Summary Though several genes governing various major traits have been reported in rice, their superior haplotype combinations for developing ideal variety remains elusive. In this study, haplotype analysis of 120 previously functionally characterized genes, influencing grain yield (87 genes) and grain quality (33 genes) revealed significant variations in the 3K rice genome ( RG ) panel. For selected genes, meta‐expression analysis using already available datasets along with co‐expression network provided insights at systems level. Also, we conducted candidate gene based association study for the 120 genes and identified 21 strongly associated genes governing 10‐grain yield and quality traits. We report superior haplotypes upon phenotyping the subset of 3K RG panel, SD 1 ‐H8 with haplotype frequency ( HF ) of 30.13% in 3K RG panel, MOC 1 ‐H9 ( HF : 23.08%), IPA 1 ‐H14 ( HF : 6.64%), DEP 3 ‐H2 ( HF : 5.59%), DEP 1 ‐H2 ( HF : 37.53%), SP 1 ‐H3 ( HF : 5.05%), LAX 1 ‐H5 ( HF : 1.56%), LP ‐H13 (3.64%), OSH 1 ‐H4 (5.52%), PHD 1 ‐H14 ( HF : 15.21%), AGO 7 ‐H15 ( HF : 3.33%), ROC 5 ‐H2 (31.42%), RSR 1 ‐H8 ( HF : 4.20%) and Os NAS 3 ‐H2 ( HF : 1.00%). For heading date, Ghd7 ‐H8 ( HF : 3.08%), TOB 1 ‐H10 ( HF : 4.60%) flowered early, Ghd7 ‐H14 ( HF : 42.60%), TRX 1 ‐H9 ( HF : 27.97%), Os VIL 3 ‐H14 ( HF : 1.72%) for medium duration flowering, while Ghd7 ‐H6 ( HF : 1.65%), SNB ‐H9 ( HF : 9.35%) were late flowering. GS 5 ‐H4 ( HF : 65.84%) attributed slender, GS 5 ‐H5 ( HF : 29.00%), GW 2 ‐H2 ( HF : 4.13%) were medium slender and GS 5 ‐H9 ( HF : 2.15%) for...

Strong seedling vigor is desirable trait in dry direct-seeded rice (DSR) for enhancing crop establishment and the ability to compete against weeds. A set of 253 BC3F4 lines derived from cross between Swarna and Moroberekan was phenotyped for early vigor (EV) and 8 related traits viz., early uniform emergence (EUE), shoot length (SHL), stem length (SL), shoot fresh weight (SFW), total fresh weight (TFW), shoot dry weight (SDW), total dry weight (TDW), and root dry weight (RDW). Composite interval mapping analysis using genotypic data from 194 SNP markers identified six genomic regions associated with traits on chromosomes 3, 4, 5, and 6 with phenotypic variance ranging from 2.5 to 18.6%. Among them 2 QTL regions; one on chr3 (id3001701-id300833) and the other on chr5 (wd5002636-id5001470) were identified as QTL hotspots A and B respectively and expressed consistently in field as well as glasshouse condition. The majority of QTLs identified for early vigor, and related traits were clustered in the QTL hotspots A (qEV3.1, qEUE3.1, qSHL3.1, qSL3.1, qSFW3.1, qTFW3.1, qRDW3.1) and QTL hotspot B (qEV5.1, qEUE5.1, qSHL5.1, qSL5.1, qSFW5.1, qSDW5.1, qTDW5.1). Ten putative candidate genes viz., 1-alpha-amylase precursor, 2-glutamate decarboxylase, 1-ethylene-insensitive 3, 3-expansin precursor, and 3-phenylalanine ammonia-lyase associated with the target traits were identified in the selected QTL regions. Mutations were identified in the coding region of alpha-amylase precursor and ethylene-insensitive 3 gene between the parents which can be utilized in marker assisted breeding. Trait relationships among the agro-physiological traits were examined to select the best genotypes for the given traits for use in future breeding programs.

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Calcium is an essential macronutrient for plants and animals and plays an indispensable role in structure and signaling. Low dietary intake of calcium in humans has been epidemiologically linked to various diseases which can have serious health consequences over time. Major staple food-grains are poor source of calcium, however, finger millet [Eleusine coracana (L.) Gaertn.], an orphan crop has an immense potential as a nutritional security crop due to its exceptionally high calcium content. Understanding the existing genetic variation as well as molecular mechanisms underlying the uptake, transport, accumulation of calcium ions (Ca 2+ ) in grains is of utmost importance for development of calcium bio-fortified crops. In this review, we have discussed molecular mechanisms involved in calcium accumulation and transport thoroughly, emphasized the role of molecular breeding, functional genomics and transgenic approaches to understand the intricate mechanism of calcium nutrition in finger millet. The objective is to provide a comprehensive up to date account of molecular mechanisms regulating calcium nutrition and highlight the significance of biofortification through identification of potential candidate genes and regulatory elements from finger millet to alleviate calcium malnutrition. Hence, finger millet could be used as a model system for explaining the mechanism of elevated calcium (Ca 2+ ) accumulation in its grains and could pave way for development of nutraceuticals or designer crops.

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