Predicting fruit maturation in kiwifruit (Actinidia deliciosa)

Summary

In New Zealand, 6.2% soluble solids concentration (SSC) is the minimum maturity at which kiwifruit destined for export can be harvested. Ambient temperature during the fruit maturation period has been shown to affect the soluble solids accumulation rate. The purpose of the present study was to describe variation in the rate of fruit soluble solids accumulation in different regions and seasons and to develop a means of quantifying the effects of temperature on the rate of fruit maturation. Measurements of fruit SCC were made over a three year period on one orchard in each of six principal kiwifruit-growing regions across New Zealand. The date at which fruit reached 6.2% SSC varied by 34 d across all sites and years. There was an 18 d range in the average date across all sites, with Riwaka, the coolest site being the earliest, and Kerikeri, the warmest site, being the latest. The variation from year to year across all sites was 12 d. We formulated a non-linear, time-dependent model to predict the rate of change of SSC with time, given the temperature and the time since flowering. This model accounted for nearly 60% of the variation in the date that 6.2% SSC was reached and 70% of the variation in the date that 6.5% SSC was reached, if a common initial SSC was assumed across all sites and seasons. No improvement was obtained if the initial SSC was measured about three months after flowering, rather than assumed. A similar model which used the day of year rather than days since flowering was found to be slightly less accurate. However, all three versions of the model performed better than a linear regression model based on mean temperature for the fruit growth period and the date at which 5.0% SSC was reached.     

硫对猕猴桃叶绿体结构及果实品质的影响

【目的】为猕猴桃种植中合理施用硫肥提供科学的参考依据。【方法】将土壤、有机肥和硫磺粉混匀后装盆,移栽1 a生猕猴桃嫁接苗,定期观察不同硫处理盆栽猕猴桃植株的生长情况;另外冬季在‘米良一号’猕猴桃老果园中采用不同浓度硫磺粉和有机肥混合作基肥进行环状沟施,翌年9月研究施硫处理对猕猴桃叶片叶绿体结构及果实品质的影响。【结果】施用适量的硫磺对翌年猕猴桃植株的生长有促进作用,当硫质量浓度大于2.5 kg·m~(-3)时,猕猴桃植株新梢生长较短,叶片较小,对猕猴桃植株的生长有抑制作用。施硫2 a后土壤性质发现了明显变化,质量浓度为1.0~2.0 kg·m~(-3)硫处理后,土壤pH符合猕猴桃适宜生长的范围,而1.5 kg·m~(-3)硫处理后,土壤的有机质、全氮和有效磷含量明显高于其他处理组。与对照不施硫相比,田间1.0 kg·m~(-3)硫处理的猕猴桃叶片中叶绿体呈规则的梭形,环绕在细胞内表面,基粒、基质片层清晰,基粒类囊体垛叠多且排列致密整齐,叶绿体内富含小颗粒的淀粉粒,且叶片细胞大小均一,排列整齐紧密;同时低、中质量浓度的硫处理明显改善了猕猴桃果实品质,其中以2.0 kg·m~(-3)硫处理效果最好,其单果质量、果形指数、果实硬度、可溶性固形物含量、维生素C含量、可溶性糖含量和可溶性蛋白含量分别比对照提高了11.19%、8.94%、32.65%、5.45%、9.16%、11.76%和26.92%;随着施硫量的增加,果实中全硫的含量也不断增加,但所有处理均在作物全硫含量安全范围内。【结论】施硫质量浓度为1.0~2.0 kg·m~(-3)时能改善土壤养分,稳定维持猕猴桃叶片细胞和叶绿体结构,明显改善果实品质。     

Pollinator selection in kiwifruit (Actinidia deliciosa)

SUMMARY

Pollinator performance was evaluated in kiwifruit to select pollinators for cv. Hayward adapted to the cultural conditions of southern Europe. Flowering time was determined in forty male seedlings. From, these, nine were selected for having a flowering period overlapping with ‘Hayward’. In these nine males, as well as in the commercial pollinators‘Matua’ and Tomuri’, the production of pollen was studied over two years, investigating pollen quantity through flower density and pollen production per flower. Likewise, in vitro pollen viability and its in vitro germination were recorded to study pollen quality. Finally, in vivo pollen performance was studied through fruit set and fruit characteristics in controlled hand pollinations. Two males have been selected with a flowering period coincident with ‘Hayward’, which produce more than twice as much germinable pollen than commercial pollinators. Whilst there were no significant differences in pollen quality or in fruit production, clear differences existed for pollen quantity in terms of both flower density and pollen production per flower. As pollen quantity, together with flowering time, can be easily evaluated at an early stage, this is encouraging for future selection ofkiwifruit pollinators.     

