Fruit set and development

Rhamnus alaternus L. is a dioecious, fleshy-fruited shrub, typical of Mediterranean vegetation, which has been recorded from the region since the tropical Tertiary. Reproductive biology of this species has been studied in Southern Italy over a period of 4 years with both field and laboratory experiments. In all the studied populations male plants predominate over the females, have a higher flower density and flower regularly every year while females are usually alternate-bearing. A strong negative association between fruit formation and vegetative growth has been found indicating that the presence of fruits on a branch reduces the growth of new shoots. This phenomenon, together with alternate-bearing, is evidence of a strong competition between vegetative growth and reproductive activity and indicates resource limitation. Flower morphology and quantity of pollen produced are typical of insect pollinated species, and flies of the Empididae and Muscidae were trapped bearing pollen at female plants but pollen is also dispersed by wind. Field experiments on pollination success showed that the exclusion of insects as pollen vectors produces a significant decrease in fruit development. Excess pollen provided by hand-pollination increases fruit set over open-pollination and reproductive success in the field is therefore pollen limited. The variability of sex expression, male fitness, fruit production, regrowth and pollination presented here suggests that these predispersal characteristics of R. alaternus have been subject to evolutionary change since the tropical Tertiary climate was replaced by a Mediterranean one. This points to the possibility that reproductive, as well as morphological and physiological characteristics, may be equally selected for in extreme environments such as the Mediterranean.

SUMMARY Fruit development and the fate of fruits was followed on 'Imperial Gala' apple (Malusdomestica Borkh.) trees thinned chemically or using shading. The percentage fruit drop, fruit growth rates using callipers and electronic gauges, and whole tree gas exchange rates were measured before, during, and after covering with a shading cloth that blocked 90% of solar radiation, applied for 1

This study examined the influence of preharvest elevated atmospheric CO2 concentration (850 ± 50 ppm) on the fruit growth, total soluble solids (TSS), fructose, glucose, sucrose, soluble and cell wall-bound acid invertase (AI) (ß-fructofuranoside fructohydrolase, EC 3. 2. 1. 26), sucrose synthase (SuSy) (UDP glucose: D-fructose 2 -glucosyltransferase, EC 2. 4. 1. 13) and sucrose phosphate synthase (SPS) (UDP glucose: D-fructose-6 -phosphate 2 -glucosyltransferase, EC 2. 4. 1. 14) activities of domesticated tomatoes (Lycopersicon esculentum Mill. cv. 'Lady First', 'Momotaro' & 'Minicarol') during fruit development. Tomato plants grown in CO2-enriched conditions accumulated more carbohydrates in their fruit and exhibited significantly larger fruits compared to the control (350 ± 50 ppm). The CO2-enriched tomato fruit contained significantly higher concentrations of TSS, fructose and glucose during development. The amount of reducing sugars increased at th...

GA 8 , GA 19 , GA 20 , GA 29 and GA 44 ) in unpollinated ovaries The role of gibberellins (GAs) in the induction of parthenoat 3 developmental stages (flower bud, FB; pre-anthesis, PR; carpic fruit-set and growth by the pat-3/pat-4 genetic sysand anthesis, AN), by gas chromatography-selected ion tem in tomato (Lycopersicon esculentum Mill.) was investigated using wild type (WT; Cuarenteno) and a near-monitoring, showed that the concentration of most of them was higher in pat-3/pat-4 than in WT ovaries at PR and isogenic line derived from the German line RP75/59 (the source of pat-3/pat-4 parthenocarpy). Unpollinated WT AN stages. The concentration of GA 1 , suggested previously to be the active GA in tomate, was 2 -4 times higher. Un-ovaries degenerated but GA 3 application induced parthenocarpic fruit growth. On the contrary, parthenocarpic growth pollinated pat-3/pat-4 ovaries at FB, PR and AN stages also contained relatively high amounts (5 -12 ng g − 1 ) of of pat-3/pat-4 fruits, which occurs in the absence of polli-GA 3 , a GA found at less than 0.5 ng g − 1 in WT ovaries. nation and hormone treatment, was not affected by applied GA 3

Fruit and vegetables have many similarities with respect to their compositions, methods of cultivation and harvesting, storage properties and processing.In reference to fruits and vegetables, the characteristics that impart distinctive quality may be described by four different attributes -1) color and appearance, 2) flavor (taste and aroma), 3) texture and 4) nutritional value.

