Gene effects for grain iron and zinc in sorghum (sorghum bicolor L. Moench)

Sorghum bicolor L. Moench is a major food crop in African and Asian countries. Eradication of hidden hunger through fortification of food consumed is an easy way. Iron and Zinc deficiencies are widespread across the world.Thus the present investigation was carried out in sorghum to determine the gene action involved in the inheritance of grain iron and zinc concentrations and other related traits using generation mean analysis. Two crosses viz., ICSB 52 × IS 13211, ICSB 52 × SPV 1359, were made using diverse parents with varied levels of grain iron and zinc concentrations. Six generations viz., P1, P2, F1, F2, B1 and B2 were developed for the above crosses and were evaluated during post-rainy season, 2012- 13 at ICRISAT, Patancheru. The results of generation mean analysis revealed the predominant role of additive gene action and additive × additive component of epistasis was found responsible in the crosses ICSB 52 × IS 13211 and ICSB 52 × SPV 1359 in governing grain iron and zinc concentrations and days to 50 % flowering. For remaining traits viz., plant height, panicle length, panicle width, grain yield plant -1, 100- grain weight had dominance component and found responsible than additive. Among the interactions, dominance × dominance component was of higher value than the remaining in governing the traits under concern. For all the traits, the magnitude of interactions was of higher value than their respective direct effects

Evaluating the Efficacy of Synthetic Fibre Pollination Control Bags in Sorghum During the Rainy Season

Background and Objective: Sorghum breeders traditionally use paper pollination control bags for hybridisation and generation advance. However, these bags get torn off in the rainy season and by birds searching for food. High incidence of grain mold also occurs in these bags. The major objective of this study was to test novel nonwoven synthetic fabrics as replacement for paper bags. Methodology: Three newly developed pollination control bags from synthetic polyester and polypropylene nonwoven fibres were tested against the paper bags at Patancheru, ICRISAT, India on four sorghum genotypes for bag traits and many quantitative characters in the rainy seasons of 2014 and 2015 years that were diverse in total rainfall which was 231.9 mm more in 2015 compared with 2014 (77% higher) with 11 more rainy days than that in 2014 (299.3 mm in 42 rainy days). Data were analysed using the factorial analysis of variance and Pearson's correlations. Results: Bags were evaluated for three bag traits: Water resistance, intactness and ease of handling. The duraweb® SG1 and duraweb® SG2 were superior to other bag types for all these traits with duraweb® SG1 being significantly superior to duraweb® SG2. The duraweb® SG3 bag was similar to the standard paper bag for all bag traits. While bags did not show significant differences for grain yield they significantly differed for other six quantitative traits; duraweb® SG1 was the best performer followed very closely by duraweb® SG2 bag. The duraweb® SG1 bag was significantly superior to no bagging as well as all other types of bags for grain mold resistance. On average 12% bird damage on panicles was observed under paper bags compared with 36% on the uncovered panicles. Contrastingly, no bird damage was observed under bags made of all three novel materials. Conclusion: The new pollination bags made from nonwoven fabrics provide an effective alternative to traditional paper bags as they ensure near-ambient micro-environment within them for seed development and are strong enough to resist wind, rain and bird damage while allowing aeration to minimize fungal development in the rainy season

Inheritance studies on grain iron and zinc concentration and agronomic traits in sorghum [Sorghum bicolor (L.) Moench]

Sorghum is a major staple globally and biofortifying sorghum with increased grain iron and zinc complements ongoing efforts to combat micronutrient malnutrition. Limited information available on the nature and magnitude of gene effects for grain iron and zinc. So generation mean analysis was done using four crosses, ICSB 52 × IS 13211, ICSB 52 × SPV 1359, IS 20843 × IS 2248 and IS 2248 × IS 20843. Six generations, P1, P2, F1, F2, B1 and B2, were generated for each of these crosses which were evaluated during the postrainy season 2012–13. The mean sum of squares due to generations were significant for days to flowering, plant height, grain yield/plant, 100-grain weight, and grain Fe and Zn. Generation mean studies revealed the presence of both additive and dominant gene interactions in inheritance of agronomic traits. Duplicative epistasis was observed for days to flowering, plant height, grain yield/plant, 100-grain weight, and grain Zn with a predominance of dominant gene action in inheritance of these traits. Panicle length, panicle width, and grain Fe showed both additive and dominance gene effects, with higher magnitude of dominance. This information can be utilized in developing sorghum lines with high grain Fe and Zn

Heterosis and combining ability for grain Fe and Zn concentration and agronomic traits in sorghum [Sorghum bicolor (L.) Moench]

