Improving green plant production via isolated microspore culture in bread wheat (Triticum aestivum L.)

Abstract

Although a high efficiency of microspore embryogenesis can be achieved for a wide range of genotypes, some genotypes regenerate a high proportion of albino plants. Significant improvements in embryo regeneration and green plant formation were achieved by adding 10% NPB98 medium to a microspore pretreatment solution containing a chemical inducer formulation. For the wheat genotype WED 202-16-2, which is known to produce a moderate frequency of albinos, the plant regeneration rate was 15% higher, and the green plant percentage increased 27% following the addition of this nutrient supplement during embryo initiation. There were no negative effects on the responsive genotype Svilena. Embryo production in both genotypes was not affected. Our results indicate that providing readily available nutrients during microspore embryo initiation is effective in promoting plant regeneration and enhancing green plant development in a wheat genotype with a propensity for albinism.

Effect of Cold-Mediated Pretreatment on Microspore Culture in Winter and Spring Wheat

“…In general, stress during pretreatment induces recombination of nuclear genes or chloroplast genome, which results in low regeneration, albino plants and somaclonal variation [18]. However, cold pretreatment was found to improve the green plants to albino ratio in our study (data not shown) as suggested by [13].…”

“…Pretreatment at cold reportedly delayed the mitotic division of the nucleus, thereby synchronizing the stage of all the microspores during pretreatment resulting in higher induction frequencies [16]. Moreover, low temperature was speculated to increase the ratio of green to albino plants [13].…”

“…Isolated microspore culture derived wheat plant was first reported by Mejza et al (1993) [10] and Tuvesson and Ohlund (1993) [11]. Since then, several methods to improve the efficiency of embryo production from isolated microspores have been published [5,6,[12][13][14].…”

Direct embryogenesis and green plant regeneration from isolated microspores of hexaploid triticale (� Triticosecale Wittmack) cv. Bogo

“…Igri plants regenerated through microspore culture, 5% were albino, while in anther culture, 40% of the regenerated plants recovered were albino. As speculated by Liu et al (2002), reduced albino frequencies in microspore cultures relative to anther culture may result from the direct availability of nutrients to the microspores in the early stages when embryogenesis is triggered, especially in poorly responsive genotypes with a history of high albino frequencies.…”

The influence of pretreatment on cell stage progression and the time of DNA synthesis in barley (Hordeum vulgare L.) uninucleate microspores

“…This developmental switch can be induced by the pretreatment of anthers or spikes. Commonly used pretreatments are temperature shock, nutrient starvation and chemical induction (Huang and Sunderland 1982;Immonen and Anttila 1999;Immonen and Robinson 2000;Liu et al 2002a;Touraev et al 1996;Zheng et al 2001). For barley, a 28-day cold pretreatment at 4C is most commonly used (Jähne and Lörz 1995).…”