不同柑橘砧木对锦橙果实品质的影响

 2006—2008年连续3年研究11种砧木对铜水72-1锦橙果实品质的影响。结果表明：不同砧木对果实颜色和内在品质均有影响,其中以卡里佐枳橙为砧的果实亮度最好,黄色度值最高,果实最大,果皮最薄;以路比枳为砧的果实红色度值和固酸比（TSS/TA）最高,果皮最厚;以沃尔卡姆为砧的亮度最差,黄色度值、单果质量和可食率最低,中心柱最小;以C35枳橙为砧的中心柱最大且维生素C含量最低;以光皮酸橙为砧的果实红色度最低而可食率最高;以里其16-6枳为砧的果实可溶性固形物（TSS）含量最高;以孙楚沙橘为砧的果实可滴定酸（TA）和维生素C含量最高,而TSS/TA最低;果实TSS和TA最低的砧木为枸头橙。品质综合评价,性状表现较好的为孙楚沙橘、卡里佐枳橙和C35枳橙,而表现较差的为兰普莱檬和沃尔卡姆柠檬。     

Rootstocks influence fruit oleocellosis in ‘Hamlin’ sweet orange (Citrus sinensis L. Osbeck)

Oil spotting or oleocellosis, is a major problem in citrus crops. As the rootstock and fertilization play important roles in citrus growth and fruit development, we investigated the influence of different rootstocks on the growth, mineral nutrition metabolism, water relations, and fruit oleocellosis of eight-year-old field ‘Hamlin’ sweet orange trees. Trees grafted onto Lichi16-6 trifoliata (Poncircus trifoliate) had the greatest rate of oleocellosis (RO), and trees grafted onto Goutou orange (Citrus aurantium) had the greatest degree of oleocellosis (DO). In contrast, trees grafted onto Rangpur lime (Citrus limonia Osbeck) had the lowest RO and DO. Trees were the most vigorous on Rangpur lime rootstocks, followed by Lichi16-6 trifoliata, and then Goutou orange. In addition, because the scion/stock girth ratio showed significant correlations with the RO and DO, oleocellosis parameters can be a good indicator of scion/stock affinity. The total N, total P, Ca²⁺, and Mg²⁺ in leaves from trees on Rangpur lime were significantly lower than in leaves from trees on Goutou orange or Lichi16-6 trifoliata. In addition, the RO showed a significant correlation with the leaf Ca²⁺ and S concentrations and with the peel Mg²⁺ concentration. The DO was significantly correlated with the total peel N and S concentrations. In addition, the RO showed a significant correlation with the net assimilation of CO₂ (ACO₂), stomatal conductance (GS), transpiration rate (ET), and water-use efficiency (WUE). However, the DO showed a significant correlation with the GS, ACO₂, and WUE. Taken together, these results indicate that rootstocks affect the development of oleocellosis in ‘Hamlin’ sweet orange due to their effects on the mineral nutrition balance and water relations.     

梁平柚矮化砧木的筛选

供试柚品种为梁平柚,砧木为枳、香橙、宜昌橙和酒饼簕、以酸柚砧为对照。1983年秋嫁接,1984年秋定植。7年观察结果表明,酒饼簕、宜昌橙、枳对梁平柚有矮化作用,其中以酒饼簕最明显。枳砧梁平柚定植后第2年(1986年),有1/3的植株试花,第3年全部开花,结果最多的一株达8个;香橙、宜昌橙、酸柚砧(对照)梁平柚定植后第3年试花;酒饼簕砧梁平柚第5年试花。枳砧梁平柚树高、树冠体积、枝条电阻值、枝条节间长度等均明显低于对照。初步认为,枳是梁平柚比较理想的矮化砧木。     

沙田柚在不同砧木上的早期表现

供试品种为沙田柚,砧木材料２８个,以酸柚砧作对照,研究了不同砧木上沙田柚树体生长发育,产量的早期表现。经过７年的观察分析,初步认为关云大叶枳,江津大叶枳,多花枳,朱砂柑、摩洛哥酸橙对沙田柚有早结,矮化作用。定植后第３年试花,第４年开始结果,结果最多的是关云大叶枳,株产达４个,树体高度比对照矮１１．８％￣２１．０％,产量比对照高２４０％￣６００％,其余砧木都比对照结果迟。     

Influence of rootstock on orchard productivity and fruit quality in peach cv. ‘Redhaven’

