Pearl millet (Pennisetum glaucum [L.] R. Br.) is the sixth most important cereal world-wide and is the main food source in the poorest regions of India and the African continent. It is a high-yielding, diploid C4 summer grass with 2 n = 14 chromosomes. Amongst the major cereals, pearl millet is highly tolerant to heat and drought, to saline and acid soils and is easy to grow in arid regions where rainfall is not sufficient for maize or even sorghum. Pearl millet is descended from wild grasses native to the central Saharan plateau region of Niger, from where it spread to East Africa and India. Pearl millet originated in a diffuse belt stretching from Senegal to western Sudan and domesticated 4000 years ago at its place of origin. Reached Eastern Africa and India about 3000 years ago and spread to Southern Africa about 2000 years ago. Pearl millet is the hardiest crop, thrives even on poor soils of dry regions in hot climates. It is the staple food for millions of people in the arid and semiarid regions of Africa and Asia. Also forms an important source of feed and forage in the Americas. It is mainly cultivated in Niger, Nigeria, Burkina Faso, Togo, Ghana, Mali, Senegal, Central African Republic, Cameroon, Sudan, Botswana, Namibia, Zambia, Zimbabwe and South Africa in Africa; and India, Pakistan and Yemen in Asia.

The success in crop improvement programs depends largely on the extent of genetic variability available to the researchers. Pearl millet is endowed with enormous genetic variability for various morphological traits, yield components, adaptation and quality traits. In ensuring that the plant breeders will have genetic resources for use in plant breeding programs, collection, conservation, characterization, evaluation, documentation and distribution of plant genetic resources is very important. Large efforts were made to collect and conserve the pearl millet diversity before it is lost forever. Genebank at ICRISAT, Patancheru, India holds 23,092 accessions from 52 countries.This is the single largest collection of pearl millet germplasm assembled at any one place in the world. The assembled germplasm is highly diverse for morphoagronomic traits. However, the utilization of germplasm is only a fraction of it. Therefore, ways to enhance the germplasm utilization was identified by augmenting a core collection of pearl millet.

Developing a core collection that represents the diversity of entire collection is an efficient approach to enhance the use of germplasm in crop improvement. Core collections are dynamic and need to be revised when additional germplasm and information become available. The pearl millet [Pennisetum glaucum (L.) R. Br.] core collection, consisting of 1,600 accessions selected from about 16,000 accessions characterized at the ICRISAT Genebank by 1998, was augmented by adding 501 accessions representing 4,717 accessions assembled and characterized in the past 9 yr. The revised core consists 2094 accessions. (Five duplicate and two male sterile accessions were deleted from original core collection.) A comparison of mean data using Newman–Keuls test, variance using Levene’s test, and distribution using ?2 test indicated that the variation in the entire collection of 20,766 accessions was preserved in the revised core collection. A few important phenotypic correlations that may be under coadapted gene complexes were preserved in the revised core collection. The Shannon–Weaver diversity index for different traits was similar in the revised core and entire collection. The revised core collection was observed to be more valuable than the original core as it has sources of resistance for important diseases such as downy mildew. The revised core collection could be a point of entry to the proper exploitation of pearl millet genetic resources for crop improvement. click here to search the data.