Differences In Fruit Size Research Articles

Variations in Fruit Ploidy Level and Cell Size between Small- and Large-Fruited Olive Cultivars during Fruit Ontogeny.

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.

Enhancing soil water, carbon, and nitrogen by partially substituting chemical fertilizer with organic fertilizer integrated with a rainwater collection system in rainfed orchards

Rainfed apple orchards, particularly in loess hilly regions of China, face significant challenges due to water scarcity and declining soil fertility, necessitating their restoration for sustainable apple production. This study investigated the impact of partially substituting chemical fertilizers with organic fertilizers integrated with a rainwater collection system on restoring soil water storage (SWS), soil organic carbon (SOC) stocks, and total nitrogen (TN) stocks and their relationship with apple production. Three orchard management practices were evaluated: (1) OSCR: partially substituting chemical fertilizer with organic fertilizer (60% N from organic fertilizer) integrated with a rainwater collection system; (2) CR: chemical fertilizer integrated with a rainwater collection system; and (3) CK: chemical fertilizer alone without a rainwater collection system. Averaged across five years, the OSCR treatment (457.83 mm) substantially enhanced SWS from 0 to 280 cm profile by 19.12% compared to the CK (384.34 mm). OSCR system outperformed CR treatment in terms of the 0–280 cm SWS compensation index (SWSCI). The OCSR and CR treatments had higher SWSCI values in 2016 (dry year) than the other years, indicating more effective SWS restoration in dry years. Average across five years, OSCR treatment had 55.26% and higher SOC stock (214.1 Mg ha–1) and 45.91% higher TN stock (5.72 Mg ha−1) from 0 to 280 cm than the CK; and the OSCR treatment positively restored SOC and TN stocks, while the CR treatment decreased SOC stock and restored TN stock from 0 to 200 cm profile. Compared to 2016, OSCR, CR and CK treatments increased SOC stock by 36.84%, −5.78% and −6.98%, and TN stock by 36.31%, 37.88 and −3.36% in 2020, respectively. Average across five years, the OSCR treatment had the highest mean apple yield (24.61 Mg ha−1) and crop water production (CWP, 48.64 kg ha−1 mm−1), 64.62% and 66.69% higher than the CK treatment across five years; no significant differences in fruit size or shape index occurred between treatments. The difference in apple yield is unfavorably connected with SWSCI and favorably connected with SOC and TN stock restoration. Overall, the OSCR system successfully restored SWS, SOC, and TN stocks, increasing apple yield and CWP, making it a promising management strategy for rainfed apple orchards.

Comparative Anatomical and Transcriptomics Reveal the Larger Cell Size as a Major Contributor to Larger Fruit Size in Apricot.

Fruit size is one of the essential quality traits and influences the economic value of apricots. To explore the underlying mechanisms of the formation of differences in fruit size in apricots, we performed a comparative analysis of anatomical and transcriptomics dynamics during fruit growth and development in two apricot cultivars with contrasting fruit sizes (large-fruit Prunus armeniaca 'Sungold' and small-fruit P. sibirica 'F43'). Our analysis identified that the difference in fruit size was mainly caused by the difference in cell size between the two apricot cultivars. Compared with 'F43', the transcriptional programs exhibited significant differences in 'Sungold', mainly in the cell expansion period. After analysis, key differentially expressed genes (DEGs) most likely to influence cell size were screened out, including genes involved in auxin signal transduction and cell wall loosening mechanisms. Furthermore, weighted gene co-expression network analysis (WGCNA) revealed that PRE6/bHLH was identified as a hub gene, which interacted with 1 TIR1, 3 AUX/IAAs, 4 SAURs, 3 EXPs, and 1 CEL. Hence, a total of 13 key candidate genes were identified as positive regulators of fruit size in apricots. The results provide new insights into the molecular basis of fruit size control and lay a foundation for future breeding and cultivation of larger fruits in apricot.

Non-Destructive Quality Evaluation of 80 Tomato Varieties Using Vis-NIR Spectroscopy.

