Acta Scientiarum: Agronomy (Apr 2011)
Micropropagation and medium-term conservation of Rosa pulverulenta = Micropropagação e conservação durante médio prazo de Rosa pulverulenta
Abstract
In Iran, a large number of Rosa species have been exposed to extinction and therefore preservation techniques are necessary to safeguard their future. In the present investigation, the objectives were to optimize the micropropagation and medium-term conservation of one of these wild species, Rosa pulverulenta. At proliferation stage, the maximum number of new leaves (9.6) were produced on the medium containing 4 ƒÊM BAP + 0 ƒÊM GA3, whereas the maximum number of axillary shoots (4.1) were observed in the medium containing 4 ƒÊM BAP + 3 ƒÊM GA3. The results for rooting experiments suggested that the highest increase in stem height (49.5 mm) at the acclimatization stage was observed in plantlets treated with 1 ƒÊM IBA + 0.5 ƒÊM NAA during the rooting stage. Comparing the refrigerator and phytotronconditions for medium-term conservation of in vitro plantlets indicated that although the refrigerator conditions resulted in lower growth rate compared with the phytotron, the survival rate in refrigerator (100%) was significantly higher than phytotron (87.5%). Furthermore, the growth rate of the plantlets from the refrigerator was accelerated during the recovery period and verged on to the ones stored in the phytotron.No Ira, um numero grande de especies de Rosa sao expostas a extincao. Por causa disto, astecnicas de preservacao sao necessarias para garantir o futuro d estas mesmas especies. Nesta investigacao, os objetivos foram aperfeicoar a micropropagacao e preservar durante medio prazo uma destas especies, Rosa pulverulenta. No estadio de proliferacao, o numero maximo de novas folhas (9,60) foi produzido no meio contendo 4 ƒÊM BAP + 0 ƒÊM GA3, mas o numero maximo de gemas axilares foi observado no meio com 4 ƒÊM BAP + 3 ƒÊM GA3. Os resultados obtidos permitiram inferir que o maior aumento na altura de haste (49,5 mm) durante o estadio de climatizacao foi observado nos explantes tratados com 1 ƒÊM IBA + 0,5 ƒÊM NAA durante oenraizamento. Observa-se que embora a geladeira tenha proporcionado uma menor taxa de crescimento, a sobrevivencia em medio prazo foi maior (100,00%) do que no phytotron (87,50%). Alem disto, a taxa de crescimento dos explantes que foram mantidos na geladeira foi acelerada durante o periodo de recuperacao e ficaram proximas daquelas mantidas no phytotron.
