锦橙果实发育过程中香气成分的变化

为了研究锦橙果实发育过程中香气成分的组成及变化,使用气相色谱-质谱联用仪分析了10月、11月、12月、翌年1月的锦橙鲜果的挥发性成分,分别检测到47,50,57,46种成分,主要成分为烃类、醛类、醇类和酯类.挥发性物质的总峰面积以及烃类、酯类在12月的果实中达到最大,反式-2-己烯醛、反式-2-己烯-1-醇、顺式-3-...     

Flower emasculation accelerates ovule degeneration and reduces fruit set in sweet cherry

Flower emasculation is commonly used to make flowers unattractive to pollinating insects and to carry out controlled pollinations. In sweet cherry, we have observed recurrent low fruit set after flower emasculation and compatible pollination without apparent causes. This led us to evaluate its effect on the progress of the reproductive phase and on fruit set in this species. Flower emasculation reduced by more than a half the fruit set obtained in crosses made during two consecutive years. This effect could be traced back to the first week after anthesis where weight increase of pistils from emasculated flowers was smaller and ovule degeneration was accelerated compared to pistils from non-emasculated flowers. Pollen tubes, which behaved similarly at the stigma-style level in emasculated and non-emasculated flowers, lost their directionality in the area close to the degenerated ovule in the ovary. While flower emasculation is valid to evaluate pollen tube performance in the style and to determine incompatibility relationships, the lower fruit set registered after emasculation alerts on its use in fruit set experiments and breeding programs.     

几种措施对新次郎甜柿坐果率和果实品质的影响

试验结果表明，以新次郎甜柿为试材，盛花期喷1次80mg／L赤霉素或与禅寺九品种自然授粉，均可显著提高新次郎甜柿的坐果率；盛花期主干环剥0．5cm后的坐果率与对照无显著差异。喷赤霉素、环剥和自然授粉各处理的果实可溶性固形物、维生素C和单宁含量与对照无显著差异，但喷赤霉素可明显减小单果重。     

Effects of different diurnal temperature combinations on fruit set of sweet pepper

Trials were carried out on sweet pepper, Capricum annuum L. cultivar ‘Ma'or’ under controlled temperature conditions and natural light. In the first trial, we examined night temperatures of 15, 18, 21 and 24°C (± 1) in combination with a day temperature of 24°C, and in the second trial day temperatures of 22, 25 and 28°C (12 hours) and divided day temperatures of 28-32-28°C (4+4+4 hours) in combination with a night temperature of 18°C. The highest fruit-set was obtained at the lowest night temperature; the highest night temperature caused considerable blossom drop. The highest tested day temperature did not cause increased blossom drop.     

Effect of fruit on flowering in relation to biennial bearing in sweet orange (Citrus sinensis)

Flowering and fruit-setting in the sweet orange cv. ‘Late Valencia’ were observed for three consecutive seasons that comprised two “off-years” and one “on-year”. Twice as many flowers per unit area of tree canopy were observed in the “on-year” as in the two “off-years”. There was a significant negative correlation between the yield of the previous crop and the number of flowers per square yard of tree canopy.

There were no significant differences between an “off-year” and an “on-year” in the proportions of inflorescences classified according to the number of flowers and number of leaves per inflorescence. Furthermore, the previous crop had no direct effect on fruit-set, the percentage fruit-set being similar in all three seasons.

Observations made during blossoming, when the trees were bearing an “on-year” crop, showed that practically no flowers were produced on fruit-bearing wood. The few inflorescences that were recorded on fruit-bearing wood tended to be of the leafless types.

It is suggested that the cause of biennial bearing in sweet orange is the diffusion of a flower inhibitor, possibly a gibberellin-like substance, from the fruit into the wood on which it is borne.     

赤霉素（GA3）对甜樱桃果实性状的影响

在果实生长第Ⅲ期的始期，用ＧＡ３溶液直接喷洒果实及叶片，果实单果重比对照增加１．２０３～２．６５５ｇ，果实直径比对照增加０．１４１～０．４５３ｃｍ，果汁的可溶性糖含量比对照提高０．１５％～２．２０％，Ｆ值均达到α＝０．０１水平．果实整齐度及着色程度均显著优于对照。综合果实性状，以１０×１Ｏ－６（１Ｏｐｐｍ）为最佳浓度。     

Leaf gas exchange and fruit yield in sweet orange trees as affected by citrus variegated chlorosis and environmental conditions

