Auxin transport capacity in relation to the dwarfing effect of apple rootstocks

SUMMARY

Basipetal auxin transport in shoots obtained from dwarfing (M.9) and less-dwarfing (MM.Ill) apple rootstocks was compared by measuring the distribution of ¹⁴C-[carboxy]-labelled indole 3-acetic acid supplied to the ends of shoot segments. Auxin was transported at a greater velocity in MM.111 than in M.9 in both woody and non-woody segments, and was effectively blocked by 2,3,5-triiodobenzoic acid. The velocities of transport were approximately 8 mmh-¹ in M.9,and 13 mmh-¹ MM.111. There was relatively little transport in the acropetal direction, and there were no significant differences between the two rootstocks in total auxin uptake. Chromatographic analysis suggested that the metabolismof the auxin supplied followed similar patterns in both rootstocks. It is proposed that the slower auxin transport in M.9 results from a lower capacity for auxin efflux from transporting cells. A limiting auxin transport capacity could explain the reduced cambial activity and subsequent xylem formation in the dwarfing M.9 rootstock, and thus make an important contribution to the dwarfing effect.     

Adventitious shoot regeneration from leaf segments of in vitro cultured shoots of the apple rootstock Jork 9

SUMMARY

Adventitious shoot formation was investigated using leaf segments of in vitro cultured shoots of the apple rootstock Jork 9. Regeneration capacity was influenced by the pretreatment of the mother shoots, macroelements, hormone concentrations, the gelling agent and the carbohydrate source. The highest regeneration rate and most shoots per leaf explant resulted from young leaves on a medium based on MS macroelements supplemented with 22 µM BAP and 0.1 µM_NAA together with sorbitol, at concentrations of 165 mM or 220 mM. Sorbitol was more effective than sucrose, glucose, fructose or a combination of these sugars. A cold and dark pretreatment of the shoots enhanced the formation of adventitious shoots.     

Adventitious root induction by substituted 2-chloro-3-phenyl-propionitriles in apple rootstocks cultured in vitro

The synthetic auxins 2-chloro-3-(3-chloro-2-methylphenyl)propionitrile (CCMPPN), 2-chloro-3-(2,3-dichlorophenyl)propionitrile (CDPPN) and 2-chloro-3-(2,3-dichlorophenyl)butyronitrile (CDPBN) were tested for their capacity to induce roots on shoots of the rootstocks M26, M27, MM104 and the scion cultivar ‘Stark Spur’ in aseptic cultures. They were compared with indolebutyric acid (IBA). CDPPN, applied at 5 × 10^?6 M concentration, was the most effective and produced up to 90% more roots than IBA. With M26 and MM104, CCMPPN and CDPBN were similar to IBA. For ‘Stark Spur’, however, CCMPPN and CDPBN were ineffective and with M27 they stimulated root formation only in a few percent of the shoots.     

苹果优系‘烟富7’不同砧穂组合的生长结果习性

【目的】探讨富士苹果优系‘烟富7’不同砧穂组合的生长结果习性,以期为‘烟富7’的现代栽培以及优质和高效提供参考依据。【方法】2008年田间定植‘烟富7’/八棱海棠、‘烟富7’/M7、‘烟富7’/M9,各年份连续调查不同砧穂组合的生长及结果习性对树高、冠径与干周、开花株率、总枝量与枝类组成、产量以及品质的影响。【结果】‘烟富7’嫁接在不同类型的砧木上,树体的大小(包括树高、冠径、干周)为八棱海棠M7M9;枝类组成上,矮化程度的不同,666.7 m2枝量、短果枝比例显著增加,营养枝比例显著降低;在早果丰产性上,‘烟富7’与各砧木组合均是第2年形成花芽,第3年形成产量,‘烟富7’/M9第5年进入盛果期,‘烟富7’/八棱海棠与‘烟富7’/M7进入初盛果期;随着矮化程度的增加,产量显著增加,进入丰产期后各砧穂组合差异不显著,‘烟富7’/M9果实品质(除果形指数、果实硬度)显著高于‘烟富7’/八棱海棠。【结论】‘烟富7’嫁接在不同砧木的生长势大小为八棱海棠M7M9;666.7 m2枝量及短果枝比例顺序则相反,M9M7八棱海棠;早果性和丰产性以M9优于M7及八棱海棠,因此‘烟富7’嫁接M9有利于早实丰产。     

