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Aromatic rice (Oryza sativaL.) germplasm conserved in global genebanks needs intensive characterization to assess genetic diversity and population structure for crop improvement. We analyzed a panel of 92 accessions of non‐Basmati aromatic rice landrace germplasm with 23 phenotypic traits and 48 microsatellite markers. The landrace accessions displayed a huge phenotypic diversity for traits, namely, culm length, flag‐leaf length, panicle‐bearing tillers (PBT), plant height, panicle length, peduncle length, panicle exsertion, grain length, grain width, hull color, and 1000‐grain weight (TGW). Phenotypic clustering revealed three major clusters and five principal components explained 81.24% of the variance. TGW was associated positively with grain length, grain width, peduