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1.
The aim of the present study was to elucidate how fruit growth was limited by the source and sink capacities in a Japanese (‘Momotaro York’) and a Dutch (‘Dundee’) tomato cultivar. The two cultivars were grown hydroponically with a high-wire system in greenhouses for 25 weeks, and the growth characteristics and sink strength of fruit were determined. Fruits were pruned to four (4F) or one (1F) per truss. The latter were used to determine potential fruit growth, an indicator of fruit sink strength. Growth was also determined under normal (LC) and enriched (HC, 700 μmol mol−1) CO2 concentrations to examine the effect of source enhancement on fruit production. In both cultivars under normal CO2, the growth rate of fruit pruned to 4F per truss was lower than that in 1F, indicating that maximum potential fruit growth was not achieved. Under HC conditions, fruit growth rate of ‘Dundee’ achieved in 4F trusses was lower than that in 1F. In ‘Momotaro York’ in HC, fruit growth in 4F trusses was close to potential. This implies that fruit growth was source-limited irrespective of CO2 concentrations in ‘Dundee’ cultivar while fruit growth in ‘Momotaro York’ under normal and enriched CO2 conditions was limited by source and sink strengths, respectively. Adjustments of cultural practices including increasing fruit number per truss and/or genetic approaches to enhancing fruit sink strength by breeding may improve fruit yields of Japanese cultivars under high source/sink conditions.  相似文献   

2.
High temperatures are known to reduce fruit size and fruit weight in strawberry, but cultivar differences in the response to high temperature stress during the reproductive stage up to the second inflorescence have not been sufficiently reported. We examined the effect of two day/night temperature regimes on fruit set and fruit growth in two cultivars, ‘Nyoho’ and ‘Toyonoka’. A high day/night temperature of 30/25 °C reduced the number of inflorescences, flowers, and fruits in both cultivars compared with plants grown at 23/18 °C. The percentage of fruit set in ‘Nyoho’ was not significantly different between the two temperature treatments, while that in ‘Toyonoka’ was much lower at 30/25 °C than at 23/18 °C. Days to ripening was shorter at 30/25 °C than at 23/18 °C, and no cultivar differences were observed. Fresh weight of primary, secondary, and tertiary fruits was greater at 23/18 °C than at 30/25 °C in both cultivars, and no cultivar differences were observed, except in tertiary fruits. The diameter of fruits from all positions was also reduced at 30/25 °C in both cultivars. Relative growth rates of fruits showed two peaks in both cultivars and in both temperature treatments. Both peaks appeared earlier at 30/25 °C than at 23/18 °C. Percentage of fruit set at 30/25 °C in the second inflorescence was also significantly lower in ‘Toyonoka’ than in ‘Nyoho’. These results indicate that high temperature stress negatively affects the reproductive process in strawberry and that plant response to high temperature stress is cultivar-related in such responses.  相似文献   

3.
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4.
To elucidate the fate of photosynthates from different current shoots and their influence on fruit growth and bud differentiation in neighboring spur complex during the period of rapid fruit growth in two late-maturing Japanese pear cultivars: ‘Atago’ and ‘Shinkou’ with contrasting fruit size, 13C labeling of single shoot was done to investigate of C-relations in fruit branches of eight shoot-combinations. The results showed that all of the current shoots investigated (bourse shoots of nonfruiting spur, bourse shoots of fruiting spur, extension shoot, nonfruiting spur, vegetative shoot, and water sprout) could export photosynthates to the neighboring fruit and buds. Water sprouts together with vegetative shoots, bourse shoots, and extension shoots are important source for fruit growth after shoot growth termination during the period of rapid fruit growth in production of late-maturing pears. The carbon transfer rate from the neighboring to the fruit bearing spur is depent (i) on the types of shoot which acts as C source, (ii) on the position of the fruiting spur and (iii) on the source-sink distance. Furthermore, the cultivar difference in carbon partitioning from different current shoot-combinations confirmed that the movement of photosynthates into the fruit was determined by sink strength of the fruit, and ‘Atago’ exhibited a greater relative sink strength of fruit than ‘Shinkou’. In addition, vegetative shoots are very important C sources for fruit growth in ‘Atago’ and the growth pattern of bourse shoot seriously affects C allocated to fruit in ‘Shinkou’.  相似文献   