Detailed crop-specific descriptions and codes are presented for the growth stages of the cherimoya tree, contributing to the standardization of national and international testing systems in fruit growing. Based on the general BBCH-scale, the codes describe growth stages using a two-digit numerical system and differentiate between principal and secondary growth stages to allow separation of developmental steps. Growth stages for bud, leaf and shoot development, inflorescence emergence, flowering and fruit development were described. A feature of the system is that homologous stages of different crops are presented by the same codes. #

Among the many plant mineral nutrients, potassium (K) stands out as a cation having the strongest influence on quality attributes that determine fruit marketability, consumer preference, and the concentration of critically important human-health associated phytonutrients. However, many plant, soil, and environmental factors often limit adequate uptake of K from the soil in sufficient amounts to satisfy fruit K requirements during development to optimize the aforementioned quality attributes. The objectives of this review are 1) to summarize published study abstracts on the effects of soil and/or foliar K fertilization as well as diverse K forms, on fruit phytonutrient concentrations; and 2) to illustrate the important role of K forms on fruit quality with a case study of Cucumis melo L (muskmelon) fruit produced with optimal soil applied K . The muskmelon studies will compare commercial sources (forms) of K applied to examine seasonal effects (spring vs. autumn) and the number of foliar K applications during fruit development on fruit marketability (maturity, yield, firmness, soluble solids, sugars, relative sweetness), consumer preference attributes (sugar content, sweetness, texture), and phytochemical concentrations (K, ascorbic acid, and β-carotene concentrations). Numerous studies have consistently demonstrated that specific K fertilizer forms, in combination with specific application regimes, can improve fruit quality attributes. Potassium fertilizer forms in order of effectiveness (Glycine (Gly)-complexed K=K 2 SO 4 ≥KCl>no K> KNO 3 ) when applied wet (foliar or hydroponic) vs. dry (soil) were generally superior in improving fruit marketability attributes, along with many humanhealth nutrients. The muskmelon case study demonstrated that two K forms: Gly-complexed K and K 2 SO 4 , combined with a silicone-based surfactant, applied weekly, as a foliar spray, during fruit development, from both autumn and spring-grown plants, had the greatest impact on improving fruit marketability attributes (maturity, yield, firmness, and sugars), as well as fruit quality attributes (human-health bioactive compounds K, ascorbic acid, and β-carotene). Among several foliar applied K salts studied under field conditions so far, salts with relatively low salt indices appeared to have the greatest impacts on fruit quality when applied during the mid-to late-season fruit development periods.

The progressive postharvest disorder of 'Nules Clementine' mandarin (Citrus reticulata Blanco), referred to as rind breakdown (RBD), starts to develop during storage, about 3-5 weeks after harvest. Variation within the tree canopy, i.e. inside or outside canopy positions, as well as postharvest handling practices such as ethylene degreening, storage temperature and storage duration, were investigated for their influence on RBD incidence. Two experiments were conducted wherein fruit were subjected, in the first experiment, to ethylene degreening and a delay in commencement of cold storage , and, in the second experiment, fruit were sampled from the inside and outside of the canopy and cold-stored at either −0.5 • C or 7.5 • C during 2005 and 2007. Rind pigment and carbohydrate contents as well as rind colour and RBD incidence were recorded during prolonged storage. The senescence-promoting treatments resulted in an increase in RBD incidence, except for storage at −0.5 • C, which resulted in a lower occurrence of RBD. Overall, results indicated that the incidence of RBD was aggravated by senescence-promoting factors during the postharvest handling of fruit and this is thought to lead to the premature senescence of the flavedo. In addition, fruit position in the tree canopy during fruit development contributed significantly to RBD sensitivity, with inside fruit having significantly higher RBD incidence compared to outside fruit.

The trioecious papaya is a unique system to study the roles of flower organ identity genes of the ABC model in a multi-sex-type plant species. We have cloned two AGAMOUS (AG) subfamily genes, CpPLE and CpSTK, and one AP1 subfamily gene, CpFUL-a FRUITFUL homolog. CpPLE, CpSTK, and CpFUL are grouped into the PLE, D, and euFUL sublineages, respectively. Both CpPLE and CpSTK were expressed only in flowers, not in roots and leaves based on Northern and RT-PCR analyses. Specifically, CpPLE was detected only in the stamens and carpels of flowers of all three sex types, from a very early stage of flower development through full maturity. CpSTK expression was detected in female and hermaphrodite flowers, but completely absent in male flowers. This is the only gene found so far that shows sex-type-specific expression in papaya but this is likely to be an indirect effect of sex determination rather than a causative agent. CpFUL was expressed in leaves and all parts of the flowers except stamens. The genomic structures and expression patterns of CpPLE and CpSTK are consistent with their potential functions as C and D class genes, respectively. CpPLE belongs to the PLE lineage and is therefore an ortholog of SHP1/2 rather than AG. However, CpPLE is likely to perform ancestral functions in carpel and stamen identity, whereas SHP1/2 are involved in fruit development. These findings demonstrate that the evolution of gene function within the AG and PLE lineages has been quite dynamic, even over relatively short phylogenetic distances.

