【Objective】The present experiment was undertaken to investigate the cold resistance of four apple varieties with parental genetic relationship and to identify the physiological indicators that can reflect the strength of cold resistance.The aim was to provide theoretical support for rapid screening of superior lines and cold-resistant cultivation management in the breeding process of apples in cold regions.【Methods】In this study,Nagano Fuji No.2,Hanfu,Dongguang and Longshuai were top-grafted （more than one meter above the ground） onto 4-year-old Pingyitiancha rootstocks in spring,and 1-year-old branches were taken as test materials in mid-January in the second year.They were treated at low temperatures of-15℃,-20℃,-25℃,-30℃ and -35℃ for 24 h,and thawed at 4℃for 24 h.The membrane structure stability,active oxygen metabolism and physiological indexes of osmotic adjustment substances were determined.The cold resistance of apples was comprehensively evaluated by principal component analysis,and the physiological factors affecting cold resistance were analyzed.【Results】With the decrease of treatment temperature,the relative electrical conductivity of the branches from four apple varieties showed a trend of gradual increase and reached the maximum at- 35℃.Moreover,the relative electrical conductivity of Nagano Fuji No.2 was still significantly higher than that of other varieties,and the difference between Longshuai and Dongguang was not significant.With the aggravation of low-temperature stress,the MDA contents in branches of different varieties showed an upward trend,and the content of MDA in branches of Nagano Fuji No.2 was always higher than that of other varieties.The MDA contents in branches of Dongguang and Longshuai was low,and there was no significant difference in MDA content between the two varieties under-20℃,-25℃and-30℃.The contents of O 2 - and H 2 O 2 in the branches of the varieties with weak cold resistance were higher,and the contents of O 2 - in the branches of Nagano Fuji No.2 were significantly higher than those of other varieties from -30℃ to -35℃.Under low-temperature stress,the contents of H 2 O 2 in the branches of Nagano Fuji No.2,Hanfu and Dongguang were higher than those of Longshuai,and the difference in H 2 O 2 content in the branches of Dongguang and Longshuai was not significant at-15℃ and -20℃,but the difference in H 2 O 2 content in the branches between Longshuai and other varieties were significantly lower than that with other low-temperature treatments.From-25℃ to -35℃,SOD and CAT activities of Longshuai branches were significantly higher than other varieties,but SOD activity decreased slightly,while CAT activity increased gradually.The APX activities of the branches of the four varieties reached the peak at-25℃and the lowest at-35℃,with no significant difference.With the decrease in temperature,the changing trend of soluble protein content in branches of different varieties was different.The soluble protein content in Longshuai branches continued to increase,and reached the maximum at-35℃,which increased by 42.24% compared with at -15℃.The free proline content of Nagano Fuji No.2 was always the lowest,and the free proline content of Dongguang was higher and reached the maximum at-35℃.With different low-temperature treatments,the soluble sugar content of Nagano Fuji No.2 was always the lowest,and Longshuai was the highest.At -15℃ and -35℃,the soluble sugar contents of Nagano Fuji No.2 and Longshuai decreased by 46.27% and 4.11%,respectively.With the decrease of temperature,the sucrose content in branches of Longshuai increased continuously and reached the maximum at -35℃,and there was no significant difference in sucrose contents among the four varieties.The contents of glucose and fructose in branches of Longshuai increased rapidly at -25℃,increasing by 21.94% and 52.5%,respectively.The contents of glucose and fructose in branches of Longshuai were significantly higher than those of other varieties at -25℃.The variation trend of sorbitol content in different varieties of apple branches was relatively stable.Comprehensive evaluation of cold resistance by the principal component analysis from strong to weak was as follows:Longshuai＞Dongguang＞Hanfu＞Nagano Fuji No.2.It was found that the relative electronic conductivity value,SOD activity,soluble protein and soluble sugar contents had a great influence on the cold resistance of apple.【Conclusion】The relative conductivity value,SOD activity,soluble protein and soluble sugar contents in one-year-old branches of apple were sensitive to low temperature stress among many physiological indexes,which could be used for early rapid selection of superior cold-resistant lines among a hybrid offspring.Longshuai,as the offspring of Hanfu,had outstanding cold resistance and could be popularized and applied in cold apple producing areas.

