Showing papers in "Journal of Horticultural Science & Biotechnology in 2000"
TL;DR: The above findings suggest that the increase in GB content is important in adaptation to salt stress in Amaranthus plants, although photosynthesis and transpiration responses occurred immediately after salt-stress.
Abstract: SummaryWe examined changes in leaf growth and chemical composition, including chlorophyll content, ribulose bisphosphate carboxylase-oxygenase (RuBisCO), and glycine betaine (GB) in relation to photosynthesis and transpiration responses to salt stress in Amaranthus tricolor leaves. To induce salt stress, plants were transferred to a growth medium containing 300 mM NaCl for 7 d followed by 7 d of relief from salinity. A decrease in leaf enlargement began 3 d after salt stress, and leaves subsequently showed the same degree of regrowth as controls after relief in non-salt medium. Chlorophyll content expressed on a leaf-area basis increased under conditions of salinity due to a reduction in leaf tissue water content. The decrease in chlorophyll content continued throughout the 7 d of relief from salinity. The RuBisCO and soluble protein contents when expressed on a leaf dry-weight basis decreased in response to salinity, and then gradually increased during the relief period. GB content increased slightly up ...
233 citations
TL;DR: In this article, the competitive ethylene (C2H4) antagonist 1-methylcyclopropene (1-MCP) was used to evaluate its feasibility as a postharvest tool for use by the apple industry.
Abstract: Summary‘McIntosh’ and ‘Delicious’ apple were treated with the competitive ethylene (C2H4) antagonist 1-methylcyclopropene (1-MCP), to evaluate its feasibility as a postharvest tool for use by the apple industry. The threshold concentration of 1-MCP required to inhibit de novo C2H4 production and action was 1 ¼l l–1. 1-MCP treatment completely inhibited C2H4production in apples for 6–10 d at20°C following storage at 0°C in air or controlled atmosphere for 60 or 120 d. 1-MCP-treated apples were significantly firmer (13 to 20 N) than untreated apples following storage and post-storage handling for 7 to 14 d at 20°C. Total soluble solids of apples was not affected by 1-MCP treatment. Inhibition of total volatiles and ∝-farnesene emanated by apples by 1-MCP treatment was parallel to the inhibition of C2H4 production by 1-MCP. Contents of ∝-farnesene and its putative superficial scald causing catabolite, conjugated triene alcohol, in the skin were reduced 60 to 98% by ≥1 μl l–1 1-MCP. Treatment with 1-MCP suppr...
174 citations
TL;DR: Only ‘Conference’ pears, when stored in 6% CO2 1 0.5% O2, exhibited a strong decline in NADP levels, which was associated with the low metabolic activity due to the high incidence of disorders and a probable relationship between energy level expressed by ATP concentrations, ATP:ADP ratios and pyridine nucleotides and the development of these disorders is discussed.
Abstract: SummaryThe effects of four controlled atmosphere (CA) storage conditions on ATP and ADP levels, and the concentrations of NAD(H) and NADP(H) were investigated in relation to the incidence of physiological disorders of ߢConference’ pears and ߢJonagold’ apples during six months at 08C(60.58C). ATP concentrations in apple and pear fruits stored in CA were lower than those in air-stored fruits but their reduction was lowest for ‘Conference’ pears stored in 1.5% CO2 1 1.5% O2. ‘Jonagold’ apples showed a sharp decrease followed by a slight increase in the ATP levels at the beginning of the second month of storage. The concentrations of NADH and NADPH in the tissues of ‘Conference’ pears and ‘Jonagold’ apples increased in both CA- and air-stored fruits. In contrast, the oxidized nucleotides, NAD and NADP, generally decreased with storage time and no signi®cant differences between the treatments were found. Only ‘Conference’ pears, when stored in 6% CO2 1 0.5% O2, exhibited a strong decline in NADP levels, which ...
122 citations
TL;DR: From the analysis of results, it appears the majority of mango cultivars originated from a local mango genepool and were domesticated later.
