The Relation Between Endogenous Hormones and Late-Germination in Buds of Avrolles Apple

In order to provide the physiological bases for selecting late-germination cultivars that can avoid late frost damage, the very late-germination variety Avrolles （Malus domestica） was used to study the relation between the dynamic changes and balance of endogenous hormones and germination time. The concentrations of endogenous GA3, ABA, IAA, and ZR were determined in buds of Avrolles and Judeline （Malus domestica） from dormancy releasing to germination by capillary electrophoresis. The dynamic changes of endogenous hormones concentration in buds of Avrolles and Judeline were similar; but the magnitude and time of the change were significantly different between the two varieties, especially for GA3. GA3 concentration increased with dormancy releasing, then decreased, and increased again before germination in the two varieties. GA3 concentration in Avrolles was 1.72 times that in Judeline at the first peak, the gap increased to 2.22 times at germination. ZR concentration exhibited a continuous increase trend, but it decreased sharply before germination. ZR accumulation in Avrolles took 36 days longer than in Judeline, the peak value was 44% higher than in Judeline. Before germination, ZR concentration in Avrolles was 2.12 times that in Judeline. The differences between IAA and ABA concentration were relatively small in the two varieties, while the ratios of GA3/ABA and （GA3 ＋ IAA ＋ ZR）/ABA in Avrolles were 2.08 and 1.58 times those in Judeline, respectively. The germination of apple bud was regulated by the endogenous hormones. For the late-germination apple Avrolles, its germination requires higher concentration of GA3 and ZR, which leads to the high ratios of GA3/ABA and （GA3＋ IAA＋ ZR）/ABA.     

Regulation of Development and Endogenous Polyamine Level in Chinese Cabbage (B. Campestris ssp. Pekinensis)

The endogenous polyamine levels were tested at every developmental stage in different ecotypes of the Chinese cabbage. The results showed that polyamincs (PAs) were decreased in the process of flower bud initiation and fornfation, but the floral stem formation and elongation were accompied by PAs increase. The level of Spm was related to the bolting date of Chinese cabbage. During the inducing of flower bud initiation and elongation of floral stem, and the changes of Spm were reversed between early bolting date and late bolting cultivars, but they have the same requirment for Spd for the starting of flower bud initiation and the starting of bolting. The level of Spd changed little during entire developmental stage for early bolting cultivars, but a lot for late bolting cultivars. The time that the highest level of Put appeared is related to the bolting date of Chinese cabbage.     

Study on Variation of Endogenous Hormonesat the Germinating Stage of Tea Spring Shoot

An HPLC method was used to analyze the contents and variation of IAA, GA3, ABA and ZT at five stages around the tea shoot germinating in spring. The contents of GA3 and ABA had a top value during the winter and decreased with the growth of tea shoots, while the contents of IAA and ZT had a low value during the winter and increased quickly at the beginning of shoot growth, but soon afterwards increased slowly or decreesed a little. The ratio of hormones was closely related to the growth of tea plant. The study indicated that the ratlos of GA3 to ABA and IAA to ABA were at low values during the winter and went up with the shoot germinating. When the activity of roots was weak, the ratio of ZT to IAA had a top value, but went down gradually with lmmriant activity of roots. The ratio d GA3 to ZT had a certain relativity with the shoot germinating, which was at a top value during the winter but went down suddenly at the begin-ning of shoot gerrminating.     

Developmental and hormonal regulation of fiber quality in two natural-colored cotton cultivars

Cotton cultivars with brown(Xiangcaimian 2), green(Wanmian 39) and white(Sumian 9) fiber were investigated to study fiber developmental characteristics of natural-colored cotton and the effect of hormones on fiber quality at different stages after anthesis. Fiber lengths of both natural-colored cottons were lower than the white-fibered control, with brown-fibered cotton longer than green. Fiber strength, micronaire and maturation of natural-colored cotton were also lower than the control. The shorter fiber of the green cultivar was due to slower growth during 10 to 30 days post-anthesis(DPA). Likewise, the lower fiber strength, micronaire and maturation of natured-colored cotton were also due to slower growth during this pivotal stage. Indole-3-acetic acid(IAA) content at 10 DPA, and abscisic acid(ABA) content at 30 to 40 DPA were lower in the fibers of the natural-colored than that of the white-fibered cotton. After applying 20 mg L~(–1) gibberellic acid(GA3), the IAA content at 20 DPA in the brown and green-fibered cottons increased by 51.07 and 64.33%, fiber ABA content increased by 38.96 and 24.40%, and fiber length increased by 8.13 and 13.96%, respectively. Fiber strength, micronaire and maturation were also enhanced at boll opening stage. Those results suggest that the level of endogenous hormones affect fiber quality. Application of external hormones can increase hormone content in natural-colored cotton fiber, improving its quality.     