Pruning as a cultural practice has been increasingly used in Southern California avocado orchards. This practice promotes the production of flush growth, which is the preferred food source of avocado thrips (Scirtothrips perseae Nakahara). Currently, most pruning activities take place in January, February or March. To determine when pruning 'Hass' avocado least affects fruit set and minimizes avocado fruit relates

In nonparthenocarpic cucumber, analysis of the interaction between season and female receptivity demonstrated two different modes of fruit development and seed set. Spring climatic conditions induced significantly longer ovaries at anthesis with an autonomous fruit set as in natural parthenocarpy. Autumn climatic conditions induced smaller ovaries with fruit set influenced by the pollination stage of the female flower. These differences involve, during fruit development, a regulation of the empty seed number especially at both ends of female receptivity period. Indeed, seasons have no effect on ovule receptivity and fertility measured by full seed number. It is supposed that priority is given to seeds with an embryo in the competition for limited maternal resources in spring as well as in autumn. In spring, the use of irradiated pollen during the whole female receptivity period did not modify the seed set profile. Moreover, a cytological study of 6-day-old ovules pollinated by irradiated pollen has revealed a similar precocious embryogenesis compared to the control. In cucumber, pollination with irradiated pollen involves stenospermocarpy rather than 'induced parthenocarpy.' However, we have not been able to determine whether the early abortive embryogenesis induced by irradiated pollen is gynogenetic or abnormal zygotic.

QTL analysis of pepper fruit characters was performed in an F 3 population derived from a cross between two Capsicum annuum genotypes, the bell-type cultivar Maor and the Indian small-fruited line Perennial. RFLP, AFLP ®1 , RAPD and morphological markers (a total of 177) were used to construct a comparative pepper-tomato genetic map for this cross, and 14 quantitatively inherited traits were evaluated in 180 F 3 families. A total of 55 QTL were identified by interval analysis using LOD 3.0 as the threshold for QTL detection. QTL for several traits including fruit diameter and weight, pericarp thickness and pedicel diameter were often located in similar chromosomal regions, thus reflecting high genetic correlations among these traits. A major QTL that accounts for more than 60% of the phenotypic variation for fruit shape (ratio of fruit length to fruit diameter) was detected in chromosome 3. This chromosome also contained QTL for most of the traits scored in the population. Markers in linkage groups 2, 3, 8 and 10 were associated with QTL for multiple traits, thereby suggesting their importance as loci that control developmental processes in pepper. Several QTL in pepper appeared to correspond to positions in tomato for loci con-trolling the same traits, suggesting the hypothesis that these QTL may be orthologous in the two species.

In the present work, the effect of assisted fertilization on anatomical, morphological and gene expression changes occurring in carpels and during early stages of berry development in Vitis vinifera were studied. Inflorescences were emasculated before capfall, immediately manually pollinated (EP) and fruit development was compared to emasculated but non-pollinated (ENP) and self-pollinated inflorescences (NESP). The diameter of berries derived from pollinated flowers (EP and NESP) was significantly higher than from non-pollinated flowers (ENP) at 21 days after emasculation/pollination (DAE), and a rapid increase in the size of the inner mesocarp, together with the presence of an embryo-like structure, were observed. The expression of gibberellin oxidases (GA20ox and GA2ox), anthranilate synthase (related to auxin synthesis) and cytokinin synthase coding genes was studied to assess the relationship between hormone synthesis and early berry development, while flower patterning genes w...

A trial was carried out to evaluate the influence of N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU), a diphenylurea derivative cytokinin, on kiwi productivity, on carbohydrate accumulation and metabolism and on post-harvest fruit performance. CPPU (20 ppm) was sprayed on fruitlets inside the canopy 2 weeks after full bloom (APB). CPPU influenced fruit growth soon after treatment and, at harvest, treated fruit weight and, consequently, yield per vine were about 25% higher than the control. During fruit growth, soluble sugars (glucose, fructose and sucrose> were higher in treated fruits than in the control ones. In the first period of fruit development glucose was the most abundant carbohydrate and CPPU treatment increased the fruit glucose content significantly. During the period of starch accumulation, treated fruits showed a higher starch content and a higher ADP-glucose pyrophosphorylase activity. Starch accumulation started earlier in treated fruits than in the control ones. At the end of the growing season the degradation of starch in treated fruits started earlier and/or was faster than in the control ones, so that at harvest treated and control fruits contained the same amount of starch. As a consequence, treated fruits at harvest had higher contents of soluble sugars. This indicates that CPPU induced faster and/or advanced fruit ripening. The chlorophyll content was higher in CPPU treated fruits. During storage, the differences in carbohydrate content disappeared and treated fruits performed as well as control ones, maintaining good quality for up to 6 months. ' Corresponding author. ' Present address: Catedra de Pomicuhura, Facultatea de Horticultura, Universitatea de Stiinte Agronomice, Bucuresti. Romania. 03044238/%/$15.00 0 1996 Elsevier Science B.V. AI1 rights reserved SSDI 0304-4238(95)00852-7 E. Antognozzi et al./ Scientin Horticulturae 65 (1996) 37-47