Abstract: SummaryDNA-based RAPD (Random Amplification of Polymorphic DNA) markers have been used extensively to study genetic relationships in a number of fruit crops. A wide genetic diversity exists in the mango fruit in India. Present day commercial cultivars originated mainly from this subcontinent. In this study, 18 commercial mango cultivars, traditionally grown in western, southern, northern and eastern parts of India, were selected to assess genetic relatedness. Total genomic DNA was extracted and subjected to RAPD analysis using 30 arbitrary 10-mer primers. Of these, 27 primers amplified mango genomic DNA. None of these primers produced unique band pattern for each cultivar. RAPD data were used to calculate a squared Euclidean distance matrix, and based on this cluster analysis was done using a minimum variance algorithm. Cluster analysis clearly showed two groups—the first consisting of western, northern and eastern mango cultivars and the second group consisting of southern cultivars. From the analysis of...
118 citations
TL;DR: This work successfully transformed plants of Carrizo citrange via Agrobacterium tumefaciens with the halotolerance gene HAL2, originally isolated from yeast and implicated in salt-tolerance mechanisms, for the first time that a gene from yeast has been stably integrated and expressed in citrus plants.
Abstract: Soil salinity significantly limits citrus production in many areas worldwide. Carrizo citrange, considered an excellent citrus rootstock, is very sensitive to salt stress, which restricts its use i...
85 citations
TL;DR: Both EDI and LDI improved fruit quality in terms of increases in: dry-matter concentration (DMC) at harvest, flesh firmness, total soluble solids, and total soluble sugars both at harvest and after storage.
Abstract: SummaryWe explored the potential of deficit irrigation (DI) applied at different times during the growing season for improving fruit quality and storage potential of ‘Braeburn’ apple growing in a commercial orchard. Because DI often reduces fruit size, effects of fruit size on fruit quality were also examined. The irrigation treatments were: commercially irrigated control (C), early deficit irrigation (EDI) applied from 63 to 118 d after full bloom (DAFB), and late decifit irrigation (LDI) applied from 118 DAFB to final harvest on 201 DAFB. Both EDI and LDI improved fruit quality in terms of increases in: dry-matter concentration (DMC) at harvest, flesh firmness, total soluble solids, and total soluble sugars both at harvest and after storage. The DI fruit had less weight loss during storage than did C fruit. Deficit irrigation affected the concentrations of a few individual aroma volatiles but not total volatile concentration. Incidence of physiological disorders was not affected by irrigation treatments...
83 citations
TL;DR: The results support an hypothesis that a potential maximum fruit size is set by about 50 DAP, determined by total fruit cell number, resulting from a temperature-responsive cell division growth phase, and ideas towards developing a practical methodology for predicting fruit weight at harvest are discussed.
Abstract: SummaryThe influence of temperature on growth of ‘Royal Gala’ apples on MM.106 rootstock was studied using trees from one site in each of three regions of New Zealand (Canterbury, Hawkes Bay and Nelson) over three consecutive seasons. Temperatures were recorded as hourly means over each season. Growing degree day accumulation with a base of 10°C (GDD10) and 5°C (GDD5) were calculated, commencing at pollination. Crop loads were established at bloom to a very low level to minimize competition between fruit and provide a clear response of fruit growth to environmental conditions. Some trees were shaded with 70% shadecloth for 7 d beginning either 60 d after pollination (DAP) or 90 DAP. In the third season, other trees were thinned to a medium crop load to compare their fruit growth with that from trees bearing low crop loads. There was a highly significant correlation between GDD10 at 30 DAP and time from pollination to harvest (r2 = 0.96). On the low crop load trees, fruit weight at 50 d was closely correla...
67 citations
TL;DR: The chilling models used in this study were inadequate in considering climatic conditions involved in the entrance to bud dormancy in Elgin and the Bokkeveld.
Abstract: SummaryOne year old, ca. 500 mm long shoots of ‘Golden Delicious’ and ‘Granny Smith’ apple were selected randomly from commercial orchards in either Elgin (34°S, 305 m, ca. 900 chill units (CU) in 1995) or the Bokkeveld (33°S, 945 m, ca. 1500 CU in 1995) regions of the Western Cape, South Africa. Twenty shoots were harvested weekly from 29 March 1995 until 23 August 1995 and forced at a constant 25°C with continuous illumination until budburst was observed on four out of 20 shoots per bundle, i.e. days to 20% budburst. The progression of bud dormancy in Elgin differed from that observed in the Bokkeveld. Both cultivars reached maximum dormancy in the Bokkeveld before any considerable chilling accumulated (<100 CU), but in Elgin, ca. 600 CU accumulated before a maximum was attained. In Elgin temperatures that normally promote chill requirement satisfaction enhanced dormancy. The chilling models used in this study were inadequate in considering climatic conditions involved in the entrance to bud dormancy. I...