水稻穗上发芽生理生化及颖壳扫描电镜观察

Scanning electron microscopy of easy or uneasy-germinated glumes,determining the contents of endogenous hormones and the activity of α-amylase were studied from at 1-4 d pre-harvest sprouting rice.The results showed that the activity of α-amylase and the contents of IAA,GA1 3 and ZR were higher in easy-germinated rice than those in the uneasy-germinated rice,while ABA content in easy-germinated rice was lower than that in uneasy-germinated rice.The change of GA1 3/ABA rate accorded with that of GA1 3.Scanning electron microscopy showed that the cell surface of glume was loose arranged with more villus and bigger hole and germinal aperture,which had lesser mechanism resistance and better water absorptivity in easy-germinated rice.This research also indicated that pre-harvest sprouting in rice related to α-amylase activity,endogenous hormone contents and glume structure.     

Endogenous Hormone Concentration in Developing Tuberous Roots of Different Sweet Potato Genotypes

A field trial was conducted to investigate the changes of endogenous hormone concentration （EHC） during formation and thickening of tuberous roots in sweet potato （Ipomoea batatas L.） of different genotypes： Xushu 18, Minamiyutaka, and L trifida-K123. The results of this study suggested that the concentrations of zeatin riboside （ZR）, dihydro-zeatin riboside （DHZR）, abscisic acid （ABA）, indole-3-acetic acid （IAA）, and isopentenyl-adenine （IPA） of Xushu 18 and Minamiyutaka were significantly higher than those of I. trifida-K123. Dry tuberous root yields were positively correlated with the concentration of ABA, ZR, and DHZR at 1 or 5% significant level, but were not obviously correlated with the concentrations of IAA, IPA, and GA4. The concentrations of ABA, ZR and DHZR played very important roles in the tuberous root formation and thickening in sweet potato. The concentrations of ZR, DHZR, ABA, and IAA in the upper or inner portion of tuberous roots were significantly higher than those toward the end of the root or its outer portion. Meanwhile, EHC of large-sized tuberous roots were significantly higher than those of medium- or small-sized tubers during the early thickening period. In the rapid thickening period of tuberous roots, EHC of medium-sized tubers were the highest, However, at the late-thickening period, EHC of small-sized tubers ranked the highest.     

Effect and Functional Mechanism of the Action of Exogenous Gibberellin on Flowering of Peach

This study was conducted to assess the effect of gibberellin and its possible mechanism of action on peach flower formation. At flower induction, 100 mg L^-1 of gibberellic acid 3 （GA3） was sprayed on the leaves of peach [Prunus persica （L.） Batsch.] cv. Bayuecui. Using anatomy, immunohistochemistry, and semi-quantitation, the in situ distribution of GAs and the expression of the key genes involved in peach flower formation in the apical meristem were studied during flowering differentiation. The results showed that induction of flowering in the Bayuecui peach occurred prior to 10 July in Beijing, China. Flower induction and further differentiation of the peach flower organs were significantly inhibited by leaf-spraying of GA3 at a concentration of 100 mg L^-1 during the induction stage. The flowering rate was only 11.67% after treatment. The distribution of GA1 in the apical meristem varied during the process of flower bud differentiation. From 13 June to 25 July, the GA1 signal from control plants was detected mainly in the vascular bundles at the base of the flower buds. No GA1 signal was detected in the apical meristem. After treatment with GA3, the distribution was similar to that of the control from 13 June to 3 July. On 13 July, a GA1 signal was detected in the apical meristem accompanied by an increase in the GA1 signal in the vascular bundles at the base of the flower buds. The GA1 signal weakened significantly in both the vascular bundles and the apical meristem on 25 July. The expression of the genes PpLEAFY and MADS6 in flower buds could be detected only on 10 October in the GA3-treated plants. The critical period for flower induction of Bayuecui peach in Beijing was in early July, during which time, leaf-spraying with 100 mg L-1 GA3 could effectively inhibit flower induction and further differentiation of the flower buds. GA1 in the gibberellin family was the suppressor for flower induction in peach. Its action was affected by the stage of flower bud differentiation. Expression of the key gen     

