苹果水心病的发病机理研究进展

苹果水心病是果实生理性内部失调现象,主要症状为果肉组织细胞间隙充满液体,呈透明状或水渍状,甜度增加,多发生在心室周围的维管束附近及梗洼处。以苹果果实中的山梨醇为关注点,通过分析果实中山梨醇的来源、运输途径、代谢路径等研究结果,总结苹果水心病产生及消失机理,讨论影响苹果水心病发生的因素,以期为苹果水心病的认知提供参考。     

苹果水心病的发生与防治

苹果水心病,又叫苹果糖蜜病,是一种苹果果实因缺钙导致的生理性病害。近几年各苹果产区普遍发生,尤其2018年部分苹果产区爆发式发生水心病,富士、嘎拉、乔纳金等品种发生较重。现对苹果水心病发病症状、致病机理、防治方法等作以介绍。     

硼与苹果水心病关系的研究

以长富2号苹果为试材,分别采用叶面喷不同浓度硼酸、硼砂加硝酸钙,增施有机肥和测定苹果水心病发病严重果园的土壤、有效硼含量等方法,研究了苹果水心病与硼的关系。结果表明,果实和土壤中硼含量越高,苹果水心病发病率就越高;硼对钙的吸收有明显的抑制作用;硼过量是苹果水心病发生严重的主要因素之一。     

我国苹果霉心病研究进展概述

苹果霉心病又称心腐病,在果实生长期直至贮藏等均可发生为害。主要为害元帅、红星等心室开放的品种,是苹果果实上的重要病害。在国内外苹果主产区均有发生,在我国北方及南方苹果产区发生也较普遍,目前在山东已栽培的北斗苹果10余万亩,其采前落果达46.8%,其中霉心病果占77.4%。北京郊区的     

松本锦苹果水心病的综合防治

松本锦苹果是近几年被广泛推广的优良早熟大果品种.栽培中发现,在树势较弱的松本锦套袋苹果上容易发生水心病.此病于果心、果肉组织都可发生.发病果肉先呈半透明水渍状,味酸甜略带酒精味,后期果肉败坏变褐色.一般果肉已腐烂,果面才能出现变褐症状.水心病多于苹果采收前发生,在气温较高、气候干燥的条件下,病情发展很快,5～7天果实就可烂掉.水心病是由于山梨糖醇、钙、氮代谢转化失调而形成的一种生理病害,对其发生应进行综合防治.     

苹果缺钙症的综合防治技术

虞城县地处黄河故道地区，是20世纪90年代新发展的果区，有大面积的苹果栽培，其中红富士苹果占3／4以上，均已进入丰产期。由于管理不善，苹果果实苦痘病、水心病、果肉褐变等缺钙性生理病害发生较普遍，严重影响果实品质，2002年果实苦痘病病果占全年总产量的30％以上，严重地片超过60％。     

果树营养诊断讲座(四)

<正> 五、果树钙、镁营养的诊断近年来,果树的钙营养在国际上引起了广泛的注意,研究工作证明,许多果实的贮藏病害都与果树的钙营养失调有关。例如,苹果的苦痘病、水心病、痘斑病和樱桃、洋李的裂果等都是由于果实缺钙所引起。而且研究还可看出,这些缺钙的生理病害,不仅在酸性土壤上发生,也出现在富含石灰的土壤上,如我国西北的陕西、甘肃等省黄土高原果区,苹果有较重的水心病,就是这种情况。果实缺钙,一般贮藏性下降,贮藏期间还易发生内部腐烂,因而对果树生产和果品外销影响很大,极须研究克服。缺镁症在国内报导较少,但国外有不少报导。前人研究资料认为钙素营养常与钾、     

叶面补充营养对苹果水心病的影响

对长富2苹果叶面喷施N、P、K、Ca、B等营养元素及不同N／Ca的试验结果表明：叶面喷B和较高的N／Ca均易导致苹果水心病的发生；当N／Ca为5：1时，水心病较轻，而当N／Ca为20：1时，发病严重；叶面单纯补钙不能控制苹果水心病的发生；随着果实存放期的延长，水心病加重。     