Summary

We have evaluated the influence of four different peach rootstocks (Prunus pumila,‘GF 655/2’ ,‘Missour’ and ‘GF 677’ as a standard) planted in medium-heavy to heavy soil on phenological events (flowering and harvest date), growth, yield, fruit quality and mortality of peach (P. persica L.) scions of cv. ‘Redhaven’. At the end of flowering, there were no significant differences between the different rootstocks in the years 1999, 2000, 2003 and 2004. In 2001, trees grafted on P. pumila reached the end of flowering 2 d before trees grafted on the other rootstocks. ‘Redhaven’ fruits ripened on the same day on trees grafted on the different rootstocks. The differences were only between years. The results showed that significantly less vigorous trees, according to their trunk cross-sectional area (TCSA) and canopy volume, with the lowest yield, were observed on P. pumila rootstock. The rootstock P. pumila had a significant negative influence on fruit dimensions and mortality was 50%. Trees grafted on ‘GF 655/2’ rootstock produced significantly lower yields than those grafted on ‘GF 677’ or ‘Missour’ rootstocks. Only the ‘GF 655/2’ rootstock had root suckers. Trees grafted on ‘GF 677’ rootstock were significantly more vigorous than on the other rootstocks, and produced the highest yield with good fruit quality. The final canopy volumes of peach trees grafted on the different rootstocks were very different. The most vigorous trees were those grafted on ‘GF 677’ rootstock, where the final tree volume was 12.8 m³. Trees grafted on P. pumila and ‘GF 655/2’ had significantly lower TCSA values than on the other rootstocks.     

Fino lemon clones compared with the lemon varieties Eureka and Lisbon on two rootstocks in Murcia (Spain)

Six clonal selections of the autochthonous Spanish lemon tress cv. Fino, named Fino 46, Fino 47, Fino 48, Fino 49 and Fino 77, and two foreign varieties Eureka and Lisbon (Citrus limon (L.) Burm. f) grafted on sour orange (C. auramtium L.) and Citrus macrophylla (C. macrophylla Wester) rootstocks were studied in Murcia (Spain). The fruit were harvested for 6 years, and fruit quality and tree size were evaluated after the sixth harvest. Fino 49, Fino 77 and Lisbon trees produced the highest cumulative yield. However, Eureka trees on macrophylla had the highest yield efficiency (cumulative yield/trunk cross-sectional area (TCSA)) due to its small TCSA. There were few differences between Fino group and Lisbon as regards fruit quality; however, Eureka trees on macrophylla produced smaller fruit with a higher concentration of total soluble solids (TSS) and titratable citric acid (TA) than the other varieties. Macrophylla was a better rootstock than sour orange for lemon trees since lemon trees grafted on macrophylla had higher cumulative yield and yield efficiency than those on sour orange. However, sour orange induced the highest TSS and TA in all lemon varieties evaluated.     

Evaluation of rootstocks for the Cyprus local lemon variety ‘Lapithkiotiki’

The effect of various rootstocks on yield, yield efficiency, tree size and fruit quality of the local lemon variety ‘Lapithkiotiki’ (Citrus limon (L.) Burm. F.) was studied under Cyprus conditions. Total cumulative yield over 13 years of production was the highest on rough lemon (C. jambhiri Lush) followed by that on Volkameriana (C. volkameriana Ten. & Pasq.), Yuma Ponderosa lemon (C. limon (L.) Burm. F.), sour orange (C. aurantium L.), Citrus macrophylla Wester, Morton citrange (C. sinensis cv. Washington navel × Poncirus trifoliata (L.) Raf.), Yuma citrange, Rangpur lime (C. limonia Obs.), Palestine sweet lime (C. limettioides Tan.), C-32 citrange and Citremon 1449 (C. limon × P. trifoliata), although no statistically significant differences were found between sour orange, the commercial rootstock used in Cyprus, and the other above mentioned rootstocks. Next in order as regards to total cumulative yield was Cleopatra mandarin (C. reticulata Blanko.) followed by Carrizo citrange, with statistically significant differences compared with sour orange. Trees on Citrumelo CPB-4475 (C. paradisi Macf. × P. trifoliata) and C-35 citrange died 3–4 years after grafting. Canopy volume was the lowest for trees on Cleopatra mandarin and Carrizo citrange. Yield efficiency A, expressed as total cumulative yield per trunk cross-sectional area, was the highest on C. macrophylla and lowest on Carrizo citrange. Rootstock significantly affected fruit size and weight, rind thickness, juice content, brix, total acids and brix:acid ratio. The results of the present study reveal that the most promising rootstocks that may replace sour orange for the local lemon variety ‘Lapithkiotiki’ under Cyprus conditions are Volkameriana, Yuma Ponderosa lemon, C. macrophylla and Citremon 1449.     

