scholarly journals CULTIVAR VARIATION IN APPLE FRUIT GROWTH RATES, SORBITOL ACCUMULATION, AND TISSUE OSMOTIC POTENTIAL

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1070b-1070
Author(s):  
Dougles D. Archbold

Absolute and relative fruit growth rates (AGR and RGR) of 5 cultivars were calculated from the oven-dry weights of fruits harvested periodically throughout the growing season. Both AGR and RGR were higher for larger fruit of different cultivars with similar days to maturity, and for summer- versus fall-ripening cultivars. Seasonal variability in AGR and RGR was observed, Apple fruit cortex disks were incubated in 14C-sorbitol solutions in vitro to determine if uptake rates at the cellular level varied between cultivars. Rates of sorbitol accumulation, expressed es μg sorbitol per mg dry weight cortex tissue, declined as the season progressed. Within a cuitivar, uptake rates were not relatad to fruit size, nor were differences found between cortex tissue samples from competing fruit on a spur. Sorbitol uptake rates were significantly lower for the more slowly-growing cultivar. The osmotic potential of the expressed cortex sap, sampled on several dates, was consistently lower for the more rapidly-growing cultivar. Thus, inherent differences in fruit growth rates among cultivars may be due to variation in regulation of osmotic potential.

1992 ◽  
Vol 117 (3) ◽  
pp. 459-462 ◽  
Author(s):  
Douglas D. Archbold

Absolute and relative fruit growth rates (AGR and RGR) of apple (Malus domestics Borkh.) were calculated from the fruit dry weights of several cultivars harvested periodically following June drop during 1988-90. AGRs were constant or varied slightly, and RGRs generally declined as the season progressed. Generally, both AGR and RGR values were higher for relatively large fruit of several cultivars with similar days to maturity, e.g., `McIntosh' vs. `Jonathan' and for summervs. fall-ripening cultivars, e.g., `Stayman' vs. others. An exception was observed in 1990, when `Golden Delicious' exhibited a higher AGR but lower RGR than `Rome Beauty', yet ripened 1 month earlier. `Golden Delicious' AGR and RGR values were lower for both fruit of a pair on a spur than the values for a single fruit on a spur, and the dominant fruit of the pair exhibited higher growth rates than the inferior fruit. Rates of sorbitol accumulation (SAR) by cortex disks incubated in 14C-labeled sorbitol solutions in vitro declined as the season progressed. Within a cultivar, SARS were not related to fruit size, nor were differences found between cortex disks from competing fruit on a spur, although SARS were higher for both competing fruit on a spur as compared to that of a single fruit per spur. Due to a positive correlation between RGR and SAR values, the SAR of cortex cells may be regulated in such a manner as to be a physiological constraint on fruit sink strength and growth rate.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 625e-625 ◽  
Author(s):  
Douglas D. Archbold

Maintenance of positive cell turgor is an essential factor in cell, and fruit, expansion. Since apple fruit partition carbohydrates between the starch and soluble pools to maintain turgor, variation among cultivars in this osmoregulatory aspect may play an important role in defining cultivar-specific fruit growth rates. Cultivar-specific apple fruit growth rates were determined over a 6 week period following June drop during 2 seasons. Fruit water relations parameters and carbohydrate levels were also measured. Although cultivar differences were evident, generally, fruit absolute growth rate increased, relative growth rate (RGR) declined, water potential and osmotic potential declined, and turgor potential increased as the season progressed. Soluble carbohydrate levels increased over 6 weeks, while starch levels fluctuated. Soluble carbohydrates contributed 50 to 90% of the osmotic potential. RGR was not correlated to either turgor potential or the relative allocation of carbohydrates between the soluble and starch pools. Thus, although positive turgor was maintained, factors other than turgor per se determine fruit growth rate.


Author(s):  
Dien Thi Kieu Pham ◽  
Kiet Thuong Do ◽  
Sanh Du Nguyen

The cherry tomato fruit size depends on the growth of the pericarp which is parenchymal cells. The blue light stimulates the expansion of cotyledon cells, hypocotyl cells and leaf cells. In this study, the cherry tomato fruit was used as a material to investigate the effects of the blue light on the pericarp cells growth in fruit growth stage and lycopene accumulation in fruit growth and ripening stage. After 7 days of the blue light (440, 450 or 460 nm) treatment, pericarp cells growth and physiological, biochemical changes of the pericarp cells of 7-day-old fruit pericarp piece in vitro were analyzed. The lycopene content and some organic compound contents of 42-day-old postharvest fruits treated by the blue light similarly in 7 days and 7, 21-day-old fruit wrapped with blue filter (440-510 nm filtered) in 7 days were measured. The results showed that the 450 nm wavelength blue light the increased pericarp thickness of 7-day-old fruits through the increasement of the pericarp cell diameter. The 460 nm wavelength blue light the increased lycopene content of 42-day-old postharvest fruits. The blue filter treatment increased the sugar total content of 7- day-old fruits and increased the lycopene content of 21-day-old fruits.