不同柑橘砧木的耐旱性评价

【目的】快速评价柑橘砧木的耐旱性。【方法】对枳及其杂种、宽皮柑橘和香橙在内的共10种砧木苗采用人工控水处理的方法进行干旱处理。通过干旱条件下植株的形态表现和对与逆境相关的生理生化指标进行测定,综合评价各种砧木的耐旱性。【结果】在干旱处理下,不同砧木的萎焉时间和萎焉程度有明显差异。丙二醛、脯氨酸、可溶性蛋白含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性等与抗逆性相关的生理生化指标的测定结果显示,10个砧木的SOD活性、CAT活性、POD活性都是先升后降,而脯氨酸含量、丙二醛含量、可溶性蛋白含量在不同砧木间的变化趋势存在差异。【结论】用综合隶属函数、主成分分析法对各生理指标进行综合分析能较为客观地对耐旱性进行评价,结合植株形态表现观察结果,发现在本次测试的10种柑橘砧木中,枳杂种‘ZZ-022’的耐旱性最强,而‘扁平橘’的耐旱性最弱。     

负载量对沙地苹果品质及枝类组成的影响

通过对比调查 ,冀东沙地富士苹果适宜负载量为 1 0kg/cm干周 ,在此负载量下 ,表现为单株枝量最大 ,果实综合指标最好     

Interaction of stock plant irradiance and auxin in the propagation of apple rootstocks by cuttings

The purpose of the investigation was to examine the effects of different irradiances (light intensities: 8, 16, 38, 54 W/m²) to stock plants on the subsequent rooting of cuttings taken from these stock plants.If the cuttings were rooted without treatment with auxin (indole butyric acid), there was no difference in rooting attributable to the irradiance pretreatments. Auxin treatment of the cuttings was most effective in increasing root numbers and rooting-percentage in cuttings taken from stock plants grown under 8 W/m².     

A method to generate the surface cell layer of the 3D virtual shoot apex from apical initials

Background

The development of cell pattern in the surface cell layer of the shoot apex can be investigated in vivo by use of a time-lapse confocal images, showing naked meristem in 3D in successive times. However, how this layer is originated from apical initials and develops as a result of growth and divisions of their descendants, remains unknown. This is an open area for computer modelling. A method to generate the surface cell layer is presented on the example of the 3D paraboloidal shoot apical dome. In the used model the layer originates from three apical initials that meet at the dome summit and develops through growth and cell divisions under the isotropic surface growth, defined by the growth tensor. The cells, which are described by polyhedrons, divide anticlinally with the smallest division plane that passes depending on the used mode through the cell center, or the point found randomly near this center. The formation of the surface cell pattern is described with the attention being paid to activity of the apical initials and fates of their descendants.

Results

The computer generated surface layer that included about 350 cells required about 1200 divisions of the apical initials and their derivatives. The derivatives were arranged into three more or less equal clonal sectors composed of cellular clones at different age. Each apical initial renewed itself 7–8 times to produce the sector. In the shape and location and the cellular clones the following divisions of the initial were manifested. The application of the random factor resulted in more realistic cell pattern in comparison to the pure mode. The cell divisions were analyzed statistically on the top view. When all of the division walls were considered, their angular distribution was uniform, whereas in the distribution that was limited to apical initials only, some preferences related to their arrangement at the dome summit were observed.

Conclusions

The realistic surface cell pattern was obtained. The present method is a useful tool to generate surface cell layer, study activity of initial cells and their derivatives, and how cell expansion and division are coordinated during growth. We expect its further application to clarify the question of a number and permanence or impermanence of initial cells, and possible relationship between their shape and oriented divisions, both on the ground of the growth tensor approach.

