RESPONSE OF LOCALLY ADAPTED PEARL MILLET POPULATIONS TO S1 PROGENY RECURRENT SELECTION FOR GRAIN YIELD AND RESISTANCE TO RUST

Abstract

In the semi-arid zones of Uganda, pearl millet ( Pennisetum glaucum (L.) R. Br.) is mainly grown for food and income; but rust (Puccinia substriata var indica (L.) R. Br.) is the main foliar constraint lowering yield. The objective of the study was to genetically improve grain yield and rust resistance of two locally adapted populations (Lam and Omoda), through two cycles of modified phenotypic S1 progeny recurrent selection. Treatments included three cycles of two locally adapted pearl millet populations, evaluated at three locations. Significant net genetic gain for grain yield (72 and 36%) were achieved in Lam and Omoda populations, respectively. This led to grain yield of 1,047 from 611 kg ha-1 in Lam population and 943 from 693 kg ha-1 in Omoda population. Significant improvement in rust resistance was achieved in the two populations, with a net genetic gain of -55 and -71% in Lam and Omoda populations, respectively. Rust severity reduced from 30 to 14% in Lam population and from 57 to 17% in Omoda population. Net positive genetic gains of 68 and 8% were also achieved for 1000-grain weight in Lam and Omoda, respectively. Traits with a net negative genetic gain in both populations were days to 50% flowering, days to 50% anthesis, days to 50% physiological maturity, flower-anthesis interval, plant height and leaf area.Dans la zones semi-arides en Ouganda, le milet perl\ue9 ( Pennisetum glaucum (L.) R. Br.) est principalement cultiv\ue9 comme culture vivri\ue8re et de rente, mais la maladie de rouille (Puccinia substriata var indica (L.) R. Br.) est la contrainte majeure affectant le rendement. L\u2019ojectif de l\u2019\ue9tude \ue9tait l\u2019am\ue9lioration du rendement en grains et la r\ue9sistance \ue0 la maladie de rouille chez deux populations localement adapt\ue9es milet perl\ue9 (Lam and Omoda), ceci \ue0 travers deux cycles de selection reccurente. Les traitements consistaient \ue0 trois cycles de deux populations localement adapt\ue9es de milet perl\ue9, \ue9valu\ue9es dans trois milieu diff\ue9rents. Un gain genetique significatif de 72 et 36% de rendements en grain a \ue9t\ue9 observe respectivement chez les populations de Lam et de Omoda. Ceci a occasionn\ue9 des rendements en grains de 1,047 kg ha-1 au lieu de 611 kg ha-1 chez la population de Lam et 943 kg ha-1 au lieu de 693 kg ha-1 chez la population de Omoda. Une am\ue9lioration significative de la r\ue9sistance \ue0 la maladie de rouille a \ue9t\ue9 obtenue au sein des deux populations, avec des gains g\ue9n\ue9tiques nets de -55 et -71% respectivement chez les populations de Lam et Omoda. La s\ue9v\ue9rit\ue9 de la maladie de rouille a \ue9t\ue9 de 30% \ue0 14% au sein de la population de Lam population et de 57% \ue0 17% au sein de la population de Omoda. Un gain g\ue9n\ue9tique positif net de 68 et 8% ont \ue9t\ue9 \ue9galement obtenu respectivement pour le poid de 1000 grains de Lam et 1000 de Omoda. Les caract\ue8res comme le nombre jours \ue0 50% de floraison, le nombre de jours \ue0 50% anth\ue8se, le nombre de jours \ue0 50% de maturit\ue9 physiologique, l\u2019intervalle de temps entre la floraison et l\u2019anth\ue8se, la hauteur des plants et la surface des feuilles