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    Zmiany anatomiczne i cytologiczne wywołane przez Myzvs ribis L. w liściach porzeczek (ribes) i próby powiązania ich ze zbiorem owoców
    (1959) Sienicka, Antonina; Wyższa Szkoła Rolnicza w Szczecinie. Katedra Botaniki
    It was the purpose of this study to give the anatomical and cytological analysis of currant leaves (Ribes) on which galls developed as consequence of Myzus ribis L. parasiting on them. The following varieties of currants have been investigated: Ribes Koehneamum Janczewski ('multif. x vulgare), Ribes Maximovichii Batalin, Ribes petraeum Wulf. var. atropurpureum C. A. Meyer, Ribes petraeum Wulf. var. bullatum Otto et Dietrich, Ribes petraeum Wulf. var. caucasicum Bieberstein, Ribes rubrum L. The investigations have been carried out both on live material and fixated in 70°/o alcohol, in Navaschin fluid, land on herbarium material. The deformations of leaves of the examined varieties of currants can be divided into three groups. We shall have the first grade deformation, where the leaf lamen is wrinkled. In these leaves no important anatomical changes are noticed. The leaves have normally formed guard-cells. The leaves on which vesicles develop, i-md in the cells anthocyanins are produced, and on the surface of epidermis multicellular filaments with fine cellular pellicle grow, we use to call deformations of the second gnade. These filaments (head-shaped) are formed by partition of one cell of the epider mis as can be seen in drawings 1—5. In young filament a zone of flat cells aajusing the growth of hair, can be distinguished (Drwg. 6). Leaves in the third grade of deformation have large vesicles spreading over the whole leaf lamen. The anatomical changes of these leaves are considerable. On the surface of the epidermis there arise structures with heavily thickened and corkyfied pellicles, that is to say big head-shaped small filaments (Drs. 13, 14, 15) and warts and emergencies of various types. Multi-headed bandy-formed filaments develop out of the common head-shaped ones, by partition of the apex (at some stage of evolution) into two or several parts. (Which oan be seen in the accompanying drawings). Sometimes there is no complete partition of the apex in the broad bandy-formed filament; the cells divide in perpendicular plane only (vertical to the width of filament) which causes the forming of a wide and short structure with some coalesced heads (Drwg. 15). There very often occur wart-like structures on the epidermis of the leaf. (Drs. 16—19) which arising initially laut of the cells of the epidermis, afterwards transform into large cupola-like emergencies. The pellicles of all the above described structures thicken and corkyfy. The leaf becomes thick, rigid, the guard-cells disappear, therefore access of light an exchange of gases is rendered more difficult. The epidermal cells, when stung by paraciting plantlice, become corky. The adjacent cells divide intensively, giving rise to a complex of large thin-walled cells. (Drwg. 23). Outside these cells there begin to form small cells, thick-walled, which eventually surround the above mentioned thin-walled cells together with the stung place, isolating them from the remaining part of the leaf (Drwg. 24) as it is the case in organ galls. This would confirm my assumption, previously raised (in my study 1950) that there is no essential difference between organ galls and tissue galls, and that this classification is purely a question of convention. Anatomical changes can also be seen in the deeper layers of the leaf. The assimilating pulp recedes gradually to the central portions of the leaf, and its place is beeing filled by Cytological changes can be observed in the growing cells, producing filaments. The cells of the head of filament have large cores; in them the core substance produces irregular, strongly dyeing in haematoxylin accumulations. Cytoplasm is spread equally in the cell. Great changes occur during the partition of the core and the cells. The mechanical filaments, occurring on sound leaves in the form of 1—2 cellular bristles, become under the influence of the Myzus ribi, long filaments sometimes consisting of several cells. The cells divide in an unusual, specific way. The core is being fragmented directly, splitting into several unequal parts, or it elongates excessively, producing ia bead-like structure, then the buds separate giving a multicore cell. Simultaneously, on the cellular pellicle in the inside direction of the cell there arise excrescences which, when growing, divide the cell into several smaller ones, with one or several cores. The pellicle excrescences may arise on one side only, or on either opposite side of the cell. In drawing 20, the stages of that interesting partition may be closely followed. In view of such great anatomical changes regarding the assimilating apparatus, a test has been carried out to ascertain whether or not the quantitative yield of fruit might be connected with the presence of Myzus ribis. Observations referring to this question have been dealt with in the second part of this study. The test has been carried out on twenty shrubs of Ribes rubrum fructu rubro. Ten of the shrubs were beeing treated as control shrubs. Galls have not been allowed to develop on them. Each control shrub had an equivalent and possibly similar shrub, growing on another site, and intended for observations on the quantitative changes of fruit bearing under the influence of galls. The observations have been carried out in the time from autumn 1954, till autumn 1956. Cultivating and disinfecting operations were alike for control plants as well as those intended for experimenting. The accompanying table shows the results of the observations. This test shows that the decrease in fruit yield seems to be in connection with third grade leaf deformations where guard-cells disappear, thick-walled cells develop under the epidermis layer, and on the epidermis corkyfied structures of various kind arise, what renders more difficult the access of sun rays and impedes transpiration. In view of this less assimilates are being produced as compared with plants where galls are not present, their inflow to produced fruits being insufficient, a large part of them does not mature and this in turn reduces the yield.