Genetic variability for shoot fly resistance, grain characteristics, and yield in the postrainy season sorghums

Sorghum shoot fly, Atherigona soccata is one of the important pests of postrainy season sorghums. Combining insect resistance with desirable agronomic and morphological traits is important to increase sorghum productivity. Of the several methods for pest control, host plant resistance is one of the major components for controlling shoot fly damage in sorghum. Evaluation of 90 sorghum genotypes for resistance to shoot fly, A. soccata across seasons indicated that RHRB 12, ICSV 713, ICSV 25026, ICSV 93046, ICSV 25027, IS 33844-5, Giddi Maldandi, and RVRT 3 were resistant to shoot fly damage in the postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, IS 5622, IS 17726, IS 18368, IS 34722, RVRT 1, ICSR 93031, and Dagidi Solapur showed resistance in the rainy season, suggesting season-specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35-1, ICSV 700, ICSV 711, ICSV 25010, ICSV 25019, ICSV 93089, IS 18662, Phule Vasudha, IS 18551, IS 33844-5, and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the components of resistance to shoot fly in these genotypes. Five genotypes exhibited resistance to shoot fly and had high grain yield across seasons

Improvement of restorer lines for strengthening pearlmillet (Pennisetum glaucum L.) hybrid breeding in West and Central Africa

Little information was available on the genetics of pearl millet restorers available in West and Central Africa. Hence, diallel analysis was carried out using six parents and 30 F1’s, to identify the nature of gene action, and improve the restorer gene pool. The genotype ICMR 157004 is early flowering with high biomass yield. The cross ICMX 1770192 (2.19 t/ha) ICMX 1770197 (2.14 t/ha) and ICMX 1770193 (2.08 t/ha) exhibited high grain yield with early days to 50% flowering and medium plant height. Grain Fe content is positively associated with grain Zn content (r = 0.93**) but exhibited negative association with other agronomic traits indicating proper care should be taken for breeding these traits. Mean sum of squares for panicle circumference, grain yield and biomass yield exhibited significant probabilities for the maternal effects indicating the influence of maternal factors in inheritance of these traits. The estimates of narrow sense heritability for days to 50% flowering, panicle length, plant height, panicle circumference, biomass yield and grain Fe and Zn content was high indicating the predominance of additive gene action in inheritance of these traits. ICMX 1770193, ICMX 1770194, ICMX 1770197, ICMX 1770204 and ICMX 1770208 exhibited significant negative sca effects for days to 50% flowering. Positive and significant sca effects for grain Fe and Zn contents were expressed by crosses ICMX 1770197, and ICMX 1770204. Identified genotypes with good GCA and crosses with good SCA, were useful in improving the restorer lines of pearl millet to promote the hybrid pearl millet breeding in West and Central Africa

Pattern of genetic inheritance of morphological and agronomic traits of sorghum associated with resistance to sorghum shoot fly, Atherigona soccata

Sorghum shoot fly, Atherigona soccata is an important pest of sorghum during the seedling stage, which influences both fodder and grain yield. To understand the nature of inheritance of shoot fly resistance in sorghum, we performed generation mean analysis using two crosses IS 18551 × Swarna and M 35-1 × ICSV 700 during the 2013–2014 cropping seasons. The F1, F2, BC1 and BC2 progenies, along with the parental lines were evaluated for agronomic and morphological traits associated with resistance/susceptibility to sorghum shoot fly, A. soccata. The cross IS 18551 × Swarna exhibited significant differences between the parents for shoot fly deadhearts (%) in the postrainy season. The progenies of this cross exhibited lower shoot fly damage, suggesting that at least one of the parents should have genes for resistance to develop shoot fly-resistant hybrids. Leaf glossiness, leafsheath pigmentation and plant vigor score during the seedling stage exhibited non-allelic gene interactions with dominant gene action, whereas 100 seed weight showed both additive and dominant gene interactions. Presence of awns showed recessive nature of the awned gene. Generation mean analysis suggested that both additive and dominance gene effects were important for most of the traits evaluated in this study, but dominance had a more pronounced effect

Mechanisms and diversity of resistance to sorghum shoot fly, Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844-5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season-specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35-1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844-5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly-resistant sorghums

Genetic variation and diversity of pearl millet [Pennisetum glaucum (L.)] genotypes assessed for millet head miner, Heliocheilus albipunctella resistance, in West Africa

