Legumes are important components of sustainable agricultural production, food, nutrition and income systems of developing countries. In spite of their importance, legume crop production is challenged by a number of biotic (diseases and pests) and abiotic stresses (heat, frost, drought and salinity), edaphic factors (associated with soil nutrient deficits) and policy issues (where less emphasis is put on legumes compared to priority starchy staples). Significant research and development work have been done in the past decade on important grain legumes through collaborative bilateral and multilateral projects as well as the CGIAR Research Program on Grain Legumes (CRP‐GL). Through these initiatives, genomic resources and genomic tools such as draft genome sequence, resequencing data, large‐scale genomewide markers, dense genetic maps, quantitative trait loci (QTLs) and diagnostic markers have been developed for further use in multiple genetic and breeding applications. Also, these mega‐initiatives facilitated release of a number of new varieties and also dissemination of on‐the‐shelf varieties to the farmers. More efforts are needed to enhance genetic gains by reducing the time required in cultivar development through integration of genomics‐assisted breeding approaches and rapid generation advancement.

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The germination of giant witchweed [Striga hermonthica (Del.) Benth], a noxious root parasite of many cereal crops, is stimulated by exudates from the roots of both host and non‐host trap plants. Forty genotypes of cotton (Gossypium hirsutum L. and G. barbadense L.), a trap crop, were screened in the laboratory, using the cut‐root technique, to investigate the variability among these genotypes for their ability to stimulate suicidal germination of S. hermonthica and to determine the inheritance of the trait. The genotypes exhibited significant differences for the trait. S. hermonthica seed germination percentages ranged from 13.3 to 50.0% for the cotton genotypes compared with 47.3% for the susceptible sorghum [Sorghum bicolor L. Moench)] cultivar CK60B. Three cotton genotypes were selected based on their S. hermonthica seed germination stimulation and used as parents in crosses of the combination low × high S. hermonthica seed germination stimulation. The F1s, F2s, and parents of the crosses, RASA(78)11b × ‘SAMCOT‐10’ and RASA(78)11b x TX‐CABS‐1‐83 were evaluated in separate experiments in batches of 12 entries. Broadsense heritability estimates for the trait ranged from 71.8 to 78.5%. This was reflected in the discrete frequency distribution of the F2 populations into two classes of high and low S. hermonthica seed germination stimulation, fitting a classical 3:1 phenotypic ratio. These results suggest that S. hermonthica seed germination stimulation by cotton is a qualitatively inherited trait, and that the gene controlling this trait is monogenic and simply inherited, with high S. hermonthica seed germination stimulation dominant over low S. hermonthica seed germination stimulation. It should be possible to select and breed cotton genotypes that produce highly active germination stimulants in large amounts, while maintaining or improving other agronomic attributes.

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