猕猴桃嫁接试验

本文报道猕猴桃不同嫁接时期、嫁接方法和不同分类群的砧木试验结果,猕猴桃最适宜的嫁接时期是落叶后至翌年萌芽前,嫁接方法以切接为好,嫁接成活率均在90％以上。同种和同一分类群的砧穗间有良好的亲和力,嫁接均有较高的成活率。不同分类群间嫁接效果较差,如中华猕猴桃桂海4号嫁接于中华猕猴桃砧木上的成活率,生长情况均比嫁接其它分类群为砧的有显著差异。     

中华猕猴桃优良雄株选择研究初报

经过多年的授粉比较试验．筛选出中华猕猴桃优良株系桂海４号的理想适配雄株Ｍ３。Ｍ３授粉所得果实体积大,果形好,产量高．基本上保持了雌性优株桂海４号的优良性状。     

中华猕猴桃优良雄株选择研究初报

经过多年的授粉比较试验,筛选出中华猕猴桃优良株系桂海４号的理想适配雄株Ｍ２。Ｍ３授粉所得果实体积大,果形好,产量高,基本上保持了雌性优株桂海４号的优良性状。     

猕猴桃属种间嫁接亲和性试验研究及抗根结线虫砧木的初步筛选

以中华猕猴桃（Actinidia chinensis)武植2号（Wuzhi-2),通山5号（Tongshan-5)品种和美味猕猴桃（A.deliciosa)金魁（Jinkui)品种为接穗,采用美味猕猴桃等9种类型猕猴桃一年生实生苗为砧木进行嫁接,研究其短期嫁接亲和性,并对这9种砧木进行抗根结线虫（Meloidogyne)筛选试验。结果表明,种间的嫁接亲和性及抗根线虫性 均有显著差异：以美味猕猴桃和中华猕猴桃优良品种实生苗为砧木,与3个品种均有高的亲和性,成活率高达100％,且抗性在9种砧木中最强;其它物种作砧木均有不足,武植2号／山猴猴桃,通山5号／M16,通山5号／山梨猕猴桃3个嫁接组合的亲和性均较好,成活率在80％以上,但山梨猕猴桃较易感病且与金魁的亲和力较低,M16抗性虽较好,但与金魁,武植2号的亲和力也较低,漓江猕猴桃是抗性较强的物种,但它与3种接穗品种的亲和力都较小,其它5种砧木,对根结线虫的抗性均不强,因此结合成活率及抗根结线虫两因素,在供试材料中,美味猴猕桃和中华猕猴桃接适应性广且抗性强,是较好的砧木或选育砧木的亲本材料。     

广西植物研究所多项科研成果通过鉴定

<正> 一、猕猴桃优良株系栽培示范及果实保鲜包装技术研究 中华猕猴桃“桂海4号”是广西植物研究所猕猴桃研究课题组近年筛选出的优良品系,具有早实、高产、果实均匀、品质优良、抗性强等优良特性。其栽培要点为:激动素和广增素(802)处理种子可提高发芽率38.06—58.34％。密封保湿切接法嫁接成活率可达90％以上。定砧后嫁接营建果园可提前一年建成新果园。中度修剪可提高产量34.18％。喷雾授粉可提高产量2—3倍。果实保鲜技术为:适时采收,采用无残毒的保鲜剂处理等综合措施,在日均室温26.2—28.3℃,相对湿度57.3—80％条件下贮藏20天,好果率     

美味猕猴桃优良株系“实美”的生物学特性观测

通过对美味猕猴桃优良株系“实美”的物候期、开花结果习性、果实生长发育规律的观测和研究 ,为其栽培管理和推广工作提供科学依据。     

不同中间砧木对寒富苹果生长、产量和果实品质的影响

本研究以10个矮化中间砧木嫁接的寒富苹果为试材,分析了不同矮化中间砧对葫芦岛产区的寒富苹果生长、产量和果实品质的影响,以期为葫芦岛产区选配优良的苹果砧穗组合。结果表明: 不同矮化中间砧对寒富苹果生长势、产量和果实品质指标的影响存在显著差异,株高、枝量、叶片鲜重、枝条鲜重、根鲜重、根系总体积、根系平均直径和总根尖数均以GM256嫁接树最高,基径、枝长、根系总长度和总表面积以CX5嫁接树最高;果实硬度、可溶性固形物和可溶性糖含量以M26嫁接树最大,果实纵径、横径和单果鲜重均以GM256嫁接树最大。采用模糊评价法综合评价显示,在葫芦岛地区,10种中间砧木嫁接寒富苹果的综合性状得分由高到低排序为: GM256、CX5、B9、JM7、CG80、辽砧2号、M26、青砧3号、SH38、MD001。建议GM256和CX5可作为冷凉气候区理想的矮化砧木。     

