内源ABA和GA3对欧洲甜樱桃花芽自然休眠的调控

 以8年生欧洲甜樱桃为试材，采用液相色谱法分析了自然休眠期间花芽内源GA₃，和ABA含量变化及相关环境因子的影响。结果表明，休眠期间，花芽ABA含量呈先升后降的趋势，11月上句达顶峰。GA₃含量变化与其相反，休眠初期急剧下降，11月下旬达最低谷，休眠解除期间含量不断上升。ABA/GA₃随休眠加深而升高，随休眠解除而不断降低。低温5℃显著增加了GA₃含量，降低了ABA含量，使ABA降低和GA₃升高的时间提前，较对照提早解除休眠。高温(20℃)则具有相反的作用，变温(5/20℃)处理对休眠解除有一定作用，但由于高温(20℃)对休眠解除的抵消作用，其破眠效果不如持续低温(50℃)处理明显。落叶前遮荫处理使GA₃ 含量稍有降低，但对ABA影响不大。长光周期处理促进了GA₃的合成，抑制了ABA的生成，从而抑制了休眠，而短光周期处理显著提高了ABA的含量，降低了GA₃ 的含量。     

几种落叶果树H2O2含量变化与自然休眠关系的研究

 以设施栽培中常见的几种核果类果树品种和两个葡萄品种为试材, 分析了芽休眠期间 H₂O₂含量变化动态, 并探讨了温度、生长调节剂及化学破眠物质对H₂O₂含量影响的效应。结果表明: 休眠期间,不同树种( 品种) 芽内 H₂O₂含量存在差异, 基本趋势是晚熟品种高于早熟品种, 花芽高于叶芽, 但葡萄品种相反, 早熟的‘京秀’高于晚熟的‘巨峰’; 休眠期芽内 H₂O₂含量基本呈稳步上升后急剧下降的趋势,不同品种急剧下降的时间略有差别, 且与自然休眠解除的时间相吻合。低温(5 ℃) 处理显著增加了芽中 H₂O₂含量, 中温(10 ℃) 使 H₂O₂含量略有增加, 而高温(20 ℃) 却导致 H₂O₂含量降低。休眠前期50 mg.L^-1 ABA 处理显著提高了芽中H₂O₂含量, 而100 mg.L^-1的GA₃和6-BA 处理有减少 H₂O₂含量的趋势, 但二者差异不明显。热带地区常用的化学破眠物质对芽 H₂O₂的影响因树种( 品种) 、使用时期不同而异, 硫脲、KNO₃前期使用对核果类果树影响明显, CaCN₂对核果类无明显效应, 但对葡萄品种作用显著。果树芽 H₂O₂含量的动态变化表明, H₂O₂可能是低温解除自然休眠的原因。     

Natural cold acclimatisation and de-acclimatisation of Magnolia wufengensis in response to alternative methods of application of abscisic acid

SUMMARY

To improve our understanding of the role of exogenous abscisic acid (ABA) during natural cold acclimatisation and de-acclimatisation to cold stress in the rare species, Magnolia wufengensis, physiological and biochemical changes in field-grown M. wufengensis seedlings subjected to a single foliar (T1) or root (T2) application of ABA were compared. During cold acclimatisation, treatments T1 and T2 accelerated the increase in freezing tolerance in shoots and the level of bud dormancy, but T2 was 40.0% and 17.5% more effective than T1 for these two parameters, respectively. During de-acclimatisation, the decline in freezing tolerance in shoots and levels of bud dormancy were not greatly influenced under T1, but were slowed by 12.5% and 15.2%, respectively, under T2. Bud-burst in Spring was delayed by 13.78 d under T2, and the rates of bud survival increased by 18.9% and 31.8% under T1 and T2, respectively. Cold-hardiness was associated with changes in water, proline, total soluble protein, total soluble sugar, glucose, and fructose concentrations. We conclude that foliar or root application of ABA advanced the process of cold acclimatisation in M. wufengensis, that root treatment was relatively more effective, and that root application played a role in inhibiting de-acclimatisation. We suggest that a single root application of ABA would be a superior method to improve winter-hardiness in M. wufengensis grown in northern China.     

