Data/hora: 06/06/2024 05:49:21

Biblioteca(s): 	Embrapa Mandioca e Fruticultura.	
Data corrente: 	14/04/2004	
Data da última atualização: 	14/04/2004	
Autoria: 	AJONYE, M; LWANGA CHARLES; SSEMAKULA, G; OTIM-NAPE, G.W; BAGUMA, Y. K; OBA, J. R.	
Título: 	Progress in cassava micropropagation in Uganda.	
Ano de publicação: 	1998	
Fonte/Imprenta: 	Revista Brasileira de Mandioca,Cruz das Almas, v.17, p.49, nov, 1998. Suplemento.	
Idioma: 	Inglês	
Conteúdo: 	Abstract: Micropropagation (in vitro culture) of some farmer prefered cassava varieties was investigated, inorder to suplement existing multiplication techniques (farme's and rapid multiplication methods). The best medium formulation for initiation and multiplication of the variety SS4 was standard modified Murashige and Skoog's (MS) (1962) medium supplemented with 0.05 mg/l benzyl aminopurine (BAP), 0.01 mg/l naphthyl acetic acid (NAA) and 1 mg/l gibberellic acid (GA). For variety TMS 2 (4) 1425, the same formulation favoured culture initiation, but further multiplication (subculturing) required basic MS medium without growth regulator supplement. Six substrates namely: coffee husks, 100%; top soil, 100%; soil/sawdust mixture, 50:50; and farmyard manure, were tested for plantlet response, for weaning and hardenig. The best growth occured in soil and the worst in coffee husks and dairy manure. The effect of plantlet age at 2,4 and 8 weeks after, was investigated in relation to plant survival. The lowest survival rates occured at  two weeks after subculture (SS4, 95% and TMS 2 (4) 1425, 93%). The optimum age for the highest survival was 4 weeks after subculture. Varietal differences significantly (P>0.05) occured at 8 weeks after subculture, with SS4 having 95% better perfomance than TMS 2 (4) 1425, 80%. Successful field establishment occured at MUARIK (100%) and Namulonge (70%). Approximately 7000 plantlets were established in the field within one year. The first generation of plantlets fron MUARIK flowered at 7 months after planting (MAP). one thousand stems were harvested at MAP, from which stakes planted 0.7 ha of land were obtained. Farmers held high opinion of in vitro cassava plantlets. All the  selected farmers for the demostration reported 100% survival in preliminary field trials. Initial tecnical and economic comparison of the multiplication techniques (conventional and rapid multiplication techniques) used, by the national cassava program in Uganda was done, against the tissue culture technique. The conventional method required the largest area and starting material. Tissue culture consumed most time, effort and operating capital, overall labour and machinery, compared with the two alternative techniques. Total direct production cost were least for the conventional technique. The tissue culture method had the highest multiplication rate (1:2000) compared to the rapid (1:16) and conventional (1:3) per year.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Mandioca e Fruticultura (CNPMF)	
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