以"寒富"/"GM256"/"山定子"一年生嫁接苗为试材,采用盆栽法,研究了不同浓度铜(Cu)处理对植株根际土壤速效养分、酶活性和微生物活性的影响,以期为土壤质量评价以及采用生物学指标预警土壤Cu污染提供参考依据.结果表明:随着Cu处理浓度的增加,根际土壤有效Cu含量随之增加,土壤pH呈现降低趋势.低浓度(30～200 mg·kg-1)的外源Cu处理对土壤有机质(SOM)及溶解性有机碳(DOC)含量影响不大,但高浓度(350、500 mg·kg-1)的Cu处理使SOM及DOC含量显著降低;土壤碱解氮、速效磷及速效钾含量呈现与二者类似的变化趋势.土壤脲酶、脱氢酶、碱性磷酸酶活性随外源Cu处理浓度的增加明显降低.土壤有效Cu含量与土壤养分及土壤酶活性呈极显著负相关.高浓度的Cu胁迫降低了微生物群落的代谢活性,抑制了土壤微生物对碳源的利用,破坏了 土壤微生物的均一性,使微生物群落代谢结构产生改变.

Sugars and auxin have important effects on almost all phases of plant life cycle, which are so fundamental to plants and regulate similar processes. However, little is known about the effect of cross-talk between glucose and indole-3-acetic acid (IAA) on growth and development of apple trees. To examine the potential roles of glucose and IAA in root architecture, root nitrogen (N) metabolism and photosynthetic capacity in 'Hanfu' (Malus domestica), a total of five treatments was established: single application of glucose, IAA, and auxin polar transport inhibitor (2, 3, 5-triiodobenzoic acid, TIBA), combined application of glucose with TIBA and that of glucose with IAA. The combined application of glucose with IAA improved root topology system and endogenous IAA content by altering the mRNA levels of several genes involved in root growth, auxin transport and biosynthesis. Moreover, the increased N metabolism enzyme activities and levels of genes expression related to N in roots may suggest higher rates of transformation of nitrate (NO3--N) into amino acids application of glucose and IAA. Contrarily, single application of TIBA decreased the expression levels of auxin transport gene, hindered root growth and decreased endogenous IAA content. Glucose combined with TIBA application effectively attenuated TIBA-induced reductions in root topology structure, photosynthesis and N metabolism activity, and mRNA expression levels involved in auxin biosynthesis and transport. Taken together, glucose application probably changes the expression level of auxin synthesis and transport genes, and induce the allocation of endogenous IAA in root, and thus improves root architecture and N metabolism of root in soil with deficit carbon.

东北地区以大陆性气候为主,冬季漫长、寒冷,传统的富士系大果型品种因不耐低温而无法栽植,因而黑龙江、吉林、辽宁北部、内蒙古东部栽培小苹果(酸甜爽口,深受人们喜爱)[1],产业区域特色鲜明.

The low root-zone temperature affected the metabolism of roots, which was not conductive to the germination and leaf spreading process of fruit tree. We have found that exogenous sucrose could increase the endogenous IAA level of Malus baccata Borkh. roots under sub-low temperature, but the physiological role of endogenous IAA in alleviating root injury from low temperature by sucrose remains unclear. In this study, the seedlings of M. baccata were used as materials in this study. The treatments included the sub-low root-zone temperature（L, 5 ℃）, L+90 mmol·L-1exogenous sucrose（L+S）, L+sucrose+300 μmol·L-1IAA synthesis inhibitor 4-biphenyl boric acid（L+S+BBo）. We measured the contents of endogenous IAA, osmotic adjustment substance, sucrose metabolism related indexes and root activity to discuss the physiological role of endogenous IAA in exogenous sucrose regulating the response of roots to sub-low temperature. The results showed that: Compared with L treatment, L+S treatment significantly increased the contents of endogenous IAA, further promoted the accumulation of osmoregulatory substances, increased root activity, L + S treatment significantly improved the enzyme activity and expression levels of genes related to sucrose metabolism, and sucrose,fructose, glucose and sorbitol in roots were significantly increased. Compared with L+S treatment, L+S+BBo treatments significantly inhibited the level of endogenous IAA and root activity, reduced sucrose and sorbitol contents significantly. The promotion effects of exogenous sucrose on root sucrose metabolism at sub-low temperature were inhibited. These results indicated that endogenous IAA was involved in the process of increasing osmotic adjustment substance and sucrose metabolism ability of roots induced by exogenous sucrose at sub-low temperature, which provided a theoretical reference for the study on the adaptability of apple roots to low temperature.

孔雀是沈阳农业大学从海棠品种绚丽实生苗中选育的品种.树姿直立,幼嫩叶片红褐色,被茸毛,成熟叶片绿色.花量极大,花蕾为红色.平均花芽率为83.0％,花序坐果率为100.0％.果实长圆锥形,萼片聚拢宿存,幼果为深红色,成熟后为亮红色,果面光滑,具有独特的观赏价值.

套袋是苹果生产的重要栽培措施之一,寒富苹果因其果柄较短,套袋操作时费时费力,采摘时果柄易脱落造成拔冠,影响经济效益.考察喷施外源赤霉素处理对寒富苹果果柄及果实品质的影响,以期解决寒富苹果果柄短导致的生产成本和果损失率高的问题.以盛果期寒富/GM256/山定子为试材,以清水为对照,调查不同GA3浓度(0.2％,0.3％,0.5％,1％)处理和不同处理时间(花芽开绽、花蕾露红、花序分离期)对不同果位苹果果柄长度的影响,比较花蕾露红期0.5％GA3和0.5％普洛马林(Pr)处理对果柄长度、细胞形态和激素含量及果实品质的影响.研究结果表明,不同浓度GA3处理对中心果和边缘果的拉长效果基本相同;花蕾露红期喷施1％浓度GA3的拉长果柄效果最好.与CK相比,Pr和GA3处理均具有拉长果柄的效果;果柄细胞显微观察结果表明,Pr和GA3处理离层细胞较CK明显增大;果柄中GA3和IAA含量增加,ABA含量先增加后降低,ZT含量变化不大;果形指数升高,果实硬度降低,果实可溶性固形物含量升高,可滴定酸和可溶性糖变化不大.综合来看,Pr处理对寒富苹果果柄长度和果实品质的改善效果更好.

国家当前推进的乡村振兴战略中,实现产业兴旺、农业生态文明发展是重要一环.随着我国社会经济快速发展,果树生产正经历单一品种大量栽培及生产过剩的时代,当前又面临着从业人员日趋老龄化、劳动力和生产资料成本大幅度上涨、果品总量供大于求导致价格不稳定等问题,制约了果树的可持续健康发展.为了提高果园生产效益,果树的发展理念必须由过去的数量效益型向质量效益型转变[1].

为增加耐寒苹果品种多样性,开创区域特色果树生产模式,提高果农综合收益,沈阳农业大学自2016年起对17个小苹果的物候期、生长结果习性和果实品质等进行了调查测定,结果发现塞外红、牛奶、金苹综合表现良好,总结了小苹果的栽培管理技术.

脆性损失是降低园艺作物果实品质与消费者购买欲望的重要原因.作为涵盖声音传导、几何特性、断裂特征等因素的综合概念,果实脆性受细胞状态、细胞壁机械强度及膨压共同影响.深入认知果实脆性,明确脆性评价方式,了解其变化过程的生理生化变化,可为生产高品质果实提供理论依据,还可为增产增收提供技术指导.本文综述了果实脆性的感知过程、脆性评价、影响脆性的因素及在相关生理生化代谢研究方面取得的重要进展.

以苹果砧木平邑甜茶(Malus hupehensis)幼苗为试材,结合15N同位素示踪技术,连续两年研究了砂培条件下低锌、适量和高锌水平(0.5、4和16μmol·L-1 Zn2+)5种供给方式[持续低锌30 d、低锌变高锌(前15 d低锌,后15 d高锌)、适量稳定供锌(30 d适量供锌)、高锌变低锌(前15 d高锌,后15d低锌)和持续高锌(30d高锌)]对幼苗生长以及氮素吸收利用的影响.结果表明:适量稳定供锌处理的幼苗总生物量、根系总长、总表面积最大,根系活力最高;持续低锌处理最低.整个处理期间,适量稳定供锌处理的叶片硝酸还原酶(NR)活性均显著高于其他处理.15N示踪结果表明,处理30 d时,各处理15N吸收量、15N利用率表现为适量稳定供锌处理最高;持续高锌、低锌变高锌处理次之;持续低锌处理最低.以上结果说明:供锌不足与过量以及供锌不稳定均抑制了平邑甜茶幼苗根系生长以及氮素的同化,限制了对氮素的吸收,不利于生长发育;而适量稳定供锌优化了根系形态,同时增强了叶片NR活性,促进了幼苗体内的氮素同化,对氮素的高效吸收利用,幼苗生长发育最有利.