Fruit development is a complex yet tightly regulated process. The developing fruit undergoes phases of cell division and expansion followed by numerous metabolic changes leading to ripening. Plant hormones are known to affect many aspects of fruit growth and development. In addition to the five classic hormones (auxins, gibberellins, cytokinins, abscisic acid and ethylene) a few other growth regulators that play roles in fruit development are now gaining recognition. Exogenous application of various hormones to different stages of developing fruits and endogenous quantifications have highlighted their importance during fruit development.

Phenological studies are important for understanding the infl uence of weather dynamics on vegetative growth, fl owering and fruiting on mango. BBCH (Biologische Bundesantalt, Bundessortenamt and Chemische Industrie) scale was used for data recording and to assess utility of the scale in mango phenological studies. Phenological stages of the mango were recorded at weekly intervals on 60 shoots of cultivar Totapuri at fi ve diverse locations for testing usefulness of scale under different diverse ecologies and data from one location, i.e., Lucknow (26 o 54´ N and 80 o 48´ E) was used for analysis. Existing BBCH scale was modifi ed on the basis of data recorded for mango in which seven out of 10 principal stages were used, starting with bud development (stage 0) and ending with maturity of fruit (stage 8). Three digit scale was used for inclusion of the mesostages between the principal and secondary growth stages. Highly recurring fl owering phenophases were 511 (18 %), 513 (20 %) recorded in standard week 9 and 517 (45 %) in standard week 11 (March). Other important phenophases, 619 (38 %) and 709 (10 %) occured during standard weeks 13 and 22 to 23, respectively. A high degree of variation in shoots representing principal growth stages viz., vegetative bud, leaf and shoot development was observed due to simultaneous transition of the stages during standard week 33 to 42 and 4 to 24. Limitations of existing BBCH scale and comprehended modifi cations have been proposed and discussed. The study revealed that the extended BBCH-scale for mango can be widely used because of its utility in describing all phenophases pertaining to bud, shoot, leaf, panicle and fruit development and indicated the incisive growth pattern of the shoots and seasonal variation. This is the fi rst report on quantitative analysis of mango phenological data using BBCH scale.

The effect of naphthaleneacetic acid (NAA) thinning sprays on fruit size of Redchief 'Delicious' apple was studied in relation to spray application volume and time of application. A constant dose of NAA resulted in similar fruit size at harvest when applied in varying spray volumes from high (near full retention, V,) to VJ8. NAA applied as a high volume spray (15 mg 1-l) at various stages of fruit development (4.6 to 22.5 mm king fruit diameter, RFD), indicated that the maximum amount of small fruit was produced following applications at about 11 mm RFD. NAA did not consistently affect growth rate of king fruit immediately after treatment when fruit competition was minimized. NAA reduced fruit size at harvest by about 11% when two competing fruits were present on the same spur, but did not significantly reduce fruit size when a single fruit was permitted to develop per spur. 0304-4238/95/$09.50 8 1995 Elsevier Science B.V. All rights reserved SSDI 0304-4238(95)00847-O

Adequate K, Mg and Ca supply is important to develop well-structured and functional cell walls and membranes in fruit, and insufficient levels or imbalances of these minerals are known to be involved in various postharvest disorders. Microclimatic variation exists in the ‘Nules Clementine’ mandarin tree canopy and results in lower photosynthetically active radiation (PAR) levels and temperature as well as a higher humidity inside the tree canopy. The aim of this experiment was to determine the impact of this variation in microclimate on accumulation patterns of K, Ca and Mg in the flavedo of the fruit rind during stages II and III of fruit development. Fruit mass, dimensions, rind colour development and mineral composition of the flavedo were measured to describe the condition of fruit borne on the outside and inside of the tree's canopy. The data revealed that canopy position influenced mineral nutrient accumulation patterns in the flavedo. Outside fruit flavedo accumulated significantly higher concentrations of Ca and Mg in all three seasons (2005–2007). In contrast, inside fruit flavedo (shaded fruit) accumulated significantly higher levels of K compared with outside fruit flavedo. The accumulation of K and Ca differed from that of kiwifruit and apple in that Ca concentration increased and K decreased towards maturity. These results suggest that xylem, as in citrus leaves, is the main vasculature supply conduit to the citrus fruit flavedo for mineral nutrients. The reduction of transpiration potential by lower temperatures and higher humidity inside the canopy could be responsible for the reduced accumulation of Ca and Mg. The high K concentration of inside fruit flavedo is suggested to be a stress response, due to the low light levels, to maintain osmotic potential in the shaded rind tissue, and this imbalance could possibly lead to a reduction in rind condition, which manifests through rind breakdown symptom development.► Fruit positioned in the outside of the canopy accumulated higher concentrations of Ca and Mg and lower K in their flavedo compared to inside fruit. ► The accumulation concentration of Ca increased whereas the K decreased towards maturity of the flavedo. ► Fruit position influenced the pedicel diameter, resulting in a smaller diameter for the inside fruit. ► Inside fruit had a higher incidence of rind breakdown compared to fruit developing in the outside of the canopy.

