氯酸钾诱导龙眼成花效应与机理的研究进展

根据有关文献综述了国内外应用氯酸钾诱导龙眼（Dimocarpus longana）成花效应与机理的研究进展，概述了使用氯酸盐促使龙眼成花的关键技术、施用量和施用方法以及成花机理的各种推测与假说。尽管用氯酸盐对龙眼进行反季节催花已获得一定的效果，但也存在催花效果不稳定、诱导成花率偏低、单株间效果差异大、成花的同步性差等现象，还无法在生产上大规模推广应用。究其原因是人们尚未从本质上掌握龙眼成花的调控机理。对龙眼成花机理已进行的研究主要是在营养和激索方面，而从蛋白质的功能、遗传物质和成花控制基因等分予生物学的方面的研究报道还较少。     

氯酸钾对储良、石硖龙眼催花效果比较

龙眼是极典型的亚热带果树，在常规栽培条件下，除了树体营养积累外，冬季12月至翌年1月间，要有一段相对低温(10～14℃)期才有利于花芽分化，这对于海南地区来说极难达到，因此，海南龙眼常年歉收。20世纪90年代末，台湾省将氯酸钾用于龙眼花期调控技术引进大陆后，全国各龙眼产区先后使用该项技术进行验证试验。但由于不同龙眼品种对氯酸钾的敏感程度不同，且气候、土壤等因素也影响氯酸钾催花效果，因而各地的试验结果也不尽相同。本试验是针对海南主栽品种储良和石硖龙眼进行催花效果比较，以期获得较科学的数据，为生产实践提供依据。     

氯酸钾不同施用方式对“桂冠早”龙眼花期调控和开花结果的影响

以"桂冠早"龙眼为试材,随机选择12株长势相近植株施用氯酸钾,设置叶面喷施、土施、叶面喷施+土施和对照(清水)等4个处理,观测不同处理开花结果状况,并测定叶片叶绿素和碳水化合物含量以及果实品质,明确氯酸钾对龙眼成花和花期调控的影响。结果表明,施用氯酸钾可以在一定程度上促进龙眼成花,降低落果率并提高产量,但果实品质会受到一定影响。12月初施用氯酸钾对龙眼正季开花有一定的推迟作用,但推迟效果并不显著。其中,催花效果最好的是叶面喷施+土施处理,土施次之,叶面喷施作用不明显。     

氯酸钾在‘福眼’龙眼不同梢期催花试验初报

为验证氯酸钾对龙眼催花效应以及不同梢期的施药效果，开展了催花试验，施用氯酸钾的处理先抽发新梢再抽发花穗；而对照没有抽发新梢也没有抽发花穗，施用氯酸钾效果明显，氯酸钾可能会促进龙眼花芽分化。此外，枝梢呈浓绿或淡绿时施药，会出现枝梢先抽一段新梢，然后再在新梢顶芽抽生花穗，花穗质量一般，抽花率较高；而在枝梢上部幼叶呈红褐色时施药，可从新梢顶芽直接抽生花穗，花穗质量好。但抽花率较低。因此，施药时间要选择在新梢未完全转绿时进行。     

氯酸钾对不同生长状态下的龙眼促花效果的比较研究

龙眼是我国华南地区的特产水果,其栽培面积和产量均居世界首位。但在一般管理状态下生长的龙眼果树,普遍都存在着开花结果难、产量低、大小年明显的问题,严重地制约了龙眼生产的发展。近年来,一些农业科技工作者经过研究和实践,已经证明了氯酸钾对龙眼正造和反季节促花都有一定的效果,可实现龙眼在不同季节都能开花结果,一定程度地解决了龙眼生产中存在的问题。本研究仅就龙眼不同生长状态下施用氯酸钾促花的效果进行试验,以期确定理想促花效果的龙眼生长状态。 1 材料和方法 1.1材料 氯酸钾,含量为99.75%,福州第一化工厂生产,供试…     