Citrus variegated chlorosis (CVC) is a disease caused by the bacterium Xylella fastidiosa. The most productive areas for citrus in Brazil are the northwestern and the northern regions of the São Paulo state, where CVC incidence is more severe. Additionally, these areas have the highest temperatures as well as significant vapor pressure deficits (VPD) and seasonal droughts. Environmental stresses are known to affect CVC-infected plants under semi-controlled conditions, but it is unclear whether similar effects occur in the field. The objective of this work was to evaluate the CVC leaf symptoms and environmental influences on fruit yield and size, and physiological parameters of healthy and CVC-affected plants (including both non-symptomatic and symptomatic leaves) in the morning and afternoon during the wet and dry seasons of 2003 in the southern, central and northern regions of the São Paulo state, Brazil. Increased VPD caused the stomatal conductance (gs) and CO₂ assimilation rates (A) to drop in healthy plants, but diseased plants had low VPD influences on gs, especially closer to the northern region and in leaves that were more symptomatic, confirming that diseased plants do not respond to changes in environmental VPD, corroborating several results reported in the literature. Although symptomatic northern leaves exhibited low stomatal apertures, the northern region had the highest air temperatures and VPDs, increasing the water loss in these plants, suggesting that towards the northern region plants face greater atmospheric and soil water stress. The fruit size of diseased plants diminished towards the north, while the fruit size of healthy plants must have been influenced by the tree fruit load. We suggest that CVC-affected plants suffer greater physiological damage if grown under environmental constraint, such as that found in the northern region of the São Paulo state.     

Rootstocks influence fruit oleocellosis in ‘Hamlin’ sweet orange (Citrus sinensis L. Osbeck)

Oil spotting or oleocellosis, is a major problem in citrus crops. As the rootstock and fertilization play important roles in citrus growth and fruit development, we investigated the influence of different rootstocks on the growth, mineral nutrition metabolism, water relations, and fruit oleocellosis of eight-year-old field ‘Hamlin’ sweet orange trees. Trees grafted onto Lichi16-6 trifoliata (Poncircus trifoliate) had the greatest rate of oleocellosis (RO), and trees grafted onto Goutou orange (Citrus aurantium) had the greatest degree of oleocellosis (DO). In contrast, trees grafted onto Rangpur lime (Citrus limonia Osbeck) had the lowest RO and DO. Trees were the most vigorous on Rangpur lime rootstocks, followed by Lichi16-6 trifoliata, and then Goutou orange. In addition, because the scion/stock girth ratio showed significant correlations with the RO and DO, oleocellosis parameters can be a good indicator of scion/stock affinity. The total N, total P, Ca²⁺, and Mg²⁺ in leaves from trees on Rangpur lime were significantly lower than in leaves from trees on Goutou orange or Lichi16-6 trifoliata. In addition, the RO showed a significant correlation with the leaf Ca²⁺ and S concentrations and with the peel Mg²⁺ concentration. The DO was significantly correlated with the total peel N and S concentrations. In addition, the RO showed a significant correlation with the net assimilation of CO₂ (ACO₂), stomatal conductance (GS), transpiration rate (ET), and water-use efficiency (WUE). However, the DO showed a significant correlation with the GS, ACO₂, and WUE. Taken together, these results indicate that rootstocks affect the development of oleocellosis in ‘Hamlin’ sweet orange due to their effects on the mineral nutrition balance and water relations.     

Sugar changes in Clementine and orange fruit during ripening

Summary

Juice and rind sugar content, fruit volume and rind colour were determined in cvs Fina, Oroval and Hernandina Clementines and in cvs Navelina, Washington Navel and Navelate oranges, cultivars that are harvested at different periods during the season. An accumulation of sugars was observed in all cultivars during ripening, mainly due to an increase of sucrose in the juice and of reducing sugars in the rind. Cv Hernandina, a late Clementine, showed a slower rate of sugar increase in rind.     