Two strawberry cDNAs showing sequence similarity to pyruvate decarboxylase (PDC) genes (Fapdc1 and Fapdc3 genes) from higher plants have been isolated by a differential display-PCR approach (DDRT-PCR). Sequence comparisons, northern and RT-PCR analysis showed that these strawberry genes are different and are expressed in a different expression pattern in vegetative tissues and in fruits during fruit development and ripening processes. RT-PCR studies indicated that only Fapdc1 gene is induced during fruit ripening whereas Fapdc3 gene is constitutively present in all tissues studied. The removal of the achenes from unripe green fruits induced the expression of Fapdc1 gene and this induction was inhibited by treatment of de-achened fruits with naphthaleneacetic acid (NAA) and indoleacetic acid (IAA), thus indicating that only the expression of Fapdc1 gene is under hormonal control. Also, Fapdc1 gene expression was increased in anoxia conditions in cultured cells. However, Fapdc3 is accumulated to high levels in strawberry cultured cells, irrespective of oxygen availability and probably controlled by sugar supply. The expression pattern of both genes in response to stress and post-harvest treatments is evaluated. All these results suggest that the strawberry Fapdc1 gene could play an important role in fruit ripening and aroma biogenesis, and also under stress conditions, whereas Fapdc3 would be involved in general metabolism to support energy production and biosynthesis of higher molecular weight compounds. The Fapdc1 genomic region has been cloned and characterised to isolate an inducible fruit ripening-related promoter for biotechnological purposes in strawberry.

The trioecious papaya is a unique system to study the roles of flower organ identity genes of the ABC model in a multi-sex-type plant species. We have cloned two AGAMOUS (AG) subfamily genes, CpPLE and CpSTK, and one AP1 subfamily gene, CpFUL-a FRUITFUL homolog. CpPLE, CpSTK, and CpFUL are grouped into the PLE, D, and euFUL sublineages, respectively. Both CpPLE and CpSTK were expressed only in flowers, not in roots and leaves based on Northern and RT-PCR analyses. Specifically, CpPLE was detected only in the stamens and carpels of flowers of all three sex types, from a very early stage of flower development through full maturity. CpSTK expression was detected in female and hermaphrodite flowers, but completely absent in male flowers. This is the only gene found so far that shows sex-type-specific expression in papaya but this is likely to be an indirect effect of sex determination rather than a causative agent. CpFUL was expressed in leaves and all parts of the flowers except stamens. The genomic structures and expression patterns of CpPLE and CpSTK are consistent with their potential functions as C and D class genes, respectively. CpPLE belongs to the PLE lineage and is therefore an ortholog of SHP1/2 rather than AG. However, CpPLE is likely to perform ancestral functions in carpel and stamen identity, whereas SHP1/2 are involved in fruit development. These findings demonstrate that the evolution of gene function within the AG and PLE lineages has been quite dynamic, even over relatively short phylogenetic distances.

Tomato, an essential crop in terms of economic importance and nutritional quality, is also used as a model species for all fleshy fruits and for genomics of Solanaceae. Tomato fruit quality at harvest is a direct function of its metabolite content, which in turn is a result of many physiological changes during fruit development. The aim of the work reported here was to develop a global approach to characterize changes in metabolic profiles in two interdependent tissues from the same tomato fruits. Absolute quantification data of compounds in flesh and seeds from 8 days to 45 days post anthesis (DPA) were obtained through untargeted (proton nuclear magnetic resonance, 1 H-NMR) and targeted metabolic profiling (liquid chromatography with diode array detection (LC-DAD) or gas chromatography with flame ionization detection (GC-FID)). These data were analyzed with chemometric approaches. Kohonen self organizing maps (SOM) analysis of these data allowed us to combine multivariate (distribution of samples on Kohonen SOMs) and univariate information (component plane representation of metabolites) in a single analysis. This strategy confirmed published data and brought new insights on tomato flesh and seed composition, thus demonstrating its potential in metabolomics. The compositional changes were related to physiological processes occurring in each tissue. They pointed to (i) some parallel changes at early stages in relation to cell division and transitory storage of carbon, (ii) metabolites participating in the fleshy trait and (iii) metabolites involved in the specific developmental patterns of the seeds.

