Towards defining heterotic gene pools using SSR markers in pearl millet [Pennisetum glaucum (L.) R. Br.]

Pearl millet is a climate resilient crop and the most widely grown millet worldwide. In a maiden attempt to identify potential heterotic groups for grain yield in pearl millet, a total of 88 polymorphic SSR markers were used to genotype 343 hybrid parental lines of pearl millet. The SSR markers generated a total of 532 alleles with a mean value of 6.05 alleles per locus, mean gene diversity of 0.55, and an average PIC of 0.50. Out of 532 alleles, 443 (83.27%) alleles were contributed by B- lines with a mean of 5.03 alleles per locus. R- lines contributed 476 alleles (89.47%) with a mean of 5.41, while 441 (82.89%) alleles were shared commonly between B- and R- lines. The gene diversity and PIC were high among R- lines (0.55 and 0.50) than B- lines (0.49 and 0.44) revealed that R- lines were more diverse than B- lines. The unweighted neighbor-joining tree based on simple matching dissimilarity matrix obtained from SSR data clearly differentiated B- lines into 10 sub-clusters (B1, B2, B3, B4, B5, B6, B7, B8, B9 and B10), and Rlines into 11 sub-clusters (R1, R2, R3, R4, R5, R6, R7, R8, R9, R10 and R11). The parents, three checks and 99 hybrids generated by crossing between representative lines of each of the B- cluster with that of each of the R- cluster were evaluated in line ? tester design over three environments. Based on pooled mean performance, the cross combinations generated between clusters B1 and R3, B2 and R4, B3 and R5, B4 and undetermined cluster, B5 and 11R, B6 and R3, B8 and R4, B9 and R7 and B10 and R5 had shown higher grain yield per plant compared to their counterparts. Based on per se performance, high sca effects and standard heterosis over superior check, F1s generated from crosses between representatives of groups B3 and B10 with representative of group R5 resulted in best heterotic combinations for grain yield. These represent putative heterotic gene pools in pearl millet.publishersversionPeer reviewe

Teamwork delivers biotechnology products to Indian small-holder crop-livestock producers: Pearl millet hybrid “HHB 67 Improved” enters seed delivery pipeline

HHB 67, released in 1990 by CCS Haryana Agricultural University, is one such single-cross pearl millet hybrid. HHB 67 is highly popular because of its extra-early maturity (it needs less than 65 days from sowing to grain maturity) and is now grown on over 500 000 ha in Haryana and Rajasthan, India. Recent surveys have indicated that this hybrid is starting to succumb to downy mildew (DM; caused by the pseudo-fungus Sclerospora graminicola), showing up to 30% incidence in farmers' fields. By rapidly adopting hybrid "HHB 67 Improved", farmers in Haryana and Rajasthan can avoid grain production losses of Rs36 crores (US$8 million) which would be expected in the first year of a major DM outbreak on the original HHB 67

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Not AvailableThe major requirement of pearl millet [Pennisetum gJaucum (L.) R. Sr.] breeding programmes targeting environmentally fragile arid regions is to breed genetically diverse materials that are both adapted to environmental stresses and also have an improved yield potential to allow them to respond to favourable conditions in good rainfall seasons. Genetic diversification of indigenous landraces using selected exotic, elite sources could be an effective mean to achieve this objective. This study evaluated 13 diverse, exotic populations for their phenotypic characteristics, their productivity under arid zone conditions, and their potential usefulness as sources of diversification for local landraces. The biomass productivity, which was the major determinant of both grain and stover productivity, varied between 747 9 m-2 and 942 g m-2. A higher panicle number and early flowering favored greater grain yield, while later flowering and greater height fC!vored higher stover yield. Although biomass and HI were negatively correlated, grain yield was similarly and positively correlated to both, suggesting that both biomass accumulation and its partitioning to grain are important in determining grain yield performance in arid environments. The best populations for grain yield were ICMV 98792, MCNELC and ICMP 96132, which outyielded two improved checks (Raj 171 and CZP 923) by 16-24%. The magnitude of superiority of best populations over two checks for stover yield was 55-83%. There existed a good opportunity to select exotic sources with different combinations of panicle length and tillering. In addition, the downy mildew reaction of elite exotic sources is not likely to be a deterrent factor in utilizing the selected elite populations as sources of diversification of landraces.Not Availabl

