Polar transport of [3H]-IAA in apical shoot segments of different apple rootstocks

Summary

The polar transport of [³H]-indole-3-acetic acid in apical shoot segments of clonal apple rootstocks (M.27, M.9, M.26, MM.111 and MM.104) was investigated in the UK using a donor-receptor system. The month in which the experiment was undertaken had a significant influence on the uptake and transport of [³H]-indole-3-acetic acid activity; uptake and transport were greater in June and July (faster extension growth period) than in August (slower extension growth period). Shoot segments from dwarfing rootstocks (M.27 and M.9) showed smaller uptake and less transport of [³H]-indole-3-acetic acid than those from invigorating rootstocks (MM.111 and MM.104). [³H]-indole-3-acetic acid was transported to the agar receptors through shoot segments from all the rootstocks in June and July; those from dwarfing rootstocks showing lower levels of transport than those from invigorating ones. However, in August, [³H]-indole-3-acetic acid activity from the agar receptors was detected only from shoot segments of invigorating rootstocks, which continued to produce extension growth slowly, when dwarfing rootstocks had already ceased shoot extension growth. These results are discussed with reference to the effects of apple rootstocks on the size of scions.     

Rootstock influence on ‘delicious’ and ‘golden delicious’ apple fruit quality at harvest and after storage

The influence of 9 rootstocks (M2, M7, M25, M26, MM104, MM106, MM109, MM111 and seedling) on fruit quality at harvest and after storage of ‘Wellspur Delicious’ (WS) and ‘Goldspur’ (GS), and of 3 rootstocks (M7, M26 and MM106) on fruit quality of ‘Red King Delicious’ (RK) and ‘Golden Delicious’ (GD) apple (Malus domestica Borkh.) was evaluated during a 4-year period. Fruits from trees on M26 were larger, developed earlier color and soluble solids (SS), and maintained higher levels of acidity (at harvest and during storage) in comparison with other rootstocks. Fruit from trees on M2 tended to have high SS. Fruit color from trees on MM104, MM106 and MM109 tended to be comparatively poor. There were significant rootstock effects on SS, starch, acidity, color, circumference, weight and box size.     

Stomatal Distribution as an Index for Predicting the Growth Potential of Apple Stocks

In the present study 27 apple rootstocks have been classified into five vigour groups, according to their stomatal distribution, which varied from 11·55 to 5·88 per unit area. Amongst the different stocks studied M. 25 had the maximum stomatal frequency, and M. 9 had the least. An indigenous apple clone M. boccata var. himalacia, very common in Kumaon hills, had 7·20 stomatal counts, i.e. between those for MM. 106 and M. 7. It is suggested that this may be an alternative dwarfing stock for apples.     

Performance of ‘Discovery’ apple on M.9, M.26 and MM.106 rootstocks at two densities

Summary

The apple rootstocks M.9, M.26, and MM.106 were evaluated for their efficiency in bringing ‘Discovery’ apple trees into production. The experiment, carried out over a ten- year period compared two planting densities at 1666 and 3333 trees per ha. Tree vigour differences between rootstocks were measured in term of trunk growth, tree volume, weight of branches pruned off and final weight of the above-ground parts of the trees. Fruit production is presented both as total yield and as the weight of first class fruit. Fruit colour development is also shown. Cropping efficiency is calculated and presented in relation to the different vigour measurements. The results confirm that ‘Discovery’ is slow to come into production. M.9 was the most productive rootstock, but due to vigour differences MM.106 gave the same yields per tree, although the latter had the lower yield efficiency. M.26 performed poorly; its vigour was similar to M.9 but it produced the lowest yields.     