龙眼药物催花试验效果

目前 ,广西的龙眼种植面积已达 2 5万 hm2 ,但大部分龙眼采收期都集中在 7～ 8月 ,鲜果供应期短。为探索药物催花新技术 ,人为地调控龙眼开花期 ,达到推迟或提早采收期 ,以调节龙眼鲜果的市场供应、提高经济效益特进行了本试验。试材为 8～ 1 0年生的石硖、储良 ;1 3～ 1 5年生的大乌圆 ,以当年无挂果、树势中等和旺盛的青壮年树在立地条件 ,田间管理水平相近条件下 ,设 5个处理 ,A.施用催花先锋 ;B.施用氯酸钾 ;C.施用氯酸钾 +氯酸钠 +微肥 ;D.施用氯酸钾 +氯酸钠 ;E.施用氯酸钠 ,单株小区 ,3次重复 ,随机排列。施药时间在 4月 ,分 2批进…     

龙眼调花技术研究初报

在传统的栽培条件下,龙眼花芽分化期所需的低温条件为10~14℃。但自从氯酸钾(KCl O3)应用于龙眼催花成功后,龙眼在高温季节也可以完成花芽分化并开花结果。但龙眼属于花芽与叶芽同体,在温度高于18℃且湿度较大时,花芽容易转化成叶芽,导致催花失败。为了防止龙眼在高温季节采用氯酸钾催花后的“冲梢”,以提高龙眼反季节催花的成花率,2005年特开展本研究。1材料与方法试验地点在海口市琼山区旧州镇农场果园,供试龙眼品种为4年生储良和石硖,株行距为5 m×5 m。供试药剂有纯KCl O3、15%多效唑、绿芬威1号、40%乙烯利、金丰牌高浓度细胞分裂素…     

"花必来"龙眼促花技术

20世纪 90年代后期 ,自我国台湾在龙眼上用药物促花取得成功后 ,泰国引进该技术并加以完善 ,成功地生产出反季节龙眼。广东、福建、广西等地也做了化学药物处理诱导龙眼反季节开花结果的试验 ,取得了成功。说明药物可以取代低温对龙眼起到成花的作用 ,但为了达到促花效果的稳定 ,必须有整套技术措施。笔者等经过反复的探索和系统试验 ,总结出一套配合药物促使龙眼四季开花的促花技术 ,即施用“花必来”(湛江海洋大学配制的复方催花肥 )促进龙眼成花。“花必来”促花技术从 2 0 0 0年开始已在粤西各县、海南、广西等地试验 ,在雷州半岛和海南…     

龙眼复合催花剂不同用量、使用期与龙眼品种的催花试验

对自主研制的龙眼复合催花剂进行不同用量、不同使用时期和不同龙眼品种的催花试验结果表明,采用龙眼复合催花剂催花,能有效提高龙眼成花株率、雌花率和成穗枝率,最佳用量为每株 850~1 360 g;不同品种上催花效果为石硖>储良>大乌圆、桂香;较好的催花时期是12月26日,其次为3月20日、11月20日、1月20日.     

几种氧化剂对龙眼的促花效应

利用三种氧化剂在正造和反季节对龙眼进行促花试验，结果表明:氯酸钾、硝酸钾、高氯酸钾在正造都有一定的促花作用，其中氯酸钾效果最明显；在进行反季节促花时，氯酸钾的效果也非常明显，硝酸钾只有微弱效果，而高氯酸钾没有促花作用；三种氧化剂对开花和果实发育有一定影响，但都能不同程度地提高产量。     

氯酸钾对龙眼成花诱导期叶片和顶芽内源激素含量的影响

对中熟龙眼品种‘凤梨穗’施用氯酸钾（KClO3）配合环割和拉枝措施,诱导其反季节成花,研究龙眼花芽诱导期叶片和顶芽间激素动态变化以及与成花状况之间的关系。结果表明：KClO3提高了叶片中生长素（IAA）含量,降低了顶芽内含量,而KClO3 + 拉枝处理的植株顶芽内IAA含量处于最低水平,且成花率最高,说明顶芽内低含量的IAA有利于成花;KClO3配合环割和拉枝处理分别降低了顶芽内赤霉素（GA3）和脱落酸（ABA）的相对含量,与IAA类似,龙眼的花芽诱导同样需要一个低水平的GA3和ABA的条件;ZT含量变化与以上激素相反,KClO3处理提高了龙眼花芽诱导期顶芽内玉米素（ZT）含量,降低了叶片中其含量,表明顶芽内ZT的增加可能是龙眼反季节成花的主要因素或信号物质,但3种处理的成花率与ZT含量水平并未呈正相关,说明细胞分裂素促进龙眼成花取决于其浓度或水平。     