     

The effect of rootstock shoot growth on the level of bud-grafting success in apple

Poor stands of ‘Queen Cox’ apple bud-grafted in summer onto M.9 rootstock were shown to be due to the scion bud not growing, or growing too late to produce a worthwhile ‘maiden’ tree, despite virtually all scion graft-chips forming unions with the rootstock. This problem was caused by raising the budding height to 30 cm above ground, as a method of increasing the height of lateral branches. The key element in higher budding which depressed subsequent scion bud growth was the complete removal of all rootstock shoots to a height of 35 cm to give a traditional ‘clean leg’ during the budding year. Removing rootstock shoots only at the budding position gave good stands of high quality trees. This appears to be a general effect, with the benefits of retaining rootstock shoots applying also to Malus tschonoskii when budded at 30 cm on M.9 rootstock. For both ‘Queen Cox’ and M. tschonoskii, failure of scion buds to grow vigorously often resulted in the development of ‘papery bark canker’ on the M.9 rootstock. The main benefit of root- stock shoots retained in the budding year was to ensure that scion buds grew early in the following ‘maiden’ year, whereas allowing these and new rootstock shoots to remain for the first two months of ‘maiden’ growth reduced the number of secondary scion buds which developed, and raised the height of laterals by delaying their emergence.     

中,西药剂在苹果褪绿叶斑病毒脱除中的应用

以鉴定明确带有褪绿叶斑病毒的新红星试管苗为试材。在培养基中分别加入南板兰根和三氮唑核苷，接入大（５ｍｍ）、小（０．５ｍｍ）两种茎尖。分化后，经一次继代，进行ＥＬＩＳＡ检测。结果南板兰根对茎尖分化略有抑制，但其浓度高低没有影响；三氮唑核苷对分化有抑制作用，浓度越高越强，因此应在低浓度下使用。两种药剂均对大茎尖的分化没有影响。经ＥＬＩＳＡ检测，南板兰根只在高浓度（４支／Ｌ）、较小茎尖时（０．５ｍｍ）．对褪绿叶斑病毒有脱除作用。而三氮唑核苷在本试验中不论浓度高低（１０ｍｇ／Ｌ、２０ｍｇ／Ｌ）和茎尖大小（０．５ｍｍ，５ｍｍ），对褪绿叶斑病毒均有很好的脱除作用。     

Influence of growth regulators and light on in vitro shoot regeneration in M.26 apple roostock

Summary

The effects of different BA and IBA concentrations and dark/light combinations, applied during both the last proliferating subculture (LPS) and the regeneration phase (RP), on shoot regeneration from leaves were evaluated in M.26 apple rootstock. A positive influence on caulogenesis was found with a low cytokinin/auxin ratio in the medium during the LPS. The increase in IBA concentration from 0.49 μM to 4.92 μM in the LPS, along with the absence or the use of a low cytokinin concentration (0.89 μM) in the medium, enhanced the subsequent shoot regeneration from leaves. During the RP, a concentration of 22.2 μM BA gave the best caulogenesis results. During both the LPS and the RP, high IBA concentrations were able to replace the combined effect of a low IBA concentration and dark treatment; this could indicate that dark treatments interact with the auxin metabolism in the leaf caulogenesis response. Auxin application could not reproduce all the effects of dark treatments, suggesting that dark also affects other biochemical and/or physiological aspects, such as gibberellin metabolism. Moreover, cytokinins applied during both the LPS and the RP influenced the size of regenerated shoots.     

Light quality regulates shoot cluster growth and development of MM106 apple genotype in in vitro culture

The interaction between shoot proliferation and regulative action of light quality was investigated in terms of cluster growth and development. In the commercial laboratory, the shoot multiplication procedure is normally conducted by growing clusters of shoots during several sub-cultures. Thus in this work the regulative action of light quality was evaluated by analysing the shoot cluster proliferation rate, the evolution of axillary bud differentiation, the axillary shoot development on both initial explant stem (order 1 axis) and three representative lateral branches (order 2 axes), growing from the lateral buds located at the bottom of the initial explant. Experiments showed that light qualities regulate bud differentiation and interact with apical dominance, leading to strong control of axillary bud outgrowth, and, finally, resulting in a differentiated architectural formation of clusters and type of branching.     

