BA、GA3和IAA对富士苹果果形形成的影响

以9年生富士苹果为材料,研究富士苹果形成过程中BA、GA,和IAA对果形、品质、内源激素含量的影响。结果表明：在花期喷GA,对富士苹果的坐果率影响效果最好,分别比清水对照和无处理对照提高49％和79．45％。BA100mg·L^-1GA3300mg·L^-1＋IAA20mg·L^-1对降低富士苹果偏斜率效果最好。在花期、花期＋幼果期和幼果期分别喷BA和在花期喷GA3可以提高果实中可溶性固形物的含量。花期喷IAA、BA、GA,和BA＋GA,＋IAA对内源激素IAA和GA3的含量均有促进作用,在整个生长季内不同处理下IAA、GA3含量均高于清水对照且差异明显;花期喷BA、GA3和BA＋GA3＋IAA对内源激素ZT含量有促进作用,尤其在果实幼果期和膨大期与清水对照相比效果明显;花期喷GA3和BA＋GA3＋IAA与清水对照相比内源激素ABA含量有明显降低,其中幼果期变化显著。     

甘蓝型油菜核不育系组织培养快速繁值

1植物名称甘蓝型油菜（Brassicanapus）胞核雄性不育系“117A”，半冬性，由贵州省油料科学研究所提供。2材料类别初花期尚未开花的上部分校苔茎段切片。3培养条件培养基：（1）B5＋6－BA2mg／L（单位下同）十谷氨酸胺2＋KTI＋GA30.5＋水解乳蛋白500；（2）B5＋6－BA10；（3）B     

多效矬(PP_(333))对桃树生长发育的作用

土壤施用和叶面喷布多效唑,一年生桃树新梢生长显著受抑,新梢节间缩短,树高降低和树冠体积减小,施用量增加抑制增强。翌年仍有后效作用。土壤施用时,可促进芽早发,但不抽出新梢,增施GA类则可。多效唑还能增加叶绿素含量及光合强度,促进花芽形成,有利于桃果产量增加,而对桃果大小、单果重及品质没有不良影响。     

药剂输液滴干对龙眼成花的影响

虹吸输液滴干技术作为一种新型的输液技术,能显著提高龙眼对调节剂的利用率。该研究利用虹吸输液滴干技术来研究氯酸钾与多效唑对龙眼成花的影响,同时探索从花芽生理分化期开始控制龙眼冲梢的方法。结果表明：氯酸钾输液滴干不但能够促使龙眼提早开花,而且能够提高其成花率、抽穗率、雌雄花比例与坐果率。不同品种龙眼对氯酸钾的敏感度不同,‘石硖’对氯酸钾最为敏感,但稳定性低;‘储良’对氯酸钾的敏感性低,但稳定度高;‘桂香’对氯酸钾的敏感性与稳定度居中。从整体上看,‘石硖’的处理效果最好,最佳处理次数为3次,每次施用7.5 L浓度为1 g·L-1的氯酸钾,处理后枝梢成花率、枝梢抽穗率、雌雄花比例、坐果率分别为53.67％、59.38％、16.01和19.58％。多效唑输液滴干对‘桂龙1号’的控梢效果显著,有效促进了龙眼成花,并以160 mg·L-1的多效唑溶液处理效果最佳,抽梢率为15.16％,抽穗率、雌花率、花穗长、花穗宽和坐果率分别为96.53％、10.36％、21.95 cm、12.96 cm和38.37％。药剂输液滴干技术施用氯酸钾和多效唑对于龙眼成花坐果有积极作用,该研究结果为实现高效、省工、环保的果园管理模式提供了借鉴。     

保鲜液对郁金香切花寿命和内源激素含量的影响（简报）

低温（4℃）条件下,4种保鲜液（1mmol·L－1硫代硫酸银＋200mg·L-1-羟基喹啉＋2％蔗糖＋300mg·L-1柠檬酸及不同浓度6－BA或GA3组合）均可延长郁金香切花的寿命,其中以含有6－BA的保鲜液作用最显著。对照和含有GA3的保鲜液处理的切花第8d出现乙烯高峰,IAA和ABA含量前期下降后期开高;而含有6－BA的保鲜液处理的切花乙烯、IAA和ABA均呈下降趋势。3种内源激素含量变化与切花衰老在时间进程上是一致的。     

