Developmental problems in over-winter off-season longan fruit. I: Effect of temperatures

Fruit development was investigated in the field in over-winter off-season (bloomed in late November) and on-season (bloomed in mid April) longans (Dimocarpus longan Lour. cv. Chuliang) in 2004–2005 and 2007–2008 crops, and in potted trees grown in phytotrons set at cold (15/10 °C, day/night, simulating winter) or warm temperatures (28/23 °C, day/night) in 2008. Development of fruit in both on-season and off-season longans could be divided into two stages based on the pattern of fresh weight increase. Stage I was characterized by the slow fruit growth, and Stage II by rapid fruit growth with aril expansion. Off-season longan had a longer period of fruit development than on-season longan, chiefly due to a longer Stage I. The development of off-season fruit, especially in Stage I, was exposed to low and abruptly fluctuating temperatures. In contrast, the temperatures during on-season fruit growth were warmer and less fluctuating. Off-season fruit were smaller with a significantly higher fruit drop. Intensive fruit drop did not occur during cold period until temperature had risen. Fruit cracking in off-season longan was severe (27.6%) in 2004–2005 with a dry and cold winter, but negligible in 2007–2008 with a wet and cold winter. In phytotron experiment, trees exposed to the cold temperature regime during early fruit development produced significantly smaller fruit compared to those exposed to the warm temperature regime (6.2 g vs 7.3 g), while there was no significant difference in fruit drop rate and cracking incidence. The results suggested temperatures lower than 15 °C were stressful for the growth of young fruit and reduced the growth potential and thus fruit size. Severe fruit drop in over-winter off-season longan might be associated with stressful cold plus abrupt temperature fluctuations, while severe fruit cracking in over-winter off-season longan might be related to cold and dry weather in the winter.     

套袋对翠冠梨果皮特征及品质的影响

翠冠为南方主栽梨品种之一,自然生长状况下果面极易形成锈斑,严重影响其外观品质。通过对翠冠梨进行不同类型果袋的套袋处理,系统定量研究了套袋条件下果皮的形态特征、果实外观和内在品质的变化。结果表明,套袋处理显著提高了无绣果和少绣果的比率,增加了果面亮度,改善了果实外观色泽,减小了果点直径,减淡了果点色泽。在电子显微镜下可清晰看到套袋使果面光洁平滑,龟裂程度远小于未套袋果面。套袋处理普遍降低了果实可溶性固形物含量;不透光袋显著提高了果肉石细胞含量。在外观品质改善上以双层透光蜡纸袋效果最好。研究结果将有助于今后对翠冠梨果实袋的正确选择和使用。     

不同果袋对砀山酥梨果实品质的影响

选用了18种不同果袋对砀山酥梨果实进行套袋试验,结果表明,套袋后砀山酥梨果实的硬度、可滴定酸含量比对照显著增大;可溶性固形物、可溶性总糖含量以及单果重均显著降低,平均比对照分别降低10.57%,11.74%,27.96%;套袋梨果的石细胞含量比对照降低10%～52.7%;套三层果袋的果实内在品质比套双层果袋和单层果袋果实的内在品质降低更显著;套袋对果实光洁度和果点等外观品质明显改善,三层果袋和双层果袋效果显著优于单层果袋。     

套袋对"石硖"龙眼果实大小和品质的影响

研究了采前使用不同套袋(白袋、黑袋、绿袋、黄袋、红袋)处理对"石硖"龙眼果实色泽、大小和品质的影响。结果表明:不同套袋处理对"石硖"龙眼果实果皮色泽无明显影响;对果实大小和品质影响差异性显著,尤以套黄色和绿色的网袋种子小,可食率高。     

不同果袋对丰水梨果实发育微环境及采后冷藏品质的影响

选择10种不同类型的果袋对丰水梨果实进行套袋处理,研究了套袋对果实发育微环境及采后冷藏品质的影响。结果表明,套袋改变了果实生长发育的微环境,套袋果实在冷藏过程中品质发生了不同变化,如冷藏80d时大部分套袋处理果实的硬度、可溶性固形物、维生素C和可滴定酸含量均显著高于对照,表明套袋处理有效地维持冷藏过程中果实的内在品质。在10种果袋类型中,外黄内黑的双层袋(编号为D-6)套袋处理的果实在冷藏80d时品质最佳。     

沙田柚幼果期套袋对果实品质的影响

本试验研究了不同类型的商品果袋在沙田柚幼果期套袋后果实品质的变化,结果表明,套袋显著地改善了柚果的外观品质,防病虫效果显著,并使单果重明显增加,虽然套袋使鲜果的可溶性固形物和维生素Ｃ的含量略有下降,但贮藏后的果实风味更佳,其中以Ｂ型果袋对提高沙田柚果实商品价值较突出。     

