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Rice false smut (RFS), an emerging major fungal disease worldwide caused by Ustilaginoidea virens,affects rice grain quality and yield. RFS cause 2.8–49% global yield loss depending upon disease severity and cultivars. In India, the yield loss due to RFS ranged from 2 to 75%. Identification of the genes or quantitative trait loci (QTLs) governing disease resistance would be of utmost importance towards mitigating the economic losses incurred due to RFS. Here, we report mapping of RFS resistance QTLs from a resistant breeding line RYT2668. The mapping population was evaluated for RFS resistance under the field condition in three cropping seasons 2013, 2015, and 2016. A positive correlation among infected panicle/plant, total smut ball/panicle, and disease score was observed in the years 2013, 2015, and the mean data. A total of seven QTLs were mapped on rice chromosomes 2, 4, 5, 7, and 9 using 2326 single nucleotide polymorphism markers. Of these, two QTLs, qRFSr5.3and qRFSr7.1a, were associated with the infected panicle per plant, one QTL qRFsr9.1with total smut ball per panicle, and four QTLs qRFSr2.2, qRFSr4.3, qRFSr5.4, and qRFSr7.1bwith disease score. Among them, a novel QTL qRFSr9.1on chromosome 9 exhibits the largest phenotypic effect. The prediction of putative candidate genes within the qRFSr9.1revealed four nucleotide-binding sites–leucine-rich repeat (NBS-LRR) domain-containing disease resistance proteins. In summary, our findings mark the hotspot region of rice chromosomes carrying genes/QTLs for resistance to the RFS disease.

A number of maize (Zea maysL.) genotypes were tested for their influence on induction and regeneration of haploid wheat (Triticum aestivumL.) embryos to improve further the efficiency of the wheat × maize system of haploid production. Fifteen maize genotypes were crossed to five diverse wheat F1hybrids in a line × tester fashion in three replications. Two efficiency parameters, caryopses formation frequency (CFF—number of caryopses/100 pollinated florets) and embryo formation frequency (EFF—number of embryo‐carrying caryopses/100 pollinated florets), were estimated. Analysis of variance revealed that lines (wheat genotypes), testers (maize genotypes), and their interaction showed significant effects on both efficiency parameters, but the effect of maize genotypes was greater than that of wheat genotypes. The EFF of individual maize genotypes ranged from 1.1 to 23.4% and the EFF of individual wheat genotypes ranged from 8.4 to 10.2%. Maize genotypes also showed significant differences for general combining ability estimates. In addition to EFF, maize genotypes had a striking effect on haploid embryo regeneration as analyzed using one of the wheat genotypes. The values ranged from 0.0 to 87.8%. For maize genotypes producing the highest EFFs, the regeneration frequency was not necessarily higher. Hence, we suggest a new index, haploid formation efficiency (HFE—number of haploid plants formed /100 pollinated florets), be used for identification of efficient pollinators. The HFE ranged from 0.0 to 9.9%. In this study, a pop corn cultivar, Pearl Pop Corn, was identified as the best pollinator with an average EFF of 15.1% across five wheat genotypes and an HFE of 9.9% with the one wheat genotype tested.