多效唑调节水稻植株生长的作用机理

多效唑处理水稻植株后使株高降低和分蘖增加,植株体内的GA类物质和IAA含量相应下降,乙烯释放率显著增加;用外源GA_3和氮肥能逆转多效唑的抑制作用而使株高增加,同时GA类物质含量也明显增加。因此,多效唑不仅调节体内的GA类物质含量,还能通过调节IAA含量和乙烯释放率而影响植物生长。     

多效唑对香蕉试管苗生长的影响（简报）

多效唑对香蕉试管苗有明显的矮化和延缓生长作用。它与NAA配合使用能促进长根,加快成苗速度,而且苗壮、耐荫。与6－BA配合使用可有效地提高分化芽的增殖系数。分化芽粗壮鲜绿,成活率高。     

几种调控措施对龙眼顶芽激素及成花坐果的影响

以当地主栽龙眼品种‘泸丰一号’为材料,在龙眼花芽形态分化期开始前,采取树冠喷施不同比例的生理调节剂、骨干枝环割、断根等调控措施,定期测定花芽分化期顶芽内源激素,在花芽分化完成后统计成花坐果率,研究调控措施对龙眼顶芽激素含量动态变化和成花坐果率的影响。结果表明:几种措施处理都不同程度地提高了龙眼的成花坐果率,适当浓度(150 mg·L-1及100 mg·L-1)乙烯调节剂组合调控措施可以显著提高树体的雌花数、雌花率及坐果率,其中雌花率分别比对照提高了32.57%和38.22%;各处理的冲梢率显著低于对照,其中处理B(100 mg·L-1乙烯利调节剂组合)的冲梢率(18.58%)最低,比对照低34.18%,且芽轴增长率与冲梢率呈显著正相关,其中以150.00 mg·L-1多效唑+100.00 mg·L-1乙烯利+1.0 mg·L-1细胞分裂素配制好的药液均匀喷洒在树冠上的处理效果最优。几种措施对于龙眼顶芽中的激素及激素的平衡的影响表现为GA3含量和ABA含量在花序主轴分化期较高,在多级侧花序快速分化期则处于较低水平,整个形态分化期ZT始终保持较低水平,则利于防止龙眼成花逆转,从而促进龙眼花芽分化;IAA含量受各处理影响变化较为复杂,并未呈现出较强的规律性;从激素比例方面看,龙眼顶芽在花序主轴分化前期IAA/GA3比值较低,末期ZT/GA3比值较高则有利于成花,在整个形态分化期ZT/ABA及GA3/ABA都处在较低的水平,可有效抑制成花逆转。研究结果可为龙眼的成花机理以及四川泸州地区龙眼的优质丰产栽培提供理论依据。     

对节白蜡的组织培养及植株再生

1植物名称对节白蜡（Fnainushupehen－sis）,又名湖北白蜡,湖北俗称对节树、望乡树。2材料类别幼嫩茎段,取自本校盆景园20～30年生中型盆景桩（高50～60cm）当年新梢。3培养条件分化培养基：（1）MS＋6－BA2．5mg·L－1（单位下同）;（2）MS＋6－BA5．0;（3）MS＋6BA10．0;（4）WPM＋6-BA2．5;（5）WPM＋6－BA5．0;（6）WPM-6-BA10．0;（7）DKW＋6－BA2．5;（8）DKW＋6－BA5．0;（9）DKW＋6－BA10．0。生根培养基：（1）WPM＋IBA0．5;（11）WPM＋IBA2．0。以上培养基均附加蔗糖30g·L－1,琼脂6g·L-1…     

不同植物生长调节剂对小麦衰老及产量构成的调节效应

研究了叶面喷施GA3、NBT、6－BA、TIBA、PP333对小麦旗叶衰老过程中若干生理指标的影响,分析了它们对成产要素的不同作用。结果表明：不同生长调节剂可以以不同的方式调节小麦旗叶的衰老,影响小麦产量构成因素水平。其中6－BA和PP333能够提高单位面积穗数,明显延缓叶片衰老,增加了穗粒数和千粒重,使成产3因素间比例协调合理,产量较高;TIBA可以明显提高叶绿素含量并显著提高千粒重。GA3和NBT对延缓旗叶衰老有一定作用,但增产效果不显著。研究指出,根据小麦生育状况有选择性地使用生长调节剂,协调成产因素关系,是一个有效的增产途径。     

