Microspore development during <Emphasis Type="Italic">in vitro</Emphasis> androgenesis in triticale

Microspore division was monitored in three triticale (× Triticosecale Wittmack) genotypes over 21 d of in vitro anther culture, on two media differing in their 2,4-dichlorophenoxyacetic acid content. After low temperature (4 °C) pre-treatment for two weeks, all the microspores were still alive, but they began to die from day one of culture. Both genotype and culture medium affected the number of microspores that aborted over time (82 – 97 % by day 21), the number of microspores that underwent the first symmetrical division (> 82 % over all), the number of microspores that attained four or more nuclei, and the number of divisions per 100 alive microspores after 21 d of culture.