66 citations
TL;DR: The anthocyanin content of tubers and shoots of the purple potato, Solanum tuberosum cv.
Abstract: SummaryThe anthocyanin content of tubers and shoots of the purple potato, Solanum tuberosum cv. Congo has been determined using various chromatographic and spectroscopic techniques to be petanin and the novel 3-O-[6-(4-ferulyl-O-α-rhamnopyranosyl)-β-glucopyranoside]-5-O-β-glucopyranosides of petunidin and malvidin. Acylated pigments constitute more than 98% of the total anthocyanin content both in tubers and shoots.
66 citations
TL;DR: The effect of UV-B irradiation at 10°C and 20°C on the quercetin glycosides procyanidins, chlorogenic acid and anthocyanin levels in the skin of detached fruit of five apple cultivars was investigated as discussed by the authors.
Abstract: SummaryThe effect of UV-B irradiation at 10°C and 20°C on the quercetin glycosides procyanidins, chlorogenic acid and anthocyanin levels in the skin of detached fruit of five apple cultivars was investigated. UV-B responsiveness was compared between sides of the fruit that were outwardly facing (exposed) and inwardly facing (shaded) when on the tree. There were no common effects of UV-B irradiation and temperature across all cultivars. UV-B irradiation increased the quercetin glycoside levels in the shaded side of ‘Gala’, ‘Royal Gala’ and ‘Braeburn’ fruit and only at 20°C. UV-B irradiation of the exposed sides of the five cultivars, of either side at 10°C, and of ‘Pacific Rose’ and ‘Aurora’ at either 10°C or 20°C had no significant effect on quercetin glycoside levels. There was no effect of UV-B irradiation on procyanidin levels at any combination of treatments. However, levels of chlorogenic acid, although one tenth of those of quercetin glycosides and procyanidins, increased markedly with UV-B irradiat...
63 citations
TL;DR: It is shown that summer is the more appropriate period to apply RDI in ‘Clementina de Nules’ mandarin trees, and correlation was better with pre-dawn leaf water potential or with pre -dawn stress integral than with those at midday.
Abstract: SummaryAn experiment on Regulated Deficit Irrigation (RDI) was performed during 1995 and 1996 in an orchard planted with drip-irrigated ‘Clementina de Nules’/Carrizo Citrange in Moncada (Valencia) Spain Treatments consisted of a control, irrigated during the whole year at 125% ETlys and RDI treatments where irrigation was reduced to 25% or to 50% of crop evapotranspiration measured by a weighing lysimeter (ETlys) during one of the following periods: I) flowering and fruit set (spring); II) initial fruit enlargement phase (summer) and III) final fruit growth and maturation phases (end of summer-autumn) An additional treatment, denominated 50%-Year, was irrigated at 50% ETlys during the whole year The effects of RDI treatments in relation to tree water status (pre-dawn Ψpd and midday Ψmd leaf water potential, as well as their integral with time) show a good relation between total shoot emergence in the different growth flushes and the stress intensity reached (Ψpd) (r2 = 080) This correlation was mainl
TL;DR: Research results seem to confirm the hypothesis of a two-step induction, eventually leading to the onset of flower bud differentiation, which appears to be started at the end of autumn.
Abstract: SummaryFlower bud induction in the olive is a long lasting process, influenced by a number of factors, both internal and external to the tree. Research results seem to confirm the hypothesis of a two-step induction, eventually leading to the onset of flower bud differentiation, which appears to be started at the end of autumn. The paper examines the various aspects of this important issue in olive flower biology, by reviewing a large number of research papers produced over almost a century.
TL;DR: Hot-water brushing treatments applied 1–3 d prior to inoculation were most effective in enhancing the disease resistance of fruit, but were much less effective when the fruit were inoculated on the same day or 7.d later.