苹果坐果的激素调控

以红富士苹果为试材,花朵数为5的花序,其坐果率明显高于花朵数为4的花序。开花前,花朵数为5的花序,其花朵子房内GAs,、Z浓度明显高于后者;开花后,后者GAs仍然低于前者,但Z浓度、Z／GAs比值则迅速增加并明显高于前者。蕾期喷施GA4 7DCPTA、Glu、SA可以明显提高花朵数为4的花序的坐果率。     

Gibberellin content of immature apple seeds from paclobutrazol-treated trees over three seasons

Seeds from heavily fruiting (on-year), mature untreated, and paclobutrazol-treated apple trees (Malus domestica Borkh. cv. Spartan) were sampled in mid-June 1987, mid-July 1987, and mid-July 1990. After seeds were freeze-dried, gibberellins (GAs) were extracted, purified, and fractionated via C₁₈ reversed-phase high-performance liquid chromatography (HPLC). Nine GAs (GA₁, GA₃, GA₄, GA₇, GA₈, GA₉, GA₁₉, GA₂₀, and GA₅₃) were quantified by the use of deuterated GA internal standards. Paclobutrazol trunk drench treatments reduced vegetative shoot elongation in the seasons that seeds were sampled by 55% or more. Between June 17, 1987 and July 15, 1987, the dry weight of seeds from both untreated and treated trees increased about 2.5 times and there were reductions, on a per seed basis, of GA₄ in seeds from both untreated and treated trees, of GA₇ in seeds from treated trees, and of GA₉ in seeds from untreated trees. However, GA₉ increased in seeds from treated trees. Changes in levels of some of the early-13-hydroxylation pathway GAs (GA₁₅ GA₃, GA₈, GA₁₉, GA₂₀, and GA₅₃) also occurred during the month. For mid-July harvested seeds, the pattern, with some exceptions, was that 2 years after paclobutrazol treatment (1987), levels of early-13-hydroxylation pathway GAs in seeds from treated trees were lower compared to controls but after 5 years (1990) their levels tended to increase. For the non-13-hydroxylated GAs (GA₄, GA₇, and GA₉), 2 years after paclobutrazol treatment, GA₄ levels were equal in seeds from untreated and treated trees, GA₇ decreased in seeds from treated trees compared with controls, but GA₉ levels increased. Levels of these three GAs were higher in seeds from treated trees 5 years after treatment (1990) but levels of GA₄, GA₇, and GA₉ dramatically increased in seeds from treated trees 4 years after treatment (1989), as we previously reported.     

EAF1 regulates vegetative-phase change and flowering time in Arabidopsis.

We have identified a new locus that regulates vegetative phase change and flowering time in Arabidopsis. An early-flowering mutant, eaf1 (early flowering 1) was isolated and characterized. eaf1 plants flowered earlier than the wild type under either short-day or long-day conditions, and showed a reduction in the juvenile and adult vegetative phases. When grown under short-day conditions, eaf1 plants were slightly pale green and had elongated petioles, phenotypes that are observed in mutants altered in either phytochrome or the gibberellin (GA) response. eaf1 seed showed increased resistance to the GA biosynthesis inhibitor paclobutrazol, suggesting that GA metabolism and/or response had been altered. Comparison of eaf1 to other early-flowering mutants revealed that eaf1 shifts to the adult phase early and flowers early, similarly to the phyB (phytochrome B) and spy (spindly) mutants. eaf1 maps to chromosome 2, but defines a locus distinct from phyB, clf (curly leaf), and elf3 (early-flowering 3). These results demonstrate that eaf1 defines a new locus involved in an autonomous pathway and may affect GA regulation of flowering.     