Patterns of assimilate transport from leaves to fruit within a kiwifruit (Actinidia deliciosa) lateral

Summary

Kiwifruit leaves began to export ¹⁴C-assimilate when they were 49 to 64% fully expanded. The translocation was bidirectional, but within an intact lateral, assimilates flowed along pathways which linked the fruit on the nth node with its subtending leaf and, at least, with the leaves at nodes n+5 and n+8. However, after the lateral was pruned, the pattern of translocation was altered, so that all the distal leaves supplied each fruit.     

The effect of cane orientation on flower production in kiwifruit (Actinidia deliciosa)

Summary

The effects of training replacement canes of kiwifruit either downwards (45° below horizontal) on a T-bar support, or upwards on a 60° sloping trellis were studied during one season. Training canes upwards reduced the percentage bud burst by 19% and the number of flowers per cane by 20%. There was no significant effect on the growth rate of the apical shoot, or on the number of flowers per flowering shoot. The timing of bud burst and flowering were not affected by cane orientation. The implications of these results for vine management techniques are discussed.     

Micrografting speeds growth and fruiting of protoplast- derived clones of kiwifruit (Actinidia deliciosa)

Protoplast-derived shoots (protoclones) of kiwifruit (Actinidia deliciosa) were cleft grafted directly from in vitro conditions onto mature rootstocks under field conditions on several different dates from June to August in 1987 and 1988. Shoots were taken from culture vessels, prepared for a cleft graft, placed in a cleft on a rootstock, covered with a glass culture tube and sealed with cotton fibres. Other plants were self-rooted in vitro and planted in the field to compare the growth rates and maturity rates of the two plant types.     

Response of kiwifruit (Actinidia deliciosa cv. Allison) to post-harvest treatment with 1-methylcyclopropene

Summary

Experiments were conducted to observe the effect of different concentrations of 1-methylcyclopropene (1-MCP) on the post-harvest life and quality of ‘Allison’ kiwifruit (Actinidia deliciosa). Fruit were treated with 1-MCP at 0.5 µl l^–1, 1.0 µl l^–1, or 2.0 µl l^–1, un-treated fruit served as controls. Each 1-MCP treatment was applied for 24 h at 20°C. After treatment, fruit were transferred to ambient temperature storage (22º ± 4ºC; 65 – 70% relative humidity) for 18 d, during which time observations on various physical, physiological, and biochemical parameters were recorded at 3 d intervals. Our results indicated that 2.0 µl l^–1 1-MCP was the most effective treatment to delay softening and ripening in ‘Allison’ kiwifruit, as such fruit showed the lowest mean weight loss (9.8 ± 0.2%), the highest mean fruit firmness value (32.7 ± 0.2 N), and began to ripen only after 12 d in storage, whereas untreated fruit started ripening on day-6 of storage. The activities of fruit softening enzymes such as polygalacturonase (PG; 58.5 ± 0.3 µg galacturonic acid g^–1 FW h^–1), and lipoxygenase (LOX; 3.96 ± 1.3 µmoles linoleic acid oxidised min^–1 g^–1 FW h^–1) were lower, and total phenolics (TP) contents (24.3 ± 0.3 mg 100 g^–1) and anti-oxidant (AOX) activities (12.5 ± 0.03 µmol Trolox g^–1 FW h^–1) were higher in 1-MCP-treated fruit than in untreated fruit (PG, 98.3 ± 0.5 µg galacturonic acid g^–1 FW h^–1; LOX, 4.39 ± 1.0 µmoles min^–1 g^–1 FW h^–1; TP, 5.3 ± 0.6 mg 100 g^–1; AOX, 4.7 ± 0.02 µmol Trolox g^–1 FW h^–1, respectively). In addition, 1-MCP-treated fruit exhibited lower rates of respiration (48.3 ± 0.4 ml CO₂ kg^–1 h^–1) and ethylene production (30.2 ± 0.02 µl kg^–1 FW h^–1) than untreated fruit (58.9 ± 0.6 ml CO₂ kg^–1 h^–1; 38.7 ± 0.04 µl kg^–1 FW h^–1, respectively). Similarly, 1-MCP-treated fruit had higher titratable acidity (TA; 1.33 ± 0.3%) and ascorbic acid (AA) contents (115.9 ± 2.6 mg 100 g^–1 pulp) and lower soluble solids contents (SSC; 8.33º ± 0.2º Brix) than untreated kiwifruit (TA, 1.0 ± 0.2 %; AA, 105.3 ± 2.2 mg 100 g^–1 pulp; SSC, 13.7º ± 0.3º Brix, respectively). Thus, 2.0 µl l^–1 1-MCP can be used for the post-harvest treatment of ‘Allison’ kiwifruit to enhance its shelf-life and marketability by approx. 6 d.     

