Résumé
Jatropha curcas (Euphorbiaceae) is an evergreen tree traditionally used in popular medicine, and also as a promising source for bio-fuel production. The in vitro propagation of this species has been studied as an alternative to conventional methods such as cutting and seedling. In vitro culture environment consists on closed flasks, with high relative humidity, reduced gas exchanges and artificial temperature and luminosity conditions. These conditions may induce physiological and anatomical alterations in cultivated plants. The occurrence of anatomical alterations on the leaves of J. curcas was examined in plants cultivated both in vitro and ex vitro, under greenhouse conditions. The stomatal index was higher on the leaves from greenhouse plants. Mesophyll thickness did not differ, but the greenhouse leaves presented an additional palisade layer, which reflects the environmental influence on cell division. The cells of the chlorophyllous parenchyma of young plants grown in greenhouse conditions have larger chloroplasts than those of the plants grown in vitro. The chloroplasts of mature leaves are similar in height, but the mitochondria are smaller. Current results indicate that the leaves of J. curcas respond distinctly to both environments. It is necessary to adjust the abiotic conditions in vitro to avoid precocious senescence, diagnosed by chloroplasts and mesophyll degradation.
Jatropha curcas (Euphorbiaceae) é uma espécie arbórea sempre-verde usada tradicionalmente na medicina popular e com potencial para produção de biodiesel. A propagação in vitro desta espécie tem sido avaliada como alternativa aos meios convencionais de estaquia e plantio. O ambiente in vitro consiste em frascos de vidro fechados, com umidade relativa elevada, trocas gasosas reduzidas, e condições artificialmente controladas de temperatura e luminosidade. Tais condições podem induzir anormalidades fisiológicas e anatômicas nas plantas cultivadas. A ocorrência de alterações anatômicas foi avaliada em folhas de J. curcas cultivadas in vitro e em casa de vegetação visando diagnosticar os efeitos do ambiente in vitro sobre o desenvolvimento das plantas. O índice estomático foi maior nas folhas de plantas crescidas em casa de vegetação. A espessura do mesofilo não apresentou alterações, mas as folhas das plantas crescidas em casa de vegetação apresentaram uma camada adicional de parênquima paliçádico. Citologicamente, as células do parênquima clorofiliano de plantas jovens crescidas em casa de vegetação possuem cloroplastos maiores do que aqueles das plantas crescidas in vitro. Nas plantas maduras, os cloroplastos apresentam tamanhos similares. As mitocôndrias possuem tamanhos reduzidos nas plantas maduras ex vitro. Nossos resultados mostram que as folhas de J. curcas respondem distintamente aos dois ambientes. Ajustes nas condições abióticas in vitro são necessários para evitar a senescência precoce, diagnosticada pela desintegração dos cloroplastos e consequentemente do mesofilo. Current results indicate that the leaves of J. curcas respond distinctly to both environments. It is necessary to adjust the abiotic conditions in vitro to avoid precocious senescence, diagnosed by chloroplasts and consequent mesophyll degradation.
Sujets)
Techniques in vitro , Euphorbiaceae , Jatropha , BiocarburantsRésumé
<B>Introduction</B><br> Currently Cambodia depends on imported foods from Viet Nam and Thailand. To address this situation, the Asian Sustainable Village Network OKAYAMA that the author belongs to, has been cooperating with Cambodian Federal Farmers Organization, a local NGO to undertake a farming project. The importance of agricultural promotion mainly in vegetable farming sector was examined and it is hoped that this project will reduce malnutrition in Cambodia, particularly among the rural poor who suffer with malnutrition, disease and disorder related conditions and will make Cambodia a sustainable society.<br><B>Method</B><br> In order to determine agricultural conditions, we investigated market places in Phnom Penh and examined utilizing farmland in Kampong Cham. In addition, we visited market places in rural districts and farmers' homes to gain more information about eating habits of the population. To find out farming production we referred to statistical data from Cambodian Ministry of Agriculture. A PubMed review was undertaken to determine aspects of malnutrition.<br><B>Results</B><br> Phnom Penh is a very busy place for the daily sale of perishable vegetables which are predominantly transported from Viet Nam. Cambodia, despite of its little irrigation system, and another technical problems is sufficient in its production due to its large farming area. Recently, cassava cultivation has increased in Cambodia in order to meet increasing demands in bio-fuel. We came to know that Cambodians do not have a favorable opinion about vegetables imported from Viet Nam. One of the dissatisfaction voted by the people in Cambodia is that the vegetables from Viet Nam have excessive chemical contamination and they lack in freshness. Restaurants and supermarkets in Phnom Penh preferred local products if they were available. In farming areas the production and consumption of vegetables are limited. For many, vegetables are a luxury. Meals predominantly consist of rice, small dried salted fish and some herbs. This situation is considered a leading factor of malnutrition. <br><B>Conclusion</B><br> As a result of the limited production and supply of vegetables in Cambodia, vegetable consumption is limited and viewed as a luxury. This situation has led to a mal-balanced diet and requires considerable effort to uplift vegetable production in Cambodia to reverse the imbalance of nutritional intake. Thus it can be very well said that agricultural promotion in Cambodia, particularly in vegetable sector is deemed extremely important for the future development of Cambodia.