Relationships between sap flow,hydraulic conductivity,and the anatomical characteristics of stems and roots in apple rootstocks of different vigour

Summary

To find a useful parameter that could be related to the degree of rootstock vigour, for rootstock breeding programmes, sap flow, hydraulic conductivity, and the anatomical characteristics of stems and roots were measured in 1-year-old trees of apple rootstocks of different vigour. Sap flow was less active in dwarfing rootstocks than in invigorating rootstocks, when taking leaf area into account, under a controlled temperature of 20ºC with the root zone at 15ºC. The hydraulic conductivities of stems and roots were not consistent with the degree of dwarfing.The hydraulic conductivity of the stem appeared to be related to the diameter and density of the large vessels in the xylem. On the other hand, the phloem-to-xylem ratio in roots with diameters of 1.5 – 2.0 mm, was closely-related to sap flow and the degree of dwarfing. The phloem-to-xylem ratio decreased as the degree of vigour increased. Moreover, the phloem-to-xylem ratio was considered to be related to the ability of roots to absorb and transport water, which was expressed as the root-specific sap flow. Therefore, the phloem-to-xylem ratio could be a useful index for evaluating the potential of apple trees as dwarfing rootstocks.     

Field resistance of apple rootstocks to Phytophthora cactorum infection

Summary

Six different two year old apple rootstocks with ‘Spur Mcintosh’ scions were inoculated with Phytophthora cactorum and evaluated for susceptibility to this pathogen at the Summerland Research Station from 1982–92. In addition the effect of nursery source on the susceptibility of three rootstocks was compared. The rootstock MM.Ill remained healthy for ten years while MM.106 was very susceptible to P. cactorum crown rot. No significant difference in resistance to P. cactorum was observed between MM.lll and M.4, and M.7a. Fruit yield was significantly lower for MM.106 than with MM.lll, M.4, M.7a, and M.7 in 1990 and 1992. The susceptibility of M.26 from both nurseries to P. cactorum was similar to that of MM.106 from Traas Nursery. A significant difference in susceptibility to P. cactorum was observed between the two sources of MM.106 rootstock from 1984–1990; the MM.106 rootstock from Budwood Orchard was more susceptible to P. cactorum than that from Traas Nursery. However, in 1991 and 1992 (final observation) no significant difference was observed between them for susceptibility to P. cactorum infection. This study indicates that the observed variability in field resistance to P. cactorum crown rot infection should be explored for breeding for P. cactorum resistance.     

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.     

Virus,Fertilizer and Rootstock Effects on the Nutrition of Young Apple Trees

The chemical analyses of leaves of young apple trees on three clonal rootstocks with four different virus infections were compared. The trees were grown on plots that had received different N, P and K treatments for 40 years.

The viruses reduced leaf-N most in the one-year-old trees, and the effect was greater than that of 63 units per acre of fertilizer-N. Interactions occurred between virus and rootstocks; the leaf-N of trees on MM. 111 was reduced more by the viruses than that of trees on the other rootstocks. The omission of fertilizer-N had little effect on the leaf-N in one-year-old trees, but as they aged the effect became significant.

Fertilizer, virus and rootstock treatments all affected the levels of leaf-P. Virus effects were greatest on the leaf-P with rootstock MM. 104 and least with MM. 111, and leaf-P with MM. 104 was generally higher than that of trees on the other rootstocks. The omission of fertilizer-N increased leaf-P more than did the application of fertilizer-P.

Rootstock and fertilizer treatments affected the level of leaf-K throughout the experiment, but virus effects were significant only in the two-year-old trees.

Magnesium and calcium levels in the leaves were affected by fertilizer, root-stock and virus treatments. The presence of viruses usually reduced both magnesium and calcium, and trees on MM. 106 were generally higher in leaf-Mg and Ca than trees on the other rootstocks. The effects of the latent viruses on nutrition as indicated by leaf analysis were less than those shown on growth and flowering.     