5.
In addition to managing soil-borne diseases in muskmelon (Cucumis melo L.) production, grafting with resistant rootstocks may impact fruit quality. The ethylene antagonist 1-methylcyclopropene (1-MCP) has been shown to extend shelf life of fresh muskmelon fruit. Postharvest characteristics of 1-MCP-treated melon fruit as affected by grafting, however, have not been well examined. This study was conducted to explore the influence of grafting with different rootstocks on ripening and quality attributes of 1-MCP-treated muskmelon fruit during postharvest storage. Grafted ‘Athena’ muskmelon with two commercial squash interspecific hybrid rootstocks including ‘Strong Tosa’ and ‘Tetsukabuto’ as well as non-grafted and self-grafted ‘Athena’ were grown in replicated field plots at the University of Florida Plant Science Research and Education Unit (Citra, FL, USA) during April–June 2010. Half-slip fruit from two harvests were treated with 1.0 μL L−1 1-MCP (18 h, 20 °C) and analyzed during storage at 13 °C. For fruit from the 27 May harvest, whole fruit and mesocarp firmness, titratable acidity, soluble solids, and ascorbic acid content were measured, while production of ethylene and CO2 was determined on fruit from the 29 June harvest. Grafting did not show a significant impact on fruit yield but affected the fruit shelf life significantly. Fruit from non-grafted ‘Athena’ and ‘Athena’ grafted onto ‘Strong Tosa’ demonstrated a shelf life of 31 d for the first harvest and 22 d for the second harvest. Shelf life of fruit from self-grafted ‘Athena’ and ‘Athena’ grafted onto ‘Tetsukabuto’ declined by 6 d and 3 d for the first and second harvest, respectively. Whole fruit firmness decreased by approximately 15.5% on average from 13 to 31 d except day 19 as a result of grafting, but to a lesser extent with ‘Strong Tosa’ rootstock. Mesocarp firmness of grafted melon was reduced by about 30.2% at days 13 and 19 compared to non-grafted ‘Athena’ fruit. In contrast, titratable acidity, soluble solid content, and ascorbic acid concentration were less affected by grafting. All the measurements except for ethylene and CO2 production declined during storage regardless of the grafting treatment. Compared with ‘Strong Tosa’ rootstock, ‘Tetsukabuto’ resulted in a more rapid ripening under 1-MCP application, as reflected by earlier increase in ethylene production and higher respiratory rate. The study demonstrates that grafting effects on postharvest ripening and quality of ‘Athena’ muskmelon can vary markedly with rootstocks used.  相似文献   

6.
Citrus creasing results in serious economic loss in many citrus orchards. Based on the different incidence of creasing, two sweet orange cultivars ‘Hong Jiang’ (grafting chimaera of which flesh is mostly from Citrus reticulata Blanco and peel is from Citrus sinensis Osbeck in) and ‘An Liu’ (Citrus sinensis Osbeck) were used to investigate the creasing rate. The ultrastructure in cellular wall, cellular wall component, cellular wall degradation-related enzymes and expansin (Ct-Exp1) of sweet orange during fruit ripening in field were comparatively analyzed. ‘Hong Jiang’ sweet orange had a higher creasing rate than ‘An Liu’ during ripening. The activities of polygalacturonase, cellulase and pectinesterase in cellular wall of ‘Hong Jiang’ increased more markedly compared with ‘An Liu’. The increases in the content of soluble pectin, ionically associated pectin, covalently bound pectin, hemicellulose and cellulose of ‘Hong Jiang’ were higher than those of ‘An Liu’. Furthermore, the enhanced degradation of the ultrastructure in the albedo cellular walls was observed in ‘Hong Jiang’. Moreover, the northern blot analysis indicated that the Ct-Exp1 gene expressed more strongly in peel of ‘Hong Jiang’ than ‘An Liu’ during fruit ripening. These data suggest that enhanced loss of pectin and cellulose in the cellular walls of peel tissue of sweet orange could result in fruit creasing.  相似文献   