中华猕猴桃桂海4号选育研究

中华猕猴桃桂海４号是广西植物研究所经近２０ａ选育出来的优良品种。该品种具有早实、丰产、品质好、抗逆性强、适应性广等特点,已成为目前广西重点推广的优良品种。本文报道该品种的选育过程及主要栽培技术要点。     

嫁接对网纹甜瓜果实乙烯生物合成及CmACO1基因表达的影响

以“新汉城翠蜜”网纹甜瓜为接穗,以“圣砧一号”南瓜为砧木进行嫁接,研究嫁接对目光温室网纹甜瓜果实乙烯生物合成及CmACO1基因转录水平表达的影响。结果表明：嫁接明显降低了网纹甜瓜果实ACC含量及乙烯释放量,在乙烯释放高峰时,嫁接的网纹甜瓜果实乙烯释放量比自根的降低了12．6％;嫁接降低了果实中ACC合成酶和ACC氧化酶活性,其最大值分别比自根网纹甜瓜降低了9．0％和6．8％;嫁接抑制了CmACO1的表达,其相对表达量最大值比自根网纹甜瓜降低了39．0％;嫁接网纹甜瓜果实中乙烯释放高峰、ACC合成酶和ACC氧化酶活性峰值及CmACO1相对表达量峰值出现的时间均比自根的延迟了3d。     

中华猕猴桃优良品种选育

从野生中华猕猴桃中选育出早熟品种厦亚1号与40号、中熟品种厦亚15号、晚熟品种厦亚20号,以及适宜早、中、晚熟雌株的优良授粉树厦亚18号雄株。它们具有结果早,高产稳产,果实品质优良,适应性强等特点。种植在低海拔的南亚热带地区,经济性状优良,遗传性状稳定。     

Root and stem hydraulic conductivity as determinants of growth potential in grafted trees of apple (Malus pumila Mill.)

The anatomy of the graft tissue between a rootstock and its shoot (scion) can provide a mechanistic explanation of the way dwarfing Malus rootstocks reduce shoot growth. Considerable xylem tissue disorganization may result in graft tissue having a low hydraulic conductivity (k(h)), relative to the scion stem. The graft may influence the movement of substances in the xylem such as ions, water and plant-growth-regulating hormones. Measurements were made on 3-year-old apple trees with a low-pressure flow system to determine k(h) of root and scion stem sections incorporating the graft tissue. A range of rootstocks was examined, with different abilities of dwarfing; both ungrafted and grafted with the same scion shoot cultivar. The results showed that the hydraulic conductivity (k(hroot)) of roots from dwarfing rootstocks was lower compared with semi-vigorous rootstocks, at least for the size class of root measured (1.5 mm diameter). Scion hydraulic conductivity (k(hs)) was linked to leaf area and also to the rootstock on to which it was grafted, i.e. hydraulic conductivity was greater for the scion stem on the semi-vigorous rootstock. Expressing conductivities relative to xylem cross-sectional areas (k(s)) did not remove these differences suggesting that there were anatomical changes induced by the rootstock. The calculated hydraulic conductivity of the graft tissue was found to be lower for grafted trees on dwarfing rootstocks compared to invigorating rootstocks. These observations are discussed in relation to the mechanism(s) by which rootstock influences shoot growth in grafted trees.     