Traditional biochemical methods are resource- and time-consuming; therefore, there is a need for cost-effective alternatives. A spectral analysis is one of the non-destructive techniques that are more widely used for fruit quality determination; however, references are needed for traditional methods. In this study, visible and near-infrared (Vis-NIR) spectroscopy was used to analyze the internal quality attributes of tomatoes. For the first time, 80 varieties with large differences in fruit size, shape, color, and internal structure were used for an analysis. The aim of this study was to develop models suitable to predict a taste index, as well as the content of lycopene, flavonoids, β-carotene, total phenols, and dry matter of intact tomatoes based on Vis-NIR reflectance spectra. The content of phytochemicals was determined in 80 varieties of tomatoes. A total of 140 Vis-NIR reflectance spectra were obtained using the portable spectroradiometer RS-3500 (Spectral Evolution Inc.). Partial least squares regression (PLS) and multiple scatter correction (MSC) were used to develop calibration models. Our results indicated that PLS models with good prediction accuracies were obtained. The present study showed the high capability of Vis-NIR spectroscopy to determine the content of lycopene and dry matter of intact tomatoes with a determination coefficient of 0.90 for both parameters. A regression fit of R2 = 0.86, R2 = 0.84, R2 = 0.82, and R2= 0.73 was also achieved for the taste index, flavonoids, β-carotene, and total phenols, respectively.

Using gorse compost as a peat-free growing substrate for organic strawberry production

ABSTRACT The demand for peat-free organic growing media has increased and green compost provide an attractive option within a circular economy. To take advantage of the inherent nutrient content, the nutrient dynamics need to be carefully considered when evaluating the agronomic potential of compost for organic production. In this study, the use of compost made from gorse (Ulex europaeus L.) was evaluated as a substrate for organic production of strawberries (Fragaria x ananassa Duch ‘Selva’), focusing particularly on the availability of nutrients. Two gorse composts were used, gorse composted with poultry manure (5% v/v) (PM100) and gorse composted on its own without manure (PM0). The composts were assessed in their original form and in formulations containing different proportions of each. A fertilised standard peat-based substrate was used as control. Both PM0 and PM100 exhibited acceptable physical properties and contained high concentrations of major nutrients (particularly PM100). The nutrient concentrations in the solutions from the different formulations decreased gradually during the growth of the crop, particularly N and K. Concentrations of N and chlorophyll levels were lower in plants grown in gorse compost formulations than in those grown in the control. There were, however, no substantial differences in fruit size or overall yield. The above-ground biomass in the compost-grown plants increased with increased proportions of PM100, but it was greater in the control plants. The gorse composts were recommended as effective peat substitutes for strawberry cultivation, although supplementary fertiliser should be applied at fruit production stage to ensure optimal production.

Determining effects of foliar boron applications on yield and fruit quality of apricot trees for reducing water stress

Aims: The research was carried out to determine the effects of different boron doses on yield, yield components and quality on 5-6 years old apricot trees of Mogador variety, which were exposed to water stress in the Amik Plain in 2019. Methods and Results: The factorial experimental design was conducted on apricot trees of Mogador variety, using four doses of foliar boron (ppm) (0-B0, 150-B150, 225-B225 and 300-B300 ppm) and four irrigation levels (100%-I100, 75%-I75, 50%-I50 and 25%-I25 of available water holding capacity) in four replications. Each replication consisted of two apricot trees. The quantity of irrigation water applied in the experiment ranged from 179 to 742 mm, while the evapotranspiration varied between 295 and 832 mm during the irrigation season. Irrigation water use efficiency (IWUE) and water use efficiency (WUE) varied between 3.51-5.18 kg m-3 and 2.89-4.17 kg m-3, respectively. Boron doses did not cause significant differences in WUE and IWUE values. Each unit increase in crop water use caused an average yield increase of 16.8 kg ha-1. Relative to the full irrigation (I100), fruit weight decreased by 13 and 3% in I25 and I50, respectively, but increased by 2% in I75. Relative to the control group (B0), fruit weight increased by 2, 4, and 2% with B150, B225, and B300, respectively. Average fruit size varied between 47.40 (I75) and 42.99 mm (I25); total soluble solids (TSS) between 16.13 (I100) and 12.65 (I25); and pH between 3.16 (I100) and 3.30 (I50). The increased boron dose did not cause a significant difference in fruit size and width. The leaf boron content increased up to the B225 dose and tended to decrease at the B300 dose.Conclusions: Boron element provides an increase in yield in deficit irrigation conditions, the yield increase is higher in fully irrigated apricot trees. In full irrigation treatment (I100), the B225 treatment was more effective on the yield.Significance and Impact of the Study: The boron element is an important element that causes an increase in photosynthesis by light adsorption. There is not a lot of research investigating the effects of nutrient elements to relieve the negative effect of water stress in orchards. This research is important in terms of revealing the effects of the element boron in water stress conditions.