The synthesis of organic acids was studied during fruit devel-23 and 108 DAB in Fantasia. In Jalousia, they were very low at 23 DAB and reached levels similar to Fantasia at 108 opment of two peach (Prunus persica L. Batsch) cultivars, DAB. For both cultivars, in vitro PEPC activity expressed on Fantasia and Jalousia, having fruits with high and low organic a dry weight basis was maximal at 24 DAB, decreased from acid content, respectively. The malate content was higher in 24 to 60 DAB, and then remained constant. The activity of cv. Fantasia than in cv. Jalousia at the end of the first rapid growth stage (50 days after bloom [DAB]). Malate and citrate peach fruit PEPC appeared extremely sensitive to malate (I 0.5 of 100 mM for Fantasia and 65 mM for Jalousia at pH 7.3) contents were higher in Fantasia than in Jalousia during the second rapid growth stage (from 100 DAB to maturity). The and low pH. PEPC may participate in the control of organic acid accumulation during fruit development in the normal-acid expression of phosphoenolpyruvate carboxylase (PEPC, EC fruit of Fantasia. However, mechanisms other than organic 4.1.1.31), which is involved in organic acid synthesis, was studied during peach fruit development. PEPC mRNA levels, acid synthesis might account for the differences in acidity and protein levels on a total soluble protein basis, peaked at between normal-acid and non-acid peach fruit.

Germination response of seeds of Tinospora cordifolia as influenced by different stages of fruit ripening based on pericarp colour was studied under nursery conditions at the Institute of Forest Genetics and Tree Breeding, Coimbatore. Maximum germination of 57.5% was observed in red fruits (ripe) followed by yellow 27.5% (partially ripe) and green 17.5% (unripe) fruits. Measurements on fruit and seed

The B class of MADS-box floral homeotic genes specifies petal and stamen identity in angiosperms. While this group is one of the most studied in herbaceous plant species, it has remained largely uncharacterized in woody species such as grapevine. Although the B class PI/GLO and AP3/DEF clades have been extensively characterized in model species, the role of the TM6 subgroup within the AP3 clade is not completely understood, since it is absent in Arabidopsis thaliana. In this study, the coding regions of VvTM6 and VvAP3 and the genomic sequence of VvPI, were cloned. VvPI and AtPI were confirmed to be functional homologues by means of complementation of the pi Arabidopsis mutant. Expression analysis revealed that VvPI and VvAP3 transcripts are restricted almost exclusively to inflorescences, although VvPI was detected at low levels in leaves and roots. VvTM6 expresses throughout the plant, with higher levels in flowers and berries. A detailed chronological study of grape flower progre...

Malic acid production, degradation, and storage during fruit development have been modelled. The model assumes that malic acid content is determined essentially by the conditions of its storage in the mesocarp cells, and provides a simplified representation of the mechanisms involved in the accumulation of malate in the vacuole and their regulation by thermodynamic constraints. Solving the corresponding system of equations made it possible to predict the malic acid content of the fruit as a function of organic acids, potassium concentration, and temperature. The model was applied to peach fruit, and parameters were estimated from the data of fruit development monitored over 2 years. The predictions were in good agreement with experimental data. Simulations were performed to analyse the behaviour of the model in response to variations in composition and temperature.

Fruit sink strength or its ability to attract assimilates depends bothon sink activity and size. This study investigated one main component of sinksize, that is the number of fruit cells during tomato plant development. Plantswere grown in a controlled climate chamber under a limiting (LS, six fruits pertruss) and non-limiting (NLS, two fruits per truss and CO2enrichment) supply of carbon assimilates. Under NLS conditions, fruit cellnumber was homogeneous among successive trusses, and fruits contained onaverage1.2 × 106 more cells than under LS conditions,though differences were not significant on the first truss which underwent thelowest competition. Under LS conditions, an ontogenetic increase in cell numberwas observed in proximal fruits of the upper trusses attributed to theenlargement of the apical meristem during plant development. The decrease ofcell number from proximal to distal fruits within a truss, that was expectedfrom the literature, was generally observed in the LS experiment, with anaverage significant difference of about1.6 × 106cells between the first and fifth fruits. Nevertheless, whereas the gradient incell number from proximal to distal fruits was steep in the upper trusses, itwas not significant on the lower trusses indicating that this gradient largelydepended on the level of competition during floral development. Thus, under lowassimilate supply, cell division is a main limiting factor for fruit growth,although cell enlargement during further fruit development is also affected,butwas not measured in this work.

