植物生長調(diào)節(jié)劑對萌芽的影響

1、Plant Growth Regulators, Buds and Bud InitiationDescribe grapevine vegetative morphology and its functionRange: buds, leaves, shoots, tendrils, permanent woodIdentify and describe factors affecting grapevine phenologyRange: environmental factors, hormonestcreagheit.ac.nz共五十八頁Plant growth RegulatorsH

2、ormones are substances synthesized by the plant to act as messengersThey are produced at one site and generally transported in the xylem or phloem to another to induce a physiological reaction (eg growth)tcreagheit.ac.nz共五十八頁Plant growth Regulators They may also cause different effects in different

3、parts of the grape vineThese reactions are complex and not always fully understoodVery small amounts of hormone are required to cause an actionThey may act either alone or interact with other hormonestcreagheit.ac.nz共五十八頁Plant growth Regulators There are five main groups of hormones in plantstcreagh

4、eit.ac.nz共五十八頁 Auxinstcreagheit.ac.nz共五十八頁 AuxinsSource of productionNew vegetative growthYoung leavesSeedstcreagheit.ac.nz共五十八頁 AuxinsActionsAttracts sugar and nutrients to site of productionStimulates cell growth in young tissueInhibits lateral budburst further down the shoot ie apical dominancePr

5、omotes growth towards lighttcreagheit.ac.nz共五十八頁Gibberellinstcreagheit.ac.nz共五十八頁GibberellinsSource of productionYoung growing shoot and leavesRoot tipsActionsSuppresses flower bud initiation and fruitfulness in cool weather/poor lightPromotes growth and cell elongationExampleGA-3 is sprayed on seed

6、less grapes to increase grape size and yield tcreagheit.ac.nz共五十八頁Cytokininstcreagheit.ac.nz共五十八頁CytokininsSource of productionRoot tipsActionsPromotes cell multiplication in differentiating tissues at apicesAttracts auxin and gibberellin, sugars, nutrientsPromotes even budburstPromotes lateral bran

7、chingtcreagheit.ac.nz共五十八頁CytokininsPromotes development of leaves, fruit structures, fruit set with gibberellins to balance fruitfulness of lateral budsDelays senescencePromotes berry as a sinkInvolved in anthocyanin and flavour formationtcreagheit.ac.nz共五十八頁Abscissic Acidtcreagheit.ac.nz共五十八頁Absci

8、ssic AcidSource of production Mature leavesSeeds, rootstcreagheit.ac.nz共五十八頁Abscissic AcidActionGenerally counteracts effects of auxin, gibberellin and cytokininInduces stomatal closure in response to water stressReduces growth in response to water stress, cold and short daysPossibly promotes ripeni

9、ng as auxin production reduces in seedstcreagheit.ac.nz共五十八頁Ethylenetcreagheit.ac.nz共五十八頁EthyleneSource of production Mature leaves and other parts of vineActionAffects many types of growth, not all of which are clearly definedPromotes ripening and berry colourPromotes abscission zone developmenttcr

10、eagheit.ac.nz共五十八頁Plant growth Regulators In general terms, auxins and gibberillins complement each other, promoting growthCytokinin induces fruit and ripening when weather conditions and other factors are suitable for fruit to ripenAbsissic acid and ethylene promotes ripening and prepares the vine

11、for dormancytcreagheit.ac.nz共五十八頁tcreagheit.ac.nzIncreaseResultAuxinLow light, temperature.Acts with gibberellins to promote growth.GibberellinsIncreased by low light, low temperature.Elongates cells producing spindly shoots.CytokininIncreased by increased light, leaf exposure, warm root environment

12、.Promotes growth and fruit ripening.Absissic acidIncreased by lack of water, cool weather, short days.Promotes fruit ripening as fruit becomes a major sink if abscissic acid is greater than auxin.EthyleneIncreased by short days, drought, nitrogen deficiency.Artificial application.Physical contact, m

13、echanical damage.Promotes abscission.Improve colour, reduce shoot growth.Reduced shoot growth, enhanced ripening.共五十八頁Some Practical Implications of Hormone Actions1Auxin is produced in the growing tips and travels downwardsTo prevent uneven budburst and end point principle, where the end bud bursts

14、 first, canes are arched during pruning to slow the movement of auxin along the caneSpur pruning is not subject to uneven budbursttcreagheit.ac.nz共五十八頁Some Practical Implications of Hormone Actions 2Removal of the growing tip will promote lateral growth, as the site of auxin inhibition of budburst i

15、s removedtcreagheit.ac.nz共五十八頁Some Practical Implications of Hormone Actions3Shaded shoots tend to grow long and spindly with long internodes until they reach light, where growth becomes normalBuds also tend to be less fruitful in shaded vines, due to the actions of gibberellintcreagheit.ac.nz共五十八頁S

16、ome Practical Implications of Hormone Actions4Berry size is related to the number of seeds (developed embryos) due partly to hormone production, increasing the berry as a sinktcreagheit.ac.nz共五十八頁Some Practical Implications of Hormone Actions5Warm, well drained soils during budbreak improve the even