Abstract: SummaryPostharvest heat treatments have been used for many years as alternatives to chemical control of fungal diseases and insect infestation of fruits and vegetables. In this study, the effects of a new hot-water brushing (HWB) treatment on the resistance of red grapefruit (C. paradisi cv. Star Ruby) to green mould decay caused by Penicillium digitatum (Pers.: Fr.) Sacc. and on the development of chilling injury (CI) symptoms during cold storage were examined. The HWB treatment comprises rinsing hot water on the fruits as they move along a belt of brush rollers. A twenty second HWB treatment at 59 or 62° reduced decay, after arti®cial inoculation of wounded fruit, by 52 or 70%, respectively, compared with control unwashed fruit, whereas rinsing and brushing the fruit with tap water (~20°) or with hot water at 53 or 56°, were ineffective. HWB treatments applied 1–3 d prior to inoculation were most effective in enhancing the disease resistance of fruit, but were much less effective when the fruit were ino...
TL;DR: Among the media where optimum proliferation was obtained, healthier and greener shoots were found when a modified WP medium was used and a BA concentration between 0.5 and 0.6 mg l–1 produced an optimum number of shoots of a good length to be transferred to further subcultures.
Abstract: SummaryThe effect of different basal media and cytokinin concentration on the proliferation of ‘Canino’ shoots were studied. Among the media where optimum proliferation was obtained, healthier and greener shoots were found when a modified WP medium was used. A BA concentration between 0.5 and 0.6 mg l–1 produced an optimum number of shoots of a good length to be transferred to further subcultures. IBA and NAA induced rooting in similar percentages and with the same number of roots per shoot. The best rooting percentages (92.8 ± 2.5%) were induced in NAA at 2 mg l–1 while the largest number of roots per shoot (5.3 ± 0.5) were obtained after induction of 6 mg l–1 of IBA.
TL;DR: The adverse and possible beneficial effects of the inclusion of these compounds in human and animal diets are reviewed together with their chemistry, biosynthesis and methods for their analysis.
Abstract: SummaryThe Brassicaceae (syn. Cruciferae) is an economically important botanical family providing a diverse range of foliar, root and seed crops for both human and domesticated animal consumption. However, in common with other plant species the Brassicacae have been endowed with the capacity to synthesize a range of antinutritional compounds, the most important of which are the glucosinolates, S-methylcysteine sulfoxide, tannins and erucic acid. In this review the adverse and possible beneficial effects of the inclusion of these compounds in human and animal diets are reviewed together with their chemistry, biosynthesis and methods for their analysis.
TL;DR: Differences in the expression of the putative ethylene receptor of cultivars with short or long flower life suggest that variation in flower longevity may be due to differences in receptor levels during flower development.
Abstract: Expression of genes for the ethylene biosynthetic enzymes ACC oxidase and ACC synthase, and the gene for a putative ethylene receptor, termed RhETR, in miniature roses (Rosa hybrida) were examined ...
TL;DR: In warm-winter regions, the need for artificial means to compensate for the lack of natural chilling becomes a dominant factor for maintaining economic production of table grapes and the involvement of ABA in dormancy induction and maintenance is discussed.
Abstract: SummaryIn warm-winter regions, the need for artificial means to compensate for the lack of natural chilling becomes a dominant factor for maintaining economic production of table grapes. However, in the absence of a reliable method of predicting the time of natural bud break, the application of the dormancy breaking agent hydrogen cyanamide (HC) entails the risk of serious bud damage if the application is mistimed. In several studies in temperate regions, concentrations of endogenous abscisic acid (ABA) were found to increase as the grape buds entered dormancy, and to decrease during winter months towards dormancy release. To assess the possibility of using bud ABA content as a marker for the stage of bud dormancy in grapevines grown in hot regions, we evaluated the dormancy depth of grape buds in the course of the dormancy cycle and monitored their endogenous ABA content in cv. Perlette vines grown in the Jordan Valley. The endogenous ABA content was highest at maximum dormancy. However, the decline in A...
TL;DR: Black chokeberry fruits are rich in anthocyanins and can be used as a raw material for the production of natural food colourants and variation among sampling dates in total acidity was negatively correlated with variation in berry weight which suggests that dilution by water uptake affectstotal acidity.
Abstract: SummaryBlack chokeberry fruits are rich in anthocyanins and can be used as a raw material for the production of natural food colourants. Fruit quality was studied during maturation in three true black chokeberry cultivars and in three cultivars derived through hybridization between chokeberry and rowans (Sorbus spp.). For each trait studied, the three black chokeberry cultivars were very similar. The three hybrid cultivars differed however from the black chokeberry cultivars for some traits in both timing and size of the response which indicates that cultivar selection for improvement of fruit quality can hardly be done among the true black chokeberry genotypes but may be efficient when the hybrid cultivars are also included. For the black chokeberry cultivars, maximum berry weight was reached already by the 22 August. Anthocyanin content increased by 180% during the period mid-August to mid-September. Meanwhile, the content of undesirable brown compounds increased by 100%. The content of malic acid remai...