Leaf Responses of Micropropagated Apple Plants to Water Stress： Changes in Endogenous Hormones and Their Influence on Carbohydrate Metabolism

The changes in the concentrations of endogenous hormones and their influence on carbohydrate metabolism in leaves of micropropagated Fuji apple plants were studied under water deficiency stress. The results showed that water stress induced a rapid increase in the concentration of abscisic acid （ABA） and led to a decrease in concentrations of both zeatin and gibberellins （GAs）. The concentration of indole-3-acetic acid （IAA） changed in an independent manner, which was not correlated with the different levels of water stress. With regard to the carbohydrates, the contents of sorbitol and sucrose increased, whereas the content of starch decreased. The increase in the concentration of ABA was significantly correlated with both the increase in the activity of aldose-6-phosphate reductase （A6PR） and the decrease in the activity of sorbitol dehydrogenase （SDH）, indicating that ABA played a regulatory role in sorbitol metabolism. The concentration of ABA was positively correlated to the activity of sucrose-phosphate synthase （SPS） but negatively correlated to the activities of acid invertase （AI） and ADP-glucose-pyrophosphorylase （ADPGppase） in water-stressed plants, which indicated that ABA promoted sucrose synthesis and inhibited sucrose degradation and starch synthesis at the same time. Under conditions of water stress, the decrease in the level of zeatin was accompanied by a decrease in the activities of SDH and ADPGPPase. GAs concentration showed positive correlation with ADPGPPase activity. IAA showed no significant correlation with any of the enzymes tested in this study. The results of this study suggested that ABA might be one of the key factors regulating the distribution of carbohydrates under water stress. The metabolism of sorbitol and starch under conditions of water stress might be regulated by the combined action of many plant hormones.     

Physiology Mechanism of Metabolisms in the Middle Scales of Lilium davidii var. unicolor Bulbs Stored at Low Temperature for Dormancy-Release

Changes in carbohydrate, phenols, free amino acids and endogenous hormones in middle scales of Lilium davidii var. unicolor bulbs during the 101 days storage at 2, 6 and 10℃ in moist sawdust were studied. The results indicated that as the storage time increased and the storage temperature delined, contents of starch and abscisic acid (ABA) decreased markedly, and the level of total soluble sugar, phenols, gibberellic acid (GA3) and indole acetic acid (IAA) increased sharply. In the first 34 days, the contents of the above substances changed most actively. Correlation analysis revealed that the increase in content of total soluble sugar and phenols was respectively caused by activation of amylase and phenylalanine ammonia-lyase (PAL). During the storage, the content of free amino acids decreased, and the level of arginine was the highest and changed most remarkably. According to the results of stepwise regression analysis and path analysis, we could primarily conclude that the metabolism of carbohydrates, phenols and free amino acids in the middle scales may be mainly regulated by endogenous GA3.     

Effects of chilling tolerance induced by spermidine pretreatment on antioxidative activity,endogenous hormones and ultrastructure of indica-japonica hybrid rice seedlings