Antagonism of micronutrient cations on sweet orange leaves

The effect of combined applications of micronutrient cations in spray solutions, usually used to correct simultaneously nutritional disorders and fungal diseases, was investigated, especially regarding absorption of Zn at the surface of sweet orange leaves. Foliar application of 0.0, 0.4, 0.8, and 1.2% CuSO₄ solutions, neutralized with Ca(OH)₂, in combination with 0.15 and 0.45% ⁶⁵ZnSO₄ solutions caused a significant and marked decrease in the absorption of ⁶⁵Zn. Application of unneutralized solutions of 0-0.8% CuSO₄ in combination with 0-0.6% of ZnSO₄· 7 H₂O showed mutual antagonism between Cu and Zn for their absorption at the leaf surfaces. Similarly, the absorption of ⁶⁵Zn in leaves decreased from 53 to 26% with simultaneous application of 0–2% MnSO₄ solutions and 0.45% ⁶⁵ZnSO₄ solutions neutralized with Ca(OH)₂. This emanated from the mutual antagonism between the two for their absorption at the surface of leaves. The absorption of ⁶⁵Zn decreased from 53 to 31% with foliar application of 0–2% FeSO₄ in combination with 0.45% ⁶⁵ZnSO₄ solution neutralized with lime. Again, Fe and Zn each inhibited the absorption of the other at the leaf surface.     

Short- and long-term growth of navel orange fruit

Summary

Seasonal patterns of fruit development of young and mature `Bellamy' navel orange trees were measured from mid November to late July. Growth of whole fruit, expressed as fresh or dry weight, was best described by a fourparameter logistic curve (R<sup>2</sup>>0.99). The fresh weight growth curves of fruit from young and mature trees were not significantly different. Dry weights and fresh weights were linearly correlated (R<sup>2</sup>>0.99). The relationship between relative growth rate (RGR) of whole fruit and time was best described by two linear regressions (R<sup>2</sup>>0.98, 0.92, respectively). The two linear phases of RGR did not correspond to ontogenic phases of fruit development as described by Bain (1958). Increases in whole fruit and pulp radii, and whole fruit, pulp, rind and albedo volume during fruit development followed single sigmoidal patterns (four parameter logistic function, R<sup>2</sup> >0.99). Relative changes in the volume of the structural parts of the fruit were small during Stage III of fruit development. Diurnal variations in growth and rind temperature of fruit from young (under continuous irrigation) and mature (under weekly irrigation) `Leng' navel orange trees were recorded during Stage II of fruit development. Inelastic growth measured by LVDTs was described better by diurnal diameter means (max 1 min)/2 than diurnal maxima or minima. Diurnal diameter means of fruit from young trees showed a significant (R² = 0.42, P<0.0001) relationship to daily ambient temperature maxima, and the diurnal growth profiles paralleled the diurnal temperature profiles of the rind. In contrast, the diurnal growth rhythms of fruit from mature trees were insensitive to ambient temperature maxima and the diurnal rhythms appeared to reflect the water status of the tree.     

Flowering,fruit set and development of the fruit and seed of sweet pepper (iCapsicum annuum L.) cultivated under conditions of high ambient temperature

Sweet pepper (Capsicum annuum L.) cvs E-84066 and Yolo Wonder were grown under ambient conditions in plastic covered greenhouses. Anthesis commenced five and six weeks after planting and rose to a peak of 39 (E-84066) and 19 (Yolo Wonder) flowers per week respectively after which there was a rapid fall. Temperatures throughout anthesis were high (>38°C (maximum) and >16°C (minimum)) and this is likely to have contributed to the magnitude of the flux. Fruit set was highest in the early stages of the crop, but subsequently declined as the majority of flowers aborted. Overall, fruit weight was correlated with seed weight and seed number, and declined throughout the life of the crop. By contrast, seed size and the percentage germination remained constant. The latter is of particular importance for seed crops where seed quality is of primary concern.     

Effects of CPPU on fruit set and fruit growth in Japanese persimmon

The effects of hand-pollination and spraying with N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) on fruit set and fruit growth of ‘Matsumoto-Wase-Fuyu’, which is a member of the pollination-constant, non-astringent group of persimmons (PCNA) were investigated. Staminate flowers of pollinizers in the orchard were eliminated before anthesis. Hand-pollination was carried out at full bloom (FB). Without prior hand-pollination, CPPU at 5 or 10 mg 1⁻¹ was sprayed 11 days after FB. Hand-pollination and spraying with CPPU increased fruit set before thinning of fruits by hand. The number of fruits after thinning did not differ among treatments. The yield of marketable fruits after hand-pollination was similar to that after treatment at 5 mg 1⁻¹, but was higher than that for untreated trees. Formation of a sunken fruit apex, which was observed in about 30% of fruits from untreated trees, was suppressed by application of CPPU. CPPU also delayed coloration of fruit. There were no differences among treatments in firmness or soluble solids concentrations of marketable fruits.     