7.
The experiments were carried out between 2003 and 2005 in the Province of Amasya. The first objective of the study was to determine the best pollinizer for the cultivar ‘0900 Ziraat’ which is the most popular sweet cherry cultivar (Prunus avium L.) in Turkey. The ‘0900 Ziraat’ was used as a female parent and ‘Türko?lu’, ‘Köro?lu’, ‘Kargayüre?i’, ‘Hac? Ali’, ‘Starks Gold’ and ‘Geçkiraz’ were used as pollinizer cultivars. In 2003, for the hand cross pollination combinations, fruit set was between 31.25% and 42.80%. In 2004, fruit set was reduced by spring frost and was between 9.69% and 15.24%. Additionally, the blooming periods of the experimental cultivars, fruit set of open pollination and hand self pollination were examined. The fruit set ratios of all tested cultivars under open pollination conditions varied between 26.73% and 53.49% in 2003 and 4.38% and 38.35% in 2004. ‘Geçkiraz’ had the highest fruit set owing to its late flowering date. For open pollination, fruit set values of ‘0900 Ziraat’ were lower than hand cross pollination with other cultivars in 2003 when the results of both treatments are compared. On the contrary, fruit set was higher than hand cross pollination in 2004. In the present study, pollen germination values varied greatly among year, cultivar and sucrose concentration. Viability percentages were generally high, not less than 66%. According to phenological observations, partial or complete overlapping of the flowering period of ‘0900 Ziraat’ and its possible pollinizer cultivars were observed in 2003 and 2005. But in 2004, the flowering period overlapped for only ‘0900 Ziraat’ and ‘Geçkiraz’ cultivars. When blooming times are taken into consideration, ‘Geçkiraz’ was found to be the best pollinizer cultivar.  相似文献   

8.
Date palms growing in hot arid regions are generally facing several kinds of environmental stresses which limit tree growth and productivity and negatively affect fruit quality. During 2009 and 2010 seasons, the effects of 5-aminolevulininc acid (5-ALA) application at different rates on yield, fruit quality, pigment contents and nutrient uptake of ‘Rabia’ and ‘Sukkariat-Yanbo’ date palm cultivars were studied. In both cultivars, the application of 5-ALA significantly increased bunch weight and yield per tree compared to control. The highest bunch weight and yield per tree was achieved by 5-ALA at 200 ppm followed by 250 ppm applied on both fruit bunches and leaves. These were reflected on higher fruit and flesh weight and fruit length, at the bisir and rutab stages. However, the application of 5-ALA at 250 ppm only on fruit bunches without leaves significantly increased bunch weight and yield per tree compared to control only in ‘Sukkariat-Yanbo’ but not in ‘Rabia’ cultivar. There were significant interaction effects between treatments and seasons on bunch weight and yield in ‘Rabia’ but not in ‘Sukkariat-Yanbo’ cultivar. The rutab % was not significantly affected by any of the applied treatments and it was higher in 2009 than in 2010 season in ‘Rabia’, however, the opposite was true in ‘Sukkariat-Yanbo’ cultivar. Most of the physical parameters of fruit quality at both the bisir and rutab stages were significantly improved in both cultivars by 5-ALA application compared to control, in contrast to the biochemical parameters that were not affected. In both cultivars, chlorophyll a concentration significantly increased by 5-ALA application especially at 200 and 250 ppm on both leaves and fruits compared to control. While chlorophyll b concentration was not significantly affected by the 5-ALA application, total chlorophyll concentration was significantly higher at 250 ppm 5-ALA application than control in both cultivars. There were no significant differences among the different rates of 5-ALA application. Chlorophyll a/b ratio was not significantly affected by 5-ALA application compared to control. The concentrations of N, P and K in the leaves of both cultivars were not significantly affected by the 5-ALA application compared to control. It was concluded that 5-ALA application has promotive effects on yield, fruit quality and chlorophyll concentration of both ‘Rabia’ and ‘Sukkariat-Yanbo’ date palms under hot arid climate.  相似文献   

9.
Seasonal changes in leaf photosynthetic rate and partitioning of 13C taken up by leaves were compared in relation to the development of early watercore using susceptible ‘Orin’ and resistant ‘Fuji’ apples (Malus domestica Borkh.). There was no difference between the cultivars in leaf photosynthetic rate from mid-July to mid-October. The extent of watercore in ‘Orin’ increased from mid-July and peaked in late-August, followed by a decrease through mid-October, while no watercore was detected during the experimental period in ‘Fuji’. Fruit fresh weight and soluble solids content (SSC) were higher in ‘Orin’ than ‘Fuji’ during the earlier stages. Leaf dry weight of ‘Orin’ was higher than that of ‘Fuji’ throughout the experimental period. Accumulation of dry matter in the fruit increased in both cultivars and ‘Orin’ kept significantly higher level than ‘Fuji’ from mid-July to mid-October. The amount of 13C distributed to ‘Orin’ fruit at 5 days after labeling was significantly higher than ‘Fuji’ in mid-July just before watercore started to occur. 13C taken up by ‘Orin’ fruit with prevalent watercore was also higher than ‘Fuji’ in late-August but the difference was not significant. In mid-October when early watercore was gradually reducing, 13C recovered by ‘Orin’ fruit decreased and was significantly lower than ‘Fuji’. The difference of partitioning pattern of 13C between the cultivars was associated with the susceptibility to early watercore as well as the changes in fruit growth and SSC. The seasonal changes in the amount of 13C distributed to ‘Orin’ fruit were also related to the fluctuations in watercore severity. The results suggest that active phloem transport might be the cause of early watercore in our previous work, which might be induced by the increased partitioning of assimilates to the fruit during summer in susceptible ‘Orin’ compared to resistant ‘Fuji’ and not by the higher potential of leaf photosynthesis.  相似文献   