The influence of fruiting on the bud sprouting and flower induction responses to chilling in Citrus

Summary

The effect of chilling temperatures on bud sprouting and flower formation was compared on fruiting and non-fruiting ‘Owari’ satsuma mandarin (Citrus unshiu Marc) trees. On non-fruiting trees, bud dormancy was weak, and a significant proportion of buds were able to sprout at high temperatures without being chilled. Separate effects of low temperatures on bud sprouting and flower induction were demonstrated. On fruiting trees these two effects of low temperatures were also demonstrated on summer-flush buds, but not on older (spring-flush) buds. The spring-flush buds from fruiting trees scarcely sprouted without being chilled. These buds required a longer chilling period for dormancy release than for flower induction, and it was not possible to separate the effect of low temperature on flower induction from the effect on dormancy release. The presence of fruit reduced flower formation by reducing bud sprouting. Furthermore, fruit had a direct inhibitive effect on vernalization which resulted in increased formation of vegetative shoots. The effect of fruit and low temperature on flowering was unrelated to carbohydrate accumulation in the leaves or the roots.     

石灰氮和水杨酸对破除葡萄芽休眠的影响

 2003年12月～2004年3月, 在江苏省镇江市南山农业科技示范园葡萄园, 以藤稔品种为试材, 分别在树体的初休眠期(12月上旬) 、深休眠期( 1月上旬) 和休眠后期( 2月上旬) , 取芽体饱满、生长充实的1年生枝条, 用不同浓度的石灰氮(CaCN2 ) 和水杨酸( SA) 进行涂芽破眠处理; 之后放入温室进行发芽培养, 并每5 d取冬芽测定H2O2及其抗氧化酶系统的变化, 21 d后统计各处理最终萌芽率。结果表明: 施用CaCN2和SA能不同程度的提高H2O2含量和POD活性, 降低CAT活性; 但在不同休眠期对SOD活性的影响不一致。而破眠或促进萌芽效果好的化学药剂处理, 花芽在培养前期的H₂O₂含量、POD和SOD活性增幅较大, CAT活性下降较明显。对萌芽率的统计表明, 初休眠期施用石灰氮和水杨酸对葡萄破眠无效; 到深休眠期及以后施用25%的石灰氮对葡萄破眠效果较为明显, 萌芽较对照提前4～6 d, 最终萌芽率达41.6%～90.0%; 而水杨酸处理对葡萄花芽破眠基本无效。     

不同温度下卵叶韭更新芽内源激素的动态变化

 运用高效液相色谱法测定了3种不同温度下卵叶韭更新芽内源激素的动态变化。结果表明:(1) 卵叶韭更新芽休眠完全解除必需经过一段时间的冷温处理, 且冷温积累量与休眠解除程度和植株长势呈正相关趋势; (3 ±1) ℃处理不少于92 d可完全解除休眠, 而5～12℃、(20 ±1) ℃处理均不能完全解除休眠。(2) 贮藏31 d后, (3 ±1) ℃和5～12℃处理的GA₃ 和ZT含量上升, ABA含量下降, 其中( 3 ±1) ℃处理的上升和下降幅度更大, 解除休眠所需时间更短; 而(20 ±1) ℃处理在鳞茎干枯腐烂前GA₃ 和ZT含量下降, ABA含量上升, 更新芽不能萌发。(3) 卵叶韭更新芽休眠过程可分为预休眠、真休眠和强制休眠3个阶段, 其中预休眠阶段更新芽的GA₃、ZT、ABA和IAA含量居中; 真休眠阶段更新芽的GA₃ 和ZT含量较低, ABA含量较高, IAA含量较高或居中; 强制休眠阶段更新芽的GA₃、ZT含量达最大值, IAA含量略有增加, ABA含量降至最小值。(4) 卵叶韭更新芽休眠的解除可能主要受控于内源激素GA₃、ABA的含量水平和GA₃ /ABA比值, 当GA₃ / IAA比值大于16.59 ±3.90时, 卵叶韭更新芽的休眠就可能完全解除, 此外ZT也对萌发起着一定的作用。     

GA3 和PP333调控苹果花芽孕育机理的研究

 连续3 年用多效唑(PP₃₃₃) 1 000 mg/L 和赤霉素(GA₃) 1 000 mg/L 处理‘首红’苹果, 结果表明, PP₃₃₃处理降低了芽内吲哚乙酸( IAA) 和赤霉素( GAS) 含量, 增加了玉米素核苷(ZR) 和脱落酸(ABA) 含量, 提高了ZR/ IAA、ZR/ GAS、ABA/ IAA 和ABA/ GAS 比值,从而促进了花芽形成。GA₃ 处理则增加了IAA、GAS 含量, 降低了ZR、ABA 含量, 降低了ZR/IAA、ZR/ GAS、ABA/ IAA 和ABA/ GAS 比值, 从而抑制了花芽形成。PP₃₃₃和GA₃ 在花芽孕育临期内应用效果显著, 在其它时期无效。     

