Evidence of a partial reproductive barrier between wild and cultivated pearl millets (Pennisetum glaucum)

Abstract

The occurrence of seed malformation in association with reduced thousand grain weight and germination ability has been observed in crosses between cultivated female plants and wild male plants. A survey of 16 cultivated accessions (P. glaucum subsp, glaucum) and 11 wild accessions (P. glaucum subsp, monodii) ranging over the whole species diversity showed this postzygotic incompatibility was general, but its intensity varied greatly with the cultivated female accession used and very little with the wild male parent origin. About 15 % of the 123 cultivated x wild crosses observed gave normal seeds. Seed malformation has never been observed in crosses between cultivated accessions and appeared independent of genetic distances between the parents. The reciprocal crosses between wild female plants and cultivated male plants gave normal-looking seeds with good germination but consistently reduced thousand grain weight. Both seed malformation and seed small size are an expression of a genetic imbalance. These slight reproductive barriers seem to have been built during the domestication process.

Polymorphism pattern at a miniature inverted‐repeat transposable element locus downstream of the domestication gene Teosinte‐branched1 in wild and domesticated pearl millet

“…(). This can be caused by the existence of partial postzygotic reproductive barriers (Amoukou & Marchais ) or pollen competition (Robert et al . ).…”

Biogeography and Genetic Diversity of Pearl Millet (Pennisetum glaucum) from Sahelian Africa

“…The phenomenon of hybridization through gene flow between wild and domesticated material in the Sahel appears to perpetually add new alleles and broaden the genetic base of this African crop complex. Because pearl millet is unusual in maintaining an active exchange of genes with its wild relatives (Brunken, de Wet, and Harlan 1977;Amoukou and Marchais 1993;Miura and Terauchi 2005), it offers a unique contrast to the predominant view of the domestication syndrome and an opportunity to refine our understanding of the domestication process and its genetic consequences. Domestication of pearl millet should be viewed as an ongoing evolutionary process, rather than an event that took place historically.…”

Mitochondrial DNA diversity in wild and cultivated sorghum

“…None of these factors alone can explain the genetic isolation of guinea margaritiferum accessions but, combined, they could contribute to a more efficient reproductive barrier. It would be difficult to consider the genetic factors, as Amoukou (1993) and Amoukou and Marchais (1993) did for pearl millet. Indeed, breeders have long used guinea in crosses and no distorted segregations have been reported (Binelli et al 1992;Dkgremont 1992).…”