Effects of grafting height of MM106 rootstock on growth,lateral shoot formation and yield in apple trees

Summary

Between 2004 and 2008, the effects of different grafting heights on sylleptic shoots were tested in the apple (Malus domestica Borkh.) cultivars ‘Granny Smith’ and ‘Gloster’, and cumulative fruit yields were evaluated. MM106 apple rootstocks were grafted 10, 20, 40, or 60 cm above soil level in August 2004. The results showed that an increased grafting height significantly decreased tree height in both cultivars. The tallest and shortest trees were observed at grafting heights of 10 cm (153.0 and 170.0 cm) and 60 cm (141.3 and 143.5 cm) in ‘Granny Smith’ and ‘Gloster’, respectively.Among the various grafting heights tested, 60 cm in ‘Granny Smith’ and 20 cm in ‘Gloster’ gave the largest stem diameters (17.6 mm and 16.8 mm, respectively). The number of lateral shoots increased significantly with increased grafting height in both cultivars. The largest numbers of lateral shoots in ‘Granny Smith’ (10.75) and ‘Gloster’ (2.00) were obtained from a grafting height of 60 cm, while 2.55 and zero lateral shoots occurred at 10 cm grafting height in ‘Granny Smith’ and ‘Gloster’, respectively. Shoot lengths decreased significantly by increasing the grafting height. Grafting heights of 10 cm and 60 cm resulted in the tallest and shortest shoots in both cultivars. Cumulative fruit yields were significantly affected by grafting height in both cultivars. The highest yield was found for a 60 cm grafting height in both ‘Granny Smith’ (11.295 kg tree^–1) and ‘Gloster’ (4.818 kg tree^–1).The results of this study suggest that grafting heights of 40 cm and 60 cm have the potential to promote branching and early bearing for apple fruit production in sustainable and organic agricultural systems.     

Root and shoot growth of newly-transplanted apple trees as affected by rootstock cultivar,defoliation and time after transplanting

Summary

An experiment with Malus demonstrated that a large proportion of the transplanted root system was lost through death and decomposition soon after transplanting in the open ground. Mortality of the roots was not influenced by the rootstock cultivars or by defoliation but increased significantly with time. In the first month, shoots of maiden trees of Malus transplanted in June when in-leaf grew, but roots did not. Subsequently, most of the new roots on the rootstock M.9 regenerated from the rootstock stem, whereas with MM.106 the old coarse roots (>2.0 mm diameter) initially present at planting were most important. Root growth occurred in concert with shoot growth such that a functional balance was maintained as shown by the existence of a constant root length:leaf area ratio over a large part of the growing season. Following transplanting, the trees appear to re-establish their optimal ‘functional’ ratio by way of a co-ordinating pattern of growth tending to correct any disturbance to the ratio resulting from transplanting. Defoliation in the early establishment phase caused only a temporary initial reduction in the root growth, but reduced all the shoot growth variables measured and increased the root length:leaf area ratio throughout the growing season.     

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.     

Effect of CPPU on fruit and shoot growth of apple

The effects of CPPU on the growth of fruits and bourse shoots of apple were examined by targeted applications of 20 mg I“1 CPPU to fruitlets and/or bourse-shoot and spur leaves. Treating fruitlets and fruitlets-plus-leaves stimulated fruit growth to a similar extent; fruit growth rate was temporarily suppressed when only the leaves were treated. Conversely, bourse shoot growth was stimulated by leaf and leaf-plus-fruit treatments. All CPPU applications reduced the content of fruit soluble solids and induced a paler yellowish- green fruit ground colour.     

不同树龄苹果园土壤微生物的差异及对苹果砧木生长的影响

以平顶海棠(Malus robusta Rehd.)为试验材料,以4个不同树龄苹果园的土壤为对象,研究了不同树龄苹果园土壤对再植平顶海棠幼苗生长的影响。结果表明,在前茬树龄为3、8、15和24 a苹果园土种植的平顶海棠幼苗比正茬土对照的平均株高分别减少31.22%、46.38%、57.66%和63.10%;再植平顶海棠幼苗地上部干质量分别减少0.96%、57.58%、76.88%和78.10%;地下部干质量分别减少40.38%、48.79%、64.03%和79.43%。在24 a生苹果树土壤中再植海棠幼苗校正发病率达到了72.73%,而在3 a生苹果树的土壤中再植海棠幼苗校正发病率只有18.18%。对不同树龄的苹果园土壤根际细菌和真菌群落结构的差异进行分析,其结果为,随着苹果树龄的提高,根际土壤中真菌种类和数量显著增加,而细菌的种类和数量则随着树龄的增加显著减少。     

Flower-bud formation and shoot growth in apple as affected by temperature

Under controlled conditions, 3-year old ‘Golden Delicious’ and ‘Cox's Orange Pippin’ trees were exposed to 2 temperatures (high: 24° and low: 17° or 19° C) in various treatments in a 4-month period starting at full bloom. In general, shoot growth was reduced at the low temperature. For ‘Golden Delicious’ flowering did not respond to the various treatments; in ‘Cox's Orange Pippin’ it was stimulated at the low temperature.A rise in temperature from 17° to 24° C seven weeks before harvest, given to ‘Cox's Orange Pippin’ trees kept at 17° C from full bloom, reduced flower-bud formation and stimulated growth. A similar temperature increase applied to trees maintained at 24° C for 4–5 weeks after full bloom favoured flower-bud formation, but did not affect growth.The inhibitory effect of the high temperature on flowering is discussed in terms of an increase of the plastochron under the influence of gibberellins produced by the growing shoot tips.     