为明确叶面施硫酸锌对苹果叶片光合产物合成及其向果实转移分配的影响机理,进而为生产上在苹果果实发育关键时期通过叶面补锌的措施提高果实品质提供理论依据,以8年生寒富/GM256/山定子为试材,设置0(CK)、0.1％(ZS1)、0.2％(ZS2)、0.3％(ZS3)和0.4％(ZS4)5种不同浓度硫酸锌处理,采用13C同位素标记技术,结合相关生理生化指标测定,研究叶面不同浓度硫酸锌对果实膨大期苹果叶片13C光合产物的合成及其向果实运输的影响.结果表明:随着叶面施锌浓度的增加,叶片Rubisco酶活性、净光合速率、PSII最大光化学效率、PSII实际光化学效率、光化学淬灭系数、PSII电子传递速率、山梨醇和蔗糖含量、6-磷酸山梨醇脱氢酶和蔗糖磷酸合酶活性及果实山梨醇脱氢酶和酸性转化酶活性均呈现先升高后降低的趋势,且均以ZS3处理最高(其值分别为8.56μmol·min-1·g-1、15.84μmol·m-2·s-1、0.838,0.751,0.843,92.1,35.41mg·g-1 FW、5.25mg·g-1 FW、412.99μg·min-1·g-1、420.87μg·min-1·g-1、7.19μmol·h-1·g-1FW和9.25μmol·h-1·g-1FW),CK处理最低.13C示踪结果表明,各处理果实13C含量随时间增加逐渐增高,而果实13C转运速率则随时间的增加逐渐降低.与其他处理相比,ZS3(0.3％ZnSO4·H2O)处理显著提高了叶片13C光合产物向果实运输速率,同时该处理下果实13C含量最高.综上表明,叶片涂抹适宜浓度硫酸锌(0.3％ZnSO4·H2O溶液)处理优化了叶片光合性能,提高了苹果叶片光合同化物的合成能力,提高了源叶的生产力;同时提高了果实糖代谢相关酶活性,提高了果实库强,增强了果实对光合同化物的竞争力,促进了叶片光合产物向果实的输送.

苹果苦痘病又称苦陷病,是苹果成熟期、贮藏期因缺钙而引发的一种常见生理病害,已成为世界范围内影响苹果经济性状的首要病害之一.作者对苹果苦痘病的症状和发生原因进行综述,并总结其防治方法,以期为生产中苹果苦痘病防治提供参考.

以'寒富'苹果为试材,采用热风干燥制作方法,分别用60、70和80℃烘干处理6、8、10h,烘干后进行真空包装、带封口塑料袋包装、保鲜袋包装和不包装处理,探究苹果干简易加工方法及分析销售前景.结果 表明,冬季'寒富'苹果去皮后在70℃条件下烘干10 h制成的苹果干软硬、酸甜、色泽和口感均好于其他处理,夏季80C条件下烘干10h效果略好于其他处理,但整体口感不如冬季处理.在包装上,简易真空包装对于保持果干质量、延长销售时间等效果好于其他处理.城市近郊观光采摘果园、专业合作社采用优化后的方法加工制作苹果干,作为待客零食及乡土地域特色产品销售,具有较大的增加果园收益空间.

为筛选适合'南果梨'疏果的化学药剂和喷施时期,以'南果梨'为试材,使用萘乙酸、多效唑、乙烯利等化学药剂,设计不同的化学药剂处理组合,于'南果梨'花后不同时期进行喷施.结果 表明:从'南果梨'的坐果率、脱萼率和果实品质综合来看,在盛花期喷施1次10 mg/L萘乙酸+500 mg/L多效唑+10 g/L氯化钙+2g/L磷酸二氢钾处理的效果最好,花朵坐果率和花序坐果率分别为16.50％、29.17％,脱萼率为80.65％,'南果梨'果实石细胞含量减少,可显著提高果实品质.

