Performance of New Lines from Anther Culture, Mutation Breeding and Interspecific Crosses, under Lowland and Irrigated Condition in Mali

Abstract

Rice productivity is still low in Mali due to many factors such biotic and abiotic stresses, and the immense rice-growing potential is underutilized. There is a need to enhance rice productivity through a development of new varieties more productive and stable. Under the partnership between the Institute of Rural Economy, AfricaRice and Korea-Africa Food and Agriculture Cooperation Initiative (KAFACI) nine new lines selected among 300 fixed lines were evaluated in 8 sites under irrigated and lowland conditions. The plant material included 4 KAFACI lines derived from Anther culture (series K), 2 lines from interspecific crosses (series DKA), one line (DKA-M50) from induced mutation on wild rice (Oryza longistaminata), and other lines from simple crosses. The objective of the study is to identify genotypes adapted to irrigated, or lowland and/or both conditions. Analysis of variance revealed the genotypes differed significantly (p < 000.1) at all environments except Kadiolo, Longorola and Manikoura, which implies that the geno types constitute a pool of germplasm with adequate genetic variability. Heritability was high with 0.76 suggesting high component of heritable portion, therefore selection for the improvement for this trait can be achieved directly based on their phenotypic performance. The combined analysis of variance indicated significant effects of environment (p < 000.1), genotype (p < 000.1) and genotype × environment interaction (GEI) (p < 000.1) on grain yield. The significance of genotype and environment interaction suggests that genotypes behaved differently in different environment and demonstrated that GEI had remarkable effect on genotypic performance in different environments. The highest environment mean grain yield was observed in San (5,197 kg/ha), followed by Baguineda (4,960 kg/ha). The genotype SIK 442-2-2 was identified as genotype adapted to wider environments, and hereby recommended for cultivation in Mali. Wild rice derivative genotypes DKA 42, DKA-M50 and DKA 37 exhibited low yield and high stability. These genotypes are more suitable for breeding specific traits. Analysis also revealed that ARS 100-5-1-B, K150849 and K150810 exhibited low yield along with low stability. GGE biplot depicted the presence of three mega environments among the test environments used for evaluation of genotypes and revealed the nature of mega-environment. Based on this, the test environment could be grouped into three diverse mega-environments. The environments of Selingué 2, Selingué 1, Manikoura, Mopti and San grouped into the same mega-environment and the interspecific line SIK 442-2-2 was identified as the best performing and candidate genotype for this mega-environment. Kadiolo and Longorola grouped into the same mega-environment with the check variety as candidate genotype for this mega-environment. In Baguineda mega-environment, K150014 was identified as the best performing genotype.