Obtaining carrot (Daucus carota L.) plants in isolated microspore cultures

Microspores were cultured on the modified B5 liquid medium containing 2.4D (0.1 mg L(-1)), NAA (0.1 mg L(-1)), L-glutamine (500 mg L(-1), L-serine (100 mg L(-1)), and sucrose (100 g L(-1)). The developmental stages of microspores and divisions were observed. Initially, the formation of binuclear and multicellular structures was noticed. Plants regenerated in the cultures in which the tetrad stage of microsporogenesis had predominated. Embryoids were still forming 24 weeks after the cultures were set up. Six weeks after the transfer of androgenetic embryos onto the B5 regeneration medium, they were converted into complete plants. Out of 90 androgenetic plants planted in a growth chamber, 42 plants adapted to the new conditions. All of those plants proved to be diploids in cytometric analysis.

[The evaluation of nitrates and nitrites food intake among Polish households in 1991-1995]

The studies on nitrates and nitrites food intakes in year 1991-1995 were carried out in four types of households i.e. works, worker-farmers, farmers, pensioners and retired persons and from 1993 in self-employed households and families maintaining themselves on non-income sources; altogether and with regard to the number of persons in family. Using household budget data and literature concerning nitrates and nitrites contents in food products, mean and maximum food intakes of these compounds were calculated and compared to acceptable daily intake (ADI) taking into consideration main sources of them. The obtained results indicated that the mean nitrate and nitrite food intakes did not exceed ADI but maximum intakes of one were several times higher than ADI. Nitrate and nitrite food intakes depended on type of household being highest at farmers, pensioners and the number of persons in family. Six persons families took nearly half less than did one-person one. There were no differences in main food sources of nitrates and nitrites for all types of households and number of person in families. Vegetables and their products supplied 94-98% of nitrates whereas meat products supplied 98% of nitrites.