Spermidine(Spd) is known to be involved in the regulation of plant responses to chilling stress and counteract the adverse effect of stress conditions.Antioxidant activities,endogenous hormones and ultrastructure change under chilling stress were investigated in indica-japonica hybrid rice seedlings.12-d-old seedlings were subjected to exogenous Spd(1 mmol L~(-1)) and then a chilling stress(6℃,4 d) was induced,followed by a subsequent recovery(25℃,4 d).Results showed that malondialdehyde(MDA) and proline content were enhanced significantly,whereas shoot fresh and dry weights decreased during chilling stress and after recovery;chlorophyll content of chilling-stressed seedlings increased slightly but declined after recovery;additionally,total soluble sugar,sucrose,fructose and starch contents increased significantly during chilling stress,and only soluble sugar and fructose contents were observed in increase after recovery;chilling stress-induced increases in superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) activities,but declined after recovery,and the level of ascorbate peroxidase was lower during chilling stress and after recovery;however,endogenous indole-3-acetic acid(IAA),zeatin riboside(ZR),gibberellic acid(GA_3),and abscisic acid(ABA) levels were induced decreased compared with Spd pretreatment.The microscopic analysis revealed that chilling stress-induced destruction of the chloroplast envelope during chilling stress and increased the number of plastoglobuli along with aberrations in thylakoid membranes after recovery.In contrast,exogenous Spd protected rice seedlings from chilling-induced injuries in terms of lower malondialdehyde,proline and carbohydrates accumulation coupled with increased endogenous hormones metabolism.After recovery,Spd pretreatment chilling-exposed seedlings showed higher activities of antioxidant enzymes and normal physiological function of chloroplasts.These results suggest that Spd could promote effectively chilling tolerance which might be largely attributable to the integrity of cell structure and normal metabolism of endogenous hormones in indica-japonica hybrid rice seedlings.     

番茄子房心室形成与花芽分化期幼苗茎尖相关代谢物质含量的关系

    为探讨番茄子房心室形成过程中相关体内代谢物质的作用,应用番茄多心室自交系(MLK1)和少心室自交系(FL1)进行正反交,研究亲本及正反交F1代(F1、RF1)花芽分化初期、花芽分化期、萼片花瓣形成期、心皮形成初期、子房心室完全形成期5个时期幼苗茎尖体内代谢物质果糖、葡萄糖、蔗糖、淀粉、可溶性蛋白、DNA、RNA含量的变化及其与子房心室形成的关系.结果表明,番茄两亲本在花芽分化5个时期的果糖、葡萄糖、蔗糖、淀粉、可溶性蛋白、DNA舍量均是多心室亲本高于少心室亲本;RNA含量则是少心室亲本高于多心室亲本;正反交F1和RF1在幼苗花芽分化各时期茎尖果糖、葡萄糖、可溶性蛋白、DNA、RNA含量均介于多心室和少心室亲本之间;这些结果与心室数的变化相一致.进一步分析番茄花芽分化5个时期幼苗茎尖相关代谢物质含量与子房心室数的相关关系表明.番茄子房心室数与萼片花瓣形成期葡萄糖、蔗糖、淀粉、可溶性蛋白含量呈极显著正相关,与RNA含量呈极显著负相关,而与果糖、DNA含量呈显著正相关;这一结果预示着番茄子房·心室形成可能是果糖、葡萄糖、蔗糖、淀粉、可溶性蛋白、DNA、RNA等体内代谢物质之间相互作用的结果,同时也预示着萼片花瓣形成期可能是番茄子房心室形成的相关体内代谢物质调控的关键时期.     

番茄幼苗茎尖碳水化合物含量与子房心室数目的相关性分析

以多心室和少心室2个心室数目差异较大的番茄品系(L.esculentum var.cerasiforme Ale f和L.esculentum var.Giant Heir-loom)为亲本,进行正反交,研究亲本及F1代幼苗在花芽分化前期、花芽分化期、萼片花瓣形成期、心皮形成初期和子房心室完全形成期茎尖果糖、葡萄糖、蔗糖、淀粉含量的变化及其与心室数目的相关性。结果表明:自番茄幼苗花芽分化前期至子房心室完全形成期,茎尖内果糖、葡萄糖、淀粉含量逐渐增加,而蔗糖含量逐渐降低。番茄幼苗萼片花瓣形成期和心皮形成初期茎尖碳水化合物含量均与心室数目显著正相关,萼片花瓣形成期的果糖对心室数目有负向直接影响,心皮形成初期蔗糖通过葡萄糖对心室数目的间接影响较大,而萼片花瓣形成期、心皮形成初期的葡萄糖含量都对心室数目有正向直接影响。     

