• Horticultural Science & Technology
• /
• v.29 no.6
• /
• pp.531-538
• /
• 2011

This study was carried out to investigate the influence of defoliation by Marssonina blotch (Diplocarpon mali Harada et Sawamura) on vegetative growth and fruit quality in 'Fuji'/M.9 apple tree. Soluble solid contents decreased when the defoliation percentage by Marssonina blotch was over 10% before the end of September, and fruit weight decreased when percentage of defoliation was over 30%. Fruit red color and starch contents tend to decrease as percentage of defoliation near the fruit increased. Return bloom, fruit weight, and shoot growth the following year tend to decrease as percentage of defoliation increased. Photosynthetic rate of healthy leaves in bourse shoot during the end of September was maintained about $10{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, effects in increasing fruit growth and soluble solid contents after the end of September. Photosynthetic rates for the damaged leaf, damaged area was over 50% on the leaf surface, while 30% of the photosynthetic rates of healthy leaf are without damage applied with Marssonina blotch at the end of September. The results show that the decrease of fruit quality in defoliation treatments may be caused by the decrease of starch contents in fruit, and that was caused by the photosynthetic rates of leaves near fruit was decreased by Marssonina blotch in the wake of August.

• Horticultural Science & Technology
• /
• v.18 no.3
• /
• pp.373-377
• /
• 2000

This study was carried out to verify the effect of fruit thinning on fruit development, and the results were as follows. The number of cells between fruit epidermis and periphery vascular bundle during 35 to 184 days after full bloom (DAFB) were constant with 14~17 cells, regardless of thinning at pink bud stage, fruitlet stage or non-thinning. However, the distance between epidermis and vascular bundle was longest in the fruit thinned at pink stage followed by fruits thinned at fruitlet stage and control. Therefore, it was seemed that the fruit size increment during 35 to 184 DAFB was due to the increment of cell size. Thinning time affected fruit size and the earlier the thinning times were the bigger the fruits were. However, there were no direct relationships between thinning time and the starch or tannin particle development in the cells of the fruit.

• Preventive Nutrition and Food Science
• /
• v.22 no.3
• /
• pp.237-240
• /
• 2017

Amygdalin contents of the seeds, endocarps, and mesocarps from three peach cultivars (i.e., Stone Peach, Hikawa Hakuho, and Bakhyang) were measured at three stages of fruit development (stone-hardening, fruit enlargement, and ripening). The peach samples were dried and defatted with a Soxhlet apparatus, reflux extracted with methanol, and analyzed using reverse phase high-performance liquid chromatography. During all fruit development stages, the amygdalin contents in the seeds were higher than those in the endocarps and mesocarps. The amygdalin contents of the Stone Peach were comparatively higher than the Hikawa Hakuho and Bakhyang (P<0.05). Further, the amygdalin contents during ripening were very low or not detected. Overall, the amygdalin contents of the three peach cultivar samples (seed, endocarp, and mesocarp) increased until the fruit enlargement stage and either remained constant or decreased during ripening.

• Horticulture, Environment, and Biotechnology : HEB
• /
• v.59 no.6
• /
• pp.787-804
• /
• 2018

Flavor quality is import for determining consumer perception and acceptance of tomato products. In this study, 'Fendou' tomato fruit were harvested at six ripening stages and sampled to investigate the development of flavor-relevant compounds during vine ripening. Results showed that upon the initiation of ripening there was an increase in respiration rate and concomitant ethylene evolution that was associated with increased membrane permeability. In accordance with these physiological changes, flavor-relevant compounds demonstrated different expression patterns as fruit ripened, which contributed to 'red-ripe' flavor characteristics of red-ripe fruit. Based on correlation analysis between ethylene evolution and the flavor-relevant compounds during 'Fendou' tomato ripening and the other researchers' reports, the activation of System 2-dependent autocatalytic ethylene production plays an important role in the development of most flavor-relevant compounds during tomato vine ripening. Overall, our results suggested that most flavor-relevant compounds that accumulated the most during tomato fruit ripening at red stage could be under ethylene regulation and were among the most important contributors to the 'red-ripe' flavor. Due to the development of these compounds, the flavor quality at late ripening stages is different from that of fruit at early ripening stages.

