Selection for improved seed set in a Rajasthan pearl millet [Pennisetum glaucum (L.) R. Sr.] landrace population

Abstract

Incomplete seed set is a common characteristic of many pearl millet landraces of western Rajasthan, although this character is not commonly recorded in germplasm evaluations [1]. Reduced seed set is a common phenomenon in plants heterozygous for certain non-standard chromosome arrangements (e.g., translocations or inversions); as a portion of female (and male) gametes produced during meiosis have lethal duplications or deletions [2]. This effectively reduces genetic recombination in affected genomic regions and thus maintains specific allele combinations. Where such allele combinations confer some advantage, the underlying non-standard chromosome arrangements will be retained in the population - especially in cross-pollinated species such as pearl millet in a stressful environment such as western Rajasthan. It is hypothesized that this phenomenon may have contributed to the substantial restructuring of the pearl millet genome compared to that of other grasses [3].