Abscisic acid relationships in dormancy of apple buds

When potted, dormant, leafless seedling of ‘Antonovka’ apple were held for 15 weeks at 4 or 24°C, the patterns of change for abscisic acid (ABA) in buds were similar. At both temperatures, ABA concentration had decreased to a low level by 6 weeks and remained at a fairly low level until Week 12. The ABA concentration showed a tendency to rise in both treatments by Week 15.When excised axillary buds of ‘Northern Spy’ seedings were placed on 10^?4 M ABA medium immediately after excision, their growth was inhibited substantially depending on the length of exposure to ABA. When similar axillary buds were first allowed to begin growth on ABA-free medium, and then subsequently transferred to 10^?4 M ABA medium, no inhibition of growth occurred, even though these buds contained about twice as much ABA as did the buds placed directly on ABA medium prior to the beginning of growth.Thus, growing buds responded much less to exogenous applications of ABA than did non-growing buds. Diminishing of bud reaction to ABA responded to emergence from dormancy after 18 weeks of chilling.     

打破巨峰葡萄种子休眠及实生苗阶段发育中内源激素的研究

研究表明,巨峰葡萄成熟种子种壳含有很高的ABA或类似物.用40%石灰氮浸出液处理18h打破休眠的效果最好.葡萄童期阶段细胞分裂素含量低,并且随节位升高变化迟缓,当临近阶段转变时,含量急剧上升.GA_3含量童期阶段高于转变期.GA_(4+7)在阶段转变部位含量急剧下降,CTK/GA_3急剧上升.生长素含量在童期阶段随着节位升高急剧增加,临近阶段转变时含量又急剧降低.脱落酸的含量则随着节位升高有缓慢上升的趋势.     

Simultaneous down-regulation of DORMANCY-ASSOCIATED MADS-box6 and SOC1 during dormancy release in Japanese apricot (Prunus mume) flower buds

In temperate deciduous fruit crops such as Prunus spp., bud endodormancy is an important physiological phase affecting the timing of blooming and subsequent fruit development. Japanese apricot (Prunus mume) bears unmixed flower buds, separate from vegetative buds, that bloom slightly more than a month before vegetative bud burst. Seasonal expression of Prunus mume DORMANCY ASSOCIATED MADS-box genes (PmDAMs) has previously been analyzed only in vegetative buds, with an association between these genes and flower bud endodormancy release not yet confirmed. In this study, we performed a seasonal expression analysis of PmDAM1–6 genes in flower buds of two Japanese apricot genotypes – namely, high-chill and low-chill cultivars. The analysis revealed that PmDAM3, PmDAM5, and PmDAM6 expressions are closely associated with dormancy release in both flower and vegetative buds. In addition, a yeast two-hybrid screening demonstrated that PmDAM6 can interact in yeast with the homolog of Arabidopsis SOC1 (PmSOC1). Synchronized expression patterns were detected in PmDAM6 and PmSOC1 during dormancy release in flower buds of the two genotypes. Taken together, these results suggest that the dimer of PmDAM6 and PmSOC1 may play a role in the regulation of dormancy transition and blooming time in Japanese apricot flower buds.     

温室葡萄休眠期不同阶段保温的生化反应

以无核白鸡心葡萄为试材,从11月初至1月末,研究不同阶段保温芽的生化反应。结果表明:葡萄深休眠期前芽具有高水平的ABA,深休眠期后进行保温ABA下降,IAA、GA3、ZT含量增加;休眠期间芽淀粉含量增加、可溶性糖下降,至保温后淀粉开始下降、可溶性糖上升,但萌芽前淀粉上升、可溶性糖下降,蛋白质进入休眠后下降,至萌发前上升,次年葡萄生长结果良好;休眠期前保温的葡萄不能正常进入休眠,最终影响生长结果。     

