Context 10
... major focus of the current study was to understand the effect of the mutation in GG on fruit size, and on mechanisms such as cell production and cell expansion. Prior to fruit set, an increase in carpel/floral-tube size was observed in GG, along with an increase in cell number and size (Figs 1A, 2; see Supplementary Fig. S1 at JXB online). These data indicate that the mutation in GG affects flower growth prior to fruit set. ...Context 11
... (E) MdCYCB2; (F) MdCYCD3; (G) MdKRP; (H) MdWEE. MdGAPDH and MdACTIN were used for normalization of gene expression data. Data show expression of a gene relative to its expression at 0 d after full bloom in 'Gala' fruits. Error bars indicate standard error of the means (n¼4). Asterisk indicates significant difference between the means (P <0.05). Fig. 2A), similar to that observed in tomato (Chevalier, 2007). This indicates a cessation of cell production prior to fruit set. However, at least a proportion of cells in the carpel/floral-tube retain competence for cell division during this period as cell production resumes after pollination and fertilization, resulting in a stimulation of ...Context 12
... G1/S phase of the cell cycle during this period. Cells in the floral-tube tissue, which retain competence for division, may divide in response to G1/S phase promotion resulting in an increase in cell number around bloom in GG. A significant increase in the cell production rate and a higher cell number around bloom in GG support this conclusion ( Fig. 2A). Cells that are not competent for division may enter endoreduplication cycles in response to the G1/S phase promotion by the mutation in GG. A large proportion of cells in the carpel/floral-tube tissue of GG exhibited a DNA content of 4C around bloom. While some of the 4C proportion is constituted by cells undergoing division (G2/M ...Context 13
... by fruit set (pollination and fertilization). This phase of cell production was initiated between 4-9 DAFB in 'Gala' and GG fruits. The higher cell number in GG fruits during early fruit growth (9-20 DAFB) was probably facilitated by a higher cell number prior to pollination and the fertilization-dependent stimulation of cell production ( Fig. 2A, inset). Similar relative cell production rates in 'Gala' and GG fruits between 4-20 DAFB support this conclusion. GG fruit cortex cells exited the cell production phase at least 4 d earlier than in 'Gala' as a result of which final cell number was not significantly different between 'Gala' and GG (Fig. 2A). These data indicate that cortex ...Context 14
... stimulation of cell production ( Fig. 2A, inset). Similar relative cell production rates in 'Gala' and GG fruits between 4-20 DAFB support this conclusion. GG fruit cortex cells exited the cell production phase at least 4 d earlier than in 'Gala' as a result of which final cell number was not significantly different between 'Gala' and GG (Fig. 2A). These data indicate that cortex cells in GG progressed through fewer cycles of cell production during fruit growth. An increase in the proportion of cells with a DNA content of 4C and a concurrent decrease in the 2C proportion were observed during the period of exit from cell production in GG, which suggests G2 arrest in GG fruit ...Context 15
... in cell size in GG fruits was observed during the period of exit from cell production (between 20-43 DAFB; Fig. 2B; see Supplementary Fig. S1 at JXB online) and was concurrent with an increase in the proportion of cells with a DNA content of 4C (Fig. 4), which suggests that the enhanced cell size of the fruit cortex cells in GG is associated with G2 arrest. It is likely that fruit cortex cells in GG expanded normally during this period but ...Similar publications
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BACKGROUND AND AIMS:
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Current approaches to monitor and quantify cell division in live cells, and reliably distinguish between acytokinesis and endoreduplication, are limited and complicate determination of stem cell pool identities. Here we overcome these limitations by generating an in vivo reporter system using the scaffolding protein anillin fused to enhanced green...
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Citations
... Monthan (Kumar, 2015). Malladi and Hirst (2010) studied the fruit characteristics of apple cultivar Gala and its mutant Grand Gala and found that the mutant is 15 per cent larger in diameter and 38 per cent heavier than Gala fruits, together with highest TSS and lowest seed count. Zhang and Dai (2011) reported that standard apple tree mutant derived from the crosses of Fuji Telamon resulted in a columnar apple mutant with larger and darker green leaves, short and strong internode, higher leaf area index, higher spur: mature branch ratio (73.5 per cent), per cent of short-shoots (68.8), chlorophyll A and B content (1.878 and 0.771mg g -¹) than standard apple. ...
