Prof. Dr. Károly Hrotkó. SZIU Faculty of Horticultural Science

Prof. Dr. Károly Hrotkó SZIU Faculty of Horticultural Science

Fertilization of flowers Dr. Hrotkó Károly Seed production systems 2

Prof. Dr. Hrotkó Károly Seed germination.. 3

Seed development types Prof. Dr. Hrotkó Károly Seed germination.. 4

Seed longevity Type Vivipary Short living seeds Orthodox seeds Moderate longevity Orthodox seeds Long living seeds Typical species Seed germinates in fruit (mangrove), corn, some cereals (lack of ABA or missing ABA sensitivity) Populus, Salix, Acer, Ulmus, Carya, Betula, Carpinus, Corylus, Castanea, Fagus, Quercus, Juglans, Aesculus 1-2 years: cotton, sunflower, soybean, bean, onion, Begonia, Coreopsis, Vinca 3-5 years: cereals, cabbage, pea, cucumber, Alyssum, Dianthus, Coleus, Cyclamen, Tagetes, Petunia, Rosaceae 5 év < luzerne, glove, beet, tomato, Zinnia, Leguminosae, Geranium (15-20 év), Nelumbo nucifera (100-500 év) Prof. Dr. Hrotkó Károly Seed germination.. 8

Viability, longevity and moisture content For longer storage low moisture content (4-6 %) is recommended. Increasing temperature --- decreasing moisture content recommended. Most of seeds of moderate longevity could be stored well at 10-14 % moisture content. Short living seeds do not survive larger water contents decrease (Acer saccharinum, Citrus sp., Quercus, Caria, Juglans, Aesculus, stb) Prof. Dr. Hrotkó Károly Seed germination.. 9

Germination: 1. requirements: viable seed optimal environmental factors seed is not dormant 2. Phases: Phase I: Water uptake by imbibition, water content increases rapidly, than slows down. Fresh weight increases, seed coat may tear up, enzymes are activated. After a shorter or longer lag phase germination, growth of radicle starts. Prof. Dr. Hrotkó Károly Seed germination.. 10

Changes in the cell due to water uptake Prof. Dr. Hrotkó Károly Seed germination.. 11

Effect of water content (at 20 C -on) and temperature on respiration of barley seed (Kunze 1983) Water % CO 2 mg 24hours -1 11 0,3 12 0,4 14-15 1,4 17 100 19,6 123 20,5 359 30 2000 Temperature CO 2 mg 24hours -1 15 C 1,3 1,5 30 C 7-8 40 C 20 52 C 249 Prof. Dr. Hrotkó Károly Seed germination.. 12

Water uptake in barley seed at 10 C (Kunze 1983) Water content % Days Prof. Dr. Hrotkó Károly Seed germination.. 13

Water uptake of Prunus mahaleb seed at different temperature Water content % Hours Prof. Dr. Hrotkó Károly Seed germination.. 14

Barley seed size (mm) and water uptake at 10 C temperature 49 48 47 46 45 44 43 42 41 40 2,9 2,8 2,7 2,6 2,5 2,4 2,3 2,2 2,1 2 water content % Seed diameter (mm) Prof. Dr. Hrotkó Károly Seed germination.. 15

Main rules of water uptake Depends on seed and fruit structure and water uptake characteristics Relative surface of small seeds related to mass is larger (soaking for 4-12 hours) Relative surface of larger seeds related to mass is smaller (soaking for 12-72 hours) Optimal water content for germination differs by species. Prof. Dr. Hrotkó Károly Seed germination.. 16

Lag phase (phase II): - Mitochondria maturation; - Protein synthesis; - Metabolism of storage reserve material; - Specific enzyme production. Harmadik szakasz: a magonc növekedése: Az embrió két növekedési pontján megkezdődik a sejtosztódás. A vízfelvétel a gyökerek növekedésével növekszik és a magonc tömege gyarapodásnak indul. - epigeus csírázás: a sziklevelek a felszín felé emelkednek és hosszabb - rövidebb ideig asszimilálnak. (cseresznyefélék, alma, körte, birs, berkenye) - hipogeus csírázás: a sziklevelek a talajban maradnak, és csak a növekvő epikotil emelkedik a talajfelszín fölé. (őszibarack, mandula) Prof. Dr. Hrotkó Károly Seed germination.. 17

