Role of genebank in Maize (Zea mays L.) and wheat (Triticum aestivum L.) breeding

Absztrakt

Maize breeding In the last three decades, a large number of maize hybrids have been developed from genotypes with a restricted genetic base. In order to decrease the genetic vulnerability, it is very important to widen the genetic base for maize breeding by the application of various methods. One particular way to increase genetic variability is treatment with various mutagens. After more than twenty-five years of research, it has been proved that such lines can be produced by mutation. In 1995, a maize gene bank was established with 1,500 lines in our department. There is large genetic variation in the maize gene bank, the exploitation of which is only possible using suitable methods of selection and evaluation. As a result of mutation, the new maize inbred lines P26, P61 and P62 were released after DUS tests. Radiation generated conspicuous changes in the plant characteristics. The most pronounced aberrations were observed for the expression of anthocyanin coloration and flowering time in various plant organs. Wheat breeding The study was designed to examine the effects of four sucrose concentrations (45, 60, 75 and 90 gL"1 ) and four maltose concentrations (65, 100, 135, 170 gL"1 ) on callus induction, plant regeneration and green plant proportions. Anthers of Pavon 76 were cultured on these induction media and embryoids induced were transferred to the standard regeneration medium to compare for differences in green plant percentage and the influence of carbon sources on it. The green plant ratio showed a linear correlation with the concentration, being the highest (22.3 green plants/100 cultured calli) at 90 gL"' fructose and that (31,7%) at 170 gL"1 maltose.