Genetic variation is essential for crop breeding. In classical plant breeding programme, variation is generated by hybridization and selections are made from the resulting segregating generations. Induced mutagenesis can supplement hybridization or able to replace as a source of variability. Since, mutations bring about variation, they provide the ultimate basis for evolution of new forms, varieties or species. Induced and spontaneous mutations have played an important role in developing improved cultivars of various fruit crops as a supplementary method to conventional breeding. But, induced mutations also have well defined limitations in fruit breeding applications, but their possibilities may be expanded by the use of in vitro mutation techniques.
... A previous study evaluating 'Arbequina' fruit developing during drought concluded that carbon and water processes can explain fruit growth, with importance placed on the combination of cell division and expansion [30]. Many previous studies of various fruit-bearing species have supported this suggestion [34][35][36][37][38]. Similarly, we found that olive fruit of the large-fruited cultivars enlarged due to relatively higher cell division and expansion rates compared with the small-fruited cultivar during early fruit development. ...
Olive (Olea europaea L.) is one of the major oil fruit tree crops worldwide. However, the mechanisms underlying olive fruit growth remain poorly understood. Here, we examine questions regarding the interaction of endoreduplication, cell division, and cell expansion with olive fruit growth in relation to the final fruit size by measuring fruit diameter, pericarp thickness, cell area, and ploidy level during fruit ontogeny in three olive cultivars with different fruit sizes. The results demonstrate that differences in the fruit size are related to the maximum growth rate between olive cultivars during early fruit growth, about 50 days post-anthesis (DPA). Differences in fruit weight between olive cultivars were found from 35 DPA, while the distinctive fruit shape became detectable from 21 DPA, even though the increase in pericarp thickness became detectable from 7 DPA in the three cultivars. During early fruit growth, intense mitotic activity appeared during the first 21 DPA in the fruit, whereas the highest cell expansion rates occurred from 28 to 42 DPA during this phase, suggesting that olive fruit cell number is determined from 28 DPA in the three cultivars. Moreover, olive fruit of the large-fruited cultivars was enlarged due to relatively higher cell division and expansion rates compared with the small-fruited cultivar. The ploidy level of olive fruit pericarp between early and late growth was different, but similar among olive cultivars, revealing that ploidy levels are not associated with cell size, in terms of different 8C levels during olive fruit growth. In the three olive cultivars, the maximum endoreduplication level (8C) occurred just before strong cell expansion during early fruit growth in fruit pericarp, whereas the cell expansion during late fruit growth occurred without preceding endoreduplication. We conclude that the basis for fruit size differences between olive cultivars is determined mainly by different cell division and expansion rates during the early fruit growth phase. These data provide new findings on the contribution of fruit ploidy and cell size to fruit size in olive and ultimately on the control of olive fruit development.
... These mutant lines show that reduced fruit size is caused by an overall smaller cell size. In apples, a spontaneous mutant of the cultivar Gala, Grand Gala, with a large fruit size was identified, which was 15% larger in diameter and 38% heavier than Gala fruit [33]. This result was largely due to altered cell production and enhanced cell size. ...
Gamma-ray irradiation is one of the most widely used mutagens worldwide. We previously conducted mutation breeding using gamma irradiation to develop new Citrus unshiu varieties. Among these mutants, Gwonje-early had an ovate shape, a protrusion of the upper part of the fruit, and a large fruit size compared with wild-type (WT) fruits. We investigated the external/internal morphological characteristics and fruit sugar/acid content of Gwonje-early. Additionally, we investigated genome-wide single-nucleotide polymorphisms (SNPs) and insertion/deletion (InDel) variants in Gwonje-early using whole-genome re-sequencing. Functional annotation by Gene Ontology analysis confirmed that InDels were more commonly annotated than SNPs. To identify specific molecular markers for Gwonje-early, allele-specific PCR was performed using homozygous SNPs detected via Gwonje-early genome re-sequencing. The GJ-SNP1 and GJ-SNP4 primer sets were effectively able to distinguish Gwonje-early from the WT and other commercial citrus varieties, demonstrating their use as specific molecular markers for Gwonje-early. These findings also have important implications in terms of intellectual property rights and the variety protection of Gwonje-early. Our results may provide insights into the understanding of morphological traits and the molecular breeding mechanisms of citrus species.
