| Influence of combined treatments of N-Nitroso-N-Methylurea
and Sodium Azide on physiological injury and the genetic effect in Triticale
JAN OIEJNICZAK and HENRYK PATYNA Institute of Plant Genetics, Polish Academy of Sciences Poznan 60-479, Strzeszynska 30/36. Poland In recent years chemical mutagens have been used commonly in cereal plants to create genetic variability for desirable traits, as a source of new germ plasm material. A mutagenic effect of N-nitroso-N-methylurea (MNUA) and sodium azide (SA) on higher plants have been known for many years. The frequency of mutations may be increased by combined treatments of MNUA with SA. There only few studies have been reported on the use of chemical mutagens in this new crop. The subject of this study was the estimation of the effect of treatments of N-nitroso-N-methylurea, sodium azide and combined of their on physiological injury in M1 generation and morphological frequency of traits in M2 and M3 generation. Materials and Methods Grains of hexaploid Triticale cultivar Grado and strain LT50/79 were presoaked in water for 12 hours at 25C. The mutagen solution were freshly preparated in 0,025M phosphate buffer at pH-3 for sodium azide, whereas N-nitroso-N-methylurea was dissolved in distilled water at pH-5, 6. Grains were soaked in 2mM of SA and 1.5 mM of MNUA for 3 hours at 25C. In combined treatments grains were expose to mutagens of SA and MNUA respectively for 3 hours at 25C. After treatments they were rinsed under running water. Grains were sown in the field at the space of 5 x 20 cm in three replication to obtain M1, M2 and M3 generation. After harvesting of M1 plants height of plant, length of spike, grains yield per spike, number grains per spike and 1000 grains weight were determined. The first three spikes of each M1 plant were use to raise M2 and M3 generation. Grains from M2 and M3 generation were sown in the field at the space 5 x 20 cm. The main pressure morphological selection in M2 and M3 generation was concerned on days to heading, plant height, spike length, resistance to diseases and leaft length. Results from M1 generation have been statistically calculated using a multivariate analyses of variance MANOVA and the other multivariate methods related. Results Height of plant was only slightly affected by sodium azide used in this experiment (Table 1). A significant difference in height of plant was found after treatments with MNUA and combined treatments of SA and MNUA. The date also indicate that height of plant was significantly reduced when MNUA was treated after application of SA. Azide applied after MNUA treatment caused less reduction of height plant as compared to the combination of SA and MNUA treatments. In general the mutagen treatments has minor effect on yield components and there was no significant difference in the grain yield per spike, number grains per spike and 1000 grains weight. Although the difference from MNUA treatments in number grains per spike was noticed compared to the controls. It is very interesting pointed out (Fig. 1) that more response to the mutagen treatment was strain LT 50/79 than cultivar Grado. |
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