We report the generation and analysis of a total of 77,583 expressed sequence tags (ESTs) from two grapevine (Vitis vinifera L.) cultivars, Cabernet Sauvignon (wine grape) and Muscat Hamburg (table grape) with a focus on EST sequence quality and assembly optimization. The majority of the ESTs were derived from normalized cDNA libraries representing berry pericarp and seed developmental series, pooled non-berry tissues including root, flower, and leaf in Cabernet Sauvignon, and pooled tissues of berry, seed, and flower in Muscat Hamburg. EST and unigene sequence quality were determined by computational filtering coupled with small-scale contig reassembly, manual review, and BLAST analyses. EST assembly was optimized to better discriminate among closely related paralogs using two independent grape sequence sets, a previously published set of Vitis spp. gene families and our EST dataset derived from pooled leaf, flower, and root tissues of Cabernet Sauvignon. Sequence assembly within individual libraries indicated that those prepared from pooled tissues contributed the most to gene discovery. Annotations based upon searches against multiple databases including tomato and strawberry sequences helped to identify putative functions of ESTs and unigenes, particularly with respect to fleshy fruit development. Sequence comparison among the three wine grape libraries identified a number of genes preferentially expressed in the pericarp tissue, including transcription factors, receptor-like protein kinases, and hexose transporters. Gene ontology (GO) classification in the biological process aspect showed that GO categories corresponding to 'transport' and 'cell organization and biogenesis', which are associated with metabolite movement and cell wall structural changes during berry ripening, were higher in pericarp than in other tissues in the wine grape studied. The sequence data were used to characterize potential roles of new genes in berry development and composition.

A 94-kD protein that accumulates predominately in tomato (Lycopersicon esculenfum) fruit during ripening was purified, and antibodies specific for the purified protein were used to isolate cDNA clones from a red-ripe fruit cDNA library. A sequence analysis of these cDNAs and cross-reactivity of the 94-kD-specific antibodies to the soybean lipoxygenase (LOX) L-1, L-2, and L-3 proteins and soybean LOX L-l-specific antibodies to the 94-kD protein identified it as a member of the LOX gene family. Maximum levels of the 94-kD LOX mRNA and protein are present in breaker to ripe and red-ripe stages, respectively. Expression of 94-kD LOX in different tissues from mature green and red-ripe tomato fruits was found to be greatest in the radial walls of ripe fruit, but immunocytolocalization using tissue printing suggests that the highest accumulation of its protein occurs in locular jelly. None of 94-kD LOX is expressed in nonripening mutant fruits of any age. Never-ripe mutant fruit accumulate the 94-kD LOX mRNA to levels similar to those obtained in wild-type fruit, but fail to accumulate the 94-kD LOX protein. Collectively, the results show that expression of 94-kD LOX is regulated by the ripening process, and ethylene may play a role in its protein accumulation.

In order to screen for putative candidate genes linked to tomato fruit weight and to sugar or acid content, genes and QTLs involved in fruit size and composition were mapped. Genes were selected among EST clones in the TIGR tomato EST database (http://www.tigr.org/tdb/tgi/ lgi/) or corresponded to genes preferentially expressed in the early stages of fruit development. These clones were located on the tomato map using a population of introgression lines (ILs) having one segment of Lycopersicon pennellii (LA716) in a L. esculentum (M82) background. The 75 ILs allowed the genome to be segmented into 107 bins. Sixty-three genes involved in carbon metabolism revealed 79 loci. They represented enzymes involved in the Calvin cycle, glycolysis, the TCA cycle, sugar and starch metabolism, transport, and a few other functions. In addition, seven cell-cyclespecific genes mapped into nine loci. Fourteen genes, primarily expressed during the cell division stage, and 23 genes primarily expressed during the cell expansion stage, revealed 24 and 26 loci, respectively. The fruit weight, sugars, and organic acids content of each IL was measured and several QTLs controlling these traits were mapped. Comparison between map location of QTLs and candidate gene loci indicated a few candidate genes that may influence the variation of sugar or acid contents. Furthermore, the gene/QTL locations could be compared with the loci mapped in other tomato populations.

Tomato texture is one of the critical components for the consumer's perception of fruit quality. Texture is a complex character composed of several attributes that are difficult to evaluate and which change during fruit ripening. This study investigated the texture of tomato fruits at the rheological, sensory, morphological, and genetic levels, and attempted to correlate several parameters. Analyses were performed on tomato fruits from introgressed lines carrying quantitative trait loci (QTLs) associated with texture traits localized on different chromosomes, in two genetic backgrounds. Rheological measurements were used to determine resistance to deformation and fruit elasticity. Sensory analysis was used to assess flesh firmness, juiciness, mealiness, and skin toughness. Image analysis was used to study fruit morphology and to define the cellular structure and heterogeneity of the pericarp. A highly significant correlation was observed between instrumental and sensory firmness. Moreover, correlations were also established between some texture traits and parameters of the pericarp cellular structure. Compared with QTLs detected in a previous study, the phenotypic effects expected for mealiness were confirmed in all lines, whereas, for firmness, they were not confirmed. Significant interactions between QTL and genetic background were observed for several traits. In addition, kinetic analysis showed that differences in firmness occurred from the early stages of fruit development. These results provide both a broad description of texture components and preliminary information to understand their genetic control.

