Putting Plant Genetic Diversity and Variability at Work for Breeding: Hybrid Rice Suitability in West Africa

Abstract

Rice is a staple food in West Africa, where its demand keeps increasing due to population growth. Hence, there is an urgent need to identify high yielding rice cultivars that fulfill this demand locally. Rice hybrids are already known to significantly increase productivity. This study evaluated the potential of Asian hybrids with good adaptability to irrigated and rainfed lowland rice areas in Mali, Nigeria, and Senegal. There were 169 hybrids from China included in trials at target sites during 2009 and 2010. The genotype × environment interaction was highly significant (p < 0.0001) for grain yield indicating that the hybrids' and their respective cultivar checks' performance differed across locations. Two hybrids had the highest grain yield during 2010 in Mali, while in Nigeria, four hybrids in 2009 and one hybrid in 2010 had higher grain yield and matured earlier than the best local cultivar. The milling recovery, grain shape and cooking features of most hybrids had the quality preferred by West African consumers. Most of the hybrids were, however, susceptible to African rice gall midge (AfRGM) and Rice Yellow Mottle Virus (RMYV) isolate Ng40. About 60% of these hybrids were resistant to blast. Hybrids need to incorporate host plant resistant for AfRGM and RYMV to be grown in West Africa.

Hybrid Rice in Africa: Progress, Prospects, and Challenges

“…The main tenet of hybrid rice technology is to employ the phenomenon of heterosis to out yield the available inbred semi-dwarf varieties. A yield advantage range of 15-20% over available inbred checks reported in other parts of the world has also been recorded in Africa [15,24,25,28]. Scaling up and promoting adopting of these hybrids, will contribute to food security in general on the African continent.…”

“…Hybrids from the project were evaluated for yield and general adaptability in the rainfed and irrigated ecologies of eight African countries (Liberia, Mali, Mozambique, Nigeria, Rwanda, Senegal, Tanzania and Uganda) [15]. Although promising hybrids out-yielded the best inbred checks, they were susceptible to the major pest and diseases in the region [15,25]. This necessitated the development of AfricaRice's in-house hybrids program with the following objectives: (i) develop new parental lines from local varieties; (ii) determine adaptability of some CMS lines in Africa; and (iii) establish a hybrid rice seed production system in some African countries [15].…”

“…This necessitated the development of AfricaRice's in-house hybrids program with the following objectives: (i) develop new parental lines from local varieties; (ii) determine adaptability of some CMS lines in Africa; and (iii) establish a hybrid rice seed production system in some African countries [15]. About 50 high-yielding hybrid rice lines were developed and evaluated in several African countries by the AfricaRice program [25]. Notable among them is the aromatic hybrid rice variety (AR051H) released in 2017 by the Senegalese Institute of Agricultural Research under the name ISRIZ 09.…”

The Genetic Variability of Floral and Agronomic Characteristics of Newly-Bred Cytoplasmic Male Sterile Rice

“…Rice (Oryza sativa) is a staple food in West Africa, where its demand keeps increasing due to population growth. Hence, there is an urgent need to identify high-yield rice cultivars that fulfill this demand locally [1]. Hybrid rice can contribute to food security by increasing the availability of staple food for consumption by farm households and increasing on-farm income through higher grain yield [2].…”

Special Issue: Plant Genetics and Biotechnology in Biodiversity

“…Three more specific contributions present the possibilities, limitations, and achievements related to improving crops by exploiting different kinds of genetic resources, landraces in the case of tomatoes [5], wild gene pools for wheat [6], and mutants for barley [7]. Research articles also offer varied examples of the study of molecular and/or phenotypic diversity in trees (olive and grape) [8,9] as well as herbaceous crops (maize, rice, and wheat) [10][11][12] and wild species [13]. These papers illustrate how recent knowledge about DNA-based analytical tools is converted into useful applications for the description, understanding, and utilization of the genetic diversity.…”