Phytochemical and antioxidant properties of selected fig (Ficus carica L.) accessions from the eastern Mediterranean region of Turkey

Fig has been a typical fruit component of the health-promoting Mediterranean diet for a very long time. Phytochemical characters and antioxidant capacity of green-, yellow-, brown-, purple-, and black-fruited fig (Ficus carica L.) accessions were investigated. In this study, total phenolics (TP), total anthocyanins (TA), fructose (FRUC), glucose (GLUC), sucrose (SUC), and variables (such as L*, a*, C*, and hue°) describing fruit skin colors were examined. Also, the antioxidant capacity (TAC) of fig fruits was determined by the ferric reducing antioxidant power (FRAP) assay. Antioxidant capacity was significantly correlated with the polyphenol and anthocyanin (r = 0.74 and 0.63, respectively) contents of fruits. Black fig accessions had the highest TAC (range of 7.9–16.1, mean 12.4 Fe²⁺ mmol/kg FW), TA (range of 32.3–356.0, mean 128.4 μg cy-3-rutinoside/g FW), and TP content (range of 69.1–220.0, mean 118.9 mg GAE/100 g FW). These black-fruited accessions had 2-fold greater TAC, 15-fold greater TA, and 2.5-fold greater TP than green and yellow fig accessions. However, the FRUC, GLUC, and SUC content of brown and purple fig accessions were higher than those of other color groups. The predominant sugars present were fructose (∼56%) and glucose (∼43%), as determined by HPLC.     

早熟梨套袋技术研究

通过开展早熟梨果实套袋试验表明：对早熟梨实施套袋,可以显著地改善果实品质,尤以对外观品质的作用显著。套袋果实的果面都较对照的果实光滑,果点较小,锈斑面积小。可见,套袋是提高果实的商品性、生产无公害梨产品的有效途径。但套袋果可溶性固形物含量稍低于对照果,风味稍变淡,内在品质不如对照果,在生产上可采取多施有机肥、根外追肥、适当晚采、采前去袋等措施弥补这一缺陷。同时,套袋纸质的选择应根据品种而确定：‘翠冠’梨选择以台湾好果袋、山东爱农果袋等质量较好的双层纸袋为好。梨套袋时间也应根据不同品种特性确定：果点大而密、颜色深、锈斑严重的应该尽早套袋;果点小、颜色淡、锈斑轻的品种套袋时期可适当晚一些。‘翠冠’梨适宜的套袋时期一般以谢花后30 d为宜。     

不同果袋对新西兰红梨品质的影响

选择5种不同类型的果袋对新西兰红梨果实进行套袋处理,研究了套袋对果实品质的影响.结果表明:套袋改善新西兰红梨果实外观品质,单果质量增加,果面光亮、洁净、着色好、果点变小且不明显;但套袋也会使新西兰红梨果实的可滳定酸有所降低,不同类型果袋使果实硬度、可溶性固形物含量、可溶性总糖含量、Vc含量降低或提高.在5种果袋类型中,编号为D-2和D-4果袋处理的果实综合品质最佳.     

不同龙眼品种果实品质和糖酸组分分析

以12个龙眼品种的果实为试材,利用常规的品质分析和高效液相色谱技术,进行了果实品质和糖酸组分分析。结果表明,品种间果实质量和可溶性固形物含量差异较大,分别为6.1～15.1g和12.2%～23.0%。可食率最高为双孖木(71.4%),最低为沙梨木(56.2%)。果糖、葡萄糖和蔗糖是龙眼假种皮的主要糖类,但不同品种这3种糖的比例有较大差异,根据单糖与双糖的比例,可将不同的龙眼品种分为3个类型:蔗糖积累型,还原糖积累型和中间类型。龙眼假种皮中的有机酸含量较低,为1.46～3.46mg/g,主要有苹果酸、草酰乙酸、α-酮戊二酸、草酸、柠檬酸、酒石酸和奎尼酸,不同品种有机酸的含量和比例有一定的差异。龙眼假种皮中也有较丰富的还原型抗坏血酸(维生素C),约占总酸的12.4%,不同品种维生素C含量有较大差异,储良最低(0.13mg/g),罗伞木最高(0.65mg/g)。     