促根压条繁育吉塞拉5号做砧木的甜樱桃苗

春季开沟斜栽吉塞拉5矮化砧木苗,每666．7m^2栽1000株,覆盖小拱棚,利用刻芽促分枝培育砧苗。待砧苗高50cm左右、基部半木质化后将母砧压平,并在砧苗基部环剥和涂ABT2号生根粉液,培土促根。6月中旬用带木质嵌芽接法嫁接甜樱桃品种。10天后在接芽以上留3片叶剪砧,促苗生长,苗高1m时摘心,当年666．7m^2可出吉塞拉5矮化砧甜樱桃苗10000余株。留圃的吉塞拉母砧可连续利用两年以上。     

新西兰苹果品种及砧木育种成就与对中国的启示

20世纪60年代新西兰的Don Mc Kenzie博士从果农J.H.Kidd配置的杂交后代中选出了世界级的苹果品种‘嘎拉’。随后,新西兰植物与食品研究所于80年代初期开始了持续专业的苹果育种研究,先后培育出了一系列优良的世界性品种。苹果育种技术也从常规育种进入了分子育种时代,一跃成为世界苹果育种强国,吸引了世界众多果树科研单位和育种者争相学习其先进技术和科研成果。为了进一步提升中国苹果育种水平,缩小与苹果育种强国的差距,作者系统的介绍了新西兰的苹果品种和砧木选育的发展历程、选育方法,特别是生物技术在新品种选育中的应用,并对比分析目前中国苹果品种及砧木选育的方法,提出中国苹果育种方法的改进建议,希望对中国的苹果育种工作有所启发。     

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.     

苹果幼树圈枝与拉枝试验

以苹果优系"06-ML/M26/八楞海棠"为试材,进行幼树圈枝与拉枝整形试验。结果表明:圈枝与拉枝适于苹果直立树形整形,中心干与其着生侧枝生长量适度,易形成良好的粗度比,成花结实效果好,圈枝效果最佳。枝条缓放中干加粗缓慢,单枝生长量大,整形困难,成花结实效果差。建议苹果幼树整形尽量不要对中干发生的枝条进行缓放,应在生长季对中心干着生的当年生侧枝进行适时圈枝或拉枝处理。拉枝以拉至水平或下垂为好,可以保证成形快、早果丰产。     

Effect of leaf excision time and age,BA concentration and dark treatments on in vitro shoot regeneration of M.26 apple rootstock

SUMMARY

The effect of benzyladenine (BA) concentrations both during the last proliferating subculture before regeneration (10-222 and, 444 µM) and during organogenesis (11.1 and 22.2 µM), leaf excision time (15 and 30 d from the beginning of the subculture), leafage and dark treatments, on adventitious shoot regeneration of M.26 apple roostock were evaluated. Leaves excised 30 d after the beginning of the last proliferating subculture and grown wkhout BA in thè medium gave the highest percentages of organogenesis, while the number of "regenerated shoots per leaf did not differ significantly among the different BA x leaf excision time combinations. The highest BA concentration (22.2 µM) in the organogeneticmedium produced thehighest percentage of regenerating leaves, with no differences between the lengths and numbers of shoots per regenerating leaf. The first twMjnfurled apical leaves showed a greater regenerative ability than the third and fourth ones, whereas the lengths and numbers of regenerated shoots per leaf were similar. The highest leaf organogenetic ratejyas observed when darkness was imposed at the begirP-ning of the last proliferating subculture and/or at the beginning of the organogenetic phase, but more regenerated shoots per leaf were obtained with darkness provided at the beginning or at the end of the lastproliferating subculture; shoot lengths were similar in all the dark treatments. The great influence onorganogenesis of all the treatments applied in the last proliferating subculture indicates the importance of this stage inpreparing explants for shoot regeneration and thus the possibility of using inductive factors in this phase.     

北京地区苹果矮砧栽培关键技术

中国是世界苹果生产大国,栽培面积和总产量占世界的50%以上;苹果产业已成为我国种植区产业结构调整、生态环境建设的主要树种,农民增收致富的主要经济支柱产业之一。但是,我国的苹果生产与世界发达国家相比,存在品种老化单一(‘富士’占70%以上)、栽培方式落后(乔砧种植比例占90%左右)、管理技术复杂、费时费工、劳动成本高、产量低、品质差、优质果率低等问题[1~4]。苹果矮砧集约高效栽培已成为世界苹果栽培的主要模式,其具有结果早、产量高、品质优、树体管理方便、便于标准化管理和机械化作业、节省劳动成本、经济利用土地、效益高等优点,已在世界苹果生产先进国家广泛应用(占90%以上)。     