The response of bud break and flowering to cool winter temperatures in kiwifruit (Actinidia deliciosa)

Summary

A range of temperatures (7°C, 10°C or 13°C mean) were imposed under controlled conditions on four year old, container-grown ‘Hayward’ kiwifruit vines. The treatments were applied for periods of from one to four months during the dormant period from May to September (Southern Hemisphere). Following these treatments the vines were held at a “forcing” temperature of 16°C mean until flowering. The objective was to define the response of bud break and flowering in spring to temperatures experienced during the preceding winter. Cool winter temperatures dramatically increased flower numbers, increased the proportion of bud break, advanced the day of bud break, and increased the duration from bud break to flowering. These responses were much larger between 13°C and 10°C than they were between 10°C and 7°C. For any treatment duration, the temperature imposed during dormancy had no effect on the time of flowering. Two months at cool temperatures produced the greatest number of flowers per winter bud, with reduced numbers at three and four months. The proportion of winter buds that produced shoots showed a similar response. The Richardson chill unit is frequently used to describe the effects of winter chilling on kiwifruit. It proved unreliable as an index to integrate the effects of temperature and time on any of the developmental variables monitored in this experiment.     

夏季遮阴对猕猴桃园生态因子和光合作用的影响

以中华猕猴桃翠玉和美味猕猴桃米良一号为试材,研究高温季节(7月初-9月底)不同遮阴强度(0、25%、50%、75%)对猕猴桃园生态因子和光合作用的影响。结果表明:未遮阴的自然条件下,猕猴桃叶、果表面温度极高,蒸腾强烈,叶片光合作用出现严重的"午休"现象,表明树体处于严重的胁迫状态;遮阴可在一定程度上降温增湿,改善猕猴桃冠幕微环境,大大降低叶温和果温,有效消除叶片光合作用的"午休"现象。翠玉适宜的遮阴强度约为25%,米良一号约为50%。遮阴对翠玉叶片蒸腾速率无显著影响,但对米良一号的影响较大。可见,适度遮阴能有效缓解夏季高温强光对猕猴桃的危害,但过度遮阴有负面影响。     

In vivo growth and tolerance to lime-induced iron chlorosis of leaf-derived cvs. Tomuri and Hayward kiwifruit (Actinidia deliciosa) somaclones

Summary

The present paper reports on somaclonal variation of leaf-derived ‘Tomuri’ and ‘Hayward’ somaclones regenerated at variable pH, and the effect of the in vitro selection pressure on their tolerance to lime-induced iron chlorosis as adult plants in pots and in the field. In most plants grown in pots, the above ground component length (AGL) and the node number (NN), and also root weight of ‘Hayward’, tended to increase with the regeneration pH (RpH). The higher vigour of ‘Hayward’ somaclones regenerated at high pH seemed to be confirmed in the field. In contrast, the pH selection pressure during regeneration had no clear effect on plant tolerance to lime. For ‘Hayward’, the group of somaclones obtained at pH 5.7 showed at high lime levels higher average AGL and NN than those of plants regenerated at pH 7; while clone 7.5-1, the only surviving somaclone among those obtained at the highest pH, was apparently the most tolerant to lime. The percentage of ‘Tomuri’ somaclones obtained at pH 7.5 that seemed less sensitive to lime was slightly higher than those of somaclones regenerated at pH 5.7 and 7. ‘Tomuri’ and ‘Hayward’ controls were both very sensitive to lime. Some somaclones which had been able to grow at high pH in vitro were also fairly tolerant to lime when cultured in pots and/or in the field, especially ‘Tomuri’ 5.7-5, -6; 7-6, -8, -14 and 7.5-6, and ‘Hayward’ 5.7-5; 7-2, -3, -5 and 7.5-1. The in vitro regeneration and selection methods here described therefore seem useful for creating and selecting new variability in kiwifruit and promising for obtaining plants tolerant to high pH and lime levels in the soil.     