Nitrate reduces the detrimental effect of potassium chlorate on longan (Dimocarpus Longan Lour.) trees

A recent finding that potassium chlorate induces longan (Dimocarpus Longan Lour.) flowering at any seasons has led to wide use of this chemical in longan industry for off-season harvest, despite the risk of injury to the tree. In this paper, we examined the influences of pretreatment of nitrate by foliar spray with 3% potassium nitrate on the responses of potted longan (Dimocarpus longan Lour.) cv. Shixia (a subtropical ecotype) trees to soil applications of potassium chlorate at 10 and 20 g plant⁻¹. Chlorate treatments caused severe leaf drop and chlorophyll breakdown and suppressed budbreak, flowering and shoot growth. Pretreatment of potassium nitrate reduced the severity of leaf drop and chlorophyll breakdown caused by chlorate but the extend was less significant in high dosage chlorate (20 g plant⁻¹) treatment than low dosage (10 g plant⁻¹) chlorate treatment. Potassium nitrate did not alleviate the suppression effect of chlorate on budbreak, flowering and shoot growth, although it promoted these processes per se. Chlorate treatment resulted in only a transient accumulation of chlorate in the leaves, which peaked around 14 days after chlorate treatment (DACT), while chloride accumulated constantly within 28 DACT. Pretreatment of potassium nitrate tended to promote chlorate accumulation but did not cause a significant change in chloride accumulation. Severity of leaf drop was not significantly correlated to chlorate accumulation but significantly to chloride accumulation, suggesting that toxicity of chlorate to longan tree was realized during the chloride-producing process of chlorate reduction. Nitrate influenced the correlations between severity of leaf drop and chloride accumulation by reducing the slopes of the regressed lines of leaf drop versus chloride, indicating that nitrate reduced the sensitivity of longan trees to the toxic intermediates produced during chlorate reduction. The results indicate that the application rates were excessive for potted trees. The potential benefit of potassium nitrate in a longan production system based on application of chlorate needs to be evaluated in field trees.     

Year around off season flower induction in longan (Dimocarpus longan,Lour.) trees by KClO3 applications: potentials and problems

Off season induction of flowering and fruit production is a desirable economical and scientific goal with many subtropical fruit trees. Both objectives have been accomplished by the application of gibberellin biosynthesis inhibitors with mango and a few other fruit trees. Recently the same was achieved with longan trees (Dimocarpus longan, Lour.) after treatment with potassium chlorate. This treatment allows the efficient induction of flowering and fruit production all over the year in an obviously species-specific manner.Experiments are described that investigated several aspects of this KClO₃ treatments, such as methods of application, seasonal effects, reactiveness of different cvs. toward the chemical, influence of leaf age, etc. The results are discussed with respect to the practical application of KClO₃ for off season fruit production, but also under the aspect of its use for more basic investigations into the endogenous regulation of the flowering induction process in perennial fruit trees.     

KClO3 applications affect Phalaenopsis orchid flowering

Potassium chlorate (KClO₃) treatments are known to promote flowering in longan plants. Potential effects of KClO₃ on Phalaenopsis orchid flowering were investigated in the present study. However, increasing application concentrations of 2, 4, 8 and 16 mmol/L KClO₃ delayed spike emergence by 5, 6, 18 and 26 days, respectively. Moreover, they reduced final spike length by 2.1%, 4.0%, 16.2% and 46.1%, respectively. Nonetheless, application of KClO₃ at 4 and 8 mmol/L advanced the time to appearance of the first open flower by 13 and 24 days, respectively. Use of 8 mmol/L KClO₃ also increased the number of floral buds by 16%. Treatments with KClO₃ tended to reduce flower size. Overall, the data suggest that application of KClO₃ at an appropriate concentration (e.g. 8 mmol/L) can increase the number of floral buds and advance the time to Phalaenopsis orchid flowering, but may reduce flower size.     