... In addition to the QTL study, genetic factors involved in fruit size were investigated through comparative analysis using sports that showed a difference in fruit size from the original variety. 'Grand Gala,' which is a sport from 'Gala' and has a larger fruit size, increased cell production and cell size when compared to 'Gala' (Malladi & Hirst, 2010). Furthermore, cell cycle-related genes MdCDKA1 and MdCYCA2 have been highlighted as candidate genes for the fruit size difference based on their expression. ...
... Sung and Chen (1990) reported that cell size in cotyledons begins to increase only when the number of cells in cotyledon approaches their maxima. Malladi and Hirst (2010) reported enhanced fruit size in an apple Gala mutant was facilitated by increased cell size. Cheniclet et al. (2005) have also reported that cell size was positively associated with fruit size in tomato, therefore, increased cell size may be one of the significant factors for large pods in the mutant TG 89. ...
A large seed mutant, TG 89 having a 76.7% increment in hundred kernel weight in comparison to its parent TG 26, was isolated from an electron beam-induced mutagenized population. Studies based on environmental scanning electron microscopy of both parent and mutant revealed that the mutant seed cotyledon had significantly bigger cell size than parent. A mapping population with 122 F2 plants derived from the mutant and a distant normal seed genotype (ICGV 15007) was utilized to map the QTL associated with higher HKW. Bulk segregant analysis revealed putative association of three markers with this mutant large seed trait. Further, genotyping of F2 individuals with polymorphic markers detected 14 linkage groups with a map distance of 1053 cM. QTL analysis revealed a significant additive major QTL for the mutant large seed trait on linkage group A05 explaining 12.7% phenotypic variation for the seed size. This QTL was located between flanking markers AhTE333 and AhTE810 having a map interval of 4.7 cM which corresponds to 90.65 to 107.24 Mbp in A05 chromosome, respectively. Within this genomic fragment, an ortholog of the BIG SEEDS 1 gene was found at 102,476,137 bp. Real-time PCR revealed down-regulation of this BIG SEEDS 1 gene in the mutant indicating a loss of function mutation giving rise to a large seed phenotype. This QTL was validated in 11 advanced breeding lines having large seed size from this mutant but with varied genetic backgrounds. This validation showcased a highly promising selection accuracy of 90.9% for the marker-assisted selection.
... In apples, fruit development from pollination to full ripping presents a simple sigmoidal growth curve (Denne 1963). Final fruit size is determined by both cell division and cell expansion during fruit growth and development (Denne 1963;Olmstead et al. 2007;Malladi & Hirst 2010). Cell number has a much close relationship with fruit size (Bain & Robertson 1951;Westwood et al. 1967;Malladi & Hirst 2010;Karim et al. 2022). ...
... Final fruit size is determined by both cell division and cell expansion during fruit growth and development (Denne 1963;Olmstead et al. 2007;Malladi & Hirst 2010). Cell number has a much close relationship with fruit size (Bain & Robertson 1951;Westwood et al. 1967;Malladi & Hirst 2010;Karim et al. 2022). The cell division occurs during the fruit set and continues until 35-50 days after anthesis (DAA), and the final fruit cell number is determined in this phase (Denne 1963;Karim et al. 2022). ...
Final fruit size of apple (Malus domestica) cultivars is related to both mesocarp cell division and cell expansion during fruit growth, but it is unclear whether the cell division and/or cell enlargement determine most of the differences in fruit size between Malus species. In this study, by using an interspecific hybrid population between Malus asiatica “Zisai Pearl” and Malus domestica cultivar “Red Fuji,” we found that the mesocarp cell number was the main causal factor of diversity in fruit size between Malus species. Rapid increase in mesocarp cell number occurred prior to 28 days after anthesis (DAA), while cell size increased gradually after 28 DAA until fruit ripening. Six candidate genes related to auxin signaling or cell cycle were predicted by combining the RNA-seq data and previous QTL data for fruit weight. Two InDels and 10 SNPs in the promoter of a small auxin upregulated RNA gene MdSAUR36 in Zisai Pearl led to a lower promoter activity than that of Red Fuji. One non-synonymous SNP G/T at 379 bp downstream of the ATG codon of MdSAUR36, which was heterozygous in Zisai Pearl, exerted significant genotype effects on fruit weight, length, and width. Transgenic apple calli by over-expressing or RNAi MdSAUR36 confirmed that MdSAUR36 participated in the negative regulation of mesocarp cell division and thus apple fruit size. These results could provide new insights in the molecular mechanism of small fruit size in Malus accession and be potentially used in molecular assisted breeding via interspecific hybridization.