In photosynthetic tissues of the CAM plant pineapple (Ananas comosus), storage of soluble sugars in the central vacuole during the daytime and their remobilization at night is required to provide carbon skeletons for nocturnal CO 2 fixation. However, soluble sugars produced photosynthetically must also be exported to support growth processes in heterotrophic tissues. To begin to address how vacuolar sugar storage and assimilate partitioning are regulated in A. comosus, degenerate PCR and cDNA library screening were used to clone three candidate sugar transporters from the leaves of this species. Subcellular localization of the three transporters was investigated via expression of YFP-fusion proteins in tobacco epidermal cells and their co-localization with subcellular markers by confocal microscopy. Using this strategy, a putative hexose transporter (AcMST1) and a putative inositol transporter (AcINT1) were identified that both localized to the tonoplast, whereas a putative sucrose transporter (AcSUT1) was found to localize to prevacuolar compartments. A cDNA (AcMST2) with high similarity to a recently characterized tonoplast hexose transporter in Arabidopsis was also identified from an A. comosus fruit EST database. Analyses of transcript abundance indicated that AcMST1 was more highly expressed in fruits compared to leaves of A. comosus, whilst transcripts of AcINT1, AcSUT1, and AcMST2 were more abundant in leaves. Transcript abundance of AcINT1, the putative inositol transporter, showed day-night changes comparable to those of other CAMrelated transcripts described in Mesembryanthemum crystallinum. The results are discussed in terms of the role of vacuolar sugar transporters in regulating carbon flow during the diel cycle in CAM plants.

Only limited information has been published to date on the similarities and differences between climacteric and non-climacteric fruit ripening on transcriptional level. To address this issue, we performed a direct comparative transcriptome analysis between tomato and pepper fruits using heterologous microarray hybridization. Given the significant differences in the morphological, physiological, and biochemical characteristics of pepper and tomato fruits, the existence of extensive common regulons is surprising. This finding suggests the conservation of ripening mechanisms in climacteric and non-climacteric fruits. However, disparate expression profiles were also observed in both fruits. This study revealed that a gene that encodes an enzyme that converts lycopene to downstream carotenoids is induced in pepper but not in tomato. Most of the genes that encode ribosomal proteins are only induced in early fruit-stage pepper fruit and show rapidly diminishing expression in the later developmental stages. The genes involved in ethylene biosynthesis were not induced in pepper fruit. However, the EIL-like genes, ethylene-mediated signaling components, were induced in pepper fruit. Divergent types of transcription factors were expressed in ripening tomato and pepper fruits, suggesting they may be key factors that differentiate these distinct ripening processes.

A combined chemical, biochemical and molecular study was conducted to understand the differential accumulation of volatile sesquiterpenes in melon fruits. Sesquiterpenes were present mainly in the rinds of climacteric varieties, and a great diversity in their composition was found among varieties. Sesquiterpenes were generally absent in non-climacteric varieties. Two climacteric melon varieties, the green-fleshed 'Noy Yizre'el', and the orange-fleshed 'Dulce' were further examined. In 'Noy Yizre'el' the main sesquiterpenes accumulated are d-cadinene, c-cadinene and a-copaene, while a-farnesene is the main sesquiterpene in 'Dulce'. Sesquiterpene synthase activities, mainly restricted to rinds of mature fruits, were shown to generate different sesquiterpenes in each variety according to the compositions found in rinds. EST melon database mining yielded two novel cDNAs coding for members of the Tps gene family termed CmTpsNY and CmTpsDul respectively, that are 43.2% similar. Heterologous expression in E. coli of CmTpsNY produced mainly d-copaene, a-copaene, b-caryophyllene, germacrene D, a-muurolene, c-cadinene, d-cadinene, and a-cadinene, while CmTpsDul produced a-farnesene only. CmTpsNY was mostly expressed in 'Noy Yizre'el' rind while CmTpsDul expression was specific to 'Dulce' rind. None of these genes was expressed in rinds of the non-climacteric 'Tam Dew' cultivar. Our results indicate that different sesquiterpene synthases encoded by different members of the Tps gene family are active in melon varieties and this specificity modulates the accumulation of sesquiterpenes. The genes are differentially transcriptionally regulated during fruit development and according to variety and are likely to be associated with chemical differences responsible for the unique aromas of melon varieties.