Biochemical changes associated with the administration of aqueous pulp extract of Irvingia gabonensis fruit on adult male Wistar rats

Biochemical changes associated with the administration of aqueous pulp extract of Irvingia gabonensis fruit on adult male Wistar rats

Effects of Endogenous Hormones and Sugars on Fruit Size Driven by Cell Division between Korla Fragrant Pear and Its Bud Mutation

Large-fruit bud mutations are important factors in fruit tree breeding. However, little is known about the differences between varieties and bud mutations. The ploidy identification of Korla fragrant pear (Pyrus sinkiangensis Yu) and its large bud mutation Zaomeixiang pear showed that the large-fruit characteristic was not caused by chromosome doubling. By counting mesocarp cells at different stages, we found that the number of cells increased continuously after pollination, and the difference was the greatest at 28 days after full bloom (DAFB), and was about 9.4 × 106. After 28 days, the difference in cell volume became bigger and bigger, so both the cell volume and cell number caused the difference in fruit size between Korla fragrant pear and Zaomeixiang pear. To obtain more insights into the differences in fruit size driven by cell division, we analyzed the endogenous hormones [indole ascetic acid (IAA), zeatin riboside (ZR), gibberellic acid (GA), and abscisic acid (ABA)], and the main sugars (glucose, fructose, sucrose, and sorbitol). The ZR content of Zaomeixiang pear was always greater than that of Korla fragrant pear at all stages. The ABA content was the opposite except for at 7 DAFB during cell division; the greatest difference was 30.87 ng/g, which appeared at 28 DAFB. ABA and ZR correlated negatively with cell number. After 7 DAFB, the ratio of IAA/ABA, ZR/ABA, and GA/ABA in Zaomeixiang pear was always greater than that for Korla fragrant pear at 28 DAFB. The difference in glucose content at 21 DAFB was the greatest, at 4.80 ng/g. Large amounts of sorbitol accumulated during whole-cell division. Glucose and sorbitol correlated positively with cell numbers. In summary, the data suggest that the different contents of glucose, sorbitol, ZR, and ABA, and the ratio of endogenous hormones might be related to cell division in Korla fragrant pear and Zaomeixiang pear. The result provides a theoretical basis for the large-size fruit’s high-quality production and genetic breeding of Korla fragrant pear and its bud mutation.

The accumulation of recombinant miraculin is independent of fruit size in tomato.

The taste-modifying protein miraculin (MIR) has received increasing interest as a new low-calorie sweetener. In our previous study using the tomato variety 'Micro-Tom,' it was shown that in transgenic tomatoes in which MIR was expressed by using the cauliflower mosaic virus 35S promoter (p35S) and a heat shock protein terminator (tHSP) cassette (p35S-MIR-tHSP), higher levels of miraculin accumulated than when MIR was driven by the nopaline synthase terminator (tNOS) cassette (p35S-MIR-tNOS). 'Micro-Tom' is a dwarf tomato used for research and shows a low yield. To achieve high productivity of MIR, it is essential to improve the MIR accumulation potential by using high-yielding cultivars. In this study, we evaluate whether the high MIR accumulation trait mediated by the tHSP appears even when fruit size increases. A line in which the p35S-MIR-tHSP cassette was introduced into a high-yielding variety was bred by backcrossing. The line homozygous for MIR showed higher accumulation of MIR than the heterozygous line. Despite large differences in fruit size, the MIR level in the backcross line was similar to that in the p35S-MIR-tHSP line (background 'Micro-Tom'). It was approximately 3.1 times and 4.0 times higher than those in miracle fruits and the p35S-MIR-tNOS tomato line 5B ('Moneymaker' background, which exhibits the highest miraculin productivity achieved thus far), respectively. These results demonstrate that the high MIR accumulation trait mediated by the tHSP appears even when fruit size is increased.