10.
An apple orchard consisting of a single cultivar under the condition of natural pollination must have suitable pollinizers such as Crab apples to ensure stable fruit production. We selected ‘Maypole’ and ‘Dolgo’ as pollinizers for the cultivar ‘Fuji’, and investigated the rate of fruit and seeds in ‘Fuji’ fruits produced by pollen of the pollinizers. We developed a method for tracing pollen flow based on the leaf color of progeny and S-RNase allele of ‘Maypole’, and on Simple Sequence Repeat (SSR) analyses of ‘Maypole’ and ‘Dolgo’. These were powerful tools for determining the distance insects (mainly Osmia cornifrons) carry pollen from the pollinizers to ‘Fuji’. Although the fruit set of ‘Fuji’ apples was not reduced with increasing distance between ‘Fuji’ apple trees and pollinizers (probably due to pollen flow from other commercial cultivars planted outside the area), the rate of ‘Fuji’ apple fruit produced by the pollen of the pollinizers decreased with increasing distance. The rate of fruit produced by the pollinizers was 84% and 77% when ‘Fuji’ was 2.5 m from ‘Maypole’ and ‘Dolgo’, respectively, and 71% and 64% when ‘Fuji’ was 5 m from ‘Maypole’ and ‘Dolgo’, respectively, but was reduced to 47% and 39% when ‘Fuji’ was 10 m from ‘Maypole’ and ‘Dolgo’, respectively. However, the spacing could cause reduced fruit size, and require extra fruit thinning for producing large fruits. It could also cause reduction of the yield for increasing the planting area of pollinizers. We recommend that pollinizers should be planted not more than 10 m from ‘Fuji’.  相似文献   

11.
The citriculture in Brazil, as well as in other important regions in the world, is based on very few mandarin cultivars. This fact leads to a short harvest period and higher prices for off-season fruit. The ‘Okitsu’ Satsuma (Citrus unshiu Marc.) is among the earliest ripening mandarin cultivars, and it is considered to be tolerant to citrus canker (Xanthomonas citri subsp. citri Schaad et al.) and to citrus variegated chlorosis (Xylella fastidiosa Wells et al.). Despite having regular fruit quality under hot climate conditions, the early fruit maturation and absence of seeds of ‘Okitsu’ fruits are well suited for the local market in the summer (December through March), when the availability of citrus fruits for fresh consumption is limited. Yet, only a few studies have been conducted in Brazil on rootstocks for ‘Okitsu’. Consequently, a field trial was carried out in Bebedouro, São Paulo State, to evaluate the horticultural performance of ‘Okitsu’ Satsuma mandarin budded onto 12 rootstocks: the citrandarin ‘Changsha’ mandarin (Citrus reticulata Blanco) × Poncirus trifoliata ‘English Small’; the hybrid Rangpur lime (Citrus limonia Osbeck) × ‘Swingle’ citrumelo (P. trifoliata (L.) Raf. × Citrus paradisi Macfad.); the trifoliates (P. trifoliata (L.) Raf.) ‘Rubidoux’, ‘FCAV’ and ‘Flying Dragon’ (P. trifoliata var. monstrosa); the mandarins ‘Sun Chu Sha Kat’ (C. reticulata Blanco) and ‘Sunki’ (Citrus sunki (Hayata) Hort. ex. Tanaka); the Rangpur limes (C. limonia Osbeck) ‘Cravo Limeira’ and ‘Cravo FCAV’; ‘Carrizo’ citrange (Citrus sinensis × P. trifoliata), ‘Swingle’ citrumelo (P. trifoliata × C. paradisi), and ‘Orlando’ tangelo (C. paradisi × Citrus tangerina cv. ‘Dancy’). The experimental grove was planted in 2001, using a 6 m × 3 m spacing, in a randomized block design. No supplementary irrigation was applied. Fruit yield, canopy volume, and fruit quality were assessed for each rootstock. A cluster multivariate analysis identified three different rootstock pairs with similar effects on plant growth, yield and fruit quality of ‘Okitsu’ mandarin. The ‘Flying Dragon’ trifoliate had a unique effect over the ‘Okitsu’ trees performance, inducing lower canopy volume and higher yield efficiency and fruit quality, and might be suitable for high-density plantings. The ‘Cravo Limeira’ and ‘Cravo FCAV’ Rangpur limes induced early-ripening of fruits, with low fruit quality. ‘Sun Chu Sha Kat’ and ‘Sunki’ mandarins and the ‘Orlando’ tangelo conferred lower yield efficiency and less content of soluble solids for the latter rootstock.  相似文献   