切花秋菊‘神马’花芽分化与内源激素的关系

 【目的】研究短日处理下菊花（Chrysanthemum morifolium）花芽分化与内源激素的关系。【方法】以切花秋菊‘神马’为试材,通过对短日处理下花芽的形态解剖观察及顶芽和叶片中内源激素的测定,研究花芽分化过程中内源激素的动态变化。【结果】花芽分化过程中顶芽中GA3含量下降且大多时期保持在较低水平,叶片中GA3变化与之相反;顶芽中IAA含量先下降,在小花原基分化初期达到最小值,到花冠形成中期达到最大,叶片内源IAA含量在总苞鳞片分化初期前呈上升趋势,随后逐渐下降,到花冠形成期趋于平稳;内源CTK含量大幅增加,均高于未分化期;顶芽中ABA含量先下降,后期呈现上升趋势,叶片中ABA含量变化与顶芽相反,呈现先积累,经短暂平稳期后逐渐减少的趋势。花芽分化开始后CTK/IAA、CTK/GA3、ABA/IAA和ABA/GA3的比值均增大。【结论】高水平的CTK和ABA与菊花花芽分化相关联。在花芽分化初期,顶芽中低浓度IAA、GA3,以及叶片中高含量的IAA、GA3关系到菊花由营养生长向生殖生长转变;在花芽分化后期,顶芽中GA3和IAA的积累关系到花冠形成。从激素平衡来看,维持高比率的CTK/IAA、CTK/GA3、ABA/IAA和ABA/GA3有利于菊花的花芽形成。     

紫薇花器官分化过程内源激素变化研究

为了研究紫薇不育与内源激素变化的关系,采用酶联免疫吸附法(ELISA),测定了不育紫薇"湘韵"与普通可育紫薇花器官分化及授粉过程4种内源激素生长素(IAA)、赤霉素(GA3)、玉米核苷素(ZR)及脱落酸(ABA)含量的动态变化。结果表明:两种紫薇花器官分化及授粉过程4种激素含量存在明显差异;花器官分化开始阶段,不育紫薇较可育紫薇具有更高水平的GA3、ABA和IAA含量,随着花器官的进一步发育,4种激素水平均有所下降,其中GA3水平高于可育紫薇,ZR含量低于可育紫薇;授粉时期,内源激素含量随着授粉过程而变化,且不育紫薇GA3水平较可育紫薇含量更低。因此认为,花器官分化及授粉时期内源激素的异常变化影响了不育紫薇花器官和果实的发育。     

光周期对菊花花芽分化和内源激素的影响

本试验以菊花品种"秀芳白"为试材,研究了不同光周期(昼/夜分别为16h/8h,12h/12h和8h/16h)对菊花花芽分化及其过程中内源激素IAA、GA3、CTK和ABA含量的影响。结果表明,16h/8h处理的植株始终没有花芽分化;8h/16h处理的植株从处理到花芽分化开始和花芽分化完成所需天数分别为12.8 d和25.1 d,比12h/12h处理的分别提前2.4 d和4.7 d。花芽分化过程中16h/8h处理的IAA和GA3含量呈现缓慢下降趋势,而8h/16h处理和12h/12h处理的呈现迅速下降趋势;16h/8h处理的CTK和ABA含量没有出现明显变化,而8h/16h处理和12h/12h处理的呈现上升趋势。CTK/IAA、CTK/GA3、ABA/IAA以及ABA/GA3在16h/8h处理区没有明显变化,而在8h/16h处理和12h/12h处理区呈现上升趋势。说明短日照促进菊花花芽分化,而且日照时数越短,花芽分化越快;花芽分化过程中叶片GA3和IAA含量减少,CTK和ABA含量增加,而且CTK/IAA和CTK/GA3以及ABA/IAA和ABA/GA3比值增加,有利于菊花花芽分化和提早开花。     

叶底红花芽分化期叶片内源激素的动态变化

应用高效液相色谱法(HPLC)测定了叶底红花芽分化期叶片中内源激素吲哚乙酸(IAA)、赤霉素(GA3)、玉米素(ZR)和脱落酸(ABA)等4种内源激素含量的动态变化。结果显示,这4种激素均有明显的变化规律,其中GA3和ZR含量在花芽分化基本完成时均达到高峰,相反IAA含量处于低谷;ABA含量在花芽分化中期达到高峰,而此时GA3和ZR含量处于低谷;内源激素含量峰、谷时间和叶底红花芽分化的完成时间相一致;4种激素含量的变化均达到极显著差异。研究表明这几种激素均与叶底红花芽分化密切相关,高水平的ABA/IAA、ZR/IAA、ZR/GA3有利于花芽分化,高水平的ABA/GA3有利于花芽孕育。     

