Citologia e fertilidade de culturas monospóricas e resultados de cruzamentos do cogumelo Agaricus blazei CS1

Abstract

Genetic breeding has been one of the main strategies aiming the improvement of productivity and or development in several agricultural and cattle growing activities. Concerning mushrooms in Brazil, several aspects can still be exploited for productivity increasing; the genetic breeding is a strategy which deserves to be considered in a recent future. Thus, the genetic stability of the cultures preserved in laboratories and the elucidation of nuclear and sexual behavior of the species are essential. In this work, the productivity of the cultures preserved in laboratory and the ones picked in different periods of time were tested. Monosporic cultures were also obtained; their nuclear pattern has been studied, as well as the resulting cultures of the offspring. Some of these cultures were also assessed regarding their mycelia growing in culture media and compost. They were also evaluated concerning their fructification capacity. The best obtained germination level was 2.1% when using chloramphenicol in the culture media for monosporic culture obtaining. The results have shown that the preserved or picked cultures in different time periods did not lose their fructification capacity. The monosporic cultures have shown a 6 nucleus average in midway compartments multinucleated hyphas, whereas the top hyphas presented a range of 2 to 3 nucleus. It was possible to observe positive reaction among some monosporic isolate in mating tests. It was not possible to observe a distinctive mycelium growth pattern, nor the nucleus number among monosporic and mating resulting cultures. It was found that IS02, IS03, IS17 and IS19 monosporic cultures as well as the offspring cultures F1 IS03/IS17 and F1 EG01/EG02 are fertile; which suggests that this mushroom may have an amphithallic life cicle. A greater number of monosporic cultures will be tested on their fertility so these results can be confirmed.