Hydraulic conductance and rootstock effects in grafted vines of kiwifruit

Whole-plant hydraulic conductance, shoot growth, and leaf photosynthetic properties were measured on kiwifruit vines with four clonal rootstocks to examine the relationship between plant hydraulic conductance and leaf stomatal conductance (gs) and to test the hypothesis that reduced hydraulic conductance can provide an explanation for reductions in plant vigour caused by rootstocks. The rootstocks were selected from four species of Actinidia and grafted with Actinidia chinensis var. chinensis 'Hort16A' (yellow kiwifruit) as the scion. Total leaf area of the scion on the least vigorous Actinidia rootstock, A. kolomikta, was 25% of the most vigorous, A. hemsleyana. Based on shoot growth and leaf area, the selections of A. kolomikta and A. polygama are low-vigour rootstocks, and A. macrosperma and A. hemsleyana are high-vigour rootstocks for A. chinensis. Whole-plant hydraulic conductance, the ratio of xylem sap flux to xylem water potential, was lower in the low-vigour rootstocks, reflecting their smaller size. However, leaf-area-specific conductance (Kl) and gs were both higher in the low-vigour rootstocks, the opposite of the expected pattern. Differences in Kl were found in the compartment from the roots to the scion stem, with no difference between rootstocks in the conductance of stems or leaves of the scion. There was no evidence that the graft union caused a significant reduction in hydraulic conductance of vines with low-vigour rootstocks. Leaf photosynthetic capacity did not vary between rootstocks, but photosynthesis and carbon isotope discrimination (Delta13C) under ambient conditions were higher in the low-vigour rootstocks because gs was higher. gs and Delta13C were positively correlated with Kl, although the mechanism for this relationship was not based on stomatal regulation of a similar xylem water potential because water potential varied between rootstocks. For Actinidia rootstocks, changes in Kl do not provide a direct explanation for changes in vigour of the scion. However, depending on the rootstock in question, changes in hydraulic conductance, biomass partitioning, and crown structure are involved in the response.     

Drought tolerance of apple rootstocks: Production and partitioning of dry matter

The drought tolerance of the commercial apple ( Malus domestica Borkh.) rootstocks M9, M26, M27 and MM111, and some new selections from the rootstock breeding programme at HRI-East Malling (AR69-7, AR295-6, AR360-19, AR486-1 and AR628-2), was assessed using potted, glasshouse-grown, unworked rootstocks. After an initial period of growth under well-watered conditions the amount of irrigation was gradually reduced, for some treatments, to simulate natural drying in the soil. At the end of a six-month growth period, the rootstocks were harvested and the production of dry matter and its partitioning to various plant parts determined. The rootstocks exhibited large differences in shoot and root dry matter, and root length but not all the rootstocks showed declines in root mass or length in response to the droughting treatment. The dwarfing rootstocks tended to have smaller amounts of both coarse (>2 mm diameter) and fine roots (<2 mm diameter), than the more vigorous rootstocks. Irrespective of rootstock or irrigation treatment there was a close linear relationship between coarse and fine root. There was also no change in the length/weight relationship for fine roots irrespective of rootstock or irrigation treatment, i.e. 42 m of fine root weighed 1 g dry weight. In some cases the amount of root produced could be directly correlated with the rootstock known potential to control scion vigour, but this was not true for all the rootstocks examined. The absence of this relationship was particularly evident in some of the new selections of rootstock. The possible causes for these differences, compared with commercially used rootstocks, is discussed in relation to the origin and parentage of the rootstock selections. Despite this lack of a root length/vigour relationship, the amount of dry matter partitioned to shoot growth reflected the rootstocks' known vigour. The different responses of these rootstocks to drought are discussed along with their implications for understanding the mechanisms by which rootstocks are thought to dwarf scion shoots.     

Quantitative trait loci controlling vegetative propagation traits mapped in European pear (<Emphasis Type="Italic">Pyrus communis</Emphasis> L.)

The ease of vegetative propagation by hardwood cuttings is a critical trait for consideration by breeders of woody perennial rootstocks. This is especially so for Pyrus, because most Pyrus rootstock are known to be difficult to propagate. This report presents progress on the identification of loci controlling rooting of hardwood cuttings in European pear (Pyrus communis L.). Quantitative trait loci (QTLs) controlling the development of adventitious roots on hardwood cuttings were identified in both parents of a mapping population developed by crossing “Old Home” and “Louise Bonne de Jersey,” with the goal of investigating the genetic control of several rootstock related traits, which would be useful for rootstock breeding. A QTL for root development was identified on chromosome 7, co-located in both parents and exhibiting male and female additive and dominance effects. These results will assist in developing genetic markers that can be utilized by rootstock breeders for marker-assisted selection for this complex trait.     

The relationship of hydraulic conductance to root system characteristics of peach (Prunus persica) rootstocks