不同倍性雄株对软枣猕猴桃坐果及果实性状的影响

【目的】了解不同倍性的雄株对软枣猕猴桃坐果及果实性状的影响,为生产上授粉雄株的选配提供依据。【方法】选用二倍体、四倍体、六倍体雄株花粉分别为四倍体软枣猕猴桃‘红宝石星’授粉。授粉30 d后,统计各授粉组合的坐果率。果实收获后,调查单果质量、果形指数、果肉颜色、可溶性固形物含量、种子数、种子质量等性状。【结果】用二倍体中华猕猴桃雄株为四倍体软枣猕猴桃‘红宝石星’授粉,落果严重,坐果率很低(4.7%~6.1%);用四倍体中华猕猴桃‘磨山4号’授粉,雌株坐果率有所增加但仅有18.6%;而用六倍体美味猕猴桃雄株的花粉授粉后,雌株坐果率为52.4%~86.3%,与用四倍体的软枣猕猴桃雄株花粉授粉的坐果率相近。用四倍体的中华猕猴桃‘磨山4号’和六倍体的美味猕猴桃‘陶木里’花粉授粉,‘红宝石星’的单果质量、果肉色调角显著减小,果实中种子千粒重均减少,其中‘磨山4号’授粉处理引起种子千粒重显著减少。【结论】不同倍性的雄株显著影响了猕猴桃的坐果状况及果实的单果质量、果肉颜色、种子千粒重等性状。用二倍体中华猕猴桃雄株花粉为四倍体软枣猕猴桃‘红宝石星’授粉,坐果率很低(4.7%~6.1%),难以满足生产上需求。用四倍体中华猕猴桃雄株花粉授粉时,雌株坐果率有所提高(18.6%)。用六倍体美味猕猴桃雄株花粉授粉时,坐果率高达86.3%,与用四倍体的软枣猕猴桃雄株花粉授粉的坐果率相近,但果实鲜质量显著减小。     

毛花猕猴桃‘华特’果实发育特性研究

【目的】‘华特’是近年来通过挖掘野生资源育成的一个大果优质毛花猕猴桃品种,为深入了解其果实发育特性、品质和利用价值。【方法】基于BBCH衡量方法,研究了从花后至衰老整个过程的果实形态、生长和发育等特性,以及果实碳水化合物和有机酸的积累及其动态变化。【结果】明确了‘华特’猕猴桃果实发育亦呈现细胞分裂、果实膨大(以淀粉积累为主)和果实成熟3个重要时期。根据BBCH衡量法,细胞分裂期主要包含70-74阶段,果实膨大期包含74-80阶段,果实成熟期包含80-90阶段。猕猴桃淀粉积累周期较短,以果糖含量为最高,糖组份分配合理,有机酸积累时间较长,能在蔓上软熟,可食期长,适合观光采摘种植。【结论】构建一个系统描述‘华特’果实生长发育的标准模型,为其进一步的分子生理研究提供依据。     

Effect of pruning intensity on peach yield and fruit quality

Light, medium and heavy pruning treatments were used with one unpruned as check (control) in Flordasun, Flordaking and Saharanpur Prabhat peaches. Fruit yield decreased with the increase in severity of pruning in Flordaking and Saharanpur Prabhat peaches, whereas, medium pruning treatment gave highest yield in Flordasun peach. Pulp weight, stone weight, pulp-stone ratio, ascorbic acid, sugar acid ratio and moisture content were not affected by pruning levels. However, fruit weight, size, TSS, sugar and acid content were significantly increased by pruning in Flordasun peach. Almost all the physico-chemical characters were significantly affected by pruning in Flordaking and Saharanpur Prabhat peaches, in which medium and heavy pruning treatments performed better, respectively.     

Thidiazuron increases current-year fruit size and production in Actinidia deliciosa without decreasing return bloom

Summary

The effects of whole-crown application of thidiazuron (TDZ), applied two weeks after full bloom, at the concentrations of 0 (control), 2 or 10 ppm, on vine yield, fruit quality and on next-season potential yield of Actinidia deliciosa ‘Hayward’ were evaluated in 1998–99. Fruit growth increased rapidly after TDZ application. Fruit fresh weight and yield increased by about 13% and 22% with the 2 and 10 ppm concentration, respectively. These responses were associated with only small changes in fruit shape, with 10 ppm-treated fruits slightly rounder than the control. During ripening, TDZ did not affect fruit soluble solid content, flesh firmness or concentration of non-structural carbohydrates. No effect was observed on the amount of winter pruning, entity of bud burst, percent of fertile buds, number of inflorescences per fertile bud or percent of vegetative buds. These results show that TDZ can be applied to the whole crown to increase fruit size and yield, without affecting fruit quality or the next-season’s crop.     