17、ness of budburst due in part to cytokinins produced from increased root growth promoted due to the warmer conditionstcreagheit.ac.nz共五十八頁Some Practical Implications of Hormone Actions 6FruitfulnessThe number of clusters is increased with warmer temperatures due to cytokinin productionWhereas in shad

18、ed or cool situations gibberellins tends to promote tendril formationtcreagheit.ac.nz共五十八頁Some Practical Implications of Hormone Actions 7As vegetative growth slows close to ripening, less auxin and gibberellins are producedLess auxin is produced as the seed ripens in stage 2tcreagheit.ac.nz共五十八頁Som

19、e Practical Implications of Hormone Actions Abscissic acid increases in proportion inducing veraison and the berry becomes a major sinktcreagheit.ac.nz共五十八頁Some Practical Implications of Hormone Actions Cytokinin also increases, attracting sugar to the berry, abscissic acid and perhaps having an eff

20、ect on berry colour and flavourContinuing ripening during cool climates may depend partially on warmer soil temperatures favouring cytokinin productiontcreagheit.ac.nz共五十八頁Hormones and Initiation of Inflorescence PrimordiaHormones are synthesized within the vine control the initiation and developmen

21、t of inflorescence primordia within the budThey do not act in isolationRelative proportions of determine what is formed tcreagheit.ac.nz共五十八頁Hormones and Initiation of Inflorescence PrimordiaThe number size of inflorescences is the first indication of yield tcreagheit.ac.nz共五十八頁Yield componentstcrea

22、gheit.ac.nz共五十八頁DefinitionsFecunditythe potential reproductive capacity of an organism or population FruitfulnessThe presence of inflorescence primordia in latent budsMean bunch number per shootThree step process:Formation of an uncommitted primordiumDevelopment into inflorescence primordiumFormatio

23、n of flowerstcreagheit.ac.nz共五十八頁Budstcreagheit.ac.nz共五十八頁BudsThe grapevine buds develop in the axil of the leaf and the shoot, that is, at the node.There are various types of grapevine buds:Prompt budCompound budLatent budtcreagheit.ac.nz共五十八頁tcreagheit.ac.nz共五十八頁Lateral or Prompt budThe lateral sh

24、oot arises from the lateral or prompt budIt is formed between the primary or new seasons shoot and the leaf arising from it, that is, in the leaf axilIt may be also referred to as the true axillary budtcreagheit.ac.nz共五十八頁tcreagheit.ac.nz共五十八頁Lateral or Prompt budThe prompt bud can burst in the curr

25、ent season to produce short shoot known as the lateralHowever, lateral shoots will form only under certain conditionsVigorous vines or if topping occurs early in the seasontcreagheit.ac.nz共五十八頁Lateral or Prompt budLateral shoots are generally unfruitful but bunches may grow on the lateral shootIf th

26、ey do they are usually small and ripen after those carried on the primary shootThese bunches are referred to as second settcreagheit.ac.nz共五十八頁Compound Buds The compound bud is formed after the prompt bud and develops more slowly These buds also develop in the leaf axil at the node. It consists of t

27、hree true buds tcreagheit.ac.nz共五十八頁tcreagheit.ac.nz共五十八頁tcreagheit.ac.nz共五十八頁Compound BudsThe compound bud does not burst until the season after its developmentGenerally only the middle, or primary, bud bursts to develop the primary (main) shoot If this is damaged (wind, frost, etc) then the second

28、ary or tertiary buds may burst However, these buds are generally less fruitful, that is they have fewer bunches per shoottcreagheit.ac.nz共五十八頁Compound BudsThe number of potential bunches per bud, and therefore per shoot, are determined as the compound bud develops, that is, in the previous season be

29、fore bud burst. Note that as the shoot develops, compound buds are developing with the shoot development. Those at the base of the shoot will be more developed than those close to the apical tip.tcreagheit.ac.nz共五十八頁Compound BudsEnvironmental factors during bud development influence the potential cr

30、op in 18 months timeA major influence is light interception at the bud and the temperature; increased light and temperature has been shown to result in greater fruitfulness.tcreagheit.ac.nz共五十八頁Latent budThese are buds that may be any type of bud that do not burst in the season that they are formedI

31、nstead they remain dormant and viable and at some later stage may burst. Latent buds may take several seasons to burst, often as a result of vine damage or heavy pruningtcreagheit.ac.nz共五十八頁tcreagheit.ac.nz共五十八頁Compound budtcreagheit.ac.nzCompound budLeaf scarLateral scar共五十八頁Bud InitiationBuds unde

32、rgo differentiationThat is, primordial structures within the bud change depending on plant growth regulators that these structures receiveThe level of plant growth regulators that the bud receives is dependant on climatic conditions during differentiationtcreagheit.ac.nz共五十八頁Bud InitiationDifferentiation coincides with floweringAnd the slowing down of vegetative growthVery sensitive to water stresstcreagheit.ac.nz共五十八頁Bud InitiationAnlagen is a primordia that can become InflorescencesRepeated branching T