Small Green Fruit Research Articles

Role of Rubus chingii BBX gene family in anthocyanin accumulation during fruit ripening.

The B-box (BBX) family, which is a class of zinc finger transcription factors, exhibits special roles in plant growth and development as well as in plants' ability to cope with various stresses. Even though Rubus chingii is an important traditional medicinally edible plant in east Asia, there are no comprehensive studies of BBX members in R. chingii. In this study, 32 RcBBX members were identified, and these were divided into five groups. A collinearity analysis showed that gene duplication events were common, and when combined with a motif analysis of the RcBBX genes, it was concluded that group V genes might have undergone deletion of gene fragments or mutations. Analysis of cis-acting elements revealed that each RcBBX gene contained hormone-, light-, and stress-related elements. Expression patterns of the 32 RcBBX genes during fruit ripening revealed that highest expression occurred at the small green fruit stage. Of note, the expression of several RcBBX genes increased rapidly as fruit developed. These findings, combined with the expression profiles of anthocyanin biosynthetic genes during fruit ripening, allowed us to identify the nuclear-targeted RcBBX26, which positively promoted anthocyanin production in R. chingii. The collective findings of this study shed light on the function of RcBBX genes in different tissues, developmental stages, and in response to two abiotic stresses.

Green Fruit Detection with a Small Dataset under a Similar Color Background Based on the Improved YOLOv5-AT.

Green fruit detection is of great significance for estimating orchard yield and the allocation of water and fertilizer. However, due to the similar colors of green fruit and the background of images, the complexity of backgrounds and the difficulty in collecting green fruit datasets, there is currently no accurate and convenient green fruit detection method available for small datasets. The YOLO object detection model, a representative of the single-stage detection framework, has the advantages of a flexible structure, fast inference speed and excellent versatility. In this study, we proposed a model based on the improved YOLOv5 model that combined data augmentation methods to detect green fruit in a small dataset with a background of similar color. In the improved YOLOv5 model (YOLOv5-AT), a Conv-AT block and SA and CA blocks were designed to construct feature information from different perspectives and improve the accuracy by conveying local key information to the deeper layer. The proposed method was applied to green oranges, green tomatoes and green persimmons, and the mAPs were higher than those of other YOLO object detection models, reaching 84.6%, 98.0% and 85.1%, respectively. Furthermore, taking green oranges as an example, a mAP of 82.2% was obtained on the basis of retaining 50% of the original dataset (163 images), which was only 2.4% lower than that obtained when using 100% of the dataset (326 images) for training. Thus, the YOLOv5-AT model combined with data augmentation methods can effectively achieve accurate detection in small green fruit datasets under a similar color background. These research results could provide supportive data for improving the efficiency of agricultural production.

Insights into the Mechanism of Flavor Loss in Strawberries Induced by Two Fungicides Integrating Transcriptome and Metabolome Analysis.

Consumers have been complaining about the deterioration of the flavor of strawberries. The use of pesticides could have potential impacts on fruit flavor but the mechanisms are unclear. Here, we spayed boscalid and difenoconazole on the small green fruit of strawberries to investigate their effect on fruit flavor quality and the mechanism. The results indicated that both fungicides decreased the contents of soluble sugar and nutrients but increased acids in mature fruits, changed the levels of volatiles, and caused oxidative damage, which ultimately reduced the flavor quality of strawberries, and the negative effect of boscalid was greater. Combined with transcriptome and metabolome, boscalid altered the genes in sugar-acid metabolism (SUT, SPS, and INV), volatiles (FaQR, FaOMT, FaLOX, and FaAAT), and amino acid synthesis pathways and metabolites. This study elaborated on the effects of fungicides on the flavor quality of strawberries from physiological-biochemical and molecular levels and laid the foundation for improving the strawberry flavor quality.