• Horticultural Science & Technology
• /
• v.32 no.5
• /
• pp.614-622
• /
• 2014

Melons (Cucumis melo L.) are generally grafted onto Cucurbita rootstocks to manage soilborne pathogens such as Monosporascus root rot and v ine decline (MRR/VD) and Fusarium wilt. However, g rafting onto Cucurbita rootstocks reportedly results in the reduction of fruit quality. In this study, the resistance to MRR/VD, yield, and fruit quality of melons grafted onto melon rootstocks were evaluated under greenhouse conditions. Eight melon rootstocks (R1 to R8) were used and the inodorus melon 'Homerunstar' was used as scion. Melon rootstocks R1 to R6 were selected based on resistance to MRR/VD under greenhouse conditions. Non-grafted 'Homerunstar' and plants grafted onto squash interspecific hybrid 'Shintozwa' rootstock (Cucurbita maxima D. ${\times}$ C. moschata D.) served as controls. Grafted melons were cultivated in the greenhouse infested with Monosporascus cannonballus during two growing seasons (summer and autumn). The responses to MRR/VD, yield, and fruit quality differed depending on the rootstocks and growing season. The melons grafted onto 'Shintozwa' exhibited less severe disease symptoms and higher survival rates than non-grafted melons in both seasons. While the melon rootstocks in the summer cultivation did not increase the survival rate compared to non-grafted melons, the melon rootstocks R1 and R2 in the autumn cultivation led to higher survival rates. The melon rootstocks resistant to MRR/VD increased the percentage of marketable fruits and marketable yields. Grafting onto the melon rootstocks caused little or no reduction of fruit quality such as low calcium content, fruit softening, and vitrescence, especially in lower-temperature autumn season. Accordingly, these results suggest that grafting onto the melon rootstocks may increase the tolerance to MRR/VD and the marketable yield without a reduction of fruit quality.

• Journal of Species Research
• /
• v.11 no.3
• /
• pp.155-161
• /
• 2022

Acetic acid bacteria (AAB) convert ethanol to acetic acid through oxidation, and the fermentation pathway of AAB is important in the vinegar industry. The genus Acetobacter is the representative one of AAB, and several Korean traditional vinegars are produced using Acetobacter strains. Until now, four species in the genus Acetobacter were reported as native species in Korea. During the past two years, we isolated several AAB strains from fruits, flowers and fermented foods, and several AAB species unrecorded in Korea were found on the basis of 16S rRNA gene sequence analyses. In this study, we report eight Acetobacter species as native ones which are A. fabarum C10-3 (=KACC 21483) isolated from plumcot fruit (Naju-si), A. lovaniensis KDG-EC1 (=KACC 22697) isolated from diced radish kimchi (Naju-si), A. okinawensis GAM12-M2 (=KACC 22696) isolated from persimmon fruit (Sangju-si), A. orientalis FR32C4 (=KACC 22370) isolated from fruit of Cudrania tricuspidata (Jeonju-si), A. papaya FR35B3 (=KACC 22046) isolated from grape fruit (Yeongdong-gun), A. suratthaniensis GAM15-R2 (=KACC 22694) isolated from persimmon fruit(Gimje-si), A. syzygii C25-1 (=KACC 22048) isolated from peach fruit (Namwon-si) and A. thailandicus JDF1-M1 (=KACC 22693) isolated from plum fruit(Seoul).

• Horticultural Science & Technology
• /
• v.28 no.3
• /
• pp.387-393
• /
• 2010

The free sugar content and related enzymes of four different parts, inner, outer, stylar end and stem end, of 'Changhowon Hwangdo' peach ($Prunus$ $persica$, L. Batsch) fruit were compared from August to September in 2006, i.e., from 120 to 150 days after full bloom (DAFB). The soluble solids content (SSC) of stylar end was the highest among the four fruit parts at 150 DAFB. Changes of free sugar content were similar to that of SSC in the four parts. The starch content at the stylar end was the highest at 120 DAFB, while all the other parts showed low starch contents at 150 DAFB. The free sugar composition of peach changed during fruit development. The sucrose was low at 120 DAFB and increased gradually in all parts of peach fruit. On the contrary glucose, fructose and sorbitol decreased with fruit development. The free sugar contents and related enzymes activities were investigated during fruit development. The rapid increase of sucrose contents during fruit development was more affected by sucrose synthase than sucrose phosphate synthase. Activity of SS in the four fruit parts increased continuously over the fruit development period, but activity of acid invertase showed a downward trend. This study found that the free sugar content was affected by enzyme activity for the synthesis or the cleavage. However, it was very difficult to explain sugar accumulation of peach segments with related-enzymes.