12.
The objective of this study was to evaluate the effect of cultivars and in-row spacing on vegetative growth and yield components in melon (Cucumis melo L.). The cultivars ‘Early Dawn’ (ED), ‘Superstar’ (SS) and ‘Medoro’ (ME) were grown in rows 1.5 m apart at plant spacing 0.6, 0.9, 1.2 or 1.5 m. Cultivars ED and SS were grown in 1998 and 1999, while ED and ME were tested in 2000. The main vine length, diameter, number of leaves and lateral branches were highest at 1.5 m in-row spacing in 1999 and 2000, while there was no influence of plant spacing on observed growth parameters in 1998. ED performed better compared with other two varieties, mostly due to more fruit per ha and per plant. Yield was significantly decreased with increased plant spacing in all 3 years of research. At in-row spacing of 1.5 m yield was in average 25% lower than at 0.6 m spacing. Average fruit weight slightly increased with plant spacing up to 1.2 m, even though the differences were significant only in 1999. Small differences among cultivars were also found. Number of fruit per ha decreased linearly while number of fruit per plant increased linearly as plant spacing increased in all cultivars except SS in 1999.  相似文献   

13.
Covering apple orchards with nets protects them from hailstorms but this changes the amount and quality of the light supplied to the trees. This study was carried out to assess the effects of shade provided by white protection net on yield and fruit quality of apple orchards in Southern Brazil, along three growing seasons (2002/2003, 2003/2004, and 2004/2005). ‘Gala’ and ‘Fuji’ apple trees (on MM111 rootstock, raised as slender spindles, with a spacing of 5.5 m × 3 m) were left uncovered (control trees) or covered with white net. The white net reduced the photosynthetically active radiation (λ = 400–700 nm) accumulated over the trees’ canopy along a day by 18.4%, leading to a higher leaf chlorophyll content in both cultivars, and a higher specific leaf area in ‘Gala’. The shade provided by the net did not affect yield and increased fruit average weight in both cultivars. At harvest, the number of seeds per fruit and severity of russet were not affected by netting in both cultivars, as well as the incidence of watercore in ‘Fuji’. The main beneficial effects of the white net were the reduced incidence of sunburn on ‘Gala’, reduced incidence of bitter pit during cold storage in both cultivars, and reduced incidence of apple scab at harvest and of decay after cold storage in ‘Fuji’. Fruit fly damage in ‘Gala’ (assessed in one season) was reduced by netting. However, netting affected negatively some fruit quality attributes. ‘Gala’ and ‘Fuji’ apples from trees protected by the net had a poor skin color (pale blush and a more intense green background color) at harvest. The net reduced flesh firmness and SSC, and increased the starch index of ‘Gala’ apples at harvest, and reduced flesh firmness and SSC, assessed after cold storage and shelf life, in fruits of both cultivars.  相似文献   