Transcriptome and hormones analysis provide insights into elongated fruit somaclonal mutant in ‘Akihime’ strawberry

Fruit shape is an important agronomic trait. However, the regulatory mechanism of strawberry fruit shape remains largely unknown. In this study, we firstly compared cultivated strawberry ‘Akihime’ with its elongated fruit somaclonal mutant (finger strawberry). The plant height, crown diameter, leaf length and some photosynthetic indexes were no significant changes between ‘Akihime’ and finger strawberry, while the fruit shape of them had obvious differences. Histological observation showed that fruit shape changes mainly resulted from the change of cell area, especially cell length, at small green fruit stage of ‘Akihime’ and finger strawberry. Next, the endogenous hormone contents of small green fruit of ‘Akihime’ and finger strawberry were investigated by HPLC-MS/MS. We found that the auxin content in the finger strawberry dramatically increased compared with ‘Akihime’, while the content of gibberellin and brassinosteroids had no significant difference between ‘Akihime’ and finger strawberry. Finally, small green fruits of ‘Akihime’ and finger strawberry were used for identifying key genes responsible for the elongated fruit phenotype through RNA-seq. A total of 674 differentially expressed genes (DEGs) were identified, including 248 up-regulated genes and 426 down-regulated genes. GO and KEGG enrichment analysis showed the DEGs were mainly enriched in DNA replication, cell cycle, plant hormone synthesis and signal transduction. Interestingly, auxin-related genes such as FaIAA33, FaSAUR76, FaSAUR34, FaARF and some transcription factors such as FaMYBs, FabHLHs, FaNACs were differentially expressed in ‘Akihime’ and finger strawberry, which may play a crucial role in the formation of elongated fruit mutant phenotype. These results will provide some insights into the regulatory mechanism of strawberry fruit shape and are helpful for appearance quality improvement of strawberry.

GHFormer-Net: Towards more accurate small green apple/begonia fruit detection in the nighttime

The accurate recognition of green fruit is of great significance for the automatic monitoring of the whole process of orchard growth, fruit harvesting, and yield estimation. However, accurate small green fruit detection, affected by many factors such as the unstructured orchard environment, the morphological diversity of target fruits, and multiple-scale fruits, is still an unsolved challenge, especially for small-scale fruits in the night environment. In this paper, we propose an optimized Retinanet-PVTv2 by introducing the gradient harmonizing mechanism to detect small green apple/begonia fruits in the night environment, namely GHFormer-Net. Specifically, PVTv2-B1 based on Transformer is applied as the backbone network to extract feature information from the global receptive, which breaks the limitation that spatial convolution is utilized to extract information from the local area; Next, with the help of FPN, shallow features and high-level features with rich semantic information are incorporated by lateral connections and a top-down structure to generate multi-scale feature maps; Then, a detector of RetinaNet is applied to detect green fruits. To adapt to small apple/begonia fruits detection in the night environment, a gradient harmonizing classification loss (GHM-R Loss) and a gradient harmonizing regression loss (GHM-R Loss) are introduced to improve RetinaNet-PVTv2. The experimental results show that our method achieves 85.2%/61.0% AP and 67.5%/45.2% APS on the benchmark of the NightFruit and Gala datasets respectively, which demonstrates the effectiveness of our method for small green apple/begonia fruits detection.

BFP Net: Balanced Feature Pyramid Network for Small Apple Detection in Complex Orchard Environment.

Despite of significant achievements made in the detection of target fruits, small fruit detection remains a great challenge, especially for immature small green fruits with a few pixels. The closeness of color between the fruit skin and the background greatly increases the difficulty of locating small target fruits in the natural orchard environment. In this paper, we propose a balanced feature pyramid network (BFP Net) for small apple detection. This network can balance information mapped to small apples from two perspectives: multiple-scale fruits on the different layers of FPN and a characteristic of a new extended feature from the output of ResNet50 conv1. Specifically, we design a weight-like feature fusion architecture on the lateral connection and top-down structure to alleviate the small-scale information imbalance on the different layers of FPN. Moreover, a new extended layer from ResNet50 conv1 is embedded into the lowest layer of standard FPN, and a decoupled-aggregated module is devised on this new extended layer of FPN to complement spatial location information and relieve the problem of locating small apple. In addition, a feature Kullback-Leibler distillation loss is introduced to transfer favorable knowledge from the teacher model to the student model. Experimental results show that APS of our method reaches 47.0%, 42.2%, and 35.6% on the benchmark of the GreenApple, MinneApple, and Pascal VOC, respectively. Overall, our method is not only slightly better than some state-of-the-art methods but also has a good generalization performance.

