一串红花芽形态分化进程

  一串红花穗、花序和单花形态分化可分为12 个时期。花芽分化与叶片生长、不同花位的花蕾发育具有相对稳定的顺序性和相关性, 并行分化相的体积随生长锥体积而变化。     

新铁炮百合花芽分化过程的形态学观察

 以新铁炮百合‘雷山’（Lilium formolongi‘Raizan’）为试材,利用石蜡切片和扫描电子显微技术,对百合花芽分化的过程进行了形态学观察。结果表明：‘雷山’低温贮藏期间鳞茎内顶端生长点尚未开始花芽分化,栽植后20～30d花芽分化开始进行,并在栽植后50～60d完成花芽分化,整个花芽分化过程约需40d。其分化进程可分为花芽未分化期、花芽分化初期、花序原基和小花原基分化期、花器官分化期、整个花序形成期五个时期。     

山楂花芽分化的观察

(一)山楂花序为多个伞房花序簇生于果枝顶端,每花序有花15～40余朵,最多达50朵左右。结果后花序梗干枯,其下的顶部数个侧芽,在条件良好时,仍能形成花芽,连续结果。 (二)山楂花芽形态分化,可分为六个时期。即花序原基分化期、花蕾期、萼片期、花瓣期、雄蕊期和雌蕊期。昌黎地区山楂花序原基于9月上旬出现,9月下旬出现花蕾原基,10月下旬到11月上旬出现萼片原基,大部分花芽以单花原基状态进入休眠期。但在休眠过程中仍缓慢进行分化,翌年早春3月上旬出现花瓣原基,3月下旬开始出现雄蕊原基,雌蕊原基出现在4月上旬以后,全部花芽分化所需时间达8个月左右。 (三)不同枝条花芽分化的开始时间不同。一般短枝顶芽分化早,长枝较晚,但到分化后期(雄蕊及雌蕊分化期),各类枝条间差异不大,基本上在同一时期分化结束。 (四)山楂花芽前期分化持续时间长,后期分化持续时间短。如花蕾原基最早于9月下旬出现,最晚为3月上旬,持续达160天,而雄蕊及雌蕊原基最早出现到最晚出现仅持续10天左右的时间。 (五)山楂花芽是在枝条停止生长3～4个月后开始分化花序原基,此时果实已接近成熟,枝条积累有机营养物质较多,加之抑花内源激素减少,促花激素增多,有利于形成大量花芽。根据山楂花芽分化开始晚,冬季休眠期中进行缓慢分化,雄蕊及雌蕊均在早春花芽萌动过程中形成的特点,应在8月中旬到采收前后增施氮、磷、钾肥料。肥水条件差的地方,早春萌动时追施速效性肥料,有利于提高花序质量,增加座果率。 (六)山楂花芽的鳞片平均数为16.1个,叶片平均数为9.5个,总节数平均为25.6节。不同年份、不同管理条件下山楂花芽分化的临界节数有一定幅度的变化,不同枝类间以长枝花芽的临界节数多,短枝及结果枝上花芽的临界节数较少。     

大雪枣的花期管理要点

大雪枣的主枝、二次枝和三次支均可在腋间开花,二次枝和三次枝为结果枝. 大雪枣具有当年分化,分化速度快,花期持续时间长、花量大,一年多次开花结果的特性,自开花到果实成熟需120 d左右,而且花芽容易形成,往往花芽分化和新梢生长同时进行.花芽分化期为5～8 d,二、三次枝为结果枝,二、三次枝的花量和结果量约占全树开花和结果总量的90%以上.当主枝和二、三次枝长到一定长度时要及时摘心,促进结果枝的生长和花芽分化,使营养生长转为生殖生长,提高坐果率.另外在初花期、盛花期、幼果期进行叶面施肥效果显著,能提高光合作用,对开花坐果很有好处,在花期喷硼砂、硫酸锌、氨基酸钙、硫酸镁等均可起到保果增产作用.在坐果期喷80～100 mg/kg的赤霉素,对提高坐果率有较明显的效果.     

