Variranje in vitro odgovora pšenice, uticaj genotipa i spoljne sredine

Abstract

The tissue culture response (TCR) of immature embryos, evaluated according to callus formation, percentage of regenerative green-spotted calli and the number of plants per embryo, was investigated in 96 wheat genotypes of worldwide origins. Immature embryos were collected 12-15 DAP from field-grown plants during three successive years 2003, 2004 and 2005. Year 2003 was with high air temperatures and tropical days during a period of vegetation, while the environmental conditions were more favorable for plant growth in the next two years, 2004 and 2005. Embryos were cultured on standard MS medium containing 2 mg l-1 2, 4-D. In all genotypes calli were efficiently induced, ranging from 36.7 to 100% (2003), 68.4 to 100% (2004), and 94.3 to 100% (2005). The calli occasionally formed green spots, but frequencies markedly differed among genotypes that varied from 0 to 72.5% (2003), 0 to 97.9% (2004), and 0 to 94.0% (2005). Coefficient of variation was highest in term of percent of regenerative calli (66.7%) following by a number of plants per embryo (35.6%) and callus formation (5.1%). Components of phenotypic variance showed that factor year (71.4%) had the highest impact on expression of callus formation, genetic factor (47,1%) on percentage of regenerative green-spotted calli and interaction year/genotype (30.3%) on number of plants per embryo. The results indicated factor genotype as the most important for determining regeneration potential in wheat.

Nezreli embrioni 96 genotipova pšenice, poreklom iz različitih delova sveta, gajeni su u kulturi i proučavanje njihov in vitro odgovor na osnovu procenta formiranja kalusa, procenta regenerativnih kalusa i broja biljaka po embrionu. Nezreli embrioni sakupljeni su sa biljaka gajenih u polju u toku tri uzastopne godine (2003, 2004, 2005). Prva godina (2003) je bila sa relativno povoljnim rasporedom padavina, ali sa visokim prosečnim temperaturama vazduha i učestalom pojavom tropskih dana u vegetacionom periodu. Sledeće dve godine (2004 i 2005) bile su znatno povoljnije u pogledu temperatura i količine i rasporeda padavina. Ebrioni su gajeni na MS podlozi sa 2 mg l-1 2,4-D. Svi genotipovi pokazali su visok potencijal za obrazovanje kalusa, koji je iznosio od 36.7 do 100% u 2003., 68.4 do 100% u 2004. i 94.3 do 100% u 2005. godini. Pojedini indukovani kalusi su formirali zelene tačke i potom pupoljke. Procenat regenerativnih kalusa je znatno varirao u zavisnosti od genotipa i godine i inosio je od 0 do 72.5% (2003), 0 do 97.9% (2004), i 0 to 94.0% (2005). Broj biljka po embrionu u prošeku za sve genotipove po godinama je iznosio 3.1, 4.5 i 6.5, respektivno. Najveći koeficijent varijacije je zabeležen kod osobine procenat regenerativnih kalusa (66.7%), zatim kod broja biljaka po embrionu (35.6%) a najmanji za procenat formiranih kalusa (5.1%). Analiza komponenti fenotipske varijabilnosti je pokazala da je najveći uticaj na variranje procenta formiranih kalusa imala godina (71.4%), regenerativnih kalusa genotip (47.1%) a na broj biljaka po embrionu interakcija godine i genotipa (30.3%).