Laboratory Device to Assess the Effect of Mechanical Thinning of Flower Buds, Flowers and Fruitlets Related to Fruitlet Developing Stage

Mandarin thinning is done by hand, increasing labor costs and raising total cropproduction costs. Mechanical thinning has been tested in peaches and other fruits. To achieve themaximum efficiency thinning has to be applied at a specific stage of vegetative development. In thisresearch study, the mechanical thinning of ‘Clemenrubi’ mandarin branches during the differentfruit development stages have been assessed using a vibratory laboratory device (amplitudes 0.015and 0.030 m and frequencies 34.8 and 37.8 Hz). Branches with flower buds, flowers, small greenfruits, and medium green fruits were tested for 12 weeks, in two different seasons. It was possibleto mechanically detach flower buds, flowers, and green fruits using different combinations ofamplitudes and frequencies. Removal percentage decreased when increasing retention tractionforce, according to a logarithmic regression model. A significant increment in equatorial diameterand retention traction force was registered when the fruit setting was finishing, while mass had asimilar development with a week delay. During fruit setting (weeks 5, 6, and 7) removal percentagewas higher, while the retention force was very low. The first weeks just after the natural thinningcould be considered the adequate time for a mechanical thinning operation.

Buchanania obovata: An Australian Indigenous food for diet diversification.

Buchanania obovata Engl., the Green Plum, is a small green fruit eaten by Australian Indigenous peoples of the Northern Territory and Western Australia that has had limited study and has potential as a source of food for diet diversification. The flesh and seed of the fruit are eaten and the plant is used as bush medicine. Physical characteristics of the fruit were measured. The flesh and seed freeze dried powders were measured separately for proximates, mineral/trace elements and heavy metals, and folate analysis. Vitamin C was analysed in the flesh. The flesh is high in protein (12.8 g/100 g dry weight (DW)) and both flesh and seed are high in dietary fibre (55.1 and 87.7 g/100 g DW, respectively). The flesh is high in potassium (2274.7 mg/100 g DW), and is a good source of magnesium (570.5 mg/100 g DW), calcium (426.0 mg/100 g DW) and phosphorous (216.8 mg/100 g DW), whereas the seed is high in iron (8.15 mg/100 g DW). The flesh contains folate at 752.4 μg/100 g DW and the seed contains 109.5 μg/100 g DW as pteroylmonoglutamic acid equivalents. The flesh and seed have good nutritional properties and the results support the use of the Green Plum for diet diversification and nutrition in Indigenous and non-Indigenous populations in Australia.

Comparative transcriptome analysis of shortened fruit mutant in woodland strawberry (Fragaria vesca) using RNA-Seq

Genes controlling fruit appearance determine fruit shape and size. In ethylmethane sulfonate (EMS)-mutagenized lines of Fragaria vesca accession Yellow Wonder (YW), two fruit shapes are observed: wild-type long fruit and mutated shortened fruit (sf). In this study, we first characterized sf based on morphology, histology, cytology and physiology. The sf was identified as a gibberellin (GA)-deficient mutant, and four complementary DNA (cDNA) libraries separately constructed from flower buds and small green fruits of YW and sf were sequenced to comparatively analyze transcriptome differences. A total of 29 differentially expressed GA pathway genes were identified by comparisons between YW1 and sf1, and 28 differentially expressed GA pathway genes were identified between YW2 and sf2. In addition, the expression patterns of 45 differentially expressed genes were validated by quantificational real-time PCR (qRT-PCR), and the results were highly concordant with the RNA-Seq results. This transcriptome analysis provides valuable information for understanding the molecular mechanisms of fruit development of strawberry.