1968 ◽  
Vol 8 (31) ◽  
pp. 244
Author(s):  
BK Taylor ◽  
den Ende B van

Methods of controlling storage pit of Granny Smith apples were studied in the Goulburn Valley from 1960 to 1966. Foliar sprays of calcium nitrate reduced pit but boron sprays did not. Most efficient control was achieved with three or more sprays applied between December and March. Residual effects from such sprays were not observed the next season. Foliar sprays of calcium nitrate increased the concentration of calcium in spur leaves but not in fruit tissues. Dipping unsprayed fruit after harvest in solutions of calcium chloride or calcium nitrate, or wrapping fruit in paper sheets impregnated with calcium salts, gave negative or inconsistent results. Such treatments did not usually alter the concentrations or amounts of calcium, magnesium, or potassium in fruit tissues. The concentration of calcium in all fruit parts declined as fruit size (dry weight) increased. Since pit severity also increased with increasing fruit size, the calcium status of the fruit, fruit size, and pit incidence were closely related. The concentration of calcium in mesocarp + endocarp showed the highest negative correlation with pit severity of any of the fruit parts, and this tissue was therefore the best indicator of the calcium status and pit susceptibility of the fruit. It is concluded that pit is not due to an inbalance between calcium, magnesium, and potassium in the fruit but that it is merely the syndrome of calcium deficiency in the apple fruit. No differences were found in flavour characteristics between pitted and sound fruit.


1970 ◽  
Vol 48 (3) ◽  
pp. 583-589 ◽  
Author(s):  
Benny K. H. Lee

Surveys of the microfungal populations in potting soil watered with tap water, a solution of anionic 15-S-3A detergent (Tergitol, 15-S-3A), and a solution of nonionic 15-S-9 detergent (Tergitol, 15-S-9), revealed a greater reduction in propagule densities in the anionic detergent watered soil than in the nonionic detergent watered soil. In the anionic detergent study, 39 species, including six dominant species which contributed 58% of the isolates, were obtained from the treated soil. In the nonionic detergent study, both sample populations contained 29 species and the four to six dominants contributed 67–68% of the 100 isolates.Twenty-two isolates representing 10 dominant species were tested in vitro for sensitivity to the two detergents. All grew at the lowest concentration (10 p.p.m.) of both detergents. The growth rates of nine isolates increased with the addition of 10 p.p.m. of the anionic detergent; four isolates showed increased growth with 10 p.p.m. of the nonionic detergent. With increasing concentration of detergent from 100 to 1000 p.p.m., the growth rates of 21 of the 22 fungi decreased. Isolates recovered from detergent-treated soil grew better in the medium containing detergent than the same species recovered from the control soil. In concentrations of 1000 p.p.m., complete inhibition was displayed by four species in the anionic series compared to five species in the nonionic series. Both detergents affected pigmentation, exudate formation, and rigidity of the sporangiophore in several of the fungi.Fourteen of the 16 isolates tested used anionic detergent and 12 isolates used nonionic detergent as a carbon source for growth. Dry weight differences indicated that the anionic detergent was more available than the nonionic detergent.


2014 ◽  
Vol 82 (11) ◽  
pp. 4477-4486 ◽  
Author(s):  
Kasper N. Kragh ◽  
Morten Alhede ◽  
Peter Ø. Jensen ◽  
Claus Moser ◽  
Thomas Scheike ◽  
...  

ABSTRACTCystic fibrosis (CF) patients have increased susceptibility to chronic lung infections byPseudomonas aeruginosa, but the ecophysiology within the CF lung during infections is poorly understood. The aim of this study was to elucidate thein vivogrowth physiology ofP. aeruginosawithin lungs of chronically infected CF patients. A novel, quantitative peptide nucleic acid (PNA) fluorescencein situhybridization (PNA-FISH)-based method was used to estimate thein vivogrowth rates ofP. aeruginosadirectly in lung tissue samples from CF patients and the growth rates ofP. aeruginosain infected lungs in a mouse model. The growth rate ofP. aeruginosawithin CF lungs did not correlate with the dimensions of bacterial aggregates but showed an inverse correlation to the concentration of polymorphonuclear leukocytes (PMNs) surrounding the bacteria. A growth-limiting effect onP. aeruginosaby PMNs was also observedin vitro, where this limitation was alleviated in the presence of the alternative electron acceptor nitrate. The finding thatP. aeruginosagrowth patterns correlate with the number of surrounding PMNs points to a bacteriostatic effect by PMNs via their strong O2consumption, which slows the growth ofP. aeruginosain infected CF lungs. In support of this, the growth ofP. aeruginosawas significantly higher in the respiratory airways than in the conducting airways of mice. These results indicate a complex host-pathogen interaction in chronicP. aeruginosainfection of the CF lung whereby PMNs slow the growth of the bacteria and render them less susceptible to antibiotic treatment while enabling them to persist by anaerobic respiration.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 455e-455
Author(s):  
J. A. Flore ◽  
M. Ventura ◽  
D. Neri ◽  
M. Sakin