Einfluss verschiedener Unterlagen auf vegetative und generative Parameter bei der Apfelsorte ‘Topaz’ unter biologischen Anbaubedingungen in Ostösterreich

In autumn 2008, in the research orchard of the University of Natural Resources and Life Sciences in Vienna, the apple cultivar ‘Topaz’ was planted on the rootstocks M9 (clone T337) with and without ‘Rubinola’ as interstem, M26, M7 grafted at 25?cm and at 55?cm respectively, M111 and ‘Bittenfelder seedling’, trained as spindles and tested for eight years according to organic production rules. The trees on seeding grew very vigorously, followed by MM111 and M7 normally grafted; the M7 highly grafted trees showed less vigor, comparable with M26, while the trees on M9 with and without interstem grew very weakly. Tree losses were only observed on M9 without interstem. The highest yields per hectare were found on M7 normally grafted, followed by M26, M7 highly grafted and M9 without interstem. M7 highly grafted showed the highest single fruit weights, followed by MM111, at the other end were M9 with and without interstem, and M26. The rootstock M7 grafted at 55?cm combines a medium growth with high yield and good fruit quality and therefore can be recommended for dry areas like our site. M9 without interstem showed a higher specific yield and fruit firmness after storage compared to the variant with interstem. Whether these advantages for ‘Topaz’ on M9 can be combined with a higher grafting height as effective preventive method to control Phytophthora cactorum, has to be examined in further research.     

The Relationship Between Growth Vigour of Rootstock and Phenolic Contents in Apple (Malus × domestica)

The aim of the study is to determine the effect of different growth vigorous rootstocks on phenolic compounds in leaves of apple. For this purpose it was used the leaves of cultivar ‘Red Chief’ grafted on dwarf (M9), semi-dwarf (M26) and semi-vigorous (MM106) rootstocks. During mid-July, the leaf samples were taken from the middle part of annual shoots. Phenolics of the leaves were determined by HPLC analysis. While significant differences among the rootstocks for p-hydroxybenzoic acid, eriodictyol, ferulic acid and p-coumaric acid were detected, these differences were insignificant for gallic acid and quercetin. It was shown that semi-vigorous rootstocks (MM106) had higher phenolic contents in total than the other two dwarf rootstocks. In addition, apigenin-7-glucoside, chlorogenic acid, caffeic acid, rosmarinic acid, epicatechin, syringic acid, catechin, rutin, resveratrol, hesperidin, naringenin, luteolin, apigenin and acacetin could not to be detected. Data showed that there is the relationship between growth vigour and phenolic contents of apple leaves. Especially, p-hydroxy benzoic acid and p-coumaric acid contents were higher in semi-vigorous rootstock than in dwarf rootstock.     

Sorten-Unterlagen-Kombinationen f��r den Mostapfelanbau

In a field trial 5 rootstocks (seedling, M 25, A 2, MM 106, MM 111) and 13 varieties were investigated under Northeast German climate conditions to obtain information on the optimal rootstock-variety combinations for intensive juice apple production. Further the sugar and acid content of the fruits were determined. Due to the fact that exclusively scab resistant varieties were examined, the occurrence and stability of the resistance were of special interest. The most favourable rootstocks were M 25 (highest absolute yield) and MM 106 (highest specific yield). The varieties ??Judeline??, ??Rebella??, ??Resi??, ??Angold??, ??Schwechow 3?? and ??Priam?? had the highest absolute yield (mean of all rootstocks). The suitability of these six varieties for juice apple production was described. Although fungicides were used for controlling apple scab, particularly varieties with the Vf resistance factor were infected. A strong scab resistance had the variety ??Reka?? (Vr).     

The effect of rootstock on yield and quality of ‘Mutsu’ apples

Summary

Yield and fruit quality parameters were studied during three years in a rootstock trial with ‘Mutsu’ apple. M.9 provided the highest total yield per tree as well as the highest quantity of intermediate and yellow fruit as compared with J.9, M.26 and B.9. Within similar colour categories, significant differences among rootstocks were also recorded for fruit starch degradation pattern (SDP), firmness, titratable acidity (TA), and soluble solids concentrations (SSC). Generally, the lowest SDP and highest fruit firmness was found in fruits from trees on rootstocks M.26 and B.9. The highest TA was found in fruits from trees on rootstocks M.26 and J.9 and the highest SSC in fruits from trees on rootstocks J.9 and B.9. However, considerable variations among years were also recorded. Correlation coefficients between rootstock and several yield and quality parameters revealed high correlation to SSC for green fruit and TA for medium and yellow fruit and some correlation to yield and number of fruits per tree.     