光周期对秋菊品种‘神马’花芽分化和开花的影响

 研究了不同光周期处理下秋菊‘神马’花芽分化的进程和生长开花状况。扫描电镜等结果表明, 花序由顶端生长点分化而成, 分为未分化期, 花芽分化起始期, 总苞鳞片分化初期及终期, 小花原基分化初期及终期, 花冠形成初期、中期和后期9个时期。分化顺序是向心的, 由外而内。雌雄蕊的发育与小花花冠分化同时进行。分化进程历时23 d, 其中花序分化与小花分化相比, 历时相对较长。短日处理植株花芽分化和花发育进程整齐均一, 生长正常; 短日加长日处理花芽分化无规律, 开花延迟, 产生畸形花;长日处理不能诱导开花。     

红树莓花芽分化的初步研究

对红树莓（ＲｕｂｕｓｉｄａｅｕｓＬ．）的花芽分化进行了观察，结果如下：１．在哈尔滨地区红树莓当年枝条无花芽产生，最早花芽分化始于翌年５月上旬的结果母枝；２．红树莓属混合芽，每芽可产生１２～１３个花序，花序为有限型，顶花最先分化，各花自上而下顺序产生；３．花芽分化持续时间较长，因而造成开花、结果及采收参差不齐。栽培上应采取相应措施     

日本矮紫薇花芽形态分化的研究

日本矮紫薇花芽由中上部侧枝和主枝顶芽发育而成,花芽分化从4月末开始至5月末结束,历时30d,包括花序分化和小花分化两个过程,分为形态分化前、开始分化期、花序原基分化期、花蕾分化期、小花花萼分化期、花瓣分化期、雄蕊分化期、雌蕊分化期8个时期,花序和小花分化的顺序分别是离心和向心的.花芽分化与春梢生长有一定的相关性.     

苹果树春季管理的关键技术

做好苹果树春季管理工作是确保苹果树丰产、稳产和优质的重要环节。春季复剪对于过旺、适龄不结果的树,冬剪延迟到发芽后进行,以缓和树势。结果期树如花量过多,可短截一部分中长花枝、串花枝,疏除弱短花枝,增加预备枝。尽早疏蕾节省营养,利于坐果和春梢生长。于4月中下旬,花序露红至花序中心花含苞待放时,按花序间距20～28cm选留花序,所留花序保留中心花和1个侧花,其余花全疏除。     

遮光处理下一品红花芽分化的形态学观察

以一品红"金奖"为试材,研究遮光处理下花芽分化的形态发育过程。结果表明:遮光处理24d后一品红开始进行花芽分化,整个花芽分化过程持续约38d,其花芽分化分为花芽未分化期、生长锥伸长期、花序原基和小花原基分化期、花器官分化期4个时期。植株的苞片数与花芽分化进程呈显著相关,苞片数为1~2片,茎尖生长锥处于伸长期;大苞片3~5片,小苞片2~4片,为花序原基和小花原基分化期;大苞片5~8片,小苞片3~5片,为花器官分化期。     

芒果花芽分化研究初报

芒果花芽分化在海南岛那大地区,早熟种青皮芒一般开始在11月中、下旬,高峰期在12月上半月;晚熟种秋芒,开始在12月中旬,高峰期在1～2月上旬。每一花序从分化开始到花序的第一花开放,全过程时间长短因气温高低而不同,一般仅20～33天。从分化开始到花开放,其间没有休眠。圆锥花序在开花期间,其主轴及分支仍继续伸长,继续进行分化。 芒果花芽分化可分为五个时期,不同品种间分化程序相同,只是分化开始时期的迟早、延续时间的长短不同。 树势、日照、乙烯利等均能影响芒果花芽分化的强度。     

生长调节剂诱导西葫芦、黄瓜雌花分化和发育的研究

应用25、50、100和200mg／kg的吲哚乙酸（LAA）、萘乙（NAA）、赤霉素（GA）喷施2～3叶期西葫芦和黄瓜幼苗及用50、100和200mg／kg的TiBA（三碘苯甲酸）喷施20-30cm高的西葫芦和黄瓜植株,发现50mg／kgIAA和200mg／kgTiBA明显促进西葫芦雌花分化和坐果,NAA的促进效果较差,GA无效;50mg／kgIAA和100mg／kgTiBA促进黄瓜雌花分化和坐果,NAA的捉拼效果较差。低浓座的GA具有一定的促进作用。     

In vitro propagation of some olive (Olea europaea sativa L.) cultivars with different root-ability,and medium development using analytical data from developing shoots and embryos