Gibberellic acid soak treatments for fully-cooled tulips

In attempts to reduce the glasshouse period of fully-cooled 5°C-forced tulips, ‘Apeldoorn’ bulbs were soaked before planting in aerated and non-aerated gibberellic acid (GA₃) solutions for 2–48 h. A 48-h treatment with 250–500 mg l^?1 GA₃ was the most effective, giving a glasshouse period 7–11 days shorter than for untreated bulbs. Soaks for 24 and 48 h caused root emergence, and 48-h soaks caused perianth segment splitting in one experiment. Aerated or non-aerated GA₃ solutions gave similar results. Soaking in water alone gave a smaller increase in earliness. In general, a shortened glasshouse period was associated with shorter whole stem and last internode lengths. In GA₃ treatments, flower losses were lower than for distilled water treated and untreated bulbs. A practical treatment would be a non-aerated soak for 24 h with between 250 and 500 mg l^?1 GA₃.     

Identification of 57 sweet orange cultivars using AFLP markers

Summary

Sweet orange (Citrus sinensis) represents an important group of Citrus fruit; however, the identification of sweet orange cultivars during vegetative growth can be difficult. A study on the genetic identification of sweet orange cultivars may be significant for the sweet orange nursery industry, for cultivar-rights protection, and is important for the genetic evaluation and conservation of these orange cultivars. In this study, amplified fragment length polymorphism (AFLP) markers were used to genotype 57 sweet orange cultivars. Ten PCR primer pairs generated 629 unique AFLP bands, with a size range of 50 ? 500 bp. Seventy-four bands (11.8%) were polymorphic. On average, each primer pair produced 62.9 fragments, with 7.4 polymorphic fragments. A dendrogram of the 57 sweet orange cultivars was constructed based on an UPGMA analysis using Jaccard?s coefficients of similarity. This provided a clear comparison of the genetic variation between cultivars and an ability to identify them. From Jaccard?s coefficients, 56 of the 57 cultivars examined were genetically close, with coefficient values ≥ 0.985. ?Variegated Navel? was less closely-related, with a much lower coefficient value (0.94). Among the 57 cultivars, 28 sub-groups, some consisting of only one cultivar, could be separated by their AFLP fingerprints. Compared to ISSR and SSR markers, AFLP seemed to be the preferential marker technique for the identification of sweet orange cultivars.     

液体授粉对苹果坐果率及果实的影响

苹果液体授粉试验结果表明:液体授粉的花朵坐果率较自然授粉提高61.41%,花序坐果率提高13.73%;偏斜果率较自然授粉降低19.6%,果实纵径较自然授粉增加6.43 mm,果实横径较自然授粉增加8.27 mm。     

甜樱桃裂果与防治研究进展

甜樱桃裂果是一种生理性病害,严重影响甜樱桃果品质量和经济效益。本文综合有关文献,深入分析了甜樱桃裂果的原因,从品种砧木、果实形态结构、果实生理生化特征、外界环境因子及钙素营养等方面阐述了影响甜樱桃裂果的因素,并归纳总结了甜樱桃裂果的综合防治方法。     

甜橙新品种——桂橙一号的选育

桂橙一号是冰糖橙优良芽变株系,成熟期11月下旬,平均单果质量154.0g,大小较均匀,可食率75.66%,可溶性固形物含量14.6%,全糖12.47%,酸0.38%,风味浓郁,有蜜香,甜脆化渣,树形开张,丰产稳产,商品性好,适应性强,果实耐贮藏。     

Seasonal carbohydrate changes in two sweet orange varieties of the Navel group

Sugar and starch levels were determined in leaves, fruits, bark and roots of the ‘Navelate’ variety (low yield) and compared with those of ‘Washington Navel’ (standard yield). Old leaves had the lowest sugar content in May, while young leaves had a decreasing content from spring to summer in both varieties. ‘Navelate’ had lower sugar content in leaves, bark and roots than ‘Washington Navel’. Starch levels in the leaves showed a maximum towards the end of May. In winter, ‘Navelate’ had a higher starch content, mainly in the roots and bark, due to its low yield.     

Gibberellic acid as an androecide for bell pepper

Gibberellic acid (GA₃, 10000 mg 1^?1) acted as an androecide for bell pepper, Capsicum annuum L., when sprayed at the onset of flowering and after an interval of 10 days. Parthenocarpic fruits were produced, but seeds could be obtained by hand-pollination. The technique can be used to produce hybrid seed and also to obtain high quality seedless fruits.