Phenotyping vigour control capacity of new peach rootstocks by xylem vessel analysis

In peach, xylem anatomical characteristics have been shown to be related to vigour of selected rootstocks. The goal of this research was to determine if xylem characteristics of a new set of rootstocks that exhibit a range of size-controlling potential and have a different genetic background from previously examined material would also exhibit similar differences in xylem characteristics. If so, then anatomical analysis of xylem may be a useful means of predicting the vigour control capacity of selected peach rootstock genotypes. Samples of xylem tissue were taken from roots, trunks and shoots of four new rootstocks that were derived from a genetic cross between ‘Harrow Blood’ and ‘Okinawa’ peaches and compared with tissue from ‘Nemaguard’, a vigorous control. Xylem samples were sectioned and analysed by optical microscope. The number and dimensions of vessels in recently developed xylem of each rootstock were measured and compared. The more dwarfing rootstocks had fewer large vessels and more small vessels than the more vigorous rootstocks. Weighted mean vessel diameter (Wm) and calculated hydraulic conductance (K_h) differed among rootstocks: more vigorous rootstocks had higher K_h and Wm than dwarfing rootstocks. Rootstock xylem vessel dimensions varied in relation to the vigour they imparted to a common scion cultivar (‘O’Henry’). After the ‘Nemaguard’ control, ‘HBOK 50’ was the most vigorous rootstock followed by ‘HBOK 10’, ‘HBOK 32’ and ‘HBOK 27’, respectively. Thus, as was seen in previous research with a separate set of rootstocks, the vigour-control capacity of this new series of peach rootstocks was strongly related to their xylem hydraulic characteristics and it appears likely that it would be possible to use xylem anatomical characteristics of shoots or roots of young trees to pre-select for size-controlling potential in a rootstock development program.     

不同砧木苹果树细根周转动态的研究

为了分析不同砧木苹果树细根的发生和周转动态,连续4年通过微根管技术研究不同砧木的5年生‘富士’苹果砧穗组合细根中的活根根长密度与死根根长密度的动态变化,以及细根年周转率和季节周转率。结果表明,乔砧树富士/八棱海棠的活根根长密度最大,矮化中间砧富士/M9/八棱海棠和富士/SH40/八棱海棠次之,矮化自根砧富士/M9、富士/SH40和富士/小金海棠最小,所有砧穗组合的活根根长密度随着树龄的增加而逐年减小。所有砧穗组合在夏秋季出现细根发生和死亡高峰期,乔砧树富士/八棱海棠的细根发生高峰期的活根根长密度和死根根长密度均最大。细根年周转率和季节周转率年度间差异大,矮化自根砧树细根的年周转率高于乔砧树。矮化自根砧和矮化中间砧树体ARLD低于乔砧树体可能与其致矮性相关。     

苹果紧凑型品种和矮化砧木内源激素的变化

 以不同矮化程度的苹果品种、砧木和嫁接植株为试材, 研究了春梢旺长期茎尖和春梢停长期叶片的内源激素变化。结果表明, 与普通型品种相比, 紧凑型品种茎尖和叶片中的赤霉素(GA₁₊₃) 含量显著降低而细胞分裂素(CTKs) 含量显著升高, 紧凑型品种的CTKs/ GA₁₊₃约是普通型品种的4. 78～6. 24 倍。不同矮化程度的砧木间相比, 春梢停长期叶片中, M9 的IAA 含量比平邑甜茶降低了53. 7 %。以M26作中间砧, 显著降低了接穗叶片和基砧新根中的IAA 含量; 但以新红星作中间砧则影响较小。将M26中间砧与紧凑型品种组合, 与乔砧普通型植株相比, 春梢停长期叶片和新根中IAA 含量分别下降了46. 1 %和33. 3 %,CTKs/ GA₁₊₃是其2. 8～3. 6 倍, 其变化幅度大于单一应用矮化砧、紧凑型品种的植株。因此, 紧凑型、矮化砧具有不同的激素调节机制, GA、CTK在紧凑型品种矮化中起重要作用, 而矮砧的矮化可能与IAA 密切相关。     