TL;DR: In this paper, the biochemical basis of inhibition of propylene-induced ethylene production in kiwifruit below a critical temperature range of 11 − 14.8°C was identified.
Abstract: SummaryPrevious studies (Stavroulakis and Sfakiotakis, 1993) have shown an inhibition of propylene-induced ethylene production in kiwifruit below a critical temperature range of 11–14.8CC. The aim of this research was to identify the biochemical basis of this inhibition in kiwifruit below 11–14.8°C. ‘Hayward’ kiwifruit were treated with increasing propylene concentrations at 10 and 20°C. Ethylene biosynthesis pathways and fruit ripening were investigated. Kiwifruit at 20°C in ah started autocatalysis of ethylene production and ripened after 19 d with a concomitant increase in respiration. Ethylene production and the respiration rise appeared earlier with increased propylene concentrations. Ripening proceeded immediately after propylene treatment, while ethylene autocatalysis needed a lag period of 24#8212;72 h. The latter event was attributed to the delay found in the induction of 1-aminocyclopropane-l-carboxylate synthase (ACC synthase) activity and consequently to the delayed increase of 1-aminocyclopro...
TL;DR: Bud break of one year old cut shoots of sweet cherry cvs Stella, Summit and Sunburst was recorded to quantify the effect of chilling on dormancy release and the data collected were used to develop a chill unit model which predicted that chilling temperatures of 3.2°C, 3.
Abstract: SummaryBud break of one year old cut shoots of sweet cherry cvs Stella, Summit and Sunburst was recorded to quantify the effect of chilling on dormancy release. Chilling was applied in the dark at constant temperatures of ‒1.2°C, 3.8°C, 6.8°C, 9.4°C, 11.9°C and 15.4°C (± 0.5°C) for 0,168, 336, 504, 672, 840, 1008, 1176 and 1334 h. Multiple regression analysis showed that at temperatures of ‒1.2°C, 3.8°C, 6.8°C, 9.4°C the proportion of bud break increased through successive chilling durations, up to approximately 1000 h of chilling. However, chilling for more than this duration reduced the percentage bud break. The control treatment (no chilling), chilling for 168 h and chilling at average temperatures of 11.9°C or 15.4°C did not break dormancy. The data collected were used to develop a chill unit model which predicted that chilling temperatures of 3.2°C, 3.2°C and 3.7°C were optimum for cvs Stella, Summit and Sunburst respectively. The chilling requirements for these cultivars were estimated to be saturat...
TL;DR: In this article, 11 types of fruit and vegetables and five types of flowers were held in an atmosphere containing a range of concentrations of nitric oxide (NO) gas in nitrogen for 2 h then stored for 24 h in air at 20°C and 60% r.h.
Abstract: SummaryEleven types of fruit and vegetables and five types of flowers were held in an atmosphere containing a range of concentrations of nitric oxide (NO) gas in nitrogen for 2 h then stored for 24 h in air at 20°C and 60% r.h. Each type of produce was weighed before treatment, and after 24 h, and the rate of water loss calculated. Treatment with NO was found to result in 20% less water loss than in produce stored in air.
TL;DR: The results indicate that the sink demand of the secondary growth and the resulting competition with the primary growth should be taken into account in the carbon economy of fruit trees, and that the competition between organs is not equally distributed between the organs of a given type but depends on their relative location.
Abstract: SummaryThe effect of crop load on the growth dynamics of individual shoots was analysed in apricot trees in the third growing season, comparing their development at two initial locations along the bearing branch. Growth dynamics were observed throughout the growing season, from April to August, and took into account both primary growth (i.e..number of expanded leaves) and secondary growth (i.e. basal diameter increment). Crop load influenced primary growth rhythmicity and more precisely growth resumption within the growing season. The length of the growing period and the number of expanded leaves were more signi®cantly reduced on shoots originated from a proximal position along the branch than in a distal position. Thus, crop load enhanced the acrotonic distribution of branching. The allometric relationship between the basal diameter and the number of expanded leaves per shoot was not dependent upon shoot type, location or crop load treatment. Arguments are provided supporting the hypothesis that cambial ...