Nitrate,abscisic acid and gibberellin interactions on the thermoinhibition of lettuce seed germination

Germination of lettuce seeds has obvious thermoinhibition, but the mechanism for thermoinhibition of seed germination is poorly understood. Here, we investigated the interactions of nitrate, abscisic acid (ABA) and gibberellin on seed germination at high temperatures to understand further the mechanism for thermoinhibition of seed germination. Our results showed that lettuce (Lactuca sativa L. ‘Jianye Xianfeng No. 1’) seeds exhibited notable thermoinhibiton of germination at ≥17°C in darkness, and at ≥23°C in light, but the thermoinhibited seeds did not exhibit secondary dormancy. Thermoinhibition of seed germination at 23 or 25°C in light was notably decreased by 5 and 10 mM nitrate, and the stimulatory effects were markedly prevented by nitric oxide (NO) scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. The sensitivity of seed germination to exogenous ABA increased with increasing temperature. Thermoinhibition of seed germination was markedly decreased by fluridone (an inhibitor of ABA biosynthesis) and GA₃, and was increased by diniconazole (an inhibitor of the ABA-catabolizing enzyme ABA 8′-hydroxylase) and paclobutrazol (an inhibitor of GA biosynthetic pathway). The effect of fluridone in decreasing thermoinhibition of seed germination was obviously antagonized by paclobutrazol, and that of GA₃ was notably added to by fluridone, and that of nitrate was antagonized by paclobutrazol, diniconazole and ABA and was added to by GA₃ and fluridone. Our data show that thermoinhibition of lettuce seed germination is decreased by nitrate in a NO-dependent manner, which is antagonized by ABA, diniconazole and paclobutrazol and added by fluridone.     

Chemical screening and development of novel gibberellin mimics

Gibberellin (GA) plays versatile roles in the regulation of plant growth and development and therefore is widely used as a regulator in agriculture. We performed a chemical library screening and identified a chemical, named 67D, as a stimulator of seed germination that was suppressed by paclobutrazol (PAC), a GA biosynthesis inhibitor. In vitro binding assays indicated that 67D binds to the GID1 receptor. Further studies on the structure–activity relationship identified a chemical, named chemical 6, that strongly promoted seed germination suppressed by PAC. Chemical 6 was further confirmed to promote the degradation of RGA (for repressor of ga1-3), a DELLA protein, and suppress the expression levels of GA3ox1 in the same manner as GA does. 67D and its analogs are supposed to be agonists of GID1 and are expected to be utilized in agriculture and basic research as an alternative to GA.     

Functional analysis of HvSPY,a negative regulator of GA response,in barley aleurone cells and <Emphasis Type="Italic">Arabidopsis</Emphasis>

SPINDLY (SPY) is an important regulator of plant development, and consists of an N-half tetratricopeptide repeat (TPR) domain containing 10 TPR motifs and a C-half catalytic domain, similar to O-GlcNAc transferase (OGT) of animals. The best characterised role of SPY is a negative regulator of GA signalling, and all known spy alleles have been isolated based on increased GA response. Of the eight alleles that directly affect the TPR domain, all alter TPRs 6, 8 and/or 9. To test the hypothesis that a subset of TPRs, including 6, 8 and 9, are both essential and sufficient for the regulation of GA response, we overexpressed the full-length barley (Hordeum vulgare L.) SPY protein (HvSPY) and several deletion mutants in barley aleurone cells and in Arabidopsis wild type (WT) and spy-4 plants. Transient assays in barley aleurone cells, that also express endogenous HvSPY, demonstrated that introduced HvSPY and HvTPR inhibited GA₃-induced α-amylase expression. With the exception of HvSPYΔ1–5, the other deletion proteins were partially active in the barley assay, including HvSPYΔ6–9 which lacks TPRs 6, 8 and 9. In Arabidopsis, analysis of seed germination under a range of conditions revealed that 35S:HvSPY increased seed dormancy. Hvspy-2, which lacks parts of the eighth and ninth TPRs, was able to partially complement all aspects of the spy-4 phenotype. In the presence of AtSPY, 35S:HvTPR caused some phenotypes consistent with a decrease in GA signalling, including increased seed sensitivity to paclobutrazol and delayed flowering. These plants also possessed distorted leaf morphology and altered epidermal cell shape. Thus, despite genetic analysis demonstrating that TPRs 6, 8 and 9 are required for regulation of GA signalling, our results suggest that these TPRs are neither absolutely essential nor sufficient for SPY activity. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.