Mobilization of reserve materials during the germination (Hartmann et al. 1997) Prof. Dr. Hrotkó Károly Seed germination.. 20

Steps of starch decomposition (Hartmann et al 1997) Prof. Dr. Hrotkó Károly Seed germination.. 21

Starch mobilization in cereals (Hartmann et al. 1997) Prof. Dr. Hrotkó Károly Seed germination.. 22

Role of gibberellic acid in barley seed germination (Kunze 1983) Diffusion of GA from embryo through scutellum into endospermium and tha to aleuron layer Enzym production in aleuron-layer: β-glukanase, α- amylase, protease (β-amylase is present in endospermium) Gibberellic acids considerable increase the amylaseproduction. Application: 1g GA solution in 50 ml alcohol or aceton, diluted by water( for 1 t barley 0,03-0,08 g GA) Germination is faster and germination rate is increasing. Prof. Dr. Hrotkó Károly Seed germination.. 23

Lag phase (phase II): - Mitochondria maturation; - Protein synthesis; - Metabolism of storgae reserve material; - Specific enzyme production. Phase III.: growth of seedling: on both end of embryo cell division is started, seedling takes up water, mass of seedling in increasing. - epigeic germination: cotyledons above soil level assimilate shorter or longer (cherry, apple pear, sorrbus, quince) - hypogeic germination: cotyledons remain in the soil, only epicotyl emerge above soil level (peach, almond) Prof. Dr. Hrotkó Károly Seed germination.. 24

Epigeic germination: Prof. Dr. Hrotkó Károly Seed germination.. 25

Hypogeic germination: Prof. Dr. Hrotkó Károly Seed germination.. 26

Days Role of temparature on apple seed germination (Haas and Schander 1952) Prof. Dr. Hrotkó Károly Seed germination.. 27

Role of soil moisture content on seed germination of onion (Hartmann et al. 1997) Prof. Dr. Hrotkó Károly Seed germination.. 28

Seed development Prof. Dr. Hrotkó Károly Seed germination.. 29

Seed dormancy: 1. Induced by seed (fruit) coat Physical dormancy Mechanical dormancy 2. Inhibitor induced dormancy 3. Morphological dormancy 4. Physiological dormancy 5. Physiological deep dormancy (embryo dormancy) Prof. Dr. Hrotkó Károly Seed germination.. 30

Dormancy induced by seed coat: - Physical: impermeable seed coat (Rosaceae). lifting: soaking, scarification, breaking fruit coat. - mechanical dormancy: in certain seds (Juglans, Prunus, Olea) the pit doesn t allow the emergence of embryo. lifting: by stratification Prof. Dr. Hrotkó Károly Seed germination.. 31

Inhibitor induced dormancy: Inhibitors (phenolic compounds, coumarin, abscizic acid) accumulated during the fruit ripening (apple, stone fruits, grape, citrus). Lifting: removal of fruit flesh, washing, soaking the seeds. Morfological dormancy: at seed abscision the embrio is not completely developed. After water uptake the embryo continues its development before germination starts. (Fraxinus, Euonymus) Prof. Dr. Hrotkó Károly Seed germination.. 32

Physiological dormancy: due to interaction of endogenous inhibitors, hormone, and environmental conditions (temperature, light) can be lifted gradually. Physiological deep dormancy (embryo - dormancy): excised embrio remains dormant even if the environmental conditions are optimal. Typical to emperate zone woody plants (oak). Seed ripes autumn, falls dawn to soil and overwinter. Lifting: stratification. Prof. Dr. Hrotkó Károly Seed germination.. 33

Seed dormancy types (Hartmann et al 1997) Dormancy type Characteristics 1. Exogen dormancy physical mechanical chemical 2. Endogen dormancy Morfological Physiological Non deep transitional Deep Epicotil dormancy 3. Double (combined dormancy) Morphophysiological Exogen endogen dormancy Factors outside of embtryo Impermeable seed coat Layers restricting the germination Inhibitors in seed coat Inner factors in embryo Underdeveloped embryo Inner factors Afterripening is needed Can be lifted by seed coat removal Seed coat removal doesn t lift Radicle grows in optimal environmental conditions Underdeveloped embryo + physiological Physical+transitional physiological 4. Secondary dormancy Prof. Dr. Hrotkó Károly Seed germination.. 34