以位于沈阳农业大学的旧石器时代考古遗址内0～425cm深度土壤为研究对象,借助种子萌发法,观察并分析每25cm土层中存有活力种子的萌发情况,以明确旧石器时代沈阳地区的气候、植被演化及人类活动特点.研究结果表明:沈阳农业大学后山旧石器遗址内0.68m3土样中共发现萌发种子471粒,隶属2个纲,14个目,15个科,16个属,且均为草本植物.仅在0～200cm土层内存在具有萌发活力的种子,而在200～425cm土层内未发现有种子萌发情况,且各层萌发草种数随土层加深逐渐降低.在旧石器时代晚期,十字花科(Cruciferae)、禾本科(Gramineae)、马齿苋科(Portulacaceae)以及蔷薇科(Rosaceae)植株数量逐渐增加.仅苘麻(Abutilon theophrasti Medicus)既存在于表层土壤也存在于175～200cm的深层土壤内.种子库的Margalef指数、Shannon-Wiener指数、Simpson指数均随土层深度的增加逐渐降低,而Pielou指数在各土层深度之间无差异.由此可知,沈阳旧石器时代0～200cm区域是以禾本科、蔷薇科和马齿苋科为主的典型草原;自旧石器时代晚期以来,气候逐渐由相对干旱变得湿润温暖,地表植被种类逐渐丰富,人类活动性加强.

[目的]氮素利用率低严重制约我国果树产业的可持续发展.通过研究不同供锌水平对苹果砧木平邑甜茶幼苗生长、光合作用、13C同化与分配和15N吸收、利用与分配的影响,探究锌对苹果氮素吸收利用的影响机制,为苹果生产中氮肥利用率的提高提供理论参考.[方法]以苹果砧木平邑甜茶幼苗为试材进行砂培试验,试验周期为30天.设置ZnO、Zn2、Zn4、Zn8、Zn16(分别相当于0、2.0、4.0、8.0、16.0 pmol/L Zn2+)5个锌浓度处理,每3天更换一次营养液,每次向营养液中加入Ca(15NO3)2 0.01 g,共计加入0.1 g.正式处理25天后进行13C标记,于13C标记后24、48和96 h取样,测定各器官13C丰度.另于正式处理第30天取样,测定幼苗各器官生物量、根系形态、光合特性、碳氮代谢相关酶活性、各器官锌含量以及各器官含氮量、15N丰度.[结果]5个处理中,Zn4处理幼苗各器官生物量与根系活力最高,根系形态指标(根系长度、根系总表面积与根尖数)最优.叶片净光合速率(Pn)、气孔导度(gs)、PSII最大光化学效率(Fv/Fm)、二磷酸核酮糖羧化酶(Rubisco)、硝酸还原酶(NR)及蔗糖磷酸合成酶(SPS)活性随供锌水平的提高呈先升高后降低的趋势,均在Zn4处理下达到最大,其值分别为15.21 μmol/(m2?s)、184.12 μmol/(m2.s)、0.839、8.4 μmol/(g?min)、103.25μg/(g?h)和96.6mg/(g?h);在ZnO处理最低,其值仅为Zn4处理的0.65、0.71、0.92、0.51、0.60和0.52倍.各器官锌含量均表现为Zn16＞Zn8＞Zn4＞Zn2＞ZnO.同位素示踪结果表明,随着供锌水平的提高,幼苗整株13C积累量、15N吸收量以及15N利用率表现为先升高后降低,均在Zn4处理下达到最高,其值分别为1.95 mg、0.57 mg和15.8％.不同供锌水平对幼苗13C与15N分配率也有一定影响.其中,Zn4处理下根系13C分配率与叶15N分配率最高,分别为ZnO处理的1.53和1.18倍.[结论]供锌不足与过量均抑制幼苗对氮素的吸收利用.而适宜供锌一方面通过改善叶片的光合作用,提高了叶片碳代谢相关酶活性,加强了叶片对碳的固定;提高了根系对光合产物的竞争力,加强了叶片光合同化物向根系的运输,促进根系生长发育的同时,改善了根系形态,提高了根系活力,进而增强了幼苗对氮素的吸收.另一方面,促进了氮素由根系向叶片的运输,同时提高了叶片硝酸还原酶活性,提高了幼苗对氮素的同化利用能力,进而促进了幼苗对氮素的吸收.因此,适宜锌营养可以有效提高幼苗的碳、氮吸收和同化效率.