Fruit size in different plum species (genus Prunus L.) is determined by post-bloom developmental processes and not by ovary characteristics at anthesis

The mechanisms driving drupe differentiation have been investigated in several plant species. Often, bigger fruits derive from bigger ovaries; however, in other species, ovary size is similar and differences in fruit size are determined by differences in post-bloom tissue development. The aim of this work was to investigate whether, in three Prunus species (P. salicina, P. domestica and P. cerasifera), fruit size is related to ovary size or whether it depends on post-bloom developmental processes. This study used microscope image analyses to evaluate ovary wall thickness at anthesis and fruit mesocarp thickness at final fruit size. In the same tissues (i.e. ovary wall and fruit mesocarp), we also measured cell area and number of cellular layers. Ovary wall thickness did not differ among the genotypes tested (except for Mirabolano, the smallest-fruited genotype, having slightly bigger ovaries) and was not correlated to either cell size or to the numbers of cell layers. Fruit mesocarp thickness varied three fold among genotypes and was strongly and positively correlated to the number of cell layers, and weakly and negatively correlated to cell size. No correlation was found between fruit weight (or mesocarp thickness or number of cell layers) and the respective ovary characteristic: bigger fruits did not derive from bigger ovaries. Fruit weight was instead related to the fruit-to-ovary weight and cell layer number ratios, indicating that fruit size in these species is related not to ovary characteristics, but to processes that occur to a different extent after bloom, particularly to a greater cell division. In particular, P. salicina cv. TC Sun, which had the biggest fruit, had a longer post bloom cell division activity and/or a higher post bloom cell division rate. Indeed, the number of TC Sun cell layers increased four times, while in the other species the mesocarp had twice the ovary layers. TC Sun also had the lowest increase in mesocarp cell area. This study represents a starting point to understand the mechanisms of cell division and expansion in Prunus species and their implication for fruit size management.

Effects of Rootstock/Scion Combination and Two Irrigation Water Qualities on Cherry Tomato Yield and Postharvest Fruit Quality

The aim of this research was to evaluate postharvest cherry tomato (Solanum lycopersicum (L.) Mill.) yield and fruit quality as affected by grafting and irrigation water quality in the desert region of Israel. Tomato plants (scion cv. Lorka) were grafted onto 3 commercial tomato rootstocks (Resistar, Beaufort and TRS2) and were irrigated with 2 water qualities: fresh water (electrical conductivity (EC)-1.6 dS m−1) and salty water (EC-4.0 dS m−1). Fresh water significantly increased fruit yield by an average of 17% and fruit size, regardless of plant grafting and rootstock, but there were no significant differences in fruit size between the water treatments. However, salty water, but not grafting, significantly improved several quality parameters of fruit stored for 12 d at 12 °C followed by 2 d at 20 °C in simulated sea transport of produce from Israel to Europe and marketing. Fruit harvested from plants irrigated with salty water showed higher sweetness, sourness and, especially, better general taste, and significantly reduced off-flavor, compared with those irrigated with fresh water. The combination of ‘Lorka’ on ‘Resistar’ rootstock and resulted in the best external, internal, and sensory quality parameters at the end of storability and marketing simulation, while the lowest-quality parameters were in fruit harvested from ‘Lorka’ on ‘Beaufort’ rootstock.

