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Protoplasts isolated from three accessions of cultivated carrot and 5-day-old protoplast-derived aggregates were subjected to selection to identify somaclonal variants with enhanced tolerance to the fungal disease black rot incited by Alternaria radicina. Different concentrations [1, 2, 3.5, 5, 10, 20, 35 and 50 % (v/v)] of a fungal culture filtrate (FCF) from 2-week-old liquid cultures of A. radicina were used. Protoplasts and aggregates were subjected to short-term selection for a period of 10 days. All FCF concentrations added to the cultures on the day of isolation decreased protoplast survival frequency and plating efficiency, while FCF applied 5 days later inhibited cell divisions in 5-50 % concentrations. The responses of protoplasts to the treatment were genotype dependent. Most R0 plants were regenerated in all accessions from cell lines grown with 1 % FCF, while only a few plants were produced from 2 to 3.5 % FCF-treated cultures of 'Dolanka' and the breeding line '9304B', respectively. Nineteen-percent of putative stress-tolerant regenerants were tetraploids, while only 5 % tetraploids were observed in the control. The incidence of unique random amplified polymorphic DNA fragments indicating possible chromosomal rearrangements was low and did not differ among regenerants after selection and those derived from the control. Mobilization of miniature inverted repeat transposable elements was not observed. Some R0 individuals regenerated both from FCF-treated and untreated cultures showed lower susceptibility to A. radicina in a laboratory assay in comparison to control plants grown from seed. Regenerants from FCF-treated cultures showed lower frequency of flowering plants and a higher rate of male sterility. Pollen viability of the putative stress-tolerant regenerants varied over a wide range (6-98 %), independently of in vitro selection conditions. Our data suggest that A. radicina FCF may be feasible for the in vitro selection to generate plants with superior phenotypic performance against A. radicina.

Registration of 'Nile' Soybean 'Nile' soybean [Glycine max (L.) Merr.] (Reg. no. CV-333, P1 572240) was developed by Southern Illinois University at Carbondale. It was released as a Maturity Group IV cultivar with resistance to soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) Race 3 (4). Nile originated as an individual F 5 plant selection from the cross 'Forrest' (2) x 'Union' (1). The ?2 and subsequent generations were advanced via pedigree selection at various locations in southern Illinois. The Fs and Fs plants were selected on SCN Race 3 infested fields. SCN resistance was determined in the F 5:6-derived line by greenhouse evaluation utilizing SCN Race 3 infested soil collected from a field near Elkville, IL. SCN resistance was verified over subsequent generations in 12 greenhouse evaluations. Each evaluation was conducted utilizing a different SCN Race 3 field population extracted from an infested field in Jackson or Gallatin County, Illinois. Nile was evaluated in southern Illinois regional tests from 1984 through 1993. It was included in the Illinois state soybean variety test from 1991 through 1994. Nile was evaluated as experimental line LS83-5616 in the Uniform Soybean Tests

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W niniejszej pracy do oceny zróżnicowania dwóch populacji sosny zwyczajnej (Pinus sylvestris L.) z okolic Zakładów Azotowych w Puławach i Żyrzyna wykorzystano 13 starterów RAPD. Uzyskano 137 produktów amplifikacji, z czego tylko 4 były monomorficzne w obydwu grupach roślin. Dla każdej z populacji oznaczono produkty charakterystyczne tylko dla niej, niepowielane w drugiej populacji. Różnorodność genetyczna (h) wynosiła 0,1718 (Azoty) i 0,1942 (Żyrzyn), natomiast średni poziom heterozygotyczności HS = 0,1830. Ponieważ zróżnicowanie skupione było głównie wewnątrz populacji i HS stanowiło 95,6% ogólnej heterozygotyczności, obie populacje pod względem genetycznym były do siebie bardzo podobne a różnorodność między nimi wynosiła HT – HS = 0,0088. Taki stan rzeczy wytłumaczyć można niewielką odległością, jaka dzieliła obie populacje (ok. 7 km), co sprzyja wymianie pyłku między nimi.