Auxin induction of ethylene, and fruit growth rates were investigated as early indicators of NAA thinning response for Golden Delicious, Red Delicious, McIntosh, Empire, and Tydeman's Red over a four period. Abscission at the end of the drop period was correlated with ethylene evolution from leaves 24-48 hours after NAA application and with changes in fruit growth at 2-3 day intervals through 10-14 days after application. Variation in ethylene evolution and fruit growth were also associated with environmental conditions prior to and at the time of NAA application to determine which factors have the greatest influence on response. Ethylene was a better predictor of final fruit drop than changes in fruit size for all varieties tested. However both performed very well. The ethylene bioassay requires more equipment, but the response is more-immediate. Bourse, and spur leaves as well as fruit were capable of producing ethylene in response to NAA application. Thinning response was greatest when all leaves and fruit were treated with NAA, followed by the bourse and spur leaves. Little or no response was produced when the fruit alone were treated. Concentration experiments and radioisotope data indicate that ethylene response is directly related to the amount of NAA absorbed. Regression analysis indicates that approximately 60% of the variation in response can be predicted by ethylene evolution


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 852F-852
Author(s):  
Paul T. Wismer ◽  
J.T.A. Proctor ◽  
D.C. Elfving

Benzyladenine (BA), carbaryl (CB), daminozide (DM), and naphthaleneacetic acid (NAA) were applied postbloom, as fruitlet thinning agents, to mature `Empire' apple trees. Although fruit set and yield were similar for BA, NAA, and CB, BA-treated fruit were larger, indicating BA increased fruit size beyond the effect attributable to thinning. BA applied at 100 mg·liter–1 increased the rate of cell layer formation in the fruit cortex, indicating that BA stimulated cortical cell division. The maximum rate of cell division occurred 10 to 14 days after full bloom (DAFB) when fruit relative growth rate and density reached a maximum and percent dry weight reached a minimum. Cell size in BA-treated fruit was similar to the control. Cell division ended by 35 DAFB in the control and BA-treated fruit when percent dry weight and dry weight began to increase rapidly and fruit density changed from a rapid to a slower rate of decreased density. These data support the hypothesis that BA-induced fruit size increases in `Empire' apple result largely from greater numbers of cells in the fruit cortex, whereas the fruit size increase due to NAA or CB is a consequence of larger cell size.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 765D-765
Author(s):  
Brent L. Black ◽  
Martin J. Bukovac ◽  
Matej Stopar

Apple fruit size is influenced by position on the spur, and location and number of competing fruits. King fruit appear to have the greatest potential to size and grow best in the absence of intraspur fruit competition (ISFC). Accel (A) and NAA (N), commercial thinning chemicals, influence fruit size beyond their effects on crop load. A 2-year study was conducted to determine the effect of ISFC and position (king, K, or lateral, L) on fruit growth in response to A and N. Branches from `Redchief Delicious' were thinned, after petal fall, to one K, one L, one K + one L, or two L fruits per spur. Whole-tree treatments of N (15 mg·liter–1), A (50 mg·liter–1, 1993; 25 mg·liter–1), and a combination (N+A) were applied at 10-mm king fruit diameter. A nontreated control was included. In 1993, N and N+A reduced fruit size only with ISFC, while A increased fruit size in the absence of ISFC. In 1994, A had no effect, but N and N+A reduced fruit growth with ISFC. In both seasons, A and N decreased the frequency of spurs bearing multiple fruit, while N+A dramatically increased number of spurs with multiple fruits (branch survey).


The total daily flux of photosynthetically fixed carbon in light- and shade-adapted phenotypes of the symbiotic coral, Stylophora pistillata , was quantified. Light adapted corals fixed four times as much carbon and respired twice as much as shade corals. Specific growth rates of zooxanthellae in situ were estimated from average daily mitotic indices and from ammonium uptake rates (nitrate uptake or nitrate reductase activity could not be demonstrated). Specific growth rates were very low, demonstrating that of the total net carbon fixed daily, only a small fraction (less than 5 %) goes into zooxanthellae cell growth. The balance of the net fixed carbon (more than 95 %) is translocated to the host. New and conventional methods of measuring total daily translocation were compared. The ‘growth rate’ method, which does not employ 14 C, emerged as superior to the conventional in vitro and in vivo methods. The contribution of translocated carbon to animal maintenance res­piration (czar) was 143 % in light corals and 58 % in shade corals. Thus, translocation in the former could supply not only the total daily carbon needed for respiration but also a fraction of the carbon needed for growth. Whereas light-adapted corals released only 6%, shade-adapted corals released almost half of their total fixed carbon as dissolved or particulate organic material. This much higher throughput of organic carbon may possibly benefit the heterotrophic microbial community in shade environments.


Sign in / Sign up

Export Citation Format

Share Document