Influence of Temperature on the Development of Peach Fruit in a Subtropical Climate Region

Understanding the growing process and fruit size differences among peach cultivars is extremely important in the technological domain of the crop and can provide information to improve the proper crop management (thinning and harvesting seasons) and the crop breeding of fruits with a larger caliber. However, this information is still incipient in subtropical regions and requires further research, especially in Brazil. The aim of this study was to determine the influence of temperature on the growing of four peach cultivars (Tropical, Aurora-2, Ouro Mel-4, and Biuti) under subtropical conditions of field cultivation. Fruit development was determined every two weeks throughout the cycle with 30 fruits from previously identified branches from six different plants of each cultivar. Regarding the thermal accumulation in growing degree-days (GDD), the cultivar ‘Tropical’ showed the lowest agronomic fruit properties (size and mass) and required a lower GDD accumulation during the development stages of the fruits, whereas the cultivar ‘Biuti’ showed higher thermal requirements and higher agronomic properties. The number of cells had greater influence on the final fruit size than the cell area.

Fruit growth, yield and oil quality changes induced by deficit irrigation at different stages of olive fruit development

Experiments were performed in a high-density olive orchard to compare the effect of regulated deficit irrigation (RDI) at two different phenological stages with fully-irrigated trees (FI) over two years. Stress was imposed either prior to pit hardening (RDI 1) or after endocarp sclerification during the initial phase of oil accumulation (RDI 2). Fully irrigated trees received 2277 and 1648 m3 ha−1 in 2012 and 2013, respectively, RDI 1 ones 76 and 53% of those volumes in 2012 and 2013, respectively (RDI 2 trees 48 and 67%). There were no differences in fruit set or return bloom due to the irrigation regime. At harvest differences in fruit size between FI and RDI treatments were significant only in the first year. The fruit yields of RDI 1 and RDI 2 trees were 70 and 81% of FI ones, respectively (means of two years), but the yield efficiency was similar across all treatments. The phenolic concentration in RDI 1 fruits was higher than that in fruits from trees subjected to the other water regimes. Verbascoside, 3–4 DHPEA-EDA, and oleuropein of RDI 1 fruits were higher in 2012 (only verbascoside in 2013). Oleuropein and 3–4 DHPEA-EDA of RDI treatments were higher than those of FI in 2013. Higher concentrations of biophenols were measured in oils from RDI 1 trees in both years, whereas FI and RDI 2 showed similar values. An early water stress was more effective to increase the phenolic concentration of olive oil compared with a late deficit or full irrigation.

Chemical composition of apricots affected by fruit size and drying methods

ABSTRACTCombined practice of sulfuration and drying is widely applied for extending shelf life of fruits. The differences in fruit size are not taken into consideration during these applications and during fresh fruit consumption. In this study, effect of fruit size and drying methods (hot air-drying and sun drying) on the chemical composition of fresh and sulfurated apricot was investigated. Total drying times for sun drying and hot air-drying were 11 d and 51 h, respectively. A temperature gradient was applied during hot air-drying. The fruit size substantially affects the composition of both fresh and dried apricots. The results were subjected to principal component analysis. The small-sized fresh apricots discriminate themselves from large ones with higher amounts of phenolic compounds, whereas the large-sized fresh apricots contain more sugar and organic acids. Size classification and hot air-drying are advisable for high-quality dried apricot production.

Fruit, mesocarp, and endocarp responses to crop load and to different estimates of source: sink ratio in olive (cv. Arauco) at final harvest

