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Improving tomatoes keeping quality is crucial for reducing post-harvest losses. Knowledge of heterosis, and combining ability is a prerequisite for breeding high yielding and good shelf life heterotic hybrids. An investigation was undertaken with each of 3 lines, testers, and 9 hybrids to identify desirable parents and crosses for 20 fruit biochemical, morpho-physiological, and yield traits and to elucidate the nature of gene action for shelf life and its contributing traits through line × tester analysis. The lines contributed to most of hybrids variability than testers and fruit quality traits had a higher degree of SCA variance as compared to GCA variance. pH, ascorbic acid, fruit firmness, and plant height governed by additive gene action. Lycopene, titratable acidity, TSS, calcium, magnesium, pericarp thickness, pulp content, locule number, fruit length, diameter, weight, shelf life, number of branches, number of clusters, number of fruit/cluster, and yield/plant were under the control of non-additive gene action. All the lines and Arka Saurabh were the best general combiners and IIHR 2349 × Arka Vikas, IIHR 2349 × Arka Saurabh, IIHR 2358 × Arka Ahuti and IIHR 2357 × Arka Ahuti were the best specific combiner in producing heterotic hybrids. IIHR 2349 × Arka Vikas and IIHR 2349 × Arka Saurabh were promising hybrids for high yield and shelf life. The crosses involved both parents with high, one parent with high and other with low and both parents with low good overall general combining ability status respectively indicated the additive, non-additive and epistatic gene action in fruit quality and yield traits inheritance. [ABSTRACT FROM AUTHOR]

Genetic improvements of iron (Fe) and zinc (Zn) content in pearl millet [Pennisetum glaucum (L.) R. Br.] may reduce the problems of anemia and stunted growth among millet dependent staple food consumers. The availability of variation in diverse-breeding lines is essential to improve grain micronutrients in high-yielding cultivars. This study aimed to determine the extent of variability, heritability and diversity for grain Fe, Zn and protein, along with key agronomic traits, in 281 advanced breeding lines bred at ICRISAT and evaluated across two seasons (environments). A pooled analysis of variance displayed significant variation for all these traits. Highest variability was recorded for Fe (35–116 mg kg−1), Zn (21–80 mg kg−1), and protein (6–18%), and a three-fold variation was observed for panicle length, panicle girth and 1000-grain-weight (TGW). Diversity analysis showed 10 clusters. Cluster-III had maximum lines (25%) and Cluster-V showed the highest mean values for Fe, Zn, protein and TGW. These results highlight the success of breeding program that aimed both the maintenance and creation of genetic variability and diversity. A significant positive correlation among Fe, Zn, protein and TGW indicated the potential for simultaneous improvement. Grain yield had a non-significant association with Fe and Zn, while protein showed a negative correlation. These results suggest that significant variability exists in elite-breeding lines, thus highlighting an opportunity to breed for biofortified varieties without compromising on the grain yield. The lines with high Fe, Zn and protein content can be used as hybrid parents and may also help in further genetic investigations. [ABSTRACT FROM AUTHOR]

Pearl millet hybrids biofortified with iron (Fe) and zinc (Zn) promise to be part of a long-term strategy to combat micronutrient malnutrition in the arid and semi-arid tropical (SAT) regions of the world. Biofortification through molecular breeding is the way forward to achieving a rapid trait-based breeding strategy. This genome-wide association study (GWAS) was conducted to identify significant marker-trait associations (MTAs) for Fe, Zn, and protein content (PC) for enhanced biofortification breeding. A diverse panel of 281 advanced inbred lines was evaluated for Fe, Zn, and PC over two seasons. Phenotypic evaluation revealed high variability (Fe: 32–120 mg kg−1, Zn: 19–87 mg kg−1, PC: 8–16%), heritability (hbs2 ≥ 90%) and significantly positive correlation among Fe, Zn and PC (P = 0.01), implying concurrent improvement. Based on the Diversity Arrays Technology (DArT) seq assay, 58,719 highly informative SNPs were filtered for association mapping. Population structure analysis showed six major genetic groups (K = 6). A total of 78 MTAs were identified, of which 18 were associated with Fe, 43 with Zn, and 17 with PC. Four SNPs viz., Pgl04_64673688, Pgl05_135500493, Pgl05_144482656, and Pgl07_101483782 located on chromosomes Pgl04 (1), Pgl05 (2) and Pgl07 (1), respectively were co-segregated for Fe and Zn. Promising genes, 'Late embryogenesis abundant protein', 'Myb domain', 'pentatricopeptide repeat', and 'iron ion binding' coded by 8 SNPs were identified. The SNPs/genes identified in the present study presents prospects for genomics assisted biofortification breeding in pearl millet. [ABSTRACT FROM AUTHOR]