• Korean Journal of Environmental Agriculture
• /
• v.39 no.4
• /
• pp.360-367
• /
• 2020

BACKGROUND: The productivity and quality of blueberry (Vaccinium ashei Reade) greatly depend on the number of fruits in a plant. Especially, fruit set more than appropriate number negatively affects productivity and marketability due to the increased number of small fruits and delayed harvest time. This study was conducted to investigate proper timing and concentration for applying chemical blossom thinners such as ammonium thiosulfate (ATS) and UREA. METHODS AND RESULTS: ATS at 1.25% and 1.50%, and UREA at 6% and 8% were applied in four developmental stages, bud swell, pink bud, full bloom and petal fall. Fruit thinning rate was calculated based on the number of fruits harvested divided by that of flowers before applying blossom thinners. Ratios of leaf to flower and leaf to fruit were calculated based on the number of fully developed leaves in 25 days after full blossom divided by that of flowers or fruits, respectively. Chemical injury of leaves was investigated by calculating the number of leaves with chemical injury divided by the total number of leaves. Fruit thinning rates were 48% and 66% for UREA treatments at 6% and 8%, respectively, and 49% and 62% for ATS treatments at 1.25% and 1.50%, respectively, in the full bloom stage. In the petal fall stage, fruit thinning rates were 18% and 24% for UREA treatments at 6% and 8%, respectively, and 49% and 35% for ATS treatments at 1.25% and 1.50%, respectively. Leaf to fruit ratio (L/FR) increased by 109% and 188% compared to leaf to flower ratio in ATS treatments at 1.25% and 1.50%, respectively, and L/FR increased 93 and 196% in UREA treatments at 6% and 8%, respectively, in the full bloom stage. In the petal fall stage, leaf to fruit ratio increased by 60% to 100% in ATS treatments, but did not significantly differ from the control in UREA treatments. Fruit harvest was delayed in all treatments of all developmental stages except for 1.5% ATS and 6% UREA treatments at the petal fall stage, whose fruit harvest was two or three days faster than the control. CONCLUSION: The application of ATS and UREA for blossom thinning should be in the petal fall and full bloom stages for early and late harvest, respectively. Considering chemical injury, integrated harvesting and fruit size, however, it is appropriate to apply ATS at 1.5% in the petal fall stage to increase fruit productivity and quality in blueberry.

• Korean Journal of Breeding Science
• /
• v.43 no.2
• /
• pp.139-144
• /
• 2011

Fifty-five sweet pepper (Capsicum annuum L.) germplasm from the Rural Development Administration (RDA) were analyzed for their fruit yield and fruit quality characters, including fruit weight, fruit size, pericarp thickness, total soluble content, fruit lobe, fruit shape, fruit surface and fruit color. Fruit yield per plot ranged from 200 g to 8150 g (average, 1884 g). Fruit fresh-weight per fruit ranged from 27.3 g to 200.0 g with an average of 97.2 g. Fruit length varied from 4.0 cm to 16.2 cm (average, 9.6 cm). Fruit length-to-width ratio ranged from 0.6 to 3.0 with an average 1.7. The fruit pericarp thickness ranged from 1.8 mm to 10.7 mm (average, 4.8 mm). Total soluble content was the highest ($8.5^{\circ}Brix$) in K156286 and the lowest ($5.3^{\circ}Brix$) in K156208 with the average value $6.7^{\circ}Brix$. Fruit lobes numbers varied from 2 to 4. Blocky, triangular, elongated, rectangular and round fruit shape identified among the sweet pepper accessions. Fruit surface varied from smooth to wrinkle and fruit color also varied. The presence of variability in fruit yield and quality traits within the sweet pepper genotypes can be utilized to develop high yielding sweet pepper variety with better fruit quality characters.

• Research in Plant Disease
• /
• v.12 no.3
• /
• pp.185-188
• /
• 2006

In September and October 2005, melons(Cucumis melo L.) from the commercial greenhouses in Naju and Gwangju exhibited severe foliar necrosis and fruit rot. Leaf symptoms initially appeared as V-shaped, necrotic lesions and extending to the midrib. Symptoms on the fruit were occurred randomly as necrotic and sunken spots. Two isolates from diseased leaves and fruits were identified as Acidovorax avenae subsp. citrulli on the basis of bacteriological and genetic characteristics. Pathogenicity of the isolates was confirmed by inoculating on 3-week-old melon and cucumber seedlings. This is the first report of bacterial fruit blotch of melon in Korea.