Navel Country

Navel Country Yelizaveta P. Renfro (bio) Riverside, California, circa 1979 We hurtle down the narrow road in Grandpa’s Ford ltd, whistling cleanly through the orange trees, the dark green foliage whipping past. Up ahead, the leaves all seem a jumble, but looking directly out my open window, I see the neat rows opening up, the cleaving of soil between the evenly spaced trees. For a split second, each row lines up straight in my line of sight, and then the next supersedes it, and the next, and the next, each one a clean part in the land. Zip-zip-zip-zip, the rows whip past with an even tempo, a corresponding music in the whoosh-whoosh-whooshing of the leaves. We’re headed up to the ranch, barreling along Palmyrita Avenue in an enormous mint-green two-door with automatic windows. I’m small on the big bench seat, skittering back and forth with the turns, clawing at the vinyl seat to keep from careening into Grandpa. He’s a fast, aggressive driver. The trees keep flying past until he slows and pulls onto a dirt road running between two groves. Creeping along it, he vigilantly peers down the rows on either side, looking for anything out of the ordinary, for trouble. Suddenly he turns the steering wheel, plunging the car right down one of the narrow rows, forcing it in, and we are riding in a wedge that passes through the trees, branches scraping on both sides. I shrink away from the foliage erupting in from my open window, the trees seeming to clamber into the car with me. Their glossy leaves fall on my lap, and occasionally an orange thuds to the floorboard. The car’s antenna bounces crazily, springing off branches. Grandpa rests his left arm on the open window, never moving, not even flinching when a branch scratches his tan skin. He’s impervious to these unruly trees because he’s the lord of this vast kingdom of citrus; as far as I know, he very nearly rules the world. [End Page 67] Looking down from the Box Springs Mountains, the orange groves are needlepoint, an elaborate embroidering upon the land. Dark green burrs set at regular intervals, the trees are globular, their full branches skirting the ground, their shiny ovate leaves present year round, unchanging but for the cycle of fruit: the saccharine blossoms, the small green fruit, and finally, the brilliant ripeness of temperate winter. January in a navel grove is a page from a storybook. The leaves seem to be a setting, a dark green satin, to display the gleaming jewels of fruit. Orange is both a color and a fruit. No other fruit can quite manage it; peach, lemon, raspberry, and watermelon are shades of colors, not colors proper, not members of the rainbow. But an orange is orange. And I feel proud that we—this country, my family—own this color, that it is ours and that it is tangible and edible and I can cup it in my hand. Brown and dusty most of the year, the Box Springs Mountains are covered in scrub with a few sycamores growing deep in gullies, the highest peak just three thousand feet. Farther off are the real mountains, the San Bernardino and San Gabriel ranges, blue and purple, snowcapped, over eleven thousand feet at the highest peak, an ornate backdrop to our life in navel country—except that on many days, the mountains don’t seem to be there at all. They’ll be invisible for weeks behind a shroud of smog, so that when they suddenly reappear on a clear day, it’s as if they’ve been unrolled from the sky, Hollywood scenery tacked up along the horizon to make our life appear idyllic. The smog is never idyllic, brownish-orange and thick, pooling up in valleys, obstructing views and lungs. The startling splendor alternates with long strings of smog alert days, when the air quality is so poor that we’re kept in at recess and p.e., so that we won’t physically exert ourselves and breathe in even more of the toxic air. We sustain ourselves...