Abstract The annual fluctuations in olive crop load due to alternate bearing and other factors often lead to large differences in fruit size and oil content between years at harvest. A better understanding of how fruit parameters respond to the different leaf: fruit (i.e., source: sink) ratios that occur with contrasting crop loads would provide important information for crop management. Thus, the primary objectives of this study conducted with the cv. Arauco in three growing seasons were to: 1) determine the weight and size responses of the fruit and its main tissues, mesocarp (pulp) and endocarp (pit), to crop load; and 2) obtain relationships between different estimates of the source: sink ratio versus various fruit and oil parameters. Fruit thinning was performed by hand on uniform trees with high initial crop loads four weeks after full bloom the first season to obtain different crop loads at harvest. The thinning percentages the first season were 24%, 48% and 87%, along with an unthinned control. The same trees were then monitored the following two seasons without any further thinning. Fruit were sampled at harvest each season to determine fruit and tissue weights and diameters, oil weight per fruit, and oil concentration (%). Fruit weight was reduced 30–40% by high crop loads in each growing season with the mesocarp being much more affected than the endocarp. Oil weight per fruit (−50%) showed a somewhat greater reduction than fruit weight to crop load due to both fruit diameters and fruit oil concentration being decreased at high crop loads. Fruit and tissue weights and oil weight per fruit all displayed bilinear functions versus source: sink ratio when the source was expressed as canopy volume (a surrogate for leaf area) and sink on both a fruit number and glucose equivalent (GE) basis. Source limited fruit growth at both medium and high crop loads due to limited photoassimilate availability based on the bilinear functions, and the slope of the endocarp response to source: sink ratio was 15 times less than that of the mesocarp when expressed on a GE basis. A quantitative comparison with previously published studies indicated that maximum fruit weight appears to be obtained in olive between 1–2 m2 of leaf area per kg of GE. The bilinear relationships of source: sink ratio versus fruit weight observed in this study could contribute to crop modelling, and further research concerning how and when the mesocarp and endocarp respond to crop load is needed to aid crop management in obtaining sufficient fruit size and quality for table olive cultivars.

Variation in cucumber (Cucumis sativus L.) fruit size and shape results from multiple components acting pre-anthesis and post-pollination.

Morphological, QTL, and gene expression analyses indicate variation in cucumber fruit size and shape results from orientation, timing, and extent of cell division and expansion, and suggest candidate gene factors. Variation in cucumber (Cucumis sativus L.) fruit size and shape is highly quantitative, implicating interplay of multiple components. Recent studies have identified numerous fruit size and shape quantitative trait loci (QTL); however, underlying factors remain to be determined. We examined ovary and fruit development of two sequenced cucumber genotypes with extreme differences in fruit size and shape, Chinese Long '9930' (CL9930), and pickling type 'Gy14'. Differences were observed in several independent factors that can influence size and shape: ovule number, rate and period of cell division in longitudinal and cross section in ovaries and fruit, timing and rate of fruit expansion in length and diameter, and cell shape. Level and timing of expression of select fruit growth stage marker genes and candidate fruit size gene homologs associated with cucumber fruit size and shape QTL were examined from 5-day pre-anthesis to 20-day post-pollination. Our results indicate that variation in fruit size and shape results from differences in cell number and shape in longitudinal and cross section, driven in turn by differences in orientation, timing, and duration of cell division and expansion, both pre- and post-anthesis, and suggest candidate genes contributing to determination of cucumber fruit size and shape.

Grazing by green sea-turtles does not affect reproductive fitness in Thalassia testudinum

The negative effects of turtle-grazing on the vegetative plants parts of seagrasses are relatively well-known, but its effects on the reproductive success have received less attention. We studied reproductive frequency and success of Thalassia testudinum under simulated (clipping for 6 months) and natural grazing regimes in the Mexican Caribbean. Simulated grazing did not affect the density (flowers m−2) of female (clipped: 10.9±4.7SD, control: 8.4±4.6SD) and male flowers (clipped: 20.7±12.0SD; control 25.6±16.8SD), resulting in a similar seed-set (overall average 55%) and fruit-set (overall average 44%) in clipped and control plots. Naturally turtle-grazed areas did not present significant differences in fruit size, fruit-set or seed-set from nearby ungrazed areas. Thus, T. testudinum maintained sexual production while grazed, and flowers and fruits were not a targeted food source for the green turtles. We expected incidental ingestion of the flowers, usually positioned above the cropping height of ∼3cm. But in the grazed areas, the flowers were shorter; being 3.6cm for female flowers, and 3.3cm for male flowers. Due to these reductions in length, the flowers and fruits were closer to the sediment than in ungrazed patches; just below the usual grazing level of the turtles. Green turtles can potentially eradicate complete meadows. Re-establishment of meadows can only occur through recolonization by seeds in floating fruits provided by nearby seagrass meadows, which can maintain a stable fruit and seed production when moderately grazed.