14.
The pedigrees of most rabbiteye blueberry (Vaccinium virgatum) cultivars can be traced back to four wild selections, ‘Ethel’, ‘Clara’, ‘Myers’, and ‘Black Giant’; thus, they result from a very narrow germplasm base and are highly related. Until now randomly amplified polymorphic DNA (RAPD) has been the only type of molecular marker used in rabbiteye blueberry. Here we have tested whether a type of sequence-tagged site (STS) marker which utilizes specific ∼20-mer primers from expressed sequence tags (ESTs) of highbush blueberry (V. corymbosum), called EST-PCR markers, are useful for genetic fingerprinting and relationship studies in rabbiteye blueberry. Of 44 EST-PCR primer pairs, from an assortment of genes expressed in flower buds of cold acclimated and non-acclimated plants, and shown to amplify polymorphic fragments among a collection of highbush genotypes, 40 (91%) resulted in successful amplification, and 33 of those (83%) amplified polymorphic fragments among the rabbiteye genotypes. The average number of scorable bands per primer pair was two. A dendrogram constructed from genetic similarity values, based on the EST-PCR marker data, tended to group siblings and parent/progeny together, generally agreeing with pedigree information. A group of 20 markers from five EST-PCR primer pairs distinguished all the genotypes in this study. These markers are as easy to generate and as affordable as RAPDs, but are based on actual gene sequences, and should have general utility for DNA fingerprinting, genetic diversity, and mapping studies.  相似文献   

15.
In this study, fruit quality characteristics of some cultivars and types of fig (Ficus carica L.) were determined in Dortyol, Hatay, Turkey, which has a Mediterranean climate. The main fig cultivars grown in Turkey (‘Sarilop’, ‘Bursa Siyahi’, ‘Goklop’, ‘Yediveren’, ‘Yesilguz’, ‘Morguz’, ‘Sari Zeybek’, and ‘Ufak Yesil’) were evaluated along with 24 selections from a larger collection from the Mediterranean Region of Turkey. Several pomological characteristics of the genotypes were determined on 5-year-old trees during the 2001 and 2002 growing season. Averaged over the 2 years, fruit weight ranged between 22 and 52 g, total soluble solids content (TSS) ranged between 20.1 and 27.4%, and acidity ranged between 0.09 and 0.26%. ‘Bursa Siyahi’, ‘Goklop’, 31-IN-17, 31-IN-11 and 31-IN-09 produced the largest fruits in terms of fruit weight and dimensions. 31-IN-01, 31-IN-02, ‘Yesilguz’, ‘Morguz’ and ‘Ufak Yesil’ had the highest TSS. ‘Yediveren’, ‘Goklop’, ‘Bursa Siyahi’ and 31-IN-16 scored the highest in overall quality according to the weighted ranked method. Based on the results obtained ‘Yediveren’, ‘Goklop’ and 31-IN-16 could be alternatives to ‘Bursa Siyahi’, currently the most favored fresh table fig cultivar. These alternatives appear to have potential for both local consumption and export markets. Our results also indicate extensive diversity among Turkish figs permitting marketing of a broad range of fresh fig traits.  相似文献   

16.
‘Yandangxueli’ is a pear cultivar with predominant citric acid in the ripe fruit, different from most of pear cultivars such as ‘Gengtouqing’ in which malic acid is the predominant acid type. It was found that ‘Yandangxueli’ accumulated citric acid for three times against that in ‘Gengtouqing’ at fruit ripening stage. To investigate the mechanism of citric acid accumulation in ‘Yandangxueli’, organic acids content, gene expression and enzyme activity were studied in both cultivars. Five genes, Pp:mtCs, Pp:cyAco, Pp:cyIdh, Pp:mtMdh and Pp:cyMe which encoded citric synthase (CS), cytosolic aconitase (cyACO), NADP-dependent isocitrate dehydrogenase (NADP-IDH), NAD-dependent malate dehydrogenase (NAD-MDH) and NADP-dependent malic enzyme (NADP-ME) respectively, were identified from pear fruit. Their expression profiles and the corresponding enzyme activities were determined throughout fruit development in both cultivars. Results from these enzymes indicated that there were no strict relationship between gene expression, enzyme activity and citric acid accumulation. Expression analysis for two Py:vVAtp genes encoding vacuolar H+-ATPase A subunit and one Py:vVpp gene encoding Vacuolar H+-pyrophosphatase showed that they were all with up-regulated expression at the later development stage of ‘Yandangxueli’ but with down-regulated expression in ‘Gengtouqing’. Therefore, it is concluded that the different ability in citric acid transportation and storage might be involved in the high citric acid content in ‘Yandangxueli’.  相似文献   

