Induction of symmetrical nucleus division and multicellular structures from the isolated microspores of lycopersicon esculentum mill

Effects of lactalbumin hydolysate (LH), casein hydrolysate (CH) and a starvation pretreatment using mannitol in the induction of symmetrical nucleus division of uninucleate microspores and formation of multicellular structures from the isolated microspores of tomato were studied. Flower buds containing uninucleate microspores were incubated on media for the pretreatment containing either mannitol or sucrose at 10 °C for seven days. Subsequently microspores were isolated and cultured on NLN basic media in the presence of BAP, NAA, LH and CH. Microspores from the cv. Fantastic, cultured in the presence of BAP at 0.5 mg l-1 and NAA at 0.5, 1.0 and 1.5 mg l-1 together with LH at 2 or 4 ml l-1 proceeded in the sporophytical pathway, microspore nuclei dividing symmetrically. Formation of multicellular structures were induced which was also the case for other cultivars cultured in the NLN medium containing 0.5 mg l-1 BAP and 0.5 mg l-1 NAA together with CH either at 5 or 10 g l-1. Mannitol pretreatment induced microspore starvation and stress therefore microspores from the mannitol pretreatment were more responsive to the symmetrical division than those from the sucrose pretreatment. © 2005 Taylor and Francis Group, LLC