TL;DR: The findings show significant genotypic differences in flowering; cold treatment is essential for floral initiation; and the length of the juvenile phase is tightly dependent on the environment.
Abstract: SummaryThe critical physiological age of shallot (Allium cepa var. aggregatum) grown from seed and sets, and the effect of temperature on stored bulbs and the flowering habit were studied in Israel. Three short-day genotypes were grown from seeds or sets. Prior to storage, bulbs were sorted according to size and incubated in low (5-10°C), intermediate(13-20°C) or high (30°C) temperatures for various periods. Plants were grown in the open fieldand inthe phytotron, and their vegetative and blooming development was investigated. Our findings show significant genotypic differences in flowering; cold treatment is essential for floral initiation; and the length of the juvenile phase is tightly dependent on the environment. In the field, early-sown shallots had a faster growth rate, accumulated more mass, and produced earlier and more auxillary buds and side shoots than those from the late sowing. Shallots can be induced to flower by cold treatment in storage, the optimum temperature being 5-10°C, whereas high a...
TL;DR: In this paper, the effect of storage temperature on ripening, shelf life and chemical composition of custard apple (Annona squamosa L.) fruits stored at 10,15,20 and 25°C was studied.
Abstract: SummaryThe effect of storage temperature on ripening, shelf life and chemical composition of custard apple (Annona squamosa L.) fruits stored at 10,15,20 and 25°C was studied. The safe range of storage temperature was found to be between 15 and 20°C, with maximum shelf life at 15°C. The ripening of fruits was observed on days 4, 6 and 9 of storage at 25,20, and 15°C respectively. The colour of the pulp, texture, taste and flavour of ripe fruits held at 25 and 20°C were superior followed by fruits stored at 15°C. At 10°C, the fruits became hard with surface blackening, messy pulp and less sweetness. The major changes during ripening were a continuous decrease in fruit firmness and starch content and a continuous increase in TSS and sugars, the changes being more rapid at 25 and 20°C than at 15 and 10°C. The acidity and ascorbic acid contents increased slightly during the initial stages of ripening followed by a decline, in the fruits stored at different temperatures. Custard apple fruits stored at 25 and 2...
TL;DR: Huangjin' peaches (Prunus persica Batsch) were harvested at commercial harvest time (commercial) and 20 d before (early) or after (later) commercial harvest, and fruit from each harvest were stored at three temperature regimes at 95% r.h.
Abstract: Summary`Huangjin' peaches (Prunus persica Batsch) were harvested at commercial harvest time (commercial) and 20 d before (early) or after (later) commercial harvest Fruit from each harvest were stored at three temperature regimes (0, 5 and 10°C) at 95% rh After four weeks of storage at 0 or 5°C, early harvested fruit developed more leatheriness but less mealiness and later harvested fruit did not develop leatheriness but developed more mealiness comparedwith fruit from commercial harvest Overall, fruit stored at 5°C developed more mealiness but less leatheriness than fruitat 0°C for the same period of storage When stored at 10°C for two weeks, after which fruit were senescent, fruit did not develop any leatheriness or mealiness regardless of harvest times Fruit with leatheriness were firmer (>30 N) thanjuicy or mealy fruit (<10 N) after the same period of cold storage and 4 d at 20°C Mealy fruit were as soft as juicy fruit 1-Aminocyclopropane-1-carboxylate oxidase (ACO) activity, 1-aminocyclopropa
TL;DR: There were significant differences in pollen tube growth between cultivars, but there were no differences between the temperature response of pollen from mono- and poly-embryonic cultivars when pollen was incubated under diurnal temperature regimes.
Abstract: SummaryThe effect of a constant (10, 15, 20 or 25°C) or a diurnal maximum/minimum (15/5, 20/10, 25/15 or 30/20°C) incubation temperature on in vitro pollen germination and pollen tube growth in the pistils of two poly-embryonic (‘Kensington’ and ‘Nam Dok Mai’), and two mono-embryonic (‘Irwin’ and ‘Sensation’) mango cultivars was studied. In in vitro experiments where pollen was incubated in a liquid germination medium for 24 h in darkness, little difference was found between pollen germination of mono- and poly-embryonic cultivars. Averaged over the four cultivars, 53.9% of pollen germinated at 10°C, this increased to 76.2% when the incubation temperature was increased to 15°C, thereafter up to 25°C the percentage germination remained stable but germination decreased slightly to 68.2% at 30°C. Similarly, there was no difference in percent germination between cultivars when pollen was incubated under diurnal temperature regimes. Mean pollen germination of all four cultivars was 52.3% at 15/5°C and pollen g...