Effect of tomato post-harvest treatment and storage conditions on the biological activity of benomyl and methylthiophanate residues in fruits and their processed products

The biological activity of benomyl and methylthiophanate residues in tomatoes and their processed products was examined. Fungicide residues were most active in concentrated pulp of tomatoes, less in pulp and the least in fresh fruits. The fungicide residues activity was very high after 90 days of storage of processed products. The pulp and concentrated pulp of tomatoes treated and stored for 14 days at 15°C, also contained very active fungicide residues. The translocation of benomyl from treated tomato skin into the tissue begun slowly. This process was faster in green or yellow fruits, but it was the fastest in small green fruits. The influence of storage conditions on the activity of fungicide residues depended on the storage length. The residues were the least active in fruits stored under low pressure of 38 mm Hg for 14 days, but this activity increased during the storage period and the residues were very active after 34 days of tomato storage.

Brassinosteroid is involved in strawberry fruit ripening

Although brassinosteroid (BR) has been suggested to play a role in strawberry fruit ripening, the defined function of this hormone remains unclear in the fruit. Here, BR content and BR receptor gene FaBRI1 expression were analysed during ‘Akihime’ strawberry fruit development. We found that BR levels increased during the later developmental stages, and the mRNA expression levels of FaBRI1 increased rapidly from white to initial red stages, suggesting that BR is associated with fruit ripening. This was further confirmed by exogenous application of BR and its inhibitor brassinazole (BZ) to big-green fruit, which significantly promoted and inhibited strawberry fruit ripening, respectively. More importantly, down-regulation of FaBRI1 expression in de-greening fruit markedly retarded strawberry red-colouring. In conclusion, we have provided physiological and molecular evidence to demonstrate that BR plays a role in strawberry fruit ripening. In addition, both BR content and FaBRI1 expression reached their peak levels in small-green fruit, suggesting that BR might also be involved in early strawberry fruit development. Further experiments are required to validate the role of BR in strawberry fruit cell division.

Determining the Optimal Timing of Fruit Harvest in Transgenic Tomato Expressing F1-V, a Candidate Subunit Vaccine against Plague

Changes in the amounts of F1-V, an antigen fusion protein and a candidate subunit vaccine against plague, and total soluble protein (TSP) in green fruit of transgenic tomato plants were investigated to identify the optimum harvest timing to maximize the F1-V yields. Two T2 progenies of the transgenic plant, ‘22.11.21’ and ‘22.11.5’, were grown. The F1-V concentration rapidly decreased at the beginning of the green stage and decreased to less than 5% of the initial concentration at the late green stage in ‘22.11.21’. The F1-V concentration also decreased as fruit size increased in ‘22.11.5’, but the pattern of the decrease was linear and different from that in ‘22.11.21’. The concentration of TSP also decreased with fruit growing in both plants. When calculated on a whole fruit basis, the F1-V content linearly decreased with increasing fruit size in ‘22.11.21’. In ‘22.11.5’, the F1-V content per fruit also tended to decrease from the middle to late green stage. Based on these observations, collecting small green fruits without pruning was proposed as a harvest practice that may maximize the F1-V yields. Thus, the optimum protocols for harvesting and pruning for plant-made pharmaceutical production may be substantially different from those currently used in commercial hydroponic greenhouses for fresh market tomato.

Ontogenetic variation of catechin biosynthesis as basis for infection and quiescence of Botrytis cinerea in developing strawberry fruits

The accumulation of catechin derived procyanidins is regarded as one fundamental factor inhibiting the growth of the pathogenic fungus Botrytis cinerea in immature strawberry fruits–a phenomenon referred to as quiescence after invasion at bloom usually ending during fruit ripening. For evaluation of that hypothesis an attempt was made to modify the concentration of flavanols in developing strawberry fruits by treatments with an inhibitor of 2-oxoglutarate-dependent dioxyge-nases which is known to affect the flavonoid pathway. The accumulation of novel flavonoids identified as luteoliflavan and eriodictyol 7-glucoside and enhanced levels of catechin were found when green fruits were treated. The effect of the bioregulator varies during fruit ontogenesis with a steady increase after flowering to the stage of small green fruits and a rapid decrease thereafter. It became obvious that young fruits just at flowering do not accumulate flavanols to a sufficient level for preventing primary receptacle infection.