... In apple, fruit development from pollination to fully ripping presents a simple sigmoidal growth curve (Denne, 1963). Final fruit size is determined by both cell division and cell expansion during fruit growth and development (Denne, 1963;Olmstead et al., 2007;Malladi & Hirst, 2010). Cell number has a much close relationship with fruit size (Bain & Robertson, 1951;Westwood et al., 1967;Malladi & Hirst, 2010;Karim et al., 2022). ...
... Final fruit size is determined by both cell division and cell expansion during fruit growth and development (Denne, 1963;Olmstead et al., 2007;Malladi & Hirst, 2010). Cell number has a much close relationship with fruit size (Bain & Robertson, 1951;Westwood et al., 1967;Malladi & Hirst, 2010;Karim et al., 2022). The cell division occurs during fruit set, continues until 35-50 day after anthesis (DAA), and the nal fruit cell number is determined in this phase (Denne, 1963;Karim et al., 2022). ...
Final fruit size of apple ( Malus domestica ) cultivars is related to both mesocarp cell division and cell expansion during fruit growth, but it is unclear whether the cell division and/or cell enlargement determine most the differences in fruit size between Malus species. In this study, by using an interspecific hybrid population between M. asiatica ‘Zisai Pearl’ and M. domestica cultivar ‘Red Fuji’, we found that the mesocarp cell number was the main causal factor of diversity in fruit size between Malus species. Rapid increase in mesocarp cell number occurred prior to 28 days after anthesis (DAA), while cell size increased gradually after 28 DAA until fruit ripening. Six candidate genes related to auxin signaling or cell cycle were predicted by combining the RNA-seq data and previous QTL data for fruit weight. Two InDels and 10 SNPs in the promoter of a small auxin upregulated RNA gene MdSAUR36 in ‘Zisai Pearl’ led to a lower promoter activity than that of ‘Red Fuji’. One non-synonymous SNP G/T at 379 bp downstream of the ATG codon of MdSAUR36, which was heterozygous in ‘Zisai Pearl’, exerted significant genotype effects on fruit weight, length, and width. Transgenic apple calli by over-expressing or RNAi MdSAUR36 confirmed that MdSAUR36 participated in the negative regulation of mesocarp cell division and thus apple fruit size. These results could provide new insights in the molecular mechanism of small fruit size in Malus accession and be potentially used in molecular assisted breeding via interspecific hybridization.
... The relative normalized expression of each gene was analyzed using CFX manager software (Bio-Rad). Gene expression was normalized using two reference genes, MdActin (Zhou et al., 2017) and MdGAPDH (Malladi and Hirst, 2010), and then calculated relative to the expression level in the control sample ('Cripps Pink' at 200 CH). The expression of each gene was compared using a student's t-test between 'Honeycrisp' and 'Cripps Pink' at each time point, using R programming language for statistical computing and graphics version 4.2.2. ...
This study endeavors to explore the transcriptomic profiles of two apple cultivars, namely, ‘Honeycrisp’ and ‘Cripps Pink,’ which represent late and early-blooming cultivars, respectively. Using RNA-sequencing technology, we analyzed floral bud samples collected at five distinct time intervals during both endodormancy and ecodormancy. To evaluate the transcriptomic profiles of the 30 sequenced samples, we conducted principal component analysis (PCA). PC1 explained 43% of the variance, separating endodormancy and ecodormancy periods, while PC2 explained 16% of the variance, separating the two cultivars. The number of differentially expressed genes (DEGs) increased with endodormancy progression and remained elevated during ecodormancy. The majority of DEGs were unique to a particular time point, with only a few overlapping among or between the time points. This highlights the temporal specificity of gene expression during the dormancy transition and emphasizes the importance of sampling at multiple time points to capture the complete transcriptomic dynamics of this intricate process. We identified a total of 4204 upregulated and 7817 downregulated DEGs in the comparison of endodormancy and ecodormancy, regardless of cultivar, and 2135 upregulated and 2413 downregulated DEGs in the comparison of ‘Honeycrisp’ versus ‘Cripps Pink,’ regardless of dormancy stage. Furthermore, we conducted a co-expression network analysis to gain insight into the coordinated gene expression profiles across different time points, dormancy stages, and cultivars. This analysis revealed the most significant module (ME 14), correlated with 1000 GDH and consisting of 1162 genes. The expression of the genes within this module was lower in ‘Honeycrisp’ than in ‘Cripps Pink.’ The top 20 DEGs identified in ME 14 were primarily related to jasmonic acid biosynthesis and signaling, lipid metabolism, oxidation-reduction, and transmembrane transport activity. This suggests a plausible role for these pathways in governing bud dormancy and flowering time in apple.
