Phenotypic and genetic diversity in the foxtail millet (setaria italica (l.) p. beauv.) core collection)

Foxtail millet core collection consisting of 155 accessions was evaluated at three environments for 12 qualitative and 13 quantitative traits to study the phenotypic diversity and to identify trait specific accessions. Foxtail millet core collection was also molecularly profiled using 84 SSR markers to study molecular genetic diversity, population structure and to identify SSR markers associated with the agronomic traits. In REML analysis variance due to genotypes (σ2 g) and genotype × environment (σ2 ge) were significant for all the 13 quantitative traits. On the basis of phenotypic dissimilarity between pair of accessions, ten pairs of most diverse accessions were identified for breeding program for the developing high yielding cultivars with a broad genetic base and for the development of mapping populations. On the basis of pooled BLUPs (Best Linear Unbiased Predictors) of three environments, we have identified trait specific accessions for economically important traits such as yield and its traits contributing to yield (15 accessions for each trait). These accessions could be used in recombination breeding to develop cultivars with desirable combination of traits. The SSR markers detected a total of 1,356 alleles with an average of 16.14 alleles per locus. Of these, 368 were rare alleles; 906 common alleles; and 82 the most frequent alleles. Sixty one unique alleles which were specific to a particular accession and useful for germplasm identification were also detected. The genetic diversity of foxtail millet in this study was correlated well with racial classification and the race indica showed greater genetic distance from the maxima and moharia. Ten pairs of genetically most diverse accessions were identified. Large molecular variation observed in core collection could be utilized effectively for selection of diverse parents for breeding cultivars and development of mapping populations. Mantel test showed significant correlation between phenotypic and molecular dissimilarity matrix. The STRUCTURE analysis provided the evidence for the presence of four subpopulations. The mixed linear model (MLM) was used and the number of significant marker trait association was 130 in E1, 69 in E2 and 106 in E3 at P≤0.05, whereas only 49 in E1, 23 in E2 and 61 in E3 were found to be highly significant MTAs at P≤0.01. In pooled BLUPs of three environments, a total of 108 MTAs were detected at P≤0.05. Of these 18 SSR markers showed 37 significant associations at P≤0.01 with yield and yield contributing traits. Fifteen MTAs, that occurred in all three environments and overall in pooled data were identified as stable. Our research provided a first report of association study for yield and yield contributing traits in foxtail millet using SSR markers. The results from this research also demonstrated the use of core collection as association mapping panel to disclose marker-trait associations in foxtail millet for yield traits that could lead to effective utilization of ex-situ conserved genetic resources

Little Millet, Panicum sumatrense, An Under-utilized Multipurpose Crop

Little millet is a native crop of India, and well adapted to varied soil and environmental conditions, short duration with considerable within species diversity, and has huge potential to produce good grain yield and high biomass with limited water supply under marginal lands of Indian condition. To assess the grain and biomass yield potentials, 200 accessions, including core collection (56) were evaluated in an alpha-design using two replications. The residual maximum likelihood (REML) analysis indicated that variance due to genotypes was significant for important traits including grain and biomass yields. A large variability was observed for days to flowering (range 38 to 97 days), plant height (94 to 198 cm), basal tillers (7.8 to 13.32), grain yield (5 to 12 g plant-1) and dry matter yield (23 to 159 g plant-1). Accessions belonging to race robusta were late flowering (79 days after sowing), taller (167 cm) and having higher dry matter yield (88 g plant-1) and slightly greater grain yield (7.8 g plant-1) than that of race nana. Accessions producing higher grain yield (>10 g plant-1; IPMr# 1021, 841, 1017, 1063, 983, 712, 1040) and for higher dry matter yield (>133 g plant-1; IPMr# 858, 1043, 1070, 1063, 877) were identified. Due to its short duration and high biomass yield, little millet an under-utilized crop has potential as bioenergy crop besides providing food and fodder. Research is in progress to assess sequence variations linked with grain and biomass yields, and other important agronomic traits

Underutilized Climate-Smart Nutrient Rich Small Millets for Food and Nutritional Security