Endogenous hormone concentrations and bud-break response to exogenous benzyl adenine in shoots of apple trees with two growth habits grown on three rootstocks

Summary

Scions from two siblings of a ‘Goldspur Delicious’ × ‘Redspur Delicious’ cross were budded to three rootstocks with different levels of vigour [M.9, M.7, and Malus domestica ‘Antanovka’ seedling] and planted in the field in 1997. The scions had two contrasting growth habits: one with narrow crotch angles, numerous short branches and an upright narrow (UN) canopy; and the other with wide crotch angles, few short branches, and a spreading round (SR) canopy. Shoot tips were collected at the time of bud-break in April 2004 and analysed for auxin (AUX), cytokinins (CK), and abscisic acid (ABA) to determine relationships between scion growth habit, size-controlling rootstock, and shoot tip hormone concentrations. Although not statistically different, the UN growth habit had numerically higher AUX, lower ABA, and equivalent CK levels as the SR growth habit. These differences resulted in statistically higher AUX:CK ratios (ACR). It is possible that the higher ACR contributed to the UN growth habit, which had more anti-gravitrophic shoot growth and appeared to have greater apical dominance than the SR growth habit. Either growth habit, grown on seedling rootstock, had nearly twice the ACR than on M.7 or M.9 rootstocks. The synthetic CK, 6-benzyl adenine (BA), was applied to 30 cm shoot explants of both growth habits in a greenhouse in March 2006. An 8.7 mM BA concentration stimulated bud-break in both growth habits, compared with controls, and bud-break was increased more in the UN than the SR growth habit. The results indicate that the ACR may be a factor regulating bud-break and the development of growth habit in apple scions, and that rootstock modified the hormone concentrations in shoot tips.     

Apple Rootstock Studies: Fifteen Years’ Results with Malling-Merton Clones

The field performance of 27 apple rootstock clones, including M.XXV and all the Malling-Merton ones is reviewed over a fifteen-year period. Three scion varieties were used, Cox’s Orange Pippin, Jonathan and Ellison’s Orange, and the trials were planted both on loam and on sand soil types.

None of the new clones made trees as small as those on M.IX, their vigour ranging from that of M.VII to that of M.XVI. MM.106 made trees similar in size and cropping to those on M.VII on the loam soil, but on the sand they were smaller. MM.I06, unlike M.VII, was free from the suckering habit. Trees on MM.III and M.Il were similar in size but Cox on MM.III yielded 20% more fruit over the whole period of the trial and during the years 11 to 15. Trees on MM.I04 were heavy-bearing and larger than those on M.Il and MM.III. In the very vigorous group, MM.Iog cropped heavily but was poorly anchored. Trees on M.XXV were superior in this respect and cropped more heavily than those on M.XVI. Cox and Ellison were unthrifty on 829, but the Jonathan trees behaved normally. Jonathan on MM.102 showed severe interveinalleaf scorch symptoms of magnesium deficiency and cropping was poor.

Many of the new rootstocks fell into similar vigour groups. It is suggested that, in other apple-growing areas of the world, other rootstocks besides MM.104, MM.106, MM.III and M.XXV, which were selected .for English conditions, should be tried experimentally. The data presented suggest MM.1O1, MM.103, MM.110, MM.115 and MM.116 as worthy of local study in addition to the four others.     