‘红丽’海棠早实植株发育过程中内源激素变化

 以童期不同的海棠（Malus sp.）植株为试材,使用酶联免疫法（ELISA）测定花芽分化期间 短枝顶芽、幼叶、细根中内源激素含量的变化,以探讨内源激素对花芽分化的影响,为缩短果树童期、 开发利用早实海棠资源奠定基础。结果显示,早实植株与成熟嫁接植株的内源激素含量变化趋势相似。 花芽分化的前期阶段,芽和根中IAA 含量均逐渐减少,到9 月初开始上升,成熟植株含量整体低于未成 熟植株;成熟植株叶中内源IAA 含量高于未成熟植株。芽中GAs 先上升后下降再上升,成熟植株8 月份 达到最低,而未成熟植株9 月份处于最低水平;叶中GAs 含量在成熟植株均保持较低水平;根中GAs 变 化与芽相反。内源ZR 含量在不同器官均有大幅增加,成熟植株均高于未成熟植株,实生早实植株中的变 化幅度最大。成熟植株芽中ABA 含量在160 ~ 170 ng · g^-1FW 上下波动,未成熟植株始终低于160 ng · g^-1FW;叶和根中的ABA 含量变化趋势一致,即先升高后逐渐下降,9 月之后回升。成熟植株较未成 熟植株在芽与叶中均表现为高比值的ABA/GAs 与ZR/GAs,而根中与此相反。     

Temperature effects on dormancy,bud break and spear growth in asparagus (Asparagus officinalis L.)

Summary

The effects of the length of chilling, chilling temperature and growing temperature on dormancy of asparagus crown buds and subsequent rates of spear growth were examined. The results showed that prior chilling enhanced bud break at low growing temperatures and stimulated the growth of spears.Thus, chilling should facilitate commercial production by hastening bud break and spear growth rates at lower temperatures. If sufficient chilling was given, the minimum temperature for rapid bud break was approx. 12.5°C for ‘Rutgers Beacon’ and ‘Jersey Giant’, and around 10°C for ‘UC 157’ and ‘Apollo’. The optimum chilling temperature appeared to be closer to 5°C than to 10°C or 2°C for ‘Rutgers Beacon’ plants grown at 12.5°C. Increasing the growing temperature had a significant effect on the relative spear growth rate (RSGR) in all cultivars. Prior chilling had no effect on the RSGR for ‘Dariana’ and ‘Apollo’; but, for ‘UC 157’, chilling plants at 5°C for 5 or 10 weeks increased growth rates at 12.5°C and at 20°C. These results demonstrate that release of bud dormancy and spear growth rates depended not only on the growing temperature, but also, at least in some cultivars at some temperatures, on the duration and temperature of chilling during the previous Winter.     

带叶休眠对休眠解除期间葡萄芽呼吸代谢的影响

 以中高需冷量葡萄品种‘夏黑’为试材,研究人工脱叶休眠处理和带叶休眠处理对休眠解除期间芽体呼吸代谢的影响。结果表明：与人工脱叶休眠处理相比,带叶休眠处理明显促进芽的休眠解除。带叶休眠处理与人工脱叶休眠处理芽在休眠解除期间的呼吸速率和途径变化趋势相似,但带叶休眠处理芽呼吸速率和途径发生显著变化的时间明显早于人工脱叶休眠处理,并且总呼吸速率和糖酵解—三羧酸循环途径、交替途径的运行活性和容量及剩余呼吸比例都高于人工脱叶处理。     

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。     

Biochemical changes in dormant grapevine shoot tissues in response to chilling: Possible role in dormancy release

At leaf fall, one-year-old shoots of cv. Superior Seedless table grape were collected and cut into single-node sections. These cuttings were subjected to 0, 100, 200, 300, 400 or 500 h of chilling at 5 °C to simulate natural chilling accumulation. After each treatment, one group of cuttings was forced to break buds while a second group was used to study biochemical changes taking place in the bud and underlying internode tissues. Carbohydrates, free polyamines and proline concentrations were determined and amylolitic and invertase (EC 3.2.1.26) activities were estimated. Low temperature treatment caused a hydrolysis of starch concomitant with an accumulation of sucrose. There was also a rapid build-up of proline, putrescine (Put) and spermidine (Spd) which reached their maximum levels at 300 positive chill units (PCU). Afterwards, as buds approached chilling satisfaction (400 and 500 PCU), hexoses accumulated in the buds while sucrose concentration increased considerably in both structures. Proline and Put, however, decreased in both tissues. Spd level remained high, while spermine (Spm) increased slightly. Changes in starch concentration seem to be controlled by α-amylase (EC 3.2.1.1). Sucrolytic activity, consisting mainly in the acid invertase form, changed inversely to sucrose concentrations. Nevertheless, at chilling satisfaction both sucrose content and invertase activity remained high in the buds implying a possible import of sucrose into the bud which acted as a strong utilizing sink. Our data suggest that limited budbreak due to a lack of chilling may be due to low hexoses availability. However, as buds approached chilling satisfaction, a high acid invertase activity, high soluble sugars concentration and a decrease in Put to Spd plus Spm ratio appear to be correlated with bud dormancy release and improve budbreak. Furthermore, endodormancy can be divided into two phases: the first one (from 0 to 300 PCU) is an acclimation period; the second (from 300 to 500 PCU) is a beginning of growth resumption.     