The Importance of Behavioral Plasticity for Maximizing Foraging Efficiency in Frugivorous Lepidopteran Larvae

In this study, we present evidence that the larvae of Acrobasis vaccinii (Lepidoptera: Pyralidae), a species that feeds on cranberry fruit, are able to take into account at least three cues (fruit size, fruit color, and the distance between fruits) when searching for food. In laboratory experiments, the relative impact of each cue depended on which cues were presented in a given bioassay. Fruit color was the dominant cue in some contexts (e.g., larvae showed a significant perference for green fruit over red ones regardless of fruit size when fruits were equidistant from the larvae) but not in others (e.g., when given a choice between a large red fruit placed close to the larvae and a small green fruit placed farther away, a significantly higher proportion of larvae chose the former). This plasticity in foraging behavior allows larvae to maximize foraging efficiency under conditions of differing fruit and larval densities, which this species experiences in nature.

First Report of Lasmenia sp. and Two Species of Gliocephalotrichum on Rambutan in Hawaii.

Rambutan (Nephelium lappaceum L.) is a tropical fruit grown in Hawaii for the exotic fruit market. Fruit rot was observed periodically during 1998 and 1999 from two islands, Hawaii and Kauai, and severe fruit rot was observed during 2000 in orchards in Kurtistown and Papaikou on Hawaii. Symptoms were characterized by brown-to-black, water-soaked lesions on the fruit surface that progressed to blackening and drying of the pericarp, which often split and exposed the aril (flesh). In certain cultivars, immature, small green fruits were totally mummified. Rambutan trees with high incidence of fruit rot also showed symptoms of branch dieback and leaf spot. Lasmenia sp. Speg. sensu Sutton, identified by Centraalbureau voor Schimmelcultures (Baarn, the Netherlands), was isolated from infected fruit and necrotic leaves. Also associated with some of the fruit rot and dieback symptoms were Gliocephalotrichum simplex (J.A. Meyer) B. Wiley & E. Simmons, and G. bulbilium J.J. Ellis & Hesseltine. G. simplex was isolated from infected fruit, and G. bulbilium was isolated from discolored vascular tissues and infected fruit. Identification of species of Gliocephalotrichum was based on characteristics of conidiophores, sterile hairs, and chlamydospores (1,4). Culture characteristics were distinctive on potato dextrose agar (PDA), where the mycelium of G. bulbilium was light orange (peach) without reverse color, while G. simplex was golden-brown to grayish-yellow with dark brown reverse color. Both species produced a fruity odor after 6 days on PDA. In pathogenicity tests, healthy, washed rambutan fruits were wounded, inoculated with 30 μl of sterile distilled water (SDW) or a fungus spore suspension (105 to 106 spores per ml), and incubated in humidity chambers at room temperature (22°C) under continuous fluorescent light. Lasmenia sp. (strain KN-F99-1), G. simplex (strain KN-F2000-1), and G. bulbilium (strains KN-F2001-1 and KN-F2001-2) produced fruit rot symptoms on inoculated fruit and were reisolated from fruit with typical symptoms, fulfilling Koch's postulates. Controls (inoculated with SDW) had lower incidence or developed less severe symptoms than the fungus treatments. Inoculation tests were conducted at least twice. To our knowledge, this is the first report of Lasmenia sp. in Hawaii and the first report of the genus Gliocephalotrichum on rambutan in Hawaii. These pathogens are potentially economically important to rambutan in Hawaii. G. bulbilium has been reported previously on decaying wood of guava (Psidium guajava L.) in Hawaii (2), and the fungus causes field and postharvest rots of rambutan fruit in Thailand (3).

Expression of six expansin genes in relation to extension activity in developing strawberry fruit.

