Novel sources of resistance to blast disease in finger millet

Finger millet (Eleusine coracana(L.) Gaertn. subsp.coracana) is the most importantmillet in eastern Africa and perhaps the oldest domesticated cereal grain in Africa.One of the major factors limiting finger millet production is blast disease caused bythe fungusMagnaporthe grisea. Crop wild relatives and landraces present a poten-tial source of novel genes. This study investigated the response of cultivated and wildrelatives of finger millet to an isolate of blast disease from western Kenya. Previousgermplasm collections were purified through two generations of single-seed descentbefore screening alongside improved and farmer-preferred varieties (FPVs) under ascreen house across three seasons. Farmer-preferred varieties were identified throughparticipatory varietal selection (PVS). The plants were inoculated twice during eachgrowth period using hand-spraying method and data on disease incidence recorded atgrain-filling stage. Genotypic data was generated using diversity arrays technology(DArT) sequencing and data analysis done using Genstat 18.2 and TASSEL 5.2.58.We observed high heritability (81%), indicating that the variation observed was pre-dominantly genetic. Wild accessions were generally more resistant to the disease incomparison to the cultivated accessions. Preliminary genome-wide association study(GWAS) using general linear model with principal component analysis led to theidentification of 19 markers associated with blast disease that will be be developedinto assays for genotype quality control and trait introgression. Wild accessions andlandraces of finger millet present a good reservoir for novel genes that can be incor-porated into crop improvement programs

Developing a Mini-Core Collection in Finger Millet Using Multilocation Data

Finger millet [Eleusine coracana (L.) Gaertn.], among small millets, is the most important food crop in some parts of Asia and Africa. The grains are a rich source of protein, fi ber, minerals, and vitamins. A core collection of 622 accessions was developed. The aim of this study was to develop a mini-core collection using multilocational evaluation data of the core collection. Six hundred and twenty-two accessions together with six controls (four common and two location-specifi c) were evaluated for 20 morphological descriptors at fi ve agroecologically diverse locations in India during the 2008 rainy season. The experiment was conducted in α design with two replications at Patancheru and in augmented design with one of the six controls repeated after every nine-test entry at other locations. The hierarchical cluster analysis of data using phenotypic distances resulted in 40 clusters. From each cluster, ~10% or a minimum of 1 accession was selected to form a mini-core, which was comprised of 80 accessions. The comparison of means, variances, frequency distribution, Shannon–Weaver diversity index (H`), and phenotypic correlations revealed that the mini-core captured the entire diversity of the core collection. This mini-core collection is an ideal pool of diverse germplasm for identifying new sources of variation and enhancing the genetic potential of fi nger millet

Genetic Diversity for Grain Nutrients Content in Finger Millet (Eleusine Coracana (L.) Gaertn.) Germplasm

Knowledge of existing genetic variability is essential for initiating a successful plant breeding program. This chapter reviews nutrient diversity studies conducted on finger millet germplasm globally. In all the studies, very high variability was observed in all the quality traits determined. Most of the nutrients were positively correlated with each other, implying that they can simultaneously be improved. Grain color and glume covering were associated with nutrient content, with darker grains having higher compared to white-colored and enclosed grains having higher nutrient content than intermediate covered having higher content. These two can be used as morphological markers. Local cultivars and varieties released in the East and South Asia (ESA) region had significantly lower levels of the main essential nutrients (Ca, Fe, and Zn) found in finger millet, most likely as a result of farmers selecting for varieties with brown-colored grain. Country of origin was highly significant for all the nutrients, with accessions from eastern and southern Africa having significantly lower nutrient contents. Grain color was associated with nutrient content with darker grains having higher compared to white colored. All nutrients were positively correlated (P < 0.001) with each other. Grain yield was not significantly correlated with any nutrient content. The substantial variability for the grain nutrients observed in the finger millet core collection and local germplasm indicates the possibility for the selection of nutrient-rich accessions for use in the breeding program