TL;DR: It is proposed that the K/Zn ratio in flowers could be used, along with the flower Fe concentration, for the prognosis of iron chlorosis in peach trees.
Abstract: SummaryA statistical approach has been applied to study the nutrient composition of flowers in a peach orchard with 50 peach trees suffering from different degrees of Fe deficiency. Flowers from each individual tree were analysed in five crop seasons. The existence of a consistent nutrient balance over years in peach flowers, with nutrient concentrations depending to some extent on the levels of other nutrients, was revealed by a principal component-type analysis. The analysis produced a dominant first principal component, which explained 21% of the total variance. The second component explained 13% of the variance, with further components explaining less than 9%. A regression analysis revealed that the first principal component was closely related to chlorophyll (Chl) concentration determined in leaves 120 d after full bloom, as it explained 59% of average Chl concentration variance (between 40 and 52% in single year analysis), which is equivalent to a correlation coefficient of 0.77. A multiple regressi...
TL;DR: DNA sequencing of PCR products from S-alleles of ‘Rainier’ and ‘Sato-Nishiki’ revealed that Ban II, Nru I, Apa LI and Ava I sites, respectively, were unique in the S1-, S3-, S4- and S6- sequences flanked by Pru-T2 and Pru-C4R primers.
Abstract: SummaryBased on the cDNA sequences encoding sweet cherry self-incompatibility associated ribonucleases (S-RNases), a PCR-based S-allele typing system for sweet cherry cultivars has been recently developed. Using this technique, we determined S-genotypes of the three newly released Japanese cvs Kouka-Nishiki, Beni-Sayaka and Beni-Shuho and one British cv Merton Glory that was classified as a Universal Donor, which is able to be used as a pollen donor for all cultivars in pollen incompatibility groups I to XIII. Furthermore, we also determined the partial sequences of the S-RNase genes of ‘Rainier’ (S1S4)‘ and ‘Sato-Nishiki (S3S6)’,which leads to the development of a more reliable S-allele identification method of PCR-RFLP for sweet cherry cultivars. Total DNA isolated from leaves of the four cultivars along with those from ten cultivars with known S-genotypes were PCR amplified with two sets of primers that were designed from DNA sequences encoding the signal peptide (Pru-T2) and two conserved domains (Pru...
TL;DR: Random Amplified Polymorphic DNA (RAPD) technique was used to characterize these three cultivars of ‘Galega Vulgar’, ‘Cordovil de Serpa’ and ‘Verdeal Alentejana’ to guarantee the varietal certification of the young trees and the establishment of new orchards in Portugal.
Abstract: SummaryCharacterization and selection of olive clones for the production of olive oil is essential in Portugal because of its profitable exploitation. “Moura-Serpa” is the most important Portuguese region for the production of olive oil relying on three cultivars for oil quality. These are ‘Galega Vulgar’, ‘Cordovil de Serpa’ and ‘Verdeal Alentejana’. Therefore, it is of great importance to guarantee the varietal certification of the young trees and the establishment of new orchards. Random Amplified Polymorphic DNA (RAPD) technique was used to characterize these three cultivars. Analysis started using twenty primers that allowed us to distinguish the three cultivars and to select a reduced set of primers. The selected primers were used for inter- and intra-varietal analysis and for establishing a profiling system to assay genetic diversity in other olive cultivars. The method has the potential for use in varietal certification and breeding programmes that need to analyse a high number of samples.
TL;DR: Compared with spring, the plants grown in summer exhibited faster growth and development, but produced fewer fruits of larger size and poorer quality due to reduced sucrose content; however, dry-matter production and partitioning to the fruits was significantly lower in summer than in spring.
Abstract: The influence of growing season on some physiological and biochemical variates related to fruit yield and quality was investigated in melon (Cucumis melo L.) plants cultivated in nutrient film tech...