Báo cáo lâm nghiệp: Morphological and physiological micropropagation

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Morphological and physiological micropropagation...
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Báo cáo lâm nghiệp: "Morphological and physiological micropropagation"Morphological and physiological lesions induced bymicropropagation C.J. Atkinson K. Oates 1A. Harbour 1 W.J. Davies 11 University of Lancaster,Institute of Environmental and Biological Sciences, Lancaster, LA14YQ,and2 Neoplants Ltd., Freckleton, Lancashire, PR4 1HU, U.K.Introduction suggested that a reduced exposure to fog- ging treatment resulted in reduced plant loss and therefore experiments wereWeaning of plantlets produced in micro- conducted where the effects of differentpropagation often requires an extended weaning conditions on structure and phy-period of growth in a fogging facility. This siology of leaves were investigated.treatment reduces the risk of damage dueto desiccation when plantlets are removedfrom culture. Desiccation injury is a parti-cular problem because of limited develop- Materials and Methodsment of cuticle, abnormal stomatal behav-iour and abnormal xylem development in On 3 different occasions, transfer- plants wereplants raised by these techniques. While red from culture to a peat-based composteffects of culture conditions are generally contained in modular trays. These trays werewell understood, much less attention has placed in the fogging house for 7 d or 21 d be- fore they were moved to the greenhouse.been directed at any morphological and Plants were: a) ’fogged’ in autumn 1987; b)physiological lesions induced by condi- ’fogged’ in early summer 1988; c) ’fogged’ intions employed during weaning. late summer 1988. Greenhouse conditions for plants from groups a and c were generally cool Photinia fraseri Red Robin is an ever- and humid, while plants in group b were ex-green woody shrub prized for its bright red posed to hot and dry conditions.young foliage. This plant can be multiplied Samples of fresh leaf tissue were taken andsuccessfully in culture and will root effec- frozen in slushy nitrogen prior to examinationtively in compost shortly after transfer from under the scanning electron microscope (SEM).a rooting medium. Problems were ob- Material was prepared on the freezing stage of the Joel JSM 840A microscope, coated withserved initially with plants that had been in gold and examined at 8 kV.a fogging house for 20 d. Older leaves of Gas exchange of single leaves was moni-well-rooted plants became flaccid, follow- tored in a system similar to that described byed rapidly by browning and death of the Atkinson, (1986). All measurements were madewhole plant. No pathological symptoms on young fully expanded leaves that had beenwere detected. Preliminary observations initiated and had expanded at least partly in the nation of the abaxial surface of leaves offog-house. Experimental conditions were: leaftemperatures 23°C, 0 21 %, PAR 1000 ymol 2 plants from group a showed that 7 d fog-M and Aw 10 mmol mol- CO assimila- , 12,1S2- ging resulted in apparently normal leaftion rate (A) was measured at various ambient development, white plants that had re-P and NC (intercellular C0 concentra- 2 ¡)2(C0 ceived 21 d fogging showed abnormal sto-tion) analysis ...