Short- and long-term objectives for research on tissue culture of the olive are described. Sterile shoots were obtained from single-node woody explants or buds of 3 olive cultivars (‘Frantoio’, ‘Dolce Agogia’ and ‘Moraiolo’) with different root-ability, collected from shoots having different degrees of juvenility (suckers, vigorous nonfruit-bearing and fruit-bearing shoots, which are easy, medium and difficult to root, respectively).Because many of the media tested did not give a satisfactory growth rate and good quality shoots, a new medium was formulated by comparing data from analysis of the main mineral elements found in the apical shoots (4–5 mm long) and in mature embryos in olive and almond. Olive tissues were characterized by a high content of Ca, Mg, S, Cu and Zn compared to almond, which is easy to propagate on MS medium. In this newly derived medium, characterized by a high content of these elements, multiplication rate (number of nodes formed per explant) was about 9× in 40 days. The shoots grew more rapidly and were more tender than when grown in other media. Washing of the explants in water or GSH (reduced glutathione) solution, before sub-culturing, improved quality and growth rate of the shoots.Explants, with 2 or 3 nodes, rooted easily in half-strength MS, in Bourgin and Nitsch, or in half Knop macro and Heller microelements, agar media, with 1 mg 1^?1 NAA and 2% sucrose. Rooting was not affected by the different degrees of juvenility of the original explants used.Hardening-off was achieved by growing plants in a 1:1 mixture of perlite and peat-moss in a transparent plastic chamber with saturated circulating air for 1 month. GA₃ sprayed on the leaves was found to be beneficial in stimulating growth resumption of plantlets.     

Growth in horizontal apple shoots: Effects of stem orientation and bud position

In horizontal apple stems extension shoots were usually produced only from buds on the upper side of the stem, while buds on the lower side remained dormant or grew into spurs, and the same tendency was shown in inclined stems bent so that the “upper” and “under” sides became reversed.

On horizontal stems lateral shoots showed a gradient of vigour, the longest shoots being produced by proximal buds. Xylem of horizontal branches was epitrophic. These responses appear to be due to effects of gravity on the distribution of endogenous growth regulating factors within stems. In trees grown horizontally and rotated, shoots and spurs grew from all sides of the stem and xylem developed concentrically.

In studies of lateral shoots of partly disbudded horizontal stems, including cincturing treatments, it was found that the vigour of basal lateral shoots was a function of bud position in relation to the apex rather than in relation to the roots.

A model for lateral shoot growth in horizontal branches is proposed, in which shoot vigour is related to the position of buds along a postulated inhibitory gradient.     

Effects of bud scales and gibberellins on dormancy of in vitro cultured Japanese pear leaf buds

Leaf buds of Japanese pear were collected in early June and early November and regarded as summer and winter dormant buds, respectively. Bud explants with and without scales were prepared from each of them, and cultured in vitro for 75 days at 25°C with 14 h photoperiod, on a medium either without growth regulators, or supplied with BA and GAs (GA₃ and GA₄₊₇), singly or in combination.When either BA or GA₄₊₇ was contained in the medium, bud expansion occurred. Thereafter, summer dormant buds grew into shoots in the presence of BA, while winter dormant buds, although they swelled profusely, remained in a rosette. In the presence of BA, GA₄₊₇ markedly stimulated shoot elongation of summer dormant buds, but GA₃ did not. In winter dormant buds, GA₄₊₇ not only failed to stimulate shoot elongation, but also interfered with the BA-induced swelling described above.The presence of bud scales delayed expansion of summer dormant buds, while it had little effect on winter dormant buds. The delaying effect of scales on expansion of summer buds was effectively removed by application of GA₄₊₇ to the medium.     

杨桃新梢花芽分化及其碳水化合物含量的变化

 以6年生盆栽甜杨桃为材料，观察了新梢上各节位芽的分化情况，比较了新梢上不同节位的碳水化合物含量。结果表明：当第2节位开始“露红”（肉眼可辨红色的花芽）时，新梢上各节位上的芽（顶芽除外）基本上进入形态分化阶段。第3和第4节位“露红”的枝条，韧皮部和木质部可溶性糖含量比第1位和第2位“露红”的枝条高。徒长枝第1节位的可溶性糖和淀粉含量都较高，第3、第5节位的含量与第1或第2节位“露红”的成花枝上相应节位的含量相当。本研究结果表明，杨桃新梢上的芽在进行形态分化的过程中，枝条仍在积累碳水化合物。     

Stimulation of axillary shoot formation of cuttings of Hylocereus trigonus (Cactaceae) by pre-soaking in benzyladenine solution