‘21世纪’桃对其砧木毛桃根系导管分子性状的影响

 采用组织离析法和显微照相技术,观测了以毛桃为砧木,‘21世纪’桃品种为接穗的嫁接树与非嫁接树根系导管分子类型和大小。结果表明：与未嫁接的实生砧木树相比,嫁接树的根系中导管分子侧壁次生增厚和木质化的方式、纹孔式及穿孔板类型未见变化,但两端具尾的导管分子数明显减少,导管分子端壁向一端壁水平一端壁倾斜的中间类型变化,导管分子长度变化不大,但直径明显变小。这意味着桃树接穗对砧木根系导管分子的类型与直径产生了一定的影响。     

Performance of Marsh Seedless Grapefruit on Six Rootstocks in Cyprus

Yield, fruit quality, growth and the levels of 12 elements in the leaves were measured for 12-year-old Marsh Seedless grapefruit trees on six rootstocks. Trees on rough lemon and Cleopatra mandarin were larger than those on sour orange and consistently produced 67 and 23 per cent more fruit respectively than on sour orange. Trees on Palestine sweet lime, Troyer and Morton citranges were the least productive. Three-year means of total soluble solids ranged from 9·4 per cent for fruit from trees on Palestine sweet lime to 11–2 per cent on Cleopatra mandarin. Fruit size was good on all rootstocks but effects of rootstock on levels of Mg, Na, Cl and B in the leaves were statistically significant.     

砧木对柑桔嫁接幼树早果影响的生理生化研究

本文研究了枳和红桔两种砧木对柑桔嫁接幼树结果早晚影响的生理生化差异。1.枳砧树较红桔树至少提早二年开花,枳砧树的单叶面积、株高、新梢生长量和干径均小于红桔砧树;2.花芽生理分化期枳砧树叶片的可溶性糖、淀粉及还原糖的含量均高于红桔砧树,叶片总氮含量变化不大,但在花芽形态分化期,砧木对叶片可溶性蛋白质含量的影响较大。叶片C/N比值与花芽形成存在一定相关关系。10月上中旬各因子二种砧木树的相对含量有一明显逆转过程,3.花芽生理分化期枳砧树叶片内源玉米素和脱落酸含量高于红桔砧树,赤霉素(GA_3)低于红桔砧树,整个试验期间,Z/GA_3和ABA/GA_3比值均为枳砧树高于红桔砧树。     

Nursery performance of ‘Cox’ apple trees with rootstocks of M.9 from either micropropagation or improved conventional propagation from micropropagated plants

Rootstocks of M.9 were produced either directly by micropropagation, by improved conventional propagation from apparently rejuvenated micropropagated plants or by conventional propagation throughout. These rootstocks were grown in the field for one year and then grafted with scions of ‘Cox’s Orange Pippin’. Performances of the composite trees were evaluated one year following grafting. Trees with rootstocks which came directly from micropropagation had many suckers and burrknots and usually had poorly developed scions. Trees with rootstocks from improved conventional propagation from micropropagated plants were similar to trees with rootstocks from conventional propagation throughout in being almost devoid of suckers and burrknots and having well developed scions.     

几种砧木对哈姆林甜橙植株生长、产量及果实品质的影响

以7种不同砧木的8年生哈姆林甜橙为试材,对植株营养生长、产量和果实品质进行了比较。结果表明,不同砧木对哈姆林甜橙生长和产量有不同影响,其中以卡里佐枳橙为砧的植株树冠体积最大,以光皮酸橘、枸头橙和李齐16-6枳为砧的植株树冠体积较小,单位树冠体积产量以光皮酸橘为砧的植株最高,单株挂果数则以李齐16-6枳和卡里佐枳橙为砧的最多。不同砧木对果实品质有显著影响,其中以光皮酸橘为砧的果实体积和单果质量最大,以兰普来檬为砧的果汁含量最高,以李齐16-6枳和卡里佐枳橙为砧的果实可溶性固形物(TSS)含量最高,以李齐16-6枳为砧的果实可滴定酸含量亦最高,而李齐16-6枳和兰普来檬为砧的果实维生素C含量最高。从外观品质看,枸头橙为砧的果实油斑病发生程度最高。综合评价认为,以卡里佐枳橙、李齐16-6枳为砧的单株具产量高、果汁TSS含量高和风味浓郁等优点,是哈姆林甜橙较为理想的砧木。     

Crown rot (Phytophthora cactorum) of apple in Britain: Observations on natural outbreaks,and experiments on artificially inducing the disease in the field