Modeling fruit growth of apple

Fruit growth of an individual apples starts after petal and is affected by different environmental factors and orchard and tree management. Prediction of fruit size is critical for management and to prepare for postharvest processing and the logistics. The objective of this study was to develop a model to predict growth of an individual apple fruit as a function of the physiological time using cumulative degree days (GDD). The cultivars 'Cripps Pink', 'Gala', and 'Red Delicious' were monitored twice weekly during four growing seasons for eleven different locations in the main apple growing regions of eastern Washington. Thirty fruits were selected and the equatorial diameter was monitored and registered weekly. Daily temperature data came from the closest automated weather station of AgWeatherNet to the orchard where the samples were collected. The model was based on the accumulation of GDD starting after the stage of full bloom. To determine GDD, the base temperature, i.e. 7.22°C, was subtracted from the average temperature for 'Cripps Pink', 5.55°C for 'Gala' and 6.11°C for 'Red Delicious' respectively. The Bon Verthalanfy statistical model was used to determine the base temperature and other model parameters and to derive growth rate of the apple using the equation δD/δt, where D is the adjusted function and t is time in days. To determine the diameter of an apple on a daily basis, the Euler integration method was used. The observed data showed differences in fruit size among years and locations. The cultivar 'Gala' was harvested earlier than the cultivars 'Cripps Pink' and 'Red Delicious' resulting in differences in base temperatures. The relative error between predicted and observed fruit diameter was in general less than 3%, but varied due to the location and year. The model will be implemented as a prototype on the AgWeatherNet portal (www.weather.wsu.edu) to help predict fruit size as a function of local temperature for locations where an automated weather station is available.

Caracterização morfológica de frutos, sementes, plântulas e germinação de Oreopanax fulvus Marchal

This study aimed to characterize the morphology of fruits, seeds and seedlings and evaluate the germination of Oreopanax fulvus Marchal. After collection, it was carried out the biometrical and morphological characterization of infructescences, fruits and seeds. Seedlings were also characterized, after germination procedures. Two germination experiments were realised: the first one to evaluate the performance of germination on different substrates and the second to test the effects of the fruit maturation on the germination parameters. The fruits are globose, indehiscent and purple when mature. There is no significant difference in fruit size regarding to maturation. The seeds are small and elliptical, with ruminated endosperm and spatulated embryo. Germination is phanero-epigeal. The cotyledons remain in the seedlings for 150 days after germination. There was no significant difference on seed germination rates over different substrates, the overall average was 42.2%. In the maturation experiment only seeds from mature fruits germinated (68.3%), demonstrating that this is an essential requirement for adequate germination of O. fulvus.

Internal seed dispersal by parrots: an overview of a neglected mutualism.

Despite the fact that parrots (Psitacifformes) are generalist apex frugivores, they have largely been considered plant antagonists and thus neglected as seed dispersers of their food plants. Internal dispersal was investigated by searching for seeds in faeces opportunistically collected at communal roosts, foraging sites and nests of eleven parrot species in different habitats and biomes in the Neotropics. Multiple intact seeds of seven plant species of five families were found in a variable proportion of faeces from four parrot species. The mean number of seeds of each plant species per dropping ranged between one and about sixty, with a maximum of almost five hundred seeds from the cacti Pilosocereus pachycladus in a single dropping of Lear’s Macaw (Anodorhynchus leari). All seeds retrieved were small (<3 mm) and corresponded to herbs and relatively large, multiple-seeded fleshy berries and infrutescences from shrubs, trees and columnar cacti, often also dispersed by stomatochory. An overview of the potential constraints driving seed dispersal suggest that, despite the obvious size difference between seeds dispersed by endozoochory and stomatochory, there is no clear difference in fruit size depending on the dispersal mode. Regardless of the enhanced or limited germination capability after gut transit, a relatively large proportion of cacti seeds frequently found in the faeces of two parrot species were viable according to the tetrazolium test and germination experiments. The conservative results of our exploratory sampling and a literature review clearly indicate that the importance of parrots as endozoochorous dispersers has been largely under-appreciated due to the lack of research systematically searching for seeds in their faeces. We encourage the evaluation of seed dispersal and other mutualistic interactions mediated by parrots before their generalized population declines contribute to the collapse of key ecosystem processes.