Small millets such as finger millet, foxtail millet, proso millet, kodo millet, little millet and barnyard millet are considered as climate-smart and nutrient rich crops. They have diverse adaptation and play an important role in food and nutritional security in rural households in areas where these crops are grown globally. However, their presence in the food basket has been declining over the years, mainly because of the increased availability of rice and wheat, lack of crop improvement efforts in developing high yielding cultivars, and lack of modern technologies for processing and utilization. Over the last few years, there is an increasing recognition of their nutrient composition and benefits as healthy food. Considering their diverse adaption and agronomic and health benefits, small millets could be an alternate/supplement crop to widen food basket to ensure food, feed and nutritional security. More research effort in germplasm collecting, conserving, evaluating and utilizing, and developing high yielding cultivars, processing and utilization technologies, and policy innervations are required to promote small millets cultivation, and for food and nutritional security of vulnerable population under climate change scenario for sustainable agriculture

Diversity and trait-specific sources for productivity and nutritional traits in the global proso millet (Panicum miliaceum L.) germplasm collection

Proso millet is an important short-duration crop that adapts well to varied climatic conditions and is grown worldwide for food, feed and fodder purposes. Owing to a lack of genetic improvement, the crop has experienced no yield improvement and provides low income to farmers. In this study, 200 accessions of proso millet originating in 30 countries were evaluated in two rainy seasons to assess phenotypic diversity for morpho-agronomic and grain nutritional traits and to identify high grain-yielding and grain nutrient-rich accessions. Proso millet diversity was structured by geographical region, by country within region, and by racial group. Race patentissimum showed high diversity and ovatum low diversity, and diverged widely from each other. The lowest divergence was observed between races compactum and ovatum. Eighteen high grain-yielding, 10 large-seeded, and 26 two or more grain nutrients-rich accessions were identified, and highly diverse pairs of accessions within and between trait groups were identified. They included IPm 9 and IPm 2661 for high grain yield and large seed size; and IPm 2069, IPm 2076, and IPm 2537 for high Fe, Zn, Ca, and protein contents. IPm 2875 had a seed coat that is readily removed by threshing. This study provides valuable information to proso millet researchers about agronomic and nutritional traits in accessions that could be tested for regional adaption and yield for direct release as cultivars, and could be used in breeding for developing high grain-yielding and nutrient-rich cultivars

Ensuring the genetic diversity of sorghum

Sorghum is a staple food crop for millions of the poorest and most food-insecure people in the semi-arid tropics, and ensuring its diversity and conservation is therefore important for global food and nutritional security. This chapter discusses the taxonomy of sorghum, in situ and ex situ germplasm conservation and diversity, the factors shaping sorghum diversity, geographical distribution of sorghum germplasm, germplasm gap analysis, and the use of cultivated and wild genepool of sorghum to enhance crop yields and broaden the genetic base of sorghum cultivars

Sorghum Germplasm Resources Characterization and Trait Mapping

Sorghum is the fifth most important cereal crop mostly grown for food, feed, fodder, and bioenergy purposes, and a staple for over 500 million resource-poor people in marginal environments. Globally, over 236,000 sorghum germplasm accessions have been conserved in genebanks, of which the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), India and the Plant Genetic Resources Conservation Unit, Southern Regional Plant Introduction Station, University of Georgia, USDA-ARS, together conserve about 32 % of the total global sorghum collections. Germplasm diversity representative subsets such as core and mini core collections and a genotyping-based reference set have been established in sorghum providing access to large diversity. The sorghum mini core collection established at the ICRISAT is being widely used for identification of sources for resistance to various biotic and abiotic stresses, and for agronomic and grain nutritional traits. Large genetic and genomic resources are available in sorghum, and resequencing of diverse germplasm resources including the mini core collection and wild and weedy relatives will provide researchers opportunities to relate sequence variations with phenotypic traits of interest and their utilization in sorghum improvement. Genomewide association mapping studies have identified genomic regions that are associated with important agronomic traits and resistance to biotic and abiotic stresses. High-throughput phenotyping platforms/technologies are required for precise phenotyping to attain greater genetic gains. The current status of germplasm, its characterization and utilization has been summarized in this chapter

Variability for Productivity and Nutritional Traits in Germplasm of Kodo Millet, an Underutilized Nutrient-Rich Climate Smart Crop