‘寒富’苹果经过近20年的迅速发展,目前已经成为辽宁省第一大主栽品种,2019年达到9.33万hm2,占全省苹果面积的近五成.其中有相当部分为GM256矮化中间砧植株.大量新建果园借鉴国内外苹果现代集约栽培制度的整形修剪技术,而集约栽培对树形要求不象传统稀植大冠那么严格,生产中的整形技术基本没有大问题,盛果期前的果园多数较为整齐.但进入盛果期后如何维持健壮树势、保证连年优质丰产的技术,却远远没有被广大果农所掌握,修剪技术的问题依然较多,成为很多果园维持树势的制约因素.笔者将近年来所在团队在技术示范推广过程中遇到的修剪方面的问题进行总结,并提出建议,供广大果农参考.

通过数据库文献检索,查找自寒富苹果育成以来,有关寒富苹果的产量及果实品质报道的参考文献数据,总结寒富苹果产量及品质的变化规律,并分析产生原因,提出有利于实现寒富苹果节本、提质和增效的发展方案.结果 分析表明,随着寒富苹果栽植面积扩大和栽培技术体系的完善与提升,全国平均单产和单果重均呈逐年上升趋势,但果实品质却有下降趋势.在不同栽培区域中,辽宁省葫芦岛地区的平均单产最高,且各果园之间差异较小.阜新地区生产的寒富苹果硬度最大,更耐贮;内在品质方面以甘肃省平凉地区寒富苹果可溶性固形物含量最高,甘肃定西地区寒富苹果可溶性总糖含量最高,这可能与甘肃当地适宜栽植的自然气候条件有较大关系.另外,即使同一省份同一地区,不同果园之间也存在较大差异,可能与大部分果农片面追求产量效益或在非适宜区栽植有关.因此,为实现寒富苹果节本提质增效发展,应该提升免套袋等新技术研发能力,建设高品质现代化生态果园;针对寒富苹果特性加快开发深加工产品,延长产业链条;实施多元化寒富苹果生产,助力新时代乡村振兴战略实施.

以湖北海棠平邑甜茶(Malus hupehensis var.pingyiensis)砧木为试材,采用砂培方式结合13C同位素示踪技术,研究了不同锌水平(Zn2+浓度分别为0.02、0.5、2.0、4.0 μmol·L-1)对幼苗叶片光合性能、荧光参数以及13C积累与分配的影响.结果 表明,低锌(0.02、0.5和2.0 μmol·L-1 Zn2+)处理下幼苗各器官生物量、净光合速率(Pn)和气孔导度(Gs)均较对照(4.0 μmol·L-1 Zn2+)处理明显降低.与对照相比,低锌胁迫明显降低了叶片光系统Ⅱ (PSⅡ)最大光化学效率(Fv/Fm)、PSⅡ实际光化学效率(ΦPsⅡ)以及PSⅡ电子传递速率(ETR).低锌胁迫处理下的叶片核酮糖-1,5-二磷酸羧化酶(Rubisco)、蔗糖合酶(SS)与蔗糖磷酸合成酶(SPS)活性随时间增长逐渐降低,在处理35 d后达到最低水平.13C同位素示踪结果表明,0.02、0.5和2.0 μmol·L-1 Zn2+处理下幼苗根系13C积累量在13C标记结束12 h后为0.03、0.05和0.16 mg·株-1,较对照分别降低了88.5％、80.8％和38.5％.13C标记结束72 h后,低锌处理下叶片13C分配率较对照提高了18.5％、12.2％和9.0％,而根系13C分配率较对照降低了47.1％、35.4％和26.0％.以上结果表明,低锌胁迫降低了叶片Pn,削弱了叶片碳同化能力,阻碍了叶片光合同化物的合成及其向根系的运输,进而抑制了根系生长.