Rootstock effect on growth of apple scions with different growth habits

Apple scions with diverse growth habits were grafted on various size-controlling rootstocks and morphological characteristics were measured after 6 years of growth in the field. Scion had more influence than rootstock on monthly growth rate. Across all rootstocks, scions with spreading growth habits grew rapidly in April and May and achieved most seasonal growth earlier than scions with upright growth habits that grew slowly early in the season. In all growth habits and rootstocks, growth rate slowed appreciably but did not cease by August and growth did not terminate earlier for any one scion–rootstock combination. Across all scions, the dwarfing rootstock, M.9, consistently had the lowest and seedling rootstock had the greatest tree height and trunk diameter. However, no one size-controlling rootstock consistently influenced dates of bud break and full bloom, shoot elongation rate, or duration of growth. Tree growth form was not fundamentally affected by rootstock. Significant interactions indicated that effects of size-controlling rootstock on components of shoot growth will vary with apple tree growth habit. These effects on phenology and development can be significant to growers and may assist breeders in developing new apple cultivars.     

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.     

Molecular analysis of genetic stability in micropropagated apple rootstock MM106

Random amplified polymorphic DNA (RAPD) markers were used to assess the genetic stability of 10 micropropagated plants regenerated through axillary buds of clonal apple (Malus pumila Mill.) rootstock MM106. Eleven random decamer primers were successfully used to analyse genomic DNA from mother plants and in vitro plant material. A total of 129 scorable fragments were amplified with an average of 11.73 bands per primer. Among them, 99 were monomorphic and 30 were polymorphic with 23.2% polymorphism. Among these 30, 12 were found monomorphic across seven plants and parent. Three plants could be regarded as off-types. Our results show that RAPD markers could be used to detect the genetic similarities and dissimilarities in micropropagated material.     

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.     

产地和砧木对华冠苹果芳香物质及风味的影响

为探明外界条件对华冠苹果主要芳香物质成分及风味的影响,采用气相色谱—质谱(GC—MS)对不同产地、不同砧木和栽培方式下的华冠果实主要芳香物质成分的变化进行了分析。结果表明,产地和不同砧木对果实芳香物质总量有很大的影响,同一产地高海拔果园有利于果实酯类和醛类的积累,而低海拔果园则有利于果实醇类、烷类和酮类物质的积累;八棱海棠(Malus robusta Rehder)实生砧上的果实芳香物质总含量低于其他砧木的果实;套袋提高了果实中醇类、烷类物质的相对含量,降低了果实中酯类和醛类物质的含量;进一步证实了较高的C4、C5类饱和醇是华冠异香味产生的主要原因。     

Light studies in a spacing trial with apple on a dwarfing and a semi-dwarfing rootstock

Light interception by the orchard canopies in a spacing trial with Golden Delicious and Jonathan on M IX and on M II was measured in 1968, 1969 and 1970. In 1969 and 1970 light distribution over the Golden Delicious hedges in the high-density plots was also measured and related to fruit and foliage distribution and to fruit quality. Simultaneously, integrated light readings at 100–200 locations were taken over 24-hour periods, using a photochemical method.Although all plots attained their ceiling yield level in 1967, the 6th year after planting, light interception continued to increase from 1968 to 1970. In the low-density plots — 1100 trees per ha on M IX and 660 trees per ha on M II — the canopies intercepted roughly half of the incident light and yields levelled off at 40 tons per ha. The high-density M IX plot (3300 trees per ha) intercepted two-thirds, the high-density M II plot (2260 trees per ha) more than three-quarters of incident light. Both plots yielded more than 70 tons per ha in 1967 and 1968, but thereafter the yield level dropped, especially for trees on M II, presumably because of mounting inter-tree competition for light.Light levels in the hedges in the high-density plots at equal distances from the hedge perimeter were very much the same for both varieties, for both rootstocks and in the two years. Light levels fell sharply towards the interior and bottom parts of the hedges. The main advantage of the M IX hedge was its smaller cross section, leaving little room for a poorly illuminated centre. At lower light levels weight per fruit and especially fruit colour declined, but the relation between light level and fruit quality was not consistent for both rootstocks and in both years. These inconsistencies could be explained on the basis of differences in pruning system, affecting the type of wood on which the fruit is borne.Fruit was concentrated in the interior part of the hedges, so that a high proportion of the crop suffered from the poor light conditions in this part. Fruit distribution was generally correlated with foliage distribution. In the M IX hedge by far the highest leaf density was found in the centre of the hedge. This is an advantage in comparison with the large leaf area — relatively unproductive and casting much shade — in the top of the M II hedge. Light measurements before and after fruit removal suggested that the shade cast by the fruit is negligible as compared to shading by the foliage.It is concluded that canopy architecture in the high-density M IX plot, with a leaf area index of 2.15, is close to the optimum for single row planting systems in Northwest Europe. Gains in percentage light interception, as in the high-density M II plot, are associated with a greatly inferior light distribution over the canopy, leading to lower yields per unit growth and deterioration of fruit quality. In addition to light, pruning strongly influences fruit quality.