17.
Sunburn on apples in the Western Cape region of South Africa can result in yield losses of up to 50%. Application of kaolin-based particle film (Surround® WP) increases leaf and fruit surface reflectivity, thus potentially reducing heat load and sunburn. Trials were performed during 2002/2003 and 2003/2004 to assess the effectiveness of kaolin particle film in controlling sunburn on ‘Granny Smith’, ‘Braeburn’, ‘Fuji’, ‘Royal Gala’ and ‘Cripps’ Pink’ apples. Fruit quality and ripening were monitored following 1–4 months in regular atmosphere cold storage at −0.5 °C. Sunburn on exposed fruit was significantly reduced in ‘Granny Smith’ and ‘Fuji’. Kaolin treatment improved fruit colour of ‘Granny Smith’ and ‘Royal Gala’, and delayed starch conversion in ‘Granny Smith’ at harvest and during the early storage period but not thereafter. Incidence of watercore at harvest was significantly reduced by kaolin treatment, but this disorder disappeared during cold storage in both treatments. There were no effects on skin anthocyanin or phenolic concentrations in any cultivar compared to unsprayed fruit.  相似文献   

18.
A new disorder known as fruit pitting has been observed in some Indian mango orchards during the recent years. In this disorder, there is a development of some sunken pits on fruit peel, which distract consumers. Based on preliminary observations, it was observed that deficiency of nutrients could be the cause, and hence systematic studies were conducted in five indigenous cultivars such as ‘Alphonso’, ‘Amrapali’, ‘Dashehari’, ‘Mallika’ and ‘Neelum’, and five exotic mango cultivars such as ‘Edward’, ‘Irwin’, ‘Rosari’, ‘Sensation’ and ‘Tommy Atkins’ with the aim to observe the fruit pitting incidence and degree, and to investigate its probable causes. Our studies indicated that nearly 13% of the mango fruit was affected by fruit pitting with variable degree and magnitude. All indigenous cultivars had higher incidence of fruit pitting than exotic cultivars. ‘Dashehari’ had the maximum incidence of fruit pitting (30.3%), followed by ‘Amrapali’ (28.6%), and ‘Rosari’ the least (3.4%). Our studies indicated that the incidence of fruit pitting in mangoes was nearly 13% with a significant variability among the cultivars (Table 1). Although the concentrations of most of the major nutrients such as N, P, K, Mg, and minor nutrients such as Cu, Mn, Fe, Zn, did not differ significantly. However, the pitted fruit had lower Ca (1.53%) and B (22 mg kg−1) concentrations than normal fruit (2.47% and 38 mg kg−1, respectively), indicating that deficiency of Ca and B probably is the cause for fruit pitting in mangoes.  相似文献   

19.
A study was conducted in different citrus cultivars to observe the incidence and degree of granulation, and to measure polyphenol oxidase (PPO) activity and phenolic content pattern in relation to granulation. Standard procedures were followed to observe the incidence and degree of granulation, phenolic content pattern, PPO activity and pheno-physicochemical fruit characteristics of citrus fruits. Across all citrus cultivars studied, 25% of the fruit were affected by granulation to the degree of about 10%. In general, granulated fruit were larger in size than normal fruit, and were inferior in quality characteristics. Among different citrus cultivars, ‘Kaula’ mandarin had highest incidence of granulation (62.5%), followed by ‘Mosambi’ sweet orange (43.6%) and the least in ‘Kagzi’ lime (12.2%). Phenolic content and polyphenol oxidase activity also varied widely among different citrus types, and were significantly higher in normal fruit than granulated fruit. Thus, it appears from the study that PPO plays some role in the occurrence of granulation in citrus.  相似文献   

20.
‘Reinette du Canada’ (RC) and ‘Reinette Grise du Canada’ (RG) apple (Malus × domestica Borkh) cultivars declared throughout the Community as Protected Designation of Origin ‘Manzana Reineta del Bierzo’ are severely affected by bitter-pit during storage. Pre-harvest treatments with calcium carbonate, authorized in organic production, and bio-activator Harpin protein were used to assess the effect on quality at harvest and during cold storage in both apple cultivars during 2007 and 2008. Bitter-pit at the end of storage was higher in ‘RC’ than in ‘RG’, due to the fact that K/Ca ratio in fruit was higher in ‘RC’. Harpin protein did not improve the quality of ‘Reinette’ apple cultivars. Calcium carbonate pre-harvest treatments were useful to decrease external and internal bitter-pit incidence of ‘Reinette’ apple cultivars after 90 days of storage, but differences at the end of storage were not significant. Therefore, calcium carbonate would be a useful product in organic production in order to decrease bitter-pit incidence in ‘Reinette’ apple cultivars during medium term storage.  相似文献   

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