30个猕猴桃品种(单株)主要果实品质特征的综合评价

[目的]通过开展猕猴桃品种(单株)果实品质特征的综合评价,为本地野生猕猴桃资源开发利用、品种选择和品种选育提供科学依据.[方法]以30个猕猴桃品种(单株)果实为材料,测定单果质量、果形指数,以及干物质、可溶性固形物、维生素C、总糖、总酸含量等主要果实品质性状,对其进行主成分分析、综合得分排序和系统聚类分析.[结果]不同...     

三峡一号美味猕猴桃组培快繁研究

在全世界约61种猕猴桃属植物中，原产我国的就有57种，目前具栽培价值的主要为中华猕猴桃和美味猕猴桃两种。“三峡一号”属美味猕猴桃种群。是湖北省林业厅1988年通过优良品种鉴定的宝贵种质资源，目前为国家林业部重点推广的优良品种之一。为迅速推出这一优良品种，从2001年起我们先后对其进行了组织培养快速繁殖研究，现总结报道如下。     

三种夏季修剪方法对“海沃德”猕猴桃生长及结果的影响

以8年生"海沃德"猕猴桃品种为试材,设置了强旺结果枝在结果部位之上留3~4叶进行摘心、强旺结果枝在结果部位之上留7~8片叶进行摘心和强旺结果枝进行捏尖控长等3个处理,通过枝蔓生长量、二次梢的发生率、翌年枝萌发率、结果能力、劳动力投入等的调查及叶片相关指标、果实品质指标测定,研究了不同夏季修剪方法对猕猴桃生长及结果的影响。结果表明:枝蔓夏季修剪以捏尖处理劳动力投入少,果实产量高,质量好,翌年结果能力强,综合效果最优;强旺结果枝结果部位以上留7~8叶摘心与捏尖处理在树体翌年萌芽、结果能力无显著差异,但是劳动力投入(二次梢发生率)较高,品质较差,综合效果次之;强旺结果枝结果部位以上留3~4叶摘心处理的劳动力投入(二次梢发生率)最高,果实产量较低、品质较差、翌年萌发、结果能力差,综合效果最差。说明枝蔓夏季修剪以捏尖处理最适合"海沃德"猕猴桃的生长。     

增施有机肥对爱甘水梨果实产量和品质的影响

试验结果表明:爱甘水梨增施有机肥、减少化肥用量可有效地改善果实的品质,有机肥数量越多,效果越明显;增施有机肥比常规施肥单果重增加3.5 %～9.8 %,可溶性固形物含量提高0.07 %～0.53 %,果实硬度提高0.01 kg/cm2～0.16 kg/cm2,一级果率提高17.6 %～21.9 %,产量增加5.2 %～11.5 %,增值9.8 %～17.6 %.     

青岛地区美味猕猴桃品种筛选研究

作者对青岛地区6个美味猕猴桃品种进行物候期、果实经济性状、早果丰产性、树体生长量进行研究,筛选出品质优良、丰产性强、适应性强的3个品种'金魁"海艳"徐香'.     

猕猴桃属(Actinidia Lindl.)植物亲缘关系研究进展

猕猴桃为全世界范围内非常重要且大规模商业化栽培最为成功的果树种类之一,在世界果树产业中具有举足轻重的地位,其中越来越多猕猴桃新品种的选育及应用则是推动猕猴桃产业不断进步与发展的主要动力,因此种质资源研究一直以来均是果树研究尤其是育种方面最为重要的基础,主要包括种质源调查、收集、评价、分析与利用等,而有关亲缘关系的研究已经成为果树种质资源研究和利用的核心内容,可为进一步探讨物种起源与进化、系统分类、种质资源保护和利用以及果树育种提供科学依据。笔者立足猕猴桃育种需求与未来发展方向,综合概述了国内外有关猕猴桃属植物的起源与分布,并从形态学、孢粉学、细胞学、生化分析和分子生物学等方面介绍了当前猕猴桃属植物亲缘关系的研究进展,同时对存在的问题及其研究前景进行了讨论和展望。