GA3 increases fruit weight in ‘Yu Her Pau’ litchi

In order to increase the fruit weight of a shriveled-seed cultivar, trees of ‘Yu Her Pau’ litchi (Litchi chinensis Sonn.) growing in Taiwan were sprayed with Gibberellic acid (GA₃) (ProGibb^®, 20% of GA₃) at 5 and 10 mg/l 14 days after full bloom (AFB) over 2 years. Both concentrations of GA₃ significantly increased fruit longitudinal and transversal diameter, and fruit, aril and pericarp weight (40–41 and 37–38 mm, and 27.3–28.4, 21.7–22.7 and 5.0–5.3 g, respectively) compared with control (35–36 and 33–34 mm, and 22.3–22.4, 17.8–17.9 and 3.9–4.0 g), but had no significant effects on seed weight, percentage of aril weight of total fruit weight or total soluble solids (0.5–0.7 g, 78.9–80.3% and 18.1–19.0 °Brix, respectively). Fruit characteristics within the two concentrations of GA₃ showed no significant difference. The results indicated that sprays of GA₃ should be evaluated in ‘Yu Her Pau’ commercial orchards, and in other elite cultivars.     

不同时期套袋对黄金梨和丰水梨果实品质的影响

以不同发育时期、不同果袋套袋处理的黄金梨和丰水梨为试材,对其套袋后的外观品质和内在品质进行了观测。结果表明:套袋越早黄金梨和丰水梨果实光洁度和果点等外观品质改善作用越明显,其单果重和可食部分减少的越多。套袋越早黄金梨和丰水梨果实的可溶性总糖和可溶性固形物以及果实石细胞含量下降的越多;而套袋时间越早,2种梨还原型VC和硬度增加的越多,但不同时期套袋对2种梨的可滴定酸含量没有显著影响。综合比较不同时期套袋对黄金梨和丰水梨果实品质的影响,认为黄金梨最佳套袋时期为盛花后21～28 d,丰水梨最佳套袋时期为盛花后28～35 d。     

套袋对茄子果实农药残留量及产量和品质的影响

以京茄20为试材,研究了套袋对茄子农药残留、产量和品质的影响。结果表明:套袋可以显著降低茄子的农药残留,提高茄子的产量,改善茄子的光洁度等外观品质;套袋处理极显著降低茄子的硬度和纤维素含量;套袋处理茄子果实的坐果率、商品率、含水量、可溶性糖、Vc、蛋白质和维生素P含量处理和对照之间差异不显著;不同袋子对花青素含量的影响不同,套紫色聚乙烯塑料薄膜袋的茄子花青素含量与对照无显著差异,其它处理花青素的含量显著低于对照。因此,应选用紫色聚乙烯塑料薄膜作为茄子套袋材料。     

套袋对红地球葡萄果实发育过程中糖代谢及转化酶活性的影响

以红地球葡萄为试材,研究套袋对葡萄果实中糖代谢及转化酶活性的影响。结果表明:套袋果实在发育过程中蔗糖、葡萄糖、果糖含量和转化酶活性变化趋势与对照基本一致。果实成熟后套袋果的可溶性总糖含量明显高于对照。在果实发育前期,套袋明显提高了果实中蔗糖的相对含量及酸性转化酶活性。套袋可能主要是通过影响果实发育早期转化酶活性来影响果实糖分积累。     

Interactive effects of planting time and mulching on ‘Chandler’ strawberry (Fragaria × ananassa Duch.)

Studies were conducted in ‘Chandler’ strawberry with the aim to optimize planting time and mulching material under the semi-arid region of north Indian plains. Three planting times viz., mid-September, mid-October and mid-November and three mulch materials viz., black polyethylene (50 μm), clear polyethylene (50 μm) and paddy straw (10 cm thickness) were tried with three replications in a split plot design. Mid-September planting favoured plant growth, enhanced flowering (77.3 days), which resulted in production of significantly larger fruit (13.0 g) and higher yield (174.4 g/plant) with fruit having higher TSS (9.23%), acidity (1.22%) and ascorbic acid content (44.1 mg/100 g of pulp) with lesser incidence of albinism (9.6%) and botrytis rot (8.1%) than other plantings. Plants mulched with black polyethylene have significantly better growth, and they flowered (80.2 days) and fruited early (29.2 days), and produced larger fruit (12.6 g) and higher yield (172.4 g/plant), with slightly higher incidence of albinism (20.1%), but with lower incidence of botrytis rot (7.3%) than those mulched either with clear polyethylene or paddy straw. Planting time × mulching interaction has significantly influenced plant growth; flowering and fruiting; fruit yield and quality, and albinism and botrytis rot. Plants have best growth parameters like, plant height (11.2 cm), crown spread (24.1 cm) and leaf area (87.9 cm²), they took lesser days to flowering (73.7 days) and fruiting (31.3 days), produced larger fruit (13.7 g) and higher yield (191.3 g/plant) with fruit having higher TSS (9.41%), acidity (1.17%) and higher ascorbic acid content (46.4 mg/100 g pulp) with a slightly higher incidence of albinism (10.3%), but comparatively lower incidence of botrytis rot (5.2%) when planted during mid-September and mulched with black polyethylene than other plantings and mulched either with clear polyethylene or paddy straw. These studies indicated that strawberry could be planted in mid-September with black polyethylene mulch under semi-arid regions of India for early fruiting, and higher yield of better quality fruits.     

