Total and seasonal distribution of dry matter yields for Pearl millet × Wild grassy subspecies hybrids

or subspecies (Harlan, 1975) that usually cross easily with the cultivated species to produce fertile hybrids. The wild grassy subspecies Pennisetum glaucum (L.) R. Br. subspeThe wild subspecies, P. glaucum subsp. monodii, becies monodii (Maire) Brunken has been used as a source of germplasm longs to the primary gene pool of pearl millet and is a for improved disease resistance and cytoplasmic diversity for improvweedy plant that grows along farmer fields and roading pearl millet [P. glaucum (L.) R. Br.] cultivars. The objective of this research was to evaluate a portion of the monodii germplasm to sides, mainly in the Sahel region of Africa (Brunken, determine if this germplasm could be used to increase the dry matter 1977). It usually has thinner stems and narrower leaves yield and extend the growing period of pearl millet forage hybrids. than the cultivated species but can be difficult to distinSeventy-nine monodii accessions from Niger, Mali, Senegal, and Bur- guish from the cultivated species in the vegetative stage. kina Faso were crossed with Tift 85DA1, a cytoplasmic-nuclear-male- Seed head characteristics such as small inflorescences, sterile (CMS) pearl millet used in commercial hybrid production. loosely arranged florets, small seed, seed shattering, and These hybrids along with ‘Tifleaf 2’ (a popular commercial hybrid) seed dormancy distinguish monodii from the cultivated and ‘Gahi 3’ were tested for 2 yr on a fine, loamy, thermic Plinthic species. Subspecies monodii is vigorous and readily Kandiudult soil at Tifton, GA, latitude north 31.488 and longitude crosses with cultivated pearl millet. Bramel-Cox et al. west 83.538. The best experimental hybrid yielded up to 31% more (1986) reported that monodii had potential for increasdry matter than Tifleaf 2. A significant hybrid 3 year effect on total ing the growth rate in pearl millet. Hanna (1997) showed yield indicated that some of the hybrids showed a differential response during the 2 yr. Tifleaf 2 produced between 23 and 32% of its total that hybrids with cytoplasms from different monodii yield in the last harvest, whereas a number of the experimental hybrids accessions produced up to 17% more dry matter yield produced significantly more (up to 50%) of their dry matter in the than Tifleaf 1, the commercial check, because of either last harvest. The experimental hybrids were consistent across years cytoplasmic and/or cytoplasmic-nuclear effects. in their superior late-season production. Variation was also observed Subspecies monodii has been an important germamong hybrids for production of dry matter in the first harvest. Early plasm source for improving pearl millet. Genetic resisproduction would be especially valuable in areas that have distinct tance to rust (Puccinia substriata Ellis & Barth; var. wet and dry seasons. This research indicates that genes for enhancing indica Ramachar & Cummins), pyricularia leafspot [Pylevel and distribution of yield in cultivated pearl millet are present ricularia grisea (Cke) Sarc.], and smut [Moesziomyces in the wild grassy subspecies, monodii. penicillariae (Bref.) Vanky] (Wilson and Hanna, 1992) has been identified in monodii accessions and incorporated into inbred lines to develop and release commerP