Studies on genetics and trait relationships with grain yield and other agronomic traits are critical for improving the micronutrients content in the grain and it forms an effective strategy for breeding bio fortified sorghum. It greatly contributes to addressing micronutrient malnutrition in poor people who are dependent on sorghum as a staple food. Development of hybrids with high grain Fe and Zn and higher yield enables delivery of commercial products that address both food and nutrition while bringing profits to farmers. The present study was aimed at developing suitable breeding strategy and improving breeding products using gene action, heterosis and combining ability analysis for improving the grain Iron (Fe) and Zinc (Zn) concentration and grain yield in sorghum. This study was conducted in Line Tester mating design involving seven parents. A total of 12 new hybrids were developed by mating three lines with four testers. The combining ability of the crosses indicated predominance of dominance variance than additive variance for the agronomic traits such as days to 50% flowering, grain yield, grain Fe and Zn concentrations except for plant height and 100 seed weight. Higher magnitude of SCA than GCA variance for grain iron and zinc concentrations indicated the importance of non-additive gene action in the improvement of nutritional traits. Hybrids exhibited heterosis for agronomic traits and for grain Fe concentration and grain Zn. Most of the traits showed significant positive heterosis over mid parent value indicating the predominance of dominant gene action except the trait 100 seed weight. Significant positive mid-parent heterosis for grain iron indicated that there would be an opportunity to exploit heterosis in improving for grain Fe. But for Zn concentration, there is a limited possibility for exploitation of heterosis. This study suggested that simple selection will improve plant height and 100 seed weight in sorghum but heterosis breeding is more useful for improving grain yield. While both parents need to be improved for improving grain Zn concentration, there is good scope for exploiting heterosis for improving grain Fe concentration in sorghum

Identification of Genomic Regions and Sources for Wheat Blast Resistance through GWAS in Indian Wheat Genotypes

Wheat blast (WB) is a devastating fungal disease that has recently spread to Bangladesh and poses a threat to the wheat production in India, which is the second-largest wheat producing country in the world. In this study, 350 Indian wheat genotypes were evaluated for WB resistance in 12 field experiments in three different locations, namely Jashore in Bangladesh and Quirusillas and Okinawa in Bolivia. Single nucleotide polymorphisms (SNPs) across the genome were obtained using DArTseq (R) technology, and 7554 filtered SNP markers were selected for a genome-wide association study (GWAS). All the three GWAS approaches used identified the 2NS translocation as the only major source of resistance, explaining up to 32% of the phenotypic variation. Additional marker-trait associations were located on chromosomes 2B, 3B, 4D, 5A and 7A, and the combined effect of three SNPs (2B_180938790, 7A_752501634 and 5A_618682953) showed better resistance, indicating their additive effects on WB resistance. Among the 298 bread wheat genotypes, 89 (29.9%) carried the 2NS translocation, the majority of which (60 genotypes) were CIMMYT introductions, and 29 were from India. The 2NS carriers with a grand mean WB index of 6.6 showed higher blast resistance compared to the non-2NS genotypes with a mean index of 46.5. Of the 52 durum wheats, only one genotype, HI 8819, had the 2NS translocation and was the most resistant, with a grand mean WB index of 0.93. Our study suggests that the 2NS translocation is the only major resistance source in the Indian wheat panel analysed and emphasizes the urgent need to identify novel non-2NS resistance sources and genomic regions

Genetic Variability, Genotype × Environment Interaction, Correlation, and GGE Biplot Analysis for Grain Iron and Zinc Concentration and Other Agronomic Traits in RIL Population of Sorghum (Sorghum bicolor L. Moench)

The low grain iron and zinc densities are well documented problems in food crops, affecting crop nutritional quality especially in cereals. Sorghum is a major source of energy and micronutrients for majority of population in Africa and central India. Understanding genetic variation, genotype × environment interaction and association between these traits is critical for development of improved cultivars with high iron and zinc. A total of 336 sorghum RILs (Recombinant Inbred Lines) were evaluated for grain iron and zinc concentration along with other agronomic traits for 2 years at three locations. The results showed that large variability exists in RIL population for both micronutrients (Iron = 10.8 to 76.4 mg kg−1 and Zinc = 10.2 to 58.7 mg kg−1, across environments) and agronomic traits. Genotype × environment interaction for both micronutrients (iron and zinc) was highly significant. GGE biplots comparison for grain iron and zinc showed greater variation across environments. The results also showed that G × E was substantial for grain iron and zinc, hence wider testing needed for taking care of G × E interaction to breed micronutrient rich sorghum lines. Iron and zinc concentration showed high significant positive correlation (across environment = 0.79; p 0.60, in individual environments) for Fe and Zn and other traits studied indicating its suitability to map QTL for iron and zinc

Heterosis and Combining ability studies for improving grain Fe and Zn concentration and agronomic traits in Sorghum [Sorghum bicolor (L.) Moench]