Floral induction (FI) in longan (Dimocarpus longan, Lour.) trees. III: Effect of shading the trees on potassium chlorate induced FI and resulting hormonal changes in leaves and shoots

Previous experiments demonstrated that treatment of longan trees with potassium chlorate (KClO₃) induces “off season floral induction” (FI) even in the absence of the naturally required cool temperature [Manochai, P., Sruamsiri, P., Wiriya-alongkorn, W., Naphrom, D., Hegele, M., Bangerth, F., 2005. Year around off season flower induction in longan (Dimocarpus longan, Lour.) trees by KClO₃ applications: potentials and problems. Sci. Hortic. 104, 379–390]. Potassium chlorate, however, cannot replace the presence of functional mature leaves and sufficient light intensity. Here we examined in more detail the effect of shade (about 10% of natural sunlight) on KClO₃ affected hormone concentrations/transport of leaves and shoot apical buds (SAB) and their interactions with FI.     

氯酸钾诱导龙眼成花与内源激素的变化

 用氯酸钾(KCIO )诱导成年龙眼树在4～8月进行花芽分化，开花，并测定内源激素含量的变化。结果表明：经KCIO 诱导处理的植株能在60 d左右开花，添加植物细胞分裂素(CTK)比单独使用KCIO 的促进成花效果更明显；在成花诱导后，成花母枝叶片中脱落酸(ABA)和玉米素核苷(ZRs)含量在成花诱导期保持在较高的水平，而进入形态建成后逐渐降低，对照树ABA和ZRs含量一直处于较低水平。提出ZRs／GA 的比值为l可作为龙眼花芽生理分化的临界指标。     

Floral induction (FI) in longan (Dimocarpus longan, Lour.) trees: Part I. Low temperature and potassium chlorate effects on FI and hormonal changes exerted in terminal buds and sub-apical tissue

Floral induction (FI) in longan (Dimocarpus longan, Lour.) trees was achieved in controlled greenhouse experiments by low temperature (LT) and by the application of potassium chlorate at high temperature (HT + KClO₃) during two consecutive seasons. The latter treatment was successful also at temperatures above 20 °C. The present experiment was conducted to investigate possible alterations in the concentrations of plant hormones exerted by these two methods and to relate them to the floral induction process. The following hormones were examined by radioimmunoassay in the shoot apical buds (SAB), and in sub-apical bark and wood: the auxin indole-3-acetic acid (IAA); gibberellins (GAs); and the cytokinins zeatin/zeatin riboside (Z/ZR) and isopentenyl-adenine/isopentenyl-adenosine (iP/iPA).     

铁线莲品种群的花期观赏性状分析

以79个观赏铁线莲(Clematis)栽培品种为对象,对Ⅰ次花的现蕾日期、孕蕾期天数、始花日期、盛花日期、落花日期、末花日期、单朵花期天数、花期天数和观赏期天数等9个性状进行了连续3年的系统观察和分析。以始花日期相差16 d为级差,将供试品种划分为极早花、早花、中花、晚花和极晚花等5大类群;以观赏期天数相差5 d为级差划分为极短花期、短花期、中长花期、长花期和超长花期5大花期长短类群。通过观赏多度指数(CDI)分析确定了铁线莲的最佳观赏期为4月中下旬至5月中下旬。温度是影响铁线莲花期的主要因素,孕蕾期天数、花期天数、观赏期天数与气温均显著相关,而单朵花期与气温相关性不显著。本结果可为铁线莲在园林应用中的品种组合配植、专类园建设、定向育种亲本选配等提供依据。     

K+/H+逆向转运体基因PpeKEA在桃开花期的表达及对钾肥施用的响应

从‘霞晖8号’桃花中克隆并鉴定了6个K+/H+逆向转运体基因PpeKEA,在转录水平分析其在桃花发育不同时期的表达模式及对钾肥施用的响应,明确关键基因并验证其功能。结果表明,钾肥施用显著增强盛花期桃花的鲜样质量,提高花朵钾素富集水平。PpeKEA1 ~ PpeKEA6在桃花开放不同时期的表达水平存在差异,均在盛花期达到最高,其转录水平对施用钾肥的响应不同;PpeKEA1在整个桃花开放不同时期的表达量较高,钾肥处理显著增强其在花蕾膨胀期和初开期的表达并抑制其在败落期的表达量;表达载体pDR196-shortKEA1能赋予酵母菌感受态细胞AXT3突变体适应高钾环境而正常生长,说明PpeKEA1的C端区域具有调节桃花组织内K+转运和平衡的功能。本研究表明PpeKEA1是一个桃花开放过程中调节K+平衡的K+/H+逆向转运体,并可能在桃树钾素营养的动态平衡中起着重要作用。