陕西渭北苹果园土壤NO_3~-—N累积的影响因素研究

为进一步研究果园土壤硝态氮的累积及分布情况,在陕西渭北主要苹果产区分别采集了0～120cm土壤剖面样品,测定了土壤硝态氮含量,分析了不同因素对果园土壤硝态氮累积的影响。结果表明,氮肥的大量施用会造成硝态氮在土壤中的累积,而配施有机肥、地表生草、合理的种植密度均可减少硝态氮的累积量。灌溉可加速硝态氮向地下的淋洗。研究为采取有效措施控制和减少果园土壤中的硝态氮累积量提供了理论依据。     

Factors affecting shoot proliferation and root initiation in organ cultures of the apple ‘Northern Spy’

Factors affecting the establishment, proliferation and adventitious root initiation of ‘Northern Spy’ are described. Shoot-tips established best in Linsmaier and Skoog medium with 5 μM BAP and 1 μM IBA supplemented with 1 mM phloroglucinol, but after the fourth sub-culture, proliferation was similar in media without phloroglucinol. Shoot proliferation was influenced by cytokinin type and concentration, light level and ex-plant type. Of the cytokinins tested, BAP was superior to zeatin, kinetin and 2iP. Proliferation was better with 10 μM BAP than with 5 or 1 μM BAP, but at 10 μM shoots were dwarfed. Single nodes and basal mass expiants produced significantly more shoots than did shoot-tips. Shoot proliferation was maximum at photon flux densities of 75 μmolm^?2s^?1. Roots can be readily induced with IBA, but salt concentration and the physical support on which shoot-tips are grown influence both root initiation and growth. Half-strength salts and 1 μM IBA gave best root initiation. With agar, coarse sand, perlite and rotated liquid medium, 90–100% root initiation occurs, but root growth was poor in agar.     

AgNO_3对梨叶片不定梢再生过程中抗氧化酶活性的影响

为探讨AgNO3在离体培养物形态发生中的作用,以金水和金花梨组培苗为外植体,研究了不同质量浓度AgNO3对梨叶片再生不定梢过程中抗氧化酶活性的影响。结果表明,0.1mg/LAgNO3能明显提高金水叶片不定梢再生率和再生数;金花叶片不定梢再生有效促进的AgNO3为0.1～0.5mg/L。经AgNO3处理后,2品种抗氧化物酶活性与对照差异显著。在暗培养期间,叶片中过氧化氢酶(CAT)和过氧化物酶(POD)活性均有较大幅度变化,特别是经0.1mg/LAgNO3处理后,金花叶片中POD活性及金水叶片中CAT活性增幅均高于其余3个处理。叶片中O·2产生速率和H2O2含量也增加但上升幅度不及对照。在进入光培养阶段后,添加适当的AgNO3可提高叶片原有的超氧化物歧化酶(SOD)峰值,且H2O2含量和O·2产生速率随之下降,但较高含量AgNO3处理易引起H2O2含量和O·2产生速率回升。虽然品种间抗氧化物酶活性变化不完全一致,但通过比较发现0.1mg/LAgNO3对提高金花和金水叶片抗氧化物酶活性效果最佳。     

