Precise evaluation of the parental forms? genetic variation is the base of rational, modern breeding. DNA patterns obtained in ISSR (inter simple sequence repeat) reactions for 24 strawberry cultivars, frequently used in the crossing programme at the Research Institute of Pomology and Floriculture, were analysed. Diversifying genotypes, polymorphic DNA products were observed in reactions with 54 out of 90 tested primers (806-896, #9 UBC). Six primers (811-814, 824, 840) generating 44 polymorphic bands with length from 270 to 2030 bp allowed to diversify all investigated cultivars. The DNA profiles characterising each of genotypes contained 10-19 polymorphic ISSR products.
Strawberry leaves (Fragaria x ananassa Duch.) cv. Kaster were transformed with the aid of Agrobacterium tumefaciens, strain 4404, carrying pBIN19 plasmid with nptII gene and iaglu gene under the control of constitutive CaMV-35S promotor. The incorporation of the transgene was confirmed in PCR with iaglu-specific primers and its expression by Northern blot. The level of esterified IAA in the leaves of transgenic plants was higher and free IAA lower than in the leaves of control plants. Of 15 transgenic clones analysed, 10 have smaller leaves and 13 shorter petioles than control plants. It was also found that 8 transgenic strawberry clones started flowering 1 ? 2 weeks earlier than control plants and 5 clones did not form any runners.
Somaclonal variants of strawberry resistant to verticillium wilt were selected by cocultivation of shoots of various cultivars obtained by both micropropagation and regeneration from a callus with a homogenate of 3-week-old liquid culture of mixed isolates of Veriticillium dahliae. There was a large variation in the resistance to the pathogen within a population of both micropropagated and regenerated from the callus shoots. After 70 days of cocultivation most of the shoots of susceptible cultivars were heavily damaged or dead, but there were some individuals that survived in a relatively good health. Those variants were transplanted on a new Boxus?s medium supplemented with 2 mg/l of benomyl to eliminate pathogen and their resistance to verticillium wilt is now tested.
The aim of the present work was to evaluate the morphological and physiological status of strawberry shoots (cv. Senga Sengana) cultivated in vitro and their subsequent (out of glass vessels) ability to form plantlets with developed autothrophic metabolism. Standard medium recommended by Boxus was supplemented with glucose or sucrose 30 g/l. Biomass production and particular shoot formation were more efficient in the presence of glucose. The capacity of the shoots to form the root system and to develop photosynthetic activity was higher for shoots taken from the glucose-medium than the sucrose containing medium.
Polygalacturonase inhibiting protein (PGIP) cDNA was isolated using RT-PCR from fruit of apple 'Golden Delicious' which was previously wounded and inoculated with Botrytis cinerea. The sequence of the cDNA showed high level of homology with the published sequence of PGIP-cDNA from apple and pear (99,7 and 97,3%) and low similarity with the sequence of cDNA from tomato (51,5%). The obtained cDNA was cloned and used for the binary construct creation. The introduction of the pBIN19-PGIP construct into strawberry plant genome seems to be a promising strategy to obtain a genotype resistant to B. cinerea, causal agent of grey mould ? the most economically important fungal disease of this species.
Chlorophyll alpha fluorescence has become a routine method for obtaining information on various aspects of photosynthesis. The terms and definitions are sometimes used convertibly, which became a source of misunderstanding. In this article, the most accepted viewpoint is presented on chlorophyll fluorescence meaning in monitoring and characterising of photosynthetic events. It was exemplified that strawberry shoot cultures show photosynthetic activity through multiplication subculture. Light and dark phases of photosynthesis function better when glucose is added to the medium in comparison to sucrose-medium. Photosynthetic efficiency of acclimated plantlets is higher than that of cultured shoots, but it is far from full activity of plants growing in natural conditions. The leaves formed during in vitro life slowly decrease, but newly formed leaves acquire the photosynthetic activity at the time of acclimatisation.
The aim of the presented work was to study the effects of changes of endogenous indole-3-acetic acid (IAA) metabolizm on in vitro shoot proliferation and rhizogenesis of transgenic strawberry shoots carrying maize IAA-glucose synthase gene (iaglu). Four iaglu-transformed strawberry clones and nontransformed 'Kaster' shoots served as a plant material for the study. The analysis of free and conjugated IAA level in leaves of transgenic and control strawberry plants showed that iaglu-containing strawberry clones had significantly higher level of ester conjugated IAA, but the level of free hormone was only slightly decreased or comparable to the control plants. iaglu-transformed clones had significantly higher proliferation rate and formed more roots than the control shoots. One of the iaglu-transformed clones had significantly shorter and other two ? longer roots than the control plantlets.
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