Crown rot (Phytophthora cactorum) of apple came to prominence in Britain in the 1960s following the introduction of certain new types of clonal rootstock. Observations on crown rot outbreaks over the period 1976 to 1984 were as follows: only rootstocks MM.104 and MM.106 were affected; infection occurred in the bark of the rootstock axis below soil level; lesions caused girdling, and sometimes appeared above soil level and spread down the main roots to a limited extent; infection occurred during the growing season but disease development ceased with the onset of winter and did not resume the following year; trees on MM. 104 were susceptible throughout the life of the orchard while trees on MM. 106 were susceptible only during the establishment years; disease outbreaks occurred sporadically. Crown rot was induced experimentally on trees grafted on MM. 104 and on M.25 in field trials by irrigating for four to six weeks through inoculum applied to the base of the trees. No crown rot occurred on grafted MM.106 or on other grafted rootstocks in the same trials, although lesions developed above soil level on a few trees. The limited experimental data indicated that MM.104 was liable to attack throughout the growing season. The importance of environmental influences on the susceptibility of rootstocks to crown rot is discussed.     

Facultative apomixis and chromosome doubling are sources of heterogeneity in citrus rootstock trials: Impact on clementine production and breeding selection

All commercial citrus rootstocks are polyembryonic and propagated by seeds. Although these seeds produce uniform plant material most of the time, zygotic or polyploid citrus seedlings may arise. The aim of this study was to understand how zygotic or tetraploid rootstock could affect a citrus rootstock selection field trial. A trifoliate orange selection field trial, which was planted in 1974 and grafted with clementine, was re-investigated with respect to the presence of rootstocks that were not true-to-type. Among the 288 trees investigated, flow cytometry identified 2.4% of rootstocks as tetraploid and SSR markers indicated that 6.6% were zygotic. Yield data showed that the presence of tetraploid rootstock dramatically decreased (by about 45%) clementine fruit production. However, zygosity did not always affect fruit production and a range of effects were observed, from a slight increase in production to a 24% decrease. Exclusion of non-true-to-type genotypes from the production analysis indicated that the best candidate for rootstock was a clone previously ranked in the middle of the 32 rootstocks under evaluation. However, the presence of zygotic rootstock did not appear to cause any significant differences in fruit quality during the first 5 years of the investigation, which suggests that non-true-to-type plants cannot be identified by fruit quality parameters. This study indicates that tetraploid and zygotic rootstocks have a strong impact on citrus fruit production in orchards, and removal of off-type seedlings is required prior to planting in any agronomic trial.     

Sap flow in ‘Hass’ avocado trees on two clonal rootstocks in relation to xylem anatomy

The rates of sap flow and xylem vessel features were studied in two-year-old nongrafted and grafted avocado (Persea americana Mill.) trees. Daily sap flow rates were measured with heat and balance stem gauges in clonal Duke 7 (D7) and Toro Canyon (TC) trees and ‘Hass’ clonal scions grafted onto clonal D7 (H/D7) and TC (H/TC) rootstocks. Vessel features as size, number and total vessel area were determined histologically in the stem of the scion and rootstock and the roots of the grafted trees. Significant differences in the sap flow rate were found among the rootstocks, where D7 had a 29% higher sap flow rate than did TC (grafted and nongrafted trees). There were no differences among xylem vessel features in the stems of any of the varieties. However in the roots, D7 had wider and fewer vessels then TC do. Also, D7 had a 19% higher total vessel area than TC. These results suggest that the differences in water consumption of ‘Hass’ on different rootstocks may be associated with differences in the efficiency of the roots to absorb water across conductive tissue which may be linked to differences in the area of xylem vessels in the root.     

锰胁迫对不同砧木苹果幼树锰吸收分配及抗氧化系统的影响

 研究山荆子、八棱海棠和辽砧2号/山荆子3种砧木富士苹果在400 mg · kg^-1锰胁迫条件下树体的生理响应和锰积累特征。结果表明,400 mg · kg^-1锰胁迫下,3种砧木的富士苹果幼树叶片先后出现中毒症状,其中山荆子砧的幼树中毒最重,辽砧2号/山荆子砧次之,八棱海棠砧的最轻。400 mg · kg^-1锰显著抑制了山荆子和辽砧2号/山荆子砧富士苹果幼树的生长,增加了锰在地上部的积累,却促进了八棱海棠富士苹果幼树地下生物量增加和锰在地下部的积累。过量锰导致山荆子和辽砧2号/山荆子苹果叶片自由基和丙二醛含量大量增加,超氧化物歧化酶活性和抗坏血酸含量增加较小,抗氧化物酶活性变化不明显。八棱海棠砧富士苹果幼树受锰胁迫后叶片抗氧化酶超氧化物歧化酶、抗氧化物酶、过氧化氢酶和抗氧化物质AsA活性显著提高,与锰胁迫前相比叶片自由基含量没有显著差异,丙二醛含量增加幅度较小。     