SDC系苹果矮化砧木生长、结果及抗逆性的研究

以SDC系苹果砧木为试材,连续9年观察测定了在其上嫁接的红星树早花、早果、产量、果实品质、树体矮化性及抗逆性等生物学特性.结果表明:(1)SDC系砧木嫁接树比M9、M7嫁接树提早1—2年开花结果,幼树期花量密度大,5年生树总花序数及单位树干面积花序数明显高于M9和M7.(2)果皮色素花青苷含量、果肉可溶性固形物含量和总糖量均高于M9和M7,果实外观及内在品质优良.(3)幼树矮化性状明显,树高/冠幅比值小,树冠开张.(4)叶片蒸腾量小.脱落酸(ABA)含量高,单位叶面积失水量小,抗旱性强.(5)嫁接树越冬期枝条自由水含量高,抽条率明显低于M9,越冬能力强.并对SDC系砧木的优缺点进行了讨论.     

Relationships among mineral nutrition,ethylene and post-harvest physiology in apples on six rootstocks

The relationships among several mineral elements of August-sampled leaf October-harvested fruit, maturity and post-harvest quality factors of ‘Starkspur Golden Delicious’ apple trees grown on Seedling, Malling (M) 1, Malling Merton (MM) 106, M 7, Oregon Apple Rootstock (OAR 1) or M 26 in a high-density orchard during 1980–1982 were evaluated. Positive correlations were found between leaf N, K and P and fruit N, K and P, respectively, in most rootstocks. Leaf Ca did not correlate with fruit Ca; thus leaf analysis cannot be recommended for estimates of fruit Ca. Both leaf and fruit N positively correlated with fruit green color and negatively with fruit soluble solids in all rootstocks. Fruit Ca and fruit P were both negatively correlated with fruit soluble solids at harvest and after 6 months of 0°C storage for all rootstocks. The ratio of fruit $\text{N}\text{Ca}$ was positively correlated with internal ethylene in MM 106, M 7 and OAR 1, while fruit $\text{K}\text{Ca}$ ratio was positively correlated with titratable acidity in all rootstocks. Fruit Ca showed negative correlations with bitterpit, storage rot and field internal ethylene, but positive correlation with firmness. Yield was positively correlated with leaf and fruit N, Ca and Cu but slightly negatively correlated with B of those tissues. Higher yield was associated with lower leaf K concentrations. Fruit green color was negatively correlated with soluble solids and titratable acidity. Fruit dry matter was highly positively correlated with soluble solids and titratable acidity in MM 106, OAR 1 and M 26. Soluble solids at harvest were strongly predicted by pre-harvest dry matter.     

渭北黄土高原苹果不同砧穗组合幼树根系发育和分布的特征

砧穗组合选配是苹果矮砧集约栽培模式的关键环节之一,幼树的早果性和易成形性是评判砧穗组合优劣的重要指标,这与幼树根系分布密切相关。以中国苹果生产上8种常见砧穗组合的3年生幼树为试材,采用壕沟法对幼树根系分布特征进行了调查分析。结果表明:8种砧穗组合幼树根构型可以分为M系自根砧、SH系自根砧、乔化实生砧木、M系中间砧和SH系中间砧等5大类。3年生幼树根系在水平和垂直方向分布的主要区域,均为0~60 cm范围,且随着距树干距离的增大而减少。不同砧穗组合,根系长度以直径2 mm级别的根系最长,其次是直径2~5 mm的,10 mm以上的最短。乔化实生砧木较无性系矮化砧木粗根多,而须根少;矮化砧木中,M系砧木根系构成以须根为主,而SH系和青砧系砧木须根均较少。砧穗组合幼树的地上分枝数、短枝比例和花芽数等早果性指标与细根(直径2 mm)根系数量、根长密度和根表面积密度呈显著正相关关系。通过对各砧穗组合易成花和易成形的综合评价,认为在渭北黄土高原有灌溉条件的地区,M系自根砧和中间砧组合早果性好和易成形较好,而SH系组合较易成形,但早果性较差,乔化组合早果性最差,这与它们的根系分布特征密切相关。