河西走廊不同砧木对‘贵人香’葡萄生长与果实品质的影响

【目的】研究不同砧木处理对‘贵人香’葡萄生长及果实品质的影响。【方法】以12个砧木与‘贵人香’葡萄进行绿枝嫁接,以‘贵人香’葡萄扦插自根苗为对照,对植株的枝条生长情况、果粒质量、产量、糖酸含量以及果实中酚类物质含量等进行对比分析。【结果】供试砧木‘圣乔治’‘5BB’‘101-14’‘SO_4’‘110R’和‘3309C’的枝条节间长度比对照增加了11.24%~19.95%。参试砧木对枝条粗度无影响,但‘5C’‘520a’‘110R’和‘贝达’枝条髓心直径分别比对照减小了20.72%、20.17%、19.06%和11.88%,显著增加了枝条成熟度。‘Flourilush’和‘贝达’增加了果穗质量和产量,其中‘Flourilush’产量最高,比对照增加10.47%,‘110R’单穗质量最高,增幅23.52%,同时发现‘520a’‘420’和‘5C’果穗质量、果粒质量和产量均比对照显著降低;不同砧木对‘贵人香’果实中还原糖含量的影响不同,其中‘SO_4’‘420’和‘5BB’分别比对照提高了15.78%、11.66%和10.61%,‘Flourilush’比对照减少了10.04%;‘5BB’‘420’‘1103P’‘520a’‘圣乔治’和‘3309C’砧穗组合显著提高了果实中糖酸比,比对照增加了7.97%~42.15%,‘5BB’明显降低了果实中可滴定酸含量,‘5C’中的可滴定酸含量远远大于对照。各砧穗组合对果实p H影响较小。供试砧木多数可提高果实总酚及单宁含量,以‘101-14’‘420’‘110R’‘贝达’和‘5C’砧木效果较为显著。‘420’‘3309C’‘101-14’和‘Flourilush’显著增加了冰酒原料中的可溶性固形物,冰酒原料采收期(10月2日至26日)‘101-14’砧穗组合果实中可溶性固形物积累速率最快,从29.63%增加至40.30%,相反,‘110R’砧穗组合果实中可溶性固形物积累增幅最小,仅由24.77%增加至28.27%,采收时显著低于对照。【结论】在河西走廊产区,通过适宜砧木选配可促进葡萄枝条的生长,且可以提高葡萄果实的产量,改善果实品质。     

The effect of soil temperature on lateral shoot formation and flower-bud formation in apple in the first year after budding

Under controlled environment conditions the influence of four soil temperatures (7°, 14°, 21°, and 28°C) on vegetative development and flower-bud formation of apple trees (cvs ‘Rode Boskoop’ and ‘Elstar’) were evaluated in the first year after budding. Relative air humidity was high, air temperature was 20°C. Broadly speaking, for both cultivars shoot growth clearly increased with increasing soil temperature. The effects on growth were mainly reflected in the number (not length) of the lateral shoots; the growth of the main shoot was little influenced by soil temperature. At 7°C the lateral shoots usually occurred higher along the main stem than at the higher temperatures. Flowering on the parent stem and on the lateral shoots was little affected by the soil temperatures tested. In general, flower-cluster quality was rather poor. If only clusters having more than four well-developed flowers are considered, flowering was favoured by higher soil temperatures; at 28°C, especially, cluster quality was much better than at the other soil temperatures. It is concluded that soil temperature is important in controlling the degree of lateral shoot-formation as well as the formation of well-developed flower clusters.     

Effects of succinic acid 2,2-dimethylhydrazide (SADH) on the gibberellin and abscisic acid levels in stem tips of M26 apple rootstocks

Spraying M26 apple rootstocks with 4000 p.p.m. SADH leads to a rapid build up in the level of ABA in the stem tips and a reduction in the level of gibberellin-like substances. These changes in the hormonal balance of the stem tips are probably the first link in the chain conducive to decreased translocation of assimilates to the tips and the transient retardation of growth.     

套不同纸袋对红富士苹果含铅量的影响

于2005年在瓦房店驼山进行了套袋对红富士苹果含铅量的影响试验。结果表明：套袋苹果果实中的平均含铅量都不同程度地高于不套袋苹果,平均含铅量比不套袋果高54％。套袋苹果含铅量符合无公害苹果标准,但有33％未达到绿色果品的指标要求。从总体看,单层袋苹果含铅量高于不套袋和套双层袋,套不同双层袋苹果果实中含铅量有明显差别,应注意果袋的选择,以降低果实中的铅含量。