Table3.DOCX

<p>Pearl millet is a climate resilient crop and one of the most widely grown millets worldwide. Heterotic hybrid development is one of the principal breeding objectives in pearl millet. In a maiden attempt to identify heterotic groups for grain yield, a total of 343 hybrid parental [maintainer (B-) and restorer (R-)] lines were genotyped with 88 polymorphic SSR markers. The SSRs generated a total of 532 alleles with a mean value of 6.05 alleles per locus, mean gene diversity of 0.55, and an average PIC of 0.50. Out of 532 alleles, 443 (83.27%) alleles were contributed by B-lines with a mean of 5.03 alleles per locus. R-lines contributed 476 alleles (89.47%) with a mean of 5.41, while 441 (82.89%) alleles were shared commonly between B- and R-lines. The gene diversity was higher among R-lines (0.55) compared to B-lines (0.49). The unweighted neighbor-joining tree based on simple matching dissimilarity matrix obtained from SSR data clearly differentiated B- lines into 10 sub-clusters (B1 through B10), and R- lines into 11 sub-clusters (R1 through R11). A total of 99 hybrids (generated by crossing representative 9 B- and 11 R- lines) along with checks were evaluated in the hybrid trial. The 20 parents were evaluated in the line trial. Both the trials were evaluated in three environments. Based on per se performance, high sca effects and standard heterosis, F₁s generated from crosses between representatives of groups B10R5, B3R5, B3R6, B4UD, B5R11, B2R4, and B9R9 had high specific combining ability for grain yield compared to rest of the crosses. These groups may represent putative heterotic gene pools in pearl millet.</p

Table2.DOCX

<p>Pearl millet is a climate resilient crop and one of the most widely grown millets worldwide. Heterotic hybrid development is one of the principal breeding objectives in pearl millet. In a maiden attempt to identify heterotic groups for grain yield, a total of 343 hybrid parental [maintainer (B-) and restorer (R-)] lines were genotyped with 88 polymorphic SSR markers. The SSRs generated a total of 532 alleles with a mean value of 6.05 alleles per locus, mean gene diversity of 0.55, and an average PIC of 0.50. Out of 532 alleles, 443 (83.27%) alleles were contributed by B-lines with a mean of 5.03 alleles per locus. R-lines contributed 476 alleles (89.47%) with a mean of 5.41, while 441 (82.89%) alleles were shared commonly between B- and R-lines. The gene diversity was higher among R-lines (0.55) compared to B-lines (0.49). The unweighted neighbor-joining tree based on simple matching dissimilarity matrix obtained from SSR data clearly differentiated B- lines into 10 sub-clusters (B1 through B10), and R- lines into 11 sub-clusters (R1 through R11). A total of 99 hybrids (generated by crossing representative 9 B- and 11 R- lines) along with checks were evaluated in the hybrid trial. The 20 parents were evaluated in the line trial. Both the trials were evaluated in three environments. Based on per se performance, high sca effects and standard heterosis, F₁s generated from crosses between representatives of groups B10R5, B3R5, B3R6, B4UD, B5R11, B2R4, and B9R9 had high specific combining ability for grain yield compared to rest of the crosses. These groups may represent putative heterotic gene pools in pearl millet.</p

Table1.DOCX

<p>Pearl millet is a climate resilient crop and one of the most widely grown millets worldwide. Heterotic hybrid development is one of the principal breeding objectives in pearl millet. In a maiden attempt to identify heterotic groups for grain yield, a total of 343 hybrid parental [maintainer (B-) and restorer (R-)] lines were genotyped with 88 polymorphic SSR markers. The SSRs generated a total of 532 alleles with a mean value of 6.05 alleles per locus, mean gene diversity of 0.55, and an average PIC of 0.50. Out of 532 alleles, 443 (83.27%) alleles were contributed by B-lines with a mean of 5.03 alleles per locus. R-lines contributed 476 alleles (89.47%) with a mean of 5.41, while 441 (82.89%) alleles were shared commonly between B- and R-lines. The gene diversity was higher among R-lines (0.55) compared to B-lines (0.49). The unweighted neighbor-joining tree based on simple matching dissimilarity matrix obtained from SSR data clearly differentiated B- lines into 10 sub-clusters (B1 through B10), and R- lines into 11 sub-clusters (R1 through R11). A total of 99 hybrids (generated by crossing representative 9 B- and 11 R- lines) along with checks were evaluated in the hybrid trial. The 20 parents were evaluated in the line trial. Both the trials were evaluated in three environments. Based on per se performance, high sca effects and standard heterosis, F₁s generated from crosses between representatives of groups B10R5, B3R5, B3R6, B4UD, B5R11, B2R4, and B9R9 had high specific combining ability for grain yield compared to rest of the crosses. These groups may represent putative heterotic gene pools in pearl millet.</p