Citrus rootstock responses to water stress

Tolerance to drought-stress (DS) of the citrus rootstock Forner–Alcaide no. 5 (FA-5) was tested and compared with that of its parents, Cleopatra mandarin (CM) and Poncirus trifoliata (PT). Nine-month-old seedlings of CM, PT and FA-5 and 15-month-old grafted trees of ‘Valencia’ orange scions on these three rootstocks were cultivated in sand under glasshouse conditions and irrigated with a nutrient solution. Plants were drought-stressed by withholding irrigation until leaves were fully wilted. Survival time of both seedlings and grafted trees under DS was linked to the water extraction rate from the soil, which depended mainly on leaf biomass and on transpiration rate. Seedling responses to DS affecting leaf water relationships and gas exchange parameters varied among genotypes. FA-5 seedlings survived longer than the other seedlings, maintaining the highest levels of water potential, stomatal conductance, transpiration rate and net CO₂ assimilation towards the end of the experiment, when water stress was most severe. Thus, FA-5 was more resistant to DS than its parents (CM and PT). Moreover, rootstock affected the performance of grafted trees under water stress conditions. The higher drought tolerance induced by FA-5 rootstock could be related to the greater osmotic adjustment (OA), which was reflected by smaller reductions in leaf relative water content (RWC) and in higher turgor potentials and leaf gas exchange than the other rootstocks.     

Micropropagation of Darjeeling orange (Citrus reticulata Blanco) by shoot-tip grafting

Summary

Micropropagation of Darjeeling orange (Darjeeling mandarin) was done by shoot-tip grafting on the local rootstocks rough lemon, sour orange and Rangpur lime. Seedlings of these plants were raised in MS medium in standard conditions of temperature, light duration and plant age. Microbuds (0.2 mm long), aseptically excised from the scion, were grafted onto the decapitated rootstock seedlings. The micrografts in culture medium were grown under standard lighting. Rootstock seedlings showed optimum growth at 25–30°C. Optimum growth of the micrografts resulted from treatment in complete darkness for 4 d after grafting followed by exposure to 750 W for 16 h d^?1 for 15 d and 1500–2000 W for 16 h d^?1 for 39 d. The success of micrografting depended on the age of the rootstock seedling which was 21 d, 14 d and 14 d for sour orange, rough lemon and Rangpur lime respectively. The micrografts were then double grafted to the two year old rootstocks seedlings of the respective species and the age of the micrografts for the successful double grafts was also standardized. The survival rate was high with 40 d, 45 d and 45 d micrografts on sour orange, rough lemon and Rangpur lime respectively. The double-grafts were then indexed for tristeza virus and greening disease after six months’ growth in an insect-proof screenhouse and found to be free from these graft transmissible diseases.     

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。     

Effect of 14 peach rootstocks on the yield,fruit quality,mortality, girth expansion and resistance to frost damages of May Crest peach variety and their susceptibility on Phytophthora citrophthora

The influence of 14 peach rootstocks (GF677, AN 1/6, PR204/84, KID 1, DSS, wild peach seedling, KID 2, IDS-37, Limnou, Loadel, D.1869, MRS 2/5, A/P Procopiou, Selfrooted) on the nutrient absorption, yield, fruit quality, mortality, girth expansion and resistance to frost damages of May Crest peach variety was evaluated. The results showed that the better rootstocks were considered PR204/84, GF677, AN 1/6, KID 1 and KID 2. Trees on these rootstocks produced the highest yields and relatively good fruit quality. Trees grafted on PR204/84, GF677, KID 1 and KID 2 rootstocks were resistant to frost damage. In contrast, scion on the rootstock AN 1/6 were susceptible to frost damage. The mortality of trees grafted on AN 1/6, KID 1 and KID 2 was 0%. Trees grafted on PR204/84 and GF677 showed 40% mortality. The rootstocks GF677, AN 1/6, KID 1 and KID 2 had similar girth expansion. In contrast, the girth expansion of PR204/84 was significantly lower. Generally, rootstocks with the lowest level of P had the highest level of K and Ca. The converse was also true.All rootstocks showed similar susceptibility to Phytophthora citrophthora.