%0 Journal Article
%T Genotype ¡Á Environment Interaction of Mosaic Disease, Root Yields and Total Carotene Concentration of Yellow-Fleshed Cassava in Nigeria
%A Norbert G. Maroya
%A Peter Kulakow
%A Alfred G. O. Dixon
%A Busie B. Maziya-Dixon
%J International Journal of Agronomy
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/434675
%X Twenty-one yellow-fleshed cassava genotypes were evaluated over two years in five major cassava growing agroecological zones in Nigeria. The trials were established in a randomized complete block design with four replications to assess genotype performance and Genotype ¡Á Environment interaction for cassava mosaic disease (CMD), fresh and dry root yield (FYLD; DYLD), root dry matter content (DMC), and total carotene concentration (TCC). Combined analysis of variance showed significant differences ( ) among genotypes (G), environment (E), and Genotype ¡Á Environment interaction (GE) for all the traits tested. For reaction to CMD, the best genotypes showing stable resistance were TMS 07/0539 and TMS 07/0628. For root yield, the best genotypes were TMS 01/1368 and TMS 07/0553. Genotype TMS 07/0593 was the best for DMC and TCC across the 10 environments. Variation among genotypes accounted for most of the Total Sum of Squares for CMD (72.1%) and TCC (34.4%). Environmental variation accounted for most of the Total Sum of Squares for FYLD (42.8%), DYLD (39.6%), and DMC (29.2%). This study revealed that TMS 07/0593 has the highest and most stable TCC, DMC with the lowest CMD severity score and appeared to be the best genotype. 1. Introduction Vitamin A deficiency (VAD) is a global problem of public health significance in under-privileged communities of the world [1]. Xerophthalmia is the most readily recognized and the most widely employed criterion for discussing whether VAD poses a significant public health problem in any particular community [2]. Vitamin A deficiency in the early stage leads to night blindness and Xerophthalmia, which may ultimately progress to blindness [3]. A nationwide food consumption and nutrition survey conducted in Nigeria revealed that 29.5% of children under 5 years of age were vitamin A deficient (serum retinol <0.70£¿ mol/L) [4]. Cassava (Manihot esculenta Crantz) is an important food security crop and a major source of calories for about two of every five Africans [5]. Although the starchy root is the primary product, fresh leaves are also used for animal and/or human consumption [6]. In 2008, Nigeria was the leading cassava producing country in sub-Saharan Africa, producing 44.6 million tons on 3.8 million ha [7]. In Nigeria, more than 70% of cassava production is processed at the village level into gari, the principal source of calories for 70¨C80 million Nigerians. Cassava varieties often demonstrate specific adaptation due to their high sensitivity to the genotype-by-environment interaction (G E) that occurs in both short-term
%U http://www.hindawi.com/journals/ija/2012/434675/