‘玉露香梨’僵芽发生与内源激素和碳氮营养的关系

针对部分梨园中‘玉露香梨’出现的僵芽现象,以河北魏县发生僵芽的‘玉露香梨’短枝顶芽为试验材料,以与该梨园相邻的,以及山西太谷地区的正常梨园中的‘玉露香梨’短枝顶芽为对照,采用石蜡切片法、间接酶联免疫测定法、蒽酮比色法和凯氏定氮法,分析僵芽的发生时间和短枝顶芽在花芽形态分化期间的内源激素、碳氮营养含量变化及其与僵芽发生的关系。结果表明,僵芽发生始于7月上中旬花萼分化期;僵芽内IAA含量在7月初—7月中上旬显著高于正常芽,ABA含量在6月中旬—8月上中旬显著低于正常芽,GA3含量在整个花芽形态分化期内显著高于正常芽,ZR含量在6月初显著高于正常芽,ZR/GA3、ABA/GA3、ABA/ZR显著低于正常芽;僵芽梨园(魏县)新梢年生长量极显著大于正常梨园,生长天数长于正常梨园,其芽内可溶性糖、淀粉等营养物质和碳氮比显著低于正常梨园。僵芽梨园(魏县)枝条旺长,芽内高含量的IAA和GA3,低含量的ABA和碳水化合物,阻断了花芽正常分化,导致僵芽的发生。     

几种化学药剂对破除葡萄与桃自然休眠的效果

以桃、葡萄为试材,探讨多种化学药剂和外源生长调节剂打破休眠的效应。结果表明:CaCN2打破葡萄的休眠效果稳定,可使萌芽提早6～17d,并提高萌芽率,其破眠效果随需冷量的增加而显著;几种化学药剂在桃树上应用,其打破休眠的效果差异较大,CaCN2、NH4NO3对打破桃休眠无效,硫脲的破眠效果最明显,可使叶芽萌发提前9～12d、花芽6d,并提高萌芽率;KNO3对破除休眠亦有一定效果。外源生长调节剂对休眠的调节作用因调节剂种类、浓度和使用时间而异:Ze(50mg/L)+GA3(100mg/L)可完全打破叶芽的休眠,100mg/L6-BA对尚未完成自然休眠的花芽萌发有明显的促进作用,IAA和2,4-D却对芽的萌发表现出强烈的抑制作用。     

不同需冷量桃休眠相关DAM基因表达特性及激素调控的响应分析

以"南山甜桃"(需冷量200 h)、"瑞光51号"(需冷量400 h)和"春美"(需冷量600 h)为试材,从大量落叶期开始至花芽萌动期间,约每15 d采样一次,RT-PCR分析DAM基因在不同冷量积累时期花芽中的表达量,PLC-MS-MS测定相同时期吲哚乙酸(IAA)、脱落酸(ABA)和玉米素(ZT)含量变化,以期了解不同需冷量桃休眠过程中DAM基因的表达特性及激素的调控机理。结果表明:DAM基因在不同需冷量桃休眠过程中的表达趋势一致,随着休眠的深入,"春美"中DAM基因的表达水平呈先升后降趋势;"南山甜桃"和"瑞光51号"在进入休眠期以后DAM基因表达水平急剧下降,与低温积累量呈负相关。"春美"中DAM基因表达量明显高于"瑞光51号"和"南山甜桃"。"春美"中DAM基因表达水平比"南山甜桃"和"瑞光51号"开始下调约晚30 d,但"瑞光51号"和"南山甜桃"中DAM基因下调的时间一致。IAA、ZT在不同需冷量桃休眠过程中的含量变化差异不显著,ABA含量变化差异显著,可能在休眠解除过程中起重要调控作用。