Expansins are proteins which have been demonstrated to induce cell wall extension in vitro. The identification and characterization of six expansin cDNAs from strawberry fruit, termed FaExp3 to FaExp7, as well as the previously identified FaExp2 is reported here. Analysis of expansin mRNAs during fruit development and in leaves, roots and stolons revealed a unique pattern of expression for each cDNA. FaExp3 mRNA was present at much lower levels than the other expansin mRNAs and was expressed in small green fruit and in ripe fruit. FaExp4 mRNA was present throughout fruit development, but was more strongly expressed during ripening. FaExp5 was the only clone to show fruit specific expression which was up-regulated at the onset of ripening. FaExp6 and FaExp7 mRNAs were present at low levels in the fruit with highest expression in stolon tissue. During fruit development FaExp6 had the highest expression at the white, turning and orange stages whereas expression of FaExp7 was highest in white fruit. The expression profiles of FaExp2 and FaExp5 in developing fruit were similar except that FaExp2 was induced at an earlier stage. Analysis of expansin protein by Western blotting using an antibody raised against CsExp1 from cucumber hypocotyls identified two bands of 29 and 31 kDa from developing fruit. Protein extracts from developing fruit were assayed for extension activity. Considerable rates of extension were observed with extracts from ripening fruit, but no extension was observed with protein from unripe green fruit. These results demonstrate the presence of at least six expansin genes in strawberry fruit and that during ripening the fruit acquires the ability to cause extension in vitro, characteristic of expansin action.

Ontogenetic changes in water in cherry tomato fruits measured by nuclear magnetic resonance imaging

Changes in water status of intact developing cherry tomato fruits were followed by 1H NMR imaging and 1H NMR spectroscopy. In small green fruits, large amounts of water were located in the epidermis and neighbouring cells, and in seed envelopes and seeds. High mobility water with long spin-lattice relaxation times ( T 1) in the seeds of small green fruits disappeared as the fruit grew. The content of high mobility water in locular cavities, including seed envelopes, increased as ontogeny advanced. Low mobility water (short T 1) in the pericarp and dissepiments of the small and large green fruits increased in quantity and mobility during maturation. In some of the several water compartments in large green fruits water content declined during maturation. Changes in the physical state of water appeared to reflect changes in the physiology of the fruits. The mobility of sugars increased during fruit ripening.

Expression of the large plastid gene, ORF2280, in tomato fruits and flowers.

The expression of ORF2280, a large plastid gene of unknown function, was examined in tomato leaves, in a developmental series of tomato fruits, and in tomato flowers. Western blots indicated that much more ORF2280 protein is present in fruits and flowers than in leaves. The most abundant proteins detected, 68 and 59 kDa, are present in about equal amounts in fruits of all stages; they are even more abundant in flowers. A 170-kDa ORF2280 protein is also present in fruit of all stages; it is most abundant in small green fruit. The presence of higher levels of ORF2280 proteins in tomato fruits and flowers indicates that it may have a specialized function in these nonphotosynthetic tissues.

WATER POTENTIAL AND CELL TURGOR OF STRAWBERRY FRUIT ARE INFLUENCED BY RIPENING.

Since large ripe strawberry fruit lose water faster than smaller unripe fruit, ripening fruit may out-compete unripe fruit for water within an inflorescence and thereby reduce yields. Xylem water potential (ψ) of greenhouse-grown `Brighton' fruit, at different stages of development, was measured with a pressure chamber during mid-afternoon. Large ripe and medium sized green-white fruit within an inflorescence had a more negative ψ than small green fruit. This suggests that small green fruit have a lower priority for xylem water moving into a strawberry inflorescence. Large ripe and small green fruit within an inflorescence had positive cell turgor (about 300 KPa), whereas turgor of medium sized green-white fruit was near zero, suggesting that these latter fruit were encountering greater water stress. When competing fruit on an inflorescence were removed, the calculated cell turgor was very similar to fruit with competition. Cell turgor of strawberry fruit is greatly influenced by developmental stage; this may moderate effects caused by water loss from neighboring fruit on an inflorescence.