Specific rootstocks can differentially influence the vegetative growth and development of fruit trees. However, the physiological mechanism involved in this phenomenon has been elusive. Recent research comparing different peach ( Prunus persica L. Batsch) rootstocks suggests that the rootstock effect on vegetative growth in peach trees is associated to water relations and more specifically to differences in rootstock hydraulic conductance. This study was intended to confirm differences in hydraulic characteristics of similar size peach trees grafted on different rootstocks and to examine root system characteristics that could be associated with rootstock hydraulic limitations. Trees on rootstocks that were known to have a size-controlling effect when grown under field conditions had lower rootstock conductance than trees on the vigorous (control) rootstock when rootstock hydraulic conductance was measured with both the high-pressure and evaporative flow methods. Rootstocks with the lowest hydraulic conductance had less fine root surface area and length per unit root dry weight than the more vigorous (control) rootstock. However, contrary to previous field studies, in this study there were no significant differences in dry matter production and distribution among trees on the different rootstocks suggesting that whatever the normal growth control mechanism was, it did not differentially influence growth under the specific conditions of this study. This research confirmed that peach rootstocks exhibiting size-controlling behavior under field conditions differed in their hydraulic and morphological characteristics under controlled growth conditions even when those growth conditions negated the expression of the size-controlling behavior.     

Shifts in xylem vessel diameter and embolisms in grafted apple trees of differing rootstock growth potential in response to drought

We investigated responses of plant growth rate, hydraulic resistance, and xylem cavitation in scion-rootstock-combinations of Malus domestica L. cv. Honeycrisp scions grafted onto a high-shoot vigor (HSV) rootstock, (semi-dwarfing Malling111), or onto a low-shoot vigor (LSV) rootstock, (dwarfing Budagovsky 9), in response to substrate moisture limitation. Adjustments in xylem vessel diameter and frequency were related to hydraulic resistance measurements for high- versus low- vigor apple trees. We observed a greater tolerance to water deficit in the high-shoot compared to the low-shoot vigor plants under water deficit as evidenced by increased growth in several plant organs, and greater scion anatomical response to limited water availability with ca. 25% increased vessel frequency and ca. 28% narrower current season xylem ring width. Whereas water limitation resulted in greater graft union hydraulic resistance of high-shoot vigor trees, the opposite was true when water was not limiting. The graft union of the low-shoot vigor rootstock exhibited higher hydraulic resistance under well-watered conditions. Scions of high-shoot vigor rootstocks had fewer embolisms at low plant water status compared to scions of low-shoot vigor rootstocks, presumably as a result of large differences in xylem vessel diameter. Our results demonstrated that anatomical differences were related to shifts in hydraulic conductivity and cavitation events, a direct result of grafting, under limited soil water.     

Changes in the anatomical structure of tree rings of the rootstock and scion in the heterografts of Siberian pine

The analysis of the anatomical characteristics of tree rings of the Pinus sibirica scions and Pinus sylvestris rootstocks is presented. The main anatomical features maintain the seasonal dynamics characteristic of the reference (ungrafted) trees of scion and rootstock, pointing to the stability of the genetic control of the xylem differentiation. However, various anatomical characteristics are reduced for rootstocks and increased for scions relative to the reference trees. A mechanism consistent with our results is that the graft union zone creates a barrier for the ascending and descending transport of substances, including phytohormones. The reaction of the scion and rootstock to climatic factors is weakened relative to the reaction of the reference trees. Thus, the presumed shift towards phytohormone disbalance reduces the influence of external factors on xylem differentiation. The interannual variation of the individual characteristics of the scions and rootstocks is increased relative to the reference trees, reflecting either the influence of the graft partners on each other or the non-uniform distribution of the growth regulators across the graft union. Thus, heterografts can be used to evaluate the interaction of the internal and external mechanisms of xylem differentiation.     

The Anatomy of the Developing Bud Union and its Relationship to Dwarfing in Apple

Light microscopy has been used to study the effect of dwarfingand semi-dwarfing apple rootstocks on the early developmentof bud-unions with 'Gala', and the anatomy of 2-year-old bud-unionsbetween 'Bramley' and the same rootstocks. The bridging of thecut edges of the cambia of bud and rootstock was achieved bydifferentiation of callus formed at an early stage in budding.New cambial cells were aligned at right angles to the pre-existingcambia, with their long axes horizontal. Subsequently-formedxylem adopted this arrangement, so that fibres and vessels werearranged obliquely to the axis of the stem. At the interfacebetween the bud and dwarfing rootstocks vessels with smallerthan normal diameter were formed, indicating the presence ofelevated levels of auxin in this region. In addition, littlexylem was produced in the adjacent rootstock tissue. In thecase of semi-dwarfing rootstocks, the rootstock produced normalxylem after a brief interruption. We suggest that failure ofauxin to cross the bud-union interface in the case of the dwarfingrootstocks leads to reduced rootstock xylem formation, and hencea poor supply of water and minerals to the scion, and this underliesthe dwarfing effect.Copyright 1994, 1999 Academic Press Apple, budding, dwarfing, anatomy, graft union