蝴蝶兰催花过程中叶片内源激素含量的动态变化

为研究蝴蝶兰‘绿熊’在催花过程中的内源激素的动态变化,以2年生健康成熟的‘绿熊’为试验材料,测定其在花芽分化期、抽梗期、着苞期和开花期内的生长素(IAA)、赤霉素(GA)、脱落酸(ABA)和玉米素核苷(ZR)的含量变化。结果表明,在催花15~45天（花芽分化期）,IAA和GA开始大幅度降低,在45天时达到了花芽分化时期内的最低值;在抽梗期内IAA和GA开始迅速升高并在催花95天时达到最大,显著高于其他各时期的IAA和GA含量;催花195~240天（开花期）内两者均降低。ABA和ZR在催花15天（花芽分化期）时开始显著上升;抽梗期内ABA的含量下降,而ZR变化不显著;着苞期和开花期内两者均上升,ABA和ZR催花240天（开花期）时达最高值,分别为催花0天（花芽分化期）时的3.2倍和2.97倍。研究认为,内源激素变化对‘绿熊’的花芽分化花器官发育起着十分显著的调控作用,低浓度的IAA、GA和高水平的ABA、ZR有促进‘绿熊’花芽分化的作用,高浓度的IAA、GA和ZR有利于‘绿熊’花梗的伸长。     

乙炔催花对凤梨‘丹尼斯’花芽分化及内源激素含量的影响

为了探讨凤梨开花的生理机制以及为凤梨花期调控提供理论依据,以凤梨‘丹尼斯’为试材,研究乙炔催花对其花芽分化及内源激素含量的影响。结果表明：乙炔催花7天后诱导‘丹尼斯’进入花芽分化状态,其花芽分化进程可分为花芽未分化期、花序原基分化期、花原基分化期、花萼花瓣分化期、雌雄蕊分化期。在整个花芽分化过程中,植株生长点及叶片中生长素（IAA）、脱落酸（ABA）含量未见明显改变,而玉米素核苷（ZRs）在花序原基分化期和花原基分化期呈现出2次显著增加,赤霉素（GAs）含量在花序原基分化期和器官分化早期显著下降,从而引起ABA/GAs、ZRs/GAs、ZRs/IAA比值在花序原基分化期、花原基分化期和器官分化早期显著增加。表明,高水平的ZRs含量、ABA/GAs、ZRs/GAs、ZRs/IAA比值以及低水平的GAs含量有利于凤梨‘丹尼斯’花芽分化的完成。     

枳椇休眠期间芽和枝皮中内源激素的变化比较

[目的]研究枳椇休眠期间芽和枝皮中内源激素的变化。[方法]以4年生枳椇植株为试材,采用ELISA法测定了枳椇休眠过程中芽和枝皮中内源激素ABA、GA、IAA和ZR含量的变化。[结果]在休眠期间,枳椇芽和枝皮中ABA含量最多,其次是IAA,ZR、GA的含量最少;芽和枝皮中ABA的含量都不随休眠的加深或休眠的解除简单的增加或减少,芽中IAA、GA、ZR含量在休眠的前期和后期分别呈增加或减少的变化趋势,在休眠期的中期有一个明显的峰,而枝皮中IAA、GA、ZR含量的变化趋势与芽中的变化趋势明显不同。[结论]芽中激素的含量并不依赖于枝皮中激素的含量,2组织中激素的含量没有显著的相关性。     

勒杜鹃花芽分化过程中内源激素含量和碳氮营养的变化研究

以勒杜鹃（Bougaivillea glabra）为材料,研究成花过程中叶片内源激素含量和碳氮营养的变化,为勒杜鹃花期调控提供理论依据。结果表明：勒杜鹃花芽分化前期L姐和GA3含量降低,ABA、ZT含量的升高;花芽分化中期GA3、ABA含量继续上升,ZT略有下降;花芽分化末期,ZT／IAA、ABA／IAA、ZT／GA3、ABA／GA3比值均呈现不同程度的上升,在初花期时ZT/IAA、ZT／GA3呈现下降趋势。勒杜鹃花芽分化过程中可溶性糖含量先升后降,总氮含量持续下降。