Either before or after curing their cut surfaces for 5 days, 7 cm- and 15-cm-long decapitated Hylocereus trigonus cuttings were treated by soaking their apical or basal ends in benzyladenine (BA) solution. They were then planted and grown in a greenhouse.For the 7 cm-long cuttings, BA (25–100 mg l^?1) applied to the apical ends for 24 h increased the ratio of cuttings with sprouted buds to 64–100%, the number of sprouted buds to 1.9–3.1 and of shoots to 1.6–2.8, and the shoot length to 35–60 mm, compared to the water control which showed 13%, 1.0, 1.0 and 12.5 mm, respectively. Soaking the basal part had only a small effect.Naphthylacetic acid (NAA) applied to the basal ends of cuttings immediately after cutting increased the number of sprouted buds and shoots by inducing early rooting. The number and length of BA-induced axillary shoots in the longer cuttings was greater than those in the shorter ones.In the 15-cm-long cuttings, increasing the soaking time from 5 min to 24 h resulted in a greater promotive effect of BA on shoot formation. BA applied before curing showed the same effect as that given after curing but caused necrosis of the tissue just under the cut surface. Enlarging the area soaked in BA solution from 5 cm to 10 cm decreased the number of sprouting buds and shoots.     

Multiple plantlets in lateral bud and leaf explant in vitro cultures of pineapple

Plantlets were obtained from usually dormant axillary buds, excised from the crown of pineapple (Ananas comosus L. Merr.) and grown in culture. Multiple shoots arose from single buds grown on Murashige and Skoog medium supplemented with auxins and kinetin. Shaking culture-flasks during growth increased the number of multiple shoots formed, when compared with stationary liquid cultures. Leaf explants excised from in vitro plantlets developed into a callus capable of plantlet regeneration. Subjecting developing buds to surgical segmentation also resulted in multiple shoot formation. Such shoots, when excised and grown on Murashige and Skoog medium supplemented with auxins, developed roots and grew into complete plantlets capable of being grown in soil.     

桃品种耐寒性研究

用电导法、萌芽生长法和组织变褐法对82个桃品种或优系的耐寒性评价,结果表明：桃一年生休眠枝的耐寒温度为-19．0～-27．0℃,叶芽为-18．5～-26．1℃,花芽为-17．0～-24．0℃;枝、叶芽和花芽三者间耐寒性呈显著正相关,抗性强弱的顺序为：枝＞叶芽＞花芽;枝组织的耐寒力顺序为：韧皮部＞木质部＞形成层＞髓;品种间、品种群间及变种间抗寒性也有不同程度的差异。提出在很少发生-23．0℃以下低温的地区为桃适宜经济栽培区。     

Chilling response of ‘Granny Smith’ apple lateral buds inhibited by distal shoot tissues

Apple (Malus×domestica Borkh.) shoots were decapitated before or after chilling and then forced to budburst to determine the influence of distal inhibition (paradormancy) on the chilling response of lateral buds. Shoots were chilled and forced with the presence or absence of an inhibitory distal disbudded shoot piece. Endogenous cytokinins were determined from distal and proximal segments of shoots segmented before and after chilling and/or forcing. The isolation of lateral buds from distal inhibition by decapitation before chilling resulted in a dramatic increase in growth rate. This increase is greater than that observed in terminal buds during the normal development of acrotony on intact shoots. Distal shoot tissues appear to inhibit the chilling response of lateral buds. On intact shoots cytokinin increased more in the distal shoot tissues, but in decapitated shoots cytokinin increased more in the proximal shoot tissues. Increased cytokinin in the proximal stem segment following decapitation is possibly associated with an increased lateral bud growth rate.     

单株留芽量及结果母枝剪留长度对猕猴桃结果性能的影响

对栽植株行距3m×4m的美味猕猴桃秦美品种连续进行了3年试验,单株分别剪留250、300、350、400个芽处理后,平均单株新梢数、叶面积指数、落叶率与留芽数量呈正相关,叶幕下层的光强度、净光合率与留芽数量呈负相关;单株果枝数、果实数及单位面积产量均以留400芽处理最高,但平均单果重最小,88g以上的优质果产量最低。综合评价以单株剪留350个有效芽的效果最佳,优级果产量达到2102.7kg/666.7m2。结果母枝分别剪留7、12、17个有效芽处理后,平均每母枝的结果枝数、果实数、产量与留芽数量呈正相关,均以17芽处理最高,分别达到9.5个、30.4个和3.09kg,各处理间的单果重差异不显著。