... The number of fruits per tree and yield were slightly higher in hand thinning than both of full-and half-strings thinning treatments but the results were not statistically different among all treatments ( Table 2). The increase in fruit size and weight is associated with the increase in cell number and cell size in fruits [29,30]. The fruit set rate and tree crop load level also influence fruit size [25]. ...
This study aimed to identify the efficiency of mechanical flower thinning (MFT) and its influence on apple fruit quality. In the first experiment, ‘Arisoo’ apple flowers were subjected to MFT with one hundred sixty-two (half) and three hundred twenty-four (full) strings at the same rotor (300 rpm) and tractor (6 km/h) speeds. Hand thinning was performed as a control. The number of removed flowers in each terminal and lateral flower cluster was slightly higher in MFT with full-strings than that of MFT with half-strings. The fruit set rate was lower in MFT with full-strings than that of MFT with half-strings. However, the use of full-strings during mechanical thinning increased the leaf damage rate compared to half-strings. Except a* value, MFT with full-strings improved flesh firmness, soluble solids content (SSC) and titratable acidity (TA), and reduced starch pattern index of fruits at harvest compared to the control. In the second experiment, ‘Fuji’ apple flowers were subjected to chemical thinning, MFT (300 rpm, 6 km/h), and MFT + chemical thinning treatments and compared with hand thinning (control). The thinning efficiency of MFT was similar to that of chemical thinning and MFT + chemical thinning treatments in terms of the removal of flowers and fruit set rates. Compared to the control, MFT, chemical thinning, and their combined treatments improved flesh firmness and SSC of fruits at harvest. TA was highest in the chemical thinning treatment compared to other thinning treatments. However, fruit size, weight, and a* value were unaffected by any treatment. In conclusion, the use of full-strings during MFT achieved optimal results in ‘Arisoo’ apples. In ‘Fuji’ apples, MFT treatment alone achieved effective results and the addition of chemical thinning after MFT had no supportive role in thinning efficiency and fruit quality.
... Mutations affecting fruit size have been previously reported in several studies [5,23]. The size increase is attributed to an increase in the number of cells, or a larger size of individual cells [24,25]; however, the exact mechanism requires further investigation. . The different small letters on the bar graphs indicate significant differences (p < 0.05). ...
... Mutations affecting fruit size have been previously reported in several studies [5,23]. The size increase is attributed to an increase in the number of cells, or a larger size of individual cells [24,25]; however, the exact mechanism requires further investigation. ...
Citrus exhibits unique nutritional values. Most citrus cultivars are derived from mutations. However, the effect of these mutations on fruit quality is unclear. We have previously found a yellowish bud mutant in the citrus cultivar ‘Aiyuan 38’. Therefore, this study aimed to determine the effect of the mutation on fruit quality. ‘Aiyuan 38’ (WT) and a bud mutant variant (MT) were used to analyze variations in fruit color variation and flavor substances using colorimetric instruments, high-performance liquid chromatography (HPLC), headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPME-GC–MS), and odor activity values (OAVs). The mutation in MT conferred yellowish characteristics to its peel. Although the differences in total sugar and acid content of the pulp were not statistically significant between WT and MT, the MT glucose content was significantly lower and the malic acid level was significantly higher. HS-SPME-GC–MS analysis revealed that the MT pulp released more types and contents of volatile organic compounds (VOCs) than the WT, whereas the opposite trend was observed for the peel. Analysis of the OAV revealed that the MT pulp contains 6 unique VOCs, whereas the peel contains only 1. This study provides a useful reference for the study of flavor substances associated with citrus bud mutations.