Objective: Sorghum is a staple food for more than 300 million people in more than 30 counties. It is a rich source of micronutrients. Biofortifying sorghum with enhanced grain Fe and Zn is a major breeding objective. The present study was aimed at formulating suitable breeding program by studying gene action, heterosis and combining ability for improving grain Fe and Zn concentration in sorghum. Materials & Methods: This study was conducted in Line × Tester mating design involving seven parents. Twelve hybrids were developed by mating three lines with four testers. The combining ability of the crosses indicated predominance of dominance variance than additive variance for the agronomic traits such as days to 50 % flowering, grain yield, grain Fe and Zn concentration except for plant height and 100 seeds weight. Main Findings: Higher magnitude of SCA than GCA variance for grain iron and zinc concentration indicated the importance of non-additive gene action in these nutritional traits improvement. Hybrids showed heterosis for agronomic traits and for grain Fe concentration and limited heterosis for grain Zn. Most of the traits showed significant positive heterosis over mid parent value indicating the predominance of dominant gene action except the trait -100 seeds weight. Significant positive midparent heterosis for grain iron (Fe) indicated that there would be an opportunity to exploit heterosis in improving for grain Iron. But for Zn concentration, there is limited possibility for exploitation of heterosis. This study suggested that simple selection will improve plant height and 100-seed weight in sorghum but heterosis breeding is more useful for improving grain yield. While both parents need to be improved for improving grain Zn concentration there is good scope for exploiting heterosis for improving grain Fe concentration in sorghum. Conclusion & Recommendations: We released first biofortified sorghum variety ‘Parbhani Shakti’ (45 ppm Fe and 32 ppm Zn) with higher yield (4 tha-1), higher protein (11.9%) and low phytates content (4.1 mg/100 g) and released in 2018. Biofortified sorghums complements the on-going approaches for combating dietary induced micronutrient malnutrition

Identification of genomic regions and sources for wheat blast resistance through GWAS in indian wheat genotypes

Wheat blast (WB) is a devastating fungal disease that has recently spread to Bangladesh and poses a threat to the wheat production in India, which is the second-largest wheat producing country in the world. In this study, 350 Indian wheat genotypes were evaluated for WB resistance in 12 field experiments in three different locations, namely Jashore in Bangladesh and Quirusillas and Okinawa in Bolivia. Single nucleotide polymorphisms (SNPs) across the genome were obtained using DArTseq® technology, and 7554 filtered SNP markers were selected for a genome-wide association study (GWAS). All the three GWAS approaches used identified the 2NS translocation as the only major source of resistance, explaining up to 32% of the phenotypic variation. Additional marker-trait associations were located on chromosomes 2B, 3B, 4D, 5A and 7A, and the combined effect of three SNPs (2B_180938790, 7A_752501634 and 5A_618682953) showed better resistance, indicating their additive effects on WB resistance. Among the 298 bread wheat genotypes, 89 (29.9%) carried the 2NS translocation, the majority of which (60 genotypes) were CIMMYT introductions, and 29 were from India. The 2NS carriers with a grand mean WB index of 6.6 showed higher blast resistance compared to the non-2NS genotypes with a mean index of 46.5. Of the 52 durum wheats, only one genotype, HI 8819, had the 2NS translocation and was the most resistant, with a grand mean WB index of 0.93. Our study suggests that the 2NS translocation is the only major resistance source in the Indian wheat panel analysed and emphasizes the urgent need to identify novel non-2NS resistance sources and genomic regions

Variability and trait‐specific accessions for grain yield and nutritional traits in germplasm of little millet ( Panicum sumatrense Roth. Ex. Roem. & Schult.)

Little millet (Panicum sumatrense Roth. Ex. Roem. & Schult.), a member of the grass family Poaceae, is native to India. It is nutritionally superior to major cereals, grows well on marginal lands, and can withstand drought and waterlogging conditions. Two-hundred diverse little millet landraces were characterized to assess variability for agronomic and nutritional traits and identify promising accessions. Highly significant variabilitywas found for all the agronomic and grain nutrient traits. Accessions of robusta were high yielding whereas those of nana were rich in grain nutrients. About 80% of the accessions showed consistent protein and zinc (Zn) contents whereas iron (Fe) and calcium (Ca) contents were less consistent (29.5 and 63.5%, respectively) over 2 yr. Promising trait-specific accessions were identified for greater seed weight (10 accessions), high grain yield (15), high biomass yield (15), and consistently high grain nutrients (30) over 2 yr (R2 = .69–.74, P ≤ .0001). A few accessions showed consistently high for two or more nutrients (IPmr 449 for Fe, Zn, Ca, and protein; IPmr 981 for Zn and protein). Five accessions (IPmr 855, 974, 877, 897, 767) were high yielding and also rich in Ca. Consumption of 100 g of little millet grains can potentially contribute to the recommended dietary allowance of up to 28% Fe, 37% Zn, and 27% protein. Multilocation evaluation of the promising accessions across different soil types, fertility levels, and climatic conditions would help to identify valuable accessions for direct release as a cultivar or use in little millet improvement