Pearl Millet (Pennisetum glaucum L.) Hybrid Breeding in West Africa Towards High Productivity and Grain Iron (Fe) and Zinc (Zn) for Adaptation to Climate Change and Human Nutrition.

Abstract

Pearl millet (Pennisetum glaucum L.), the world’s sixth most important cereal crop is known as a climate smart crop due to its tolerance to drought, heat, soil salinity, low soil fertility, high nutritive and high capacity to buffer variable environmental conditions. Climate change and ecological production constraints is expected to increase the currently challenges facing by agriculture to ensure future food security for the growing population in West Africa (WA). Morever, the alarming status of micronutrient deficiency in the WA region exacerbates this situation and calls for effective strategies to combat malnutrition. Thereby, the main goal of this study was to identify the high yielding biofortified hybrids of pearl millet and establish an efficient scientific basis for hybrid breeding in WA with high adaptability across the region. The experiments were conducted in replicated trials in different locations of WA. The experimental material consisted of L × T analysis of 9 lines and 12 testers, a full diallel of 6 restorers and 30 F1’s and evaluation of 68 single cross hybrids and 42 top cross hybrids including the checks. GCA effects revealed that, among the lines, ICMB 177004, ICMB 177005 and ICMB 177007 were good general combiners for days to 50% flowering; ICMB 177002 and ICMB 177090 for panicle length; ICMB 177111 for plant height, panicle circumference and grain yield. ICMB 177003 and ICMB 177001 were good general combiners for grain Fe and Zn content, respectively. Almost all the testers were good general combiners for plant height. Testers, ICMR 08888, ICMR 1301 and ICMR IS 16007 were good general combiners for number of days to 50% flowing; ICMR 157003 and ICMR IS 16008 for panicle length; ICMR 08666, ICMR 08777 and ICMR 157003 for panicle circumference, ICMR 08666, ICMR 08777, ICMR 157003 and ICMR 157004 for grain yield. ICMR 08666 and ICMR 1301 for grain Fe and Zn content. On the basis of SCA, the hybrids namely ICMH 177016, ICMX 187851, ICMX 187892 and ICMX 187895 were identified as superior for grain yield, grain Fe and Zn content simultaneously across locations. Five hybrids namely, ICMX 187807, ICMX 187851, ICMX 187998, ICMX 1871029, ICMX 1871046 exhibited positive heterosis both over mid-parent and better-parent for grain yield, grain Fe and Zn content across locations. Regarding the restorer’s improvement, the crosses ICMX 1770192, ICMX 1770193, ICMX 1770194, ICMX 1770197, ICMX 1770204 and ICMX 1770208 exhibited significant negative sca effects for days to 50% flowering with high grain yield. Positive and significant sca effects for grain Fe and Zn contents were expressed by crosses ICMX 1770197, and ICMX 1770204. Identified restorers with good GCA and crosses with good SCA, were useful in improving the restorer lines of pearl millet to promote the hybrid pearl millet breeding in WA. Grain yield is of economic importance for which considerable variable degree of standard xiv heterosis was registered in a number of crosses over CHAKTI and ICMV 167005 whereas, few hybrids showed positive heterosis over CHAKTI, check for grain Fe and Zn. Despite their yield advantage, top cross hybrids had shown some important characteristics like plant height and panicle length as important as grain yield for multiple purpose. While single cross hybrids were present better for biofortified hybrid of pearl millet. AMMI stability value (ASV) identified, the hybrids ICMX 1871018 to be the most stable for grain yield, ICMH IS 16187 for grain Fe content and ICMX 187778 for grain Zn. The stability index showed the hybrids ICMX 187827, ICMX 187026 and ICMX 1871037 as the hybrids that combined stability with high mean values for yield, high grain Fe and Zn content. The hybrids ICMX 187830 and ICMX 1871042 combined high mean value, adaptability and stability for grain yield whereas, ICMX 187895 combined high mean performance, adaptability and stability for grain Fe and Zn. ICMX 187766 and ICMH 177016 combined high grain Zn content with adaptability and stability. Parents which combine well for yield, Fe and Zn content and other traits will be used for the production of biofortified hybrids, while stable and adapted hybrids with high yields and Fe and Zn contents could be extended in WA.