套袋对苹果果皮特征的影响

以10年生寒富苹果为试材,进行了不同的套袋(反光膜袋、双层纸袋、塑膜袋)处理,以不套袋果为对照,研究了不同微域环境下寒富苹果果皮的外观特征和解剖结构的特点。结果表明,套反光膜袋能明显提高果实的光洁度,改善果实的着色,果点不明显;套双层纸袋的次之;套塑膜袋和不套袋果实光洁度差,着色过浓,果点多且大,果面粗糙,不利于生产优质果;套不同类型的果袋,果皮解剖结构差异明显,套反光膜袋,角质层变薄,角质层光滑均匀度好,个别处有“V”型凹陷,表皮细胞变大,形状近圆形;套双层纸袋和塑膜袋,角质层均变厚,有较深的“V”型凹陷,表皮细胞形状不规则;不套袋果,角质层较均匀光滑,表皮细胞狭长且小。另外,套袋后,果实的表皮细胞变大且细胞壁变厚,改变了表皮细胞的排列方式,减少了表皮细胞层数,降低了机械组织的厚度及层数。     

套袋对红富士苹果色素及糖、酸含量的影响

 以苹果(Malus pumila) ‘长富2’品种为试材, 研究了套袋对果皮色素及果肉糖、酸含量的影响。结果表明, 套袋果果皮色素、可溶性糖、可滴定酸具有同对照果基本相同的消长规律, 但含量均始终低于对照; 摘袋后果实可溶性糖含量迅速升高, 且花青苷积累速度明显快于对照; 套袋主要降低了果实中山梨醇和蔗糖的含量, 果糖和葡萄糖降低幅度相对较小。     

果袋透光性对宁海白枇杷果实品质及抗氧化能力的影响

以白沙枇杷品种宁海白为试材,分析了白色单层、黄色单层、外浅黄内白双层、黄色双层和外灰内黑双层等5种不同透光率纸袋套袋对枇杷果实品质以及抗氧化能力的影响。结果表明,套袋能提高果实表面的明亮度。套袋后果实的总糖含量较对照下降,下降程度随果袋透光率性的下降而增强,其中外灰内黑纸袋与对照相比差异达到显著水平。套袋还降低了果实的总酚含量、类黄酮含量和果实的抗氧化能力,其中以透光性低的外灰内黑双层纸袋下降最大;但对类胡萝卜素含量影响较少。套袋后果实的抗氧化能力下降,与总酚和类黄酮含量降低呈显著正相关。     

‘妃子笑’荔枝果实着色不良原因的研究

 以着色不良的‘妃子笑’和着色良好的‘糯米糍’两个荔枝品种为试材, 对比研究了果实成熟和着色的进程、果皮中色素组成、叶绿体的形态结构以及套袋处理对着色的效应。试验结果表明, 妃子笑果实着色不良的主要原因为果皮中的高叶绿素含量。高叶绿素含量一方面加重了果面的底色, 遮掩了花青苷色泽的显现; 另一方面阻延了花青苷的合成, 从而使着色落后于假种皮内的糖积累。当妃子笑假种皮中的含糖量达到最高时, 果实着色面积尚不及18 %。若延迟采收, 着色面积虽然能继续增加, 但果肉含糖量减少, 即所谓“退糖”现象。为了保证妃子笑的食用品质, 生产上常不得不在着色尚差时采收, 牺牲了商品的外观质量。用无纺布套袋能有效地降低叶绿素的含量, 使果面的红色色泽更艳。     

套袋对苹果果皮花青苷合成及着色的影响

套袋是提高苹果果实着色的主要技术措施之一,也是研究苹果果皮花青苷合成和基因表达的重要手段。苹果果皮花青苷的合成经由苯丙烷类代谢途径,编码苹果花青苷合成酶类的基因已得到克隆。套袋后果皮花青苷合成酶类的基因表达受到抑制,因而抑制了花青苷合成;摘袋后果皮花青苷迅速合成,与套袋后果皮光受体浓度增加和叶绿素含量降低从而提高对光的敏感度、迅速启动花青苷合成酶类的基因协同表达有关。果皮色素特别是花青苷和叶绿素的含量、比例和分布决定果实的着色状况,套袋促进果皮花青苷合成的同时大大降低了叶绿素含量,从而使果实着色鲜艳。