Pearl millet (Pennisetum glaucum L.), the major source of minerals and dietary energy for people living in the semi-arid regions of Sahel, is regularly damaged by millet head miner, Heliocheilus albipunctella. In order to identify the plant-based resistance sources for millet head miner along with high grain Fe and Zn, we have screened forty pearl millet genotypes, using an artificial infestation method. Analysis of variance revealed significant differences in the genotypes tested for head miner resistance. The genotypes Gamoji, ICMP 177001, ICMP 177002, ICMV 177003, ICMV IS 90311, LCIC9702, Souna 3, ICMV IS 94206 and PE08043 exhibited antibiosis resistance mechanism to Heliocheilus albipunctella with appreciable agronomy and grain yield when compared with the susceptible check ICMV IS 92222. The genotypes Faringuero, ICMV 167005, ICMV IS 99001, Sadore local, SOSAT-C88, and ICMP 177004 exhibited tolerance to head miner damage with good per se performance. The genotypes ICMP 177001, ICMP 177002, ICMV 177003, and Moro exhibited resistance to millet head miner and had consistent grain Fe content across seasons (ranging from 44 to 70 ppm). Association between the head miner resistance and morphological traits showed a positive and significant correlation of larval production index (%) with head miner damage (r = 0.59**). Grain Fe and Zn contents exhibited negative association with panicle length and grain yield indicating proper care should be taken in breeding for these traits. Hence, the identified resistance sources can be effectively utilized in breeding head miner resistant pearl millet OPV’s/ hybrids, with high grain yield including Fe and Zn concentrations, to overcome the hunger and malnutrition seen in populations living in the semi-arid tropics

Genomic-Assisted Enhancement in Stress Tolerance for Productivity Improvement in Sorghum

Sorghum [Sorghum bicolor (L.) Moench], the fifth most important cereal crop in the world after wheat, rice, maize, and barley, is a multipurpose crop widely grown for food, feed, fodder, forage, and fuel, vital to the food security of many of the world’s poorest people living in fragile agroecological zones. Globally, sorghum is grown on ~42 million hectares area in ~100 countries of Africa, Asia, Oceania, and the Americas. Sorghum grain is used mostly as food (~55%), in the form of flat breads and porridges in Asia and Africa, and as feed (~33%) in the Americas. Stover of sorghum is an increasingly important source of dry season fodder for livestock, especially in South Asia. In India, area under sorghum cultivation has been drastically come down to less than one third in the last six decades but with a limited reduction in total production suggesting the high-yield potential of this crop. Sorghum productivity is far lower compared to its genetic potential owing to a limited exploitation of genetic and genomic resources developed in the recent past. Sorghum production is challenged by various abiotic and biotic stresses leading to a significant reduction in yield. Advances in modern genetics and genomics resources and tools could potentially help to further strengthen sorghum production by accelerating the rate of genetic gains and expediting the breeding cycle to develop cultivars with enhanced yield stability under stress. This chapter reviews the advances made in generating the genetic and genomics resources in sorghum and their interventions in improving the yield stability under abiotic and biotic stresses to improve the productivity of this climate-smart cereal

Genotype-by-environment interactions for starch, mineral, and agronomic traits in pearl millet hybrids evaluated across five locations in West Africa

Introduction: Pearl millet is a staple cereal grown in the harshest environments of arid and semi-arid regions of Asia and sub-Saharan Africa. It is the primary source of calories for millions of people in these regions because it has better adaptation to harsh environmental conditions and better nutritional traits than many other cereals. By screening the pearl millet inbred germplasm association panel (PMiGAP), we earlier reported the best genotypes with the highest concentration of slowly digestible and resistant starch in their grains. Methods: In the current study, we tested these 20 top-performing pearl millet hybrids, identified based on starch data, in a randomised block design with three replications at five locations in West Africa, viz. Sadore and Konni (Niger), Bambey (Senegal), Kano (Nigeria), and Bawku (Ghana). Phenotypic variability was assessed for agronomic traits and mineral traits (Fe and Zn). Results and discussion: Analysis of variance demonstrated significant genotypic, environmental, and GEI effects among five testing environments for agronomic traits (days to 50% flowering, panicle length, and grain yield), starch traits (rapidly digestible starch, slowly digestible starch, resistant starch, and total starch), and mineral trait (iron and zinc). Starch traits, such as rapidly digestible starch (RDS) and slowly digestible starch (SDS), showed nonsignificant genotypic and environmental interactions but high heritability, indicating the lower environmental influence on these traits in the genotype × testing environments. Genotype stability and mean performance across all the traits were estimated by calculating the multi-trait stability index (MTSI), which showed that genotypes G3 (ICMX207070), G8 (ICMX207160), and G13 (ICMX207184) were the best performing and most stable among the five test environments