Example for combined dormancy at peach (Prunus persica) seeds: 1. Fruit flesh (inhibitors in fruit flesh) inhibitor induced dormancy 2. Pit (hard coat, endocarpium ) mechanical 3. Seed coat (gas-impermeable seed coat, modifying gas exchange) Physical dormancy 4. Seed (epikotil dormant gibberellic acid production is inhibited)- physiological deep dormancy Prof. Dr. Hrotkó Károly Seed germination.. 35

Germination of peach seeds treated with GA at different temperature Prof. Dr. Hrotkó Károly Seed germination.. 37

Germination of GA treated Prunus mahaleb seeds Germinated % 120 100 80 60 40 R 2 = 0,9781 R 2 = 0,9947 R 2 = 0,9949 20 0-20 2008.03.20 2008.03.27 2008.04.03 2008.04.10 2008.04.17 2008.04.24 2008.05.01 2008.05.08 2008.05.15 2008.05.22 Kontroll GA 3 GA 4+7 Prof. Dr. Hrotkó Károly Seed germination.. 38

Lifting the dormancy in practice: stratification - stratification in pit (fig 1.) - stratification bed (fig 2. and 3.) - basement or cellars - controlled cold storage 1. 2. 3. Prof. Dr. Hrotkó Károly Seed germination.. 39

Raising of seedlings Outdoor seedbed - sowing seeds outdoor in autumn or after stratification in spring - product: one-year-old bareroot seedling (1/0) Magoncnevelés az oltványtáblában (őszibarack, mandula) - csírás mag ültetés tavasszal rétegezés és előcsíráztatás után csemete szemezhető VIII.-ra - magvetés ősszel csak enyhe klímájú területeken Magoncnevelés szabályozott körülmények között - üvegházban, fóliaházban, szaporítóláda, cserép, tápkocka, földlabdás szaporítótálcákba - magvetés kora tavasszal az esetleg szükséges rétegezés, előcsíráztatás után - szabadba kiültethető földlabdával kellő edzés után Prof. Dr. Hrotkó Károly Csírázás és kelés.. 40

Seedbeds in outdoor Prof. Dr. Hrotkó Károly Csírázás és kelés.. 41

Seedbeds in outdoor

Lifting machinery

Prof. Dr. Hrotkó Károly Csírázás és kelés.. 46

Prof. Dr. Hrotkó Károly Csírázás és kelés.. 47

Raising of seedlings Outdoor seedbed - sowing seeds outdoor in autumn or after stratification in spring - product: one-year-old bareroot seedling (1/0) Raising rootstocks in field of budding (peach, almond) - stratification planting germinating seeds into field of budding budding is carried out in August. - mild climate allows sowing seed in autumn Magoncnevelés szabályozott körülmények között - üvegházban, fóliaházban, szaporítóláda, cserép, tápkocka, földlabdás szaporítótálcákba - magvetés kora tavasszal az esetleg szükséges rétegezés, előcsíráztatás után - szabadba kiültethető földlabdával kellő edzés után Prof. Dr. Hrotkó Károly Csírázás és kelés.. 48

Peach seeds prepared for planting (right: radicle is pinched) Branching of taproot on walnut after pinching/cutting back Prof. Dr. Hrotkó Károly Csírázás és kelés.. 49

Rootstocks raised from planting of germinated seed are ready for budding in August Dr. Hrotkó Károly Seed production systems 50

Raising up seedlings in soil blocks or pots Prof. Dr. Károly Hrotkó

Mahaleb seedlings sown in spring in China (Sanyuan Nursery, Sahaanxi, China) Prof. Dr. Hrotkó Károly Csírázás és kelés.. 52

Mahaleb seedlings ready for budding in Aksun (Xinjiang, China)

Raising of seedlings Outdoor seedbed - sowing seeds outdoor in autumn or after stratification in spring - product: one-year-old bareroot seedling (1/0) Raising rootstocks in field of budding (peach, almond) - stratification planting germinating seeds into field of budding budding is carried out in August. - mild climate allows sowing seed in autumn Raising seedlings under controlled conditions (greenhouse) - Vegetables, ornamentals, bedflowers (greenhouse, in pots, trays) - Sowing seeds in spring, if needed, after stratification (herbaceous perennials) - after hardening off planting to outdoor conditions Prof. Dr. Hrotkó Károly Csírázás és kelés.. 54

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