Kodo millet (Paspalum scrobiculatum L.) is an important drought-tolerant crop cultivated on marginal soils under diverse environmental conditions. Its grains are nutritionally superior to those of major cereals. Knowledge of the variability in agronomic and nutritional traits is important to identify germplasm for use in crop improvement and by farmers. Two hundred kodo millet accessions were evaluated in 2 yr during the rainy season to assess variability for morphoagronomic and grain nutritional traits and to identify high grain-yielding and nutrient-rich accessions. Large variability was observed for important traits including days to maturity, grain yield, and Fe, Zn, Ca, and protein content with moderate to high heritability. Three kodo millet races did not differ significantly for grain yield or Fe, Zn, Ca, and protein content. For Zn, Fe, protein, and Ca, 78.5, 75.0, 67.5, and 54.0% of accessions, respectively, were consistent between the years, indicating the relative sensitivity of these nutrients to the environment and genotype × environment interaction. Considering data of both the years separately, 50 promising trait-specific accessions were identified, including those for early maturity (8 accessions), greater 100-seed weight (10), high grain yield (15), Fe (8), Zn (14), Ca (6) and protein content (7), and 10 with a combination of agronomic and nutritional traits. The extensive multilocation evaluation of these high-yielding, nutrient-rich accessions would be useful to identify promising genotypes for direct cultivar release or for use in crop improvement to contribute to the food and nutritional security of resource-poor farmers in a changing climate scenario

Phenotypic diversity and stability of early maturing Barnyard Millet (Echinochloa sp.) germplasm for grain yield and its contributing traits

Barnyard millet is one of the oldest domesticated millets in the semi-arid tropics of Asia and Africa. Developing early maturing cultivars is one of the important breeding goals in barnyard millet, which can fit well when main crops fail, or during the late onset of monsoon. Thus, this study was carried out to test the phenotypic diversity, character association and path coefficients, and stability of early maturing barnyard millet accessions. The MDU 1, a slightly late-maturing (95 days) cultivar, was used to identify early maturing accessions than the control with a considerably higher yield. Diversity as revealed by D2 analysis indicated that the trait grain yield had contributed the most towards the diversity followed by the traits such as thousand-grain weight and fodder yield per plant. The accessions IEc 350 and IEc 356 showed the highest fodder yield and grain yield per plant, and higher per day productivity than the control, MDU 1. Genotypic correlations revealed a significantly positive correlation of the grain yield with most traits investigated including days to maturity and fodder yield, and the trait fodder yield per plant showed a highly positive indirect effect on grain yield. Hence, these traits could be considered during the selection process for improving grain yield. Stability analysis identified two accessions, IEc 350 and IEc 356, and the MDU 1, as the stable high-yielding accessions. Hence, these high-yielding stable accessions can efficiently be used in barnyard millet improvement for developing early maturing varieties

Genetic resources conservation and strategies for enhanced utilization in crop improvement

Global food production will need to double to feed the more than 9 billion people by 2050..

Genetic diversity analysis of geographically diverse landraces and wild accessions in Sorghum

Landraces are highly dynamic populations with historical origins. Several factors have influenced the evolution of landraces and some of them were selection by farmers, natural selection, gene-flow from various neighboring populations, genetic drifts, etc. In this study, we phenotyped 36 landraces and wild populations of sorghum conserved at ICRISAT genebank, Hyderabad, India, to assess the diversity among the populations of sorghum. Since landraces are diverse populations, we phenotyped more plants (over 100 plants) in each accession for nine economically important quantitative traits, thus capturing the entire variability. Our study revealed that the clustering pattern based on D2 statistics grouped the 36 accessions into 5 clusters, in which cluster 1 holds the maximum number of 15 accessions and cluster 3 with the least (2 accessions). Minimal intra cluster distance (3.66) was observed in cluster 3 followed by cluster 5 (9.52), while the maximum intra cluster distance was found in cluster 2 (12.50). The highest inter cluster distance was found between clusters 1 and 4 (16.29) indicating the presence of wide diversity between accessions of these two clusters. Accessions in cluster 1 were early maturing (67 days after sowing, DAS) while those in cluster 4 were late maturing (129 DAS) and high yielding (36.9 g). Results from this study provide information about the diversity of landraces and wild sorghum populations for their utilization in crop improvemen