辽宁省绥中县苹果缺钙症发生与对策

苹果袋培普遍采取果实套袋措施,但套袋后的苹果果实缺钙症的发生机率明显升高。缺钙症的表现因苹果品种不同而有异,主要有苦痘病、痘斑病、水心病、果肉绵变及采前落果等。导致苹果缺钙症的原因有多种,应依果园和品种的具体情况,采取相应防控措施。叶面喷施钙肥给树体补钙,是预防缺钙症发生最为普遍采取的措施。     

苹果霉心病的发生与防治

苹果霉心病的发生与防治郭岩苹果霉心病又称心腐病、果腐病。主要危害红星、红冠等元帅系的品种，金冠、红玉、国光等品种上也有发病。在苹果贮藏期，霉心病是造成大量腐烂损耗的主要原因之一。贮至元旦、春节，果实腐烂率可达到２０－５０％，即使在冷藏条件下发病率亦在...     

Watercore in Japanese pear (Pyrus serotina Rehder var. ‘Culta’ Rehder). II. Chemical changes in watercored tissue

Sorbitol was detected in the fruit and leaf of Japanese pear, as well as in those of apple. Soluble sugars in the fruit were mainly composed of sorbitol, fructose, glucose and sucrose, and fructose was the dominant component among them. On the other hand, sorbitol was the main component in the leaf.At an early stage of watercore, sorbitol, fructose and glucose were accumulated, but as the watercore became severer, sorbitol and sucrose were accumulated mostly in the affected tissue. Moreover, the decrease in respiratory activity and pectin contents, especially protopectin, was already observed in the affected tissues even at an early stage. This tendency too became more conspicuous with severer watercore. From the above results it follows that the alteration of sugar metabolism and the degradation of cellular tissue may be connected with the appearance of watercore in Japanese pear.     

碳水化合物、矿质元素及活性氧代谢与富士苹果水心发生的关系

以新疆阿克苏地区水心（冰糖心）富士苹果为试材,分析讨论了果实碳水化合物、矿质元素和活性氧代谢与水心发生的关系。结果表明：果实可溶性固形物（SSC）含量越高,水心指数越高,呈显著正相关（P < 0.05）;而单果质量、果实纵横径比及L、b*、h°值与水心果率和水心指数相关不显著;进一步分析发现,与正常果实和组织相比,水心果实和组织中,山梨醇和蔗糖含量均显著升高,尤其是山梨醇含量,分别是正常果实和组织的2.19倍和2.86倍,果糖和葡萄糖含量相对较低;此外,水心组织中K和B含量显著高于正常组织,而Ca、Zn及Fe含量则显著降低;同时,水心果实和组织中超氧阴离子和过氧化氢含量较正常果实和组织显著升高,分别高282.39%、68.17%和12.6%、107.62%;POD、SOD和CAT等抗氧化酶活性显著降低,MDA含量和相对电导率显著升高,膜质过氧化水平严重。     

Relationship between early watercore development and leaf photosynthesis or partitioning of photosynthates in apple

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.     

Relationship between watercore and maturity or sorbitol in apples affected by preharvest fruit temperature

The effect of preharvest fruit temperature on the relationships between development of watercore and ethylene evolution, flesh firmness, membrane permeability and sorbitol level in two watercore-susceptible apple (Malus domestica Borkh.) cultivars, ‘Himekami' and ‘Fuji', was investigated at ambient or modified temperatures of 10, 15 or 25°C. Watercore occurrence was completely inhibited at 25°C in both cultivars whereas fruit subjected to 10 or 15°C exhibited significantly higher watercore ratings after two or three weeks of the treatment than those at 25°C and ambient temperatures. Ethylene production of ‘Himekami' apples increased at 25°C and ambient temperature but not at 15°C. Ethylene production was not affected by treatment in ‘Fuji' apples. Flesh firmness of ‘Himekami' tended to maintain a higher level at 15°C than at 25°C, while there was no clear difference among the treatments in ‘Fuji'. The rate of potassium (K) ion elution from the flesh tissues of either cultivar was not affected by fruit temperature treatment. Sorbitol content at 15°C maintained significantly higher level than that at 25°C during the treatment in ‘Himekami' apples although no sorbitol difference was observed among the temperature treatments in ‘Fuji' apples.     

Seasonal changes in cellular compartmentation and membrane permeability to sugars in relation to early or high temperature-induced watercore in ‘Orin’ apples

Summary

The intensity of watercore in ‘Orin’ apples (Malus domestica Borkh.) from the outer canopy increased from early-July to mid-August, followed by a decrease through late-October, while no watercore was detected in inner canopy fruit during the same period. Seasonal changes in sorbitol content in each cellular compartment paralleled the development of watercore. Significantly higher sorbitol, fructose and glucose contents in the vacuoles of cells in outer canopy fruit than in inner canopy fruit suggest that active metabolism and uptake of sorbitol might occur in watercored apples in mid-August. The permeability of sorbitol across the tonoplast was significantly higher in outer than in inner canopy fruit after mid-August, whereas no difference was observed between bearing position for the other sugars or for the plasma membrane. These data suggest that elevated sorbitol levels in the intercellular spaces might result from active apoplastic unloading and not from an inhibition of metabolism and/or an increase in leakage from cells.     

Cellular compartmentation and membrane permeability to sugars in relation to early or high temperature-induced watercore in apples

Early watercore was observed in apples (Malus domestica Borkh.) from the outer canopy of ‘Orin’, an early watercore susceptible cultivar, while there was no watercore in ‘Orin’ fruit from the inner canopy and resistant ‘Fuji’. Sorbitol content was higher not only in the free space but also in the vacuole and cytoplasm in watercored ‘Orin’ than in other non-watercored fruit. Comparing watercored apples to non-watercored fruit of ‘Orin’, higher fructose and glucose in the vacuole and no significant difference in the distribution rate of sorbitol to each compartment were observed. Watercored ‘Orin’ apples showed significantly higher permeability of tonoplast to fructose, glucose, and sorbitol than those in other non-watercored apples. The permeability of plasma membrane to each sugar was much higher than that of tonoplast but no marked difference was observed among the treatments. The results suggest that metabolism of sorbitol could be active even in watercored ‘Orin’ apples and the accumulated sorbitol in the intercellular spaces might be primarily due to an active unloading from the phloem and not be brought by increased leakage from the cells.     

关于我国苹果矮砧密植栽培的思考

乔砧密植是目前我国苹果栽培的主要形式,但苹果乔砧密植存在许多问题,如单产低、果实品质差、费工、技术复杂推广难度大等;矮砧密植具有结果早、产量高、果实品质优良、省工、技术简化易推广等优点,因此应用矮砧密植是苹果发展的必然趋势;我国矮砧密植栽培实践中存在着矮砧选择不当、栽植过深、栽培技术不配套等问题,直接影响了矮砧效果的发挥。从苹果生长结果习性、我国苹果栽培区域的立地条件等方面探讨了应用矮化砧木的必要性及适合矮砧密植栽培的条件,针对当前矮化栽培中出现的一些问题,结合作者多年的实践,从育苗、建园、整形修剪等方面提出了苹果矮砧密植栽培的技术要点,并举出成功的实例。     

Yield and fruit quality of ‘Gala’ and ‘Fuji’ apple trees protected by white anti-hail net

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.     

粉红女士苹果品质特性分析评价

观察测定了粉红女士苹果成熟采收时和常温贮藏后果实的外观、抗性、果实硬度、总酸、可溶性固形物、维生素C、蒸腾失水率、出汁率、果汁密度以及果汁性状;全面分析评价了该品种的外在、内在、贮藏品质和果汁加工特性。结果表明,粉红女士苹果是一个综合性状优良、耐贮藏的鲜食、果汁加工兼用型苹果新品种。     

土壤有机质对"红富士"苹果产量和品质的影响

测定了"红富士"苹果园0~40 cm土层的有机质含量,分析了相应果园苹果的产量和果实品质,为果园科学施肥提供依据。结果表明:土壤有机质含量在2%以上的果园苹果产量高、果实品质好,几乎不发生苦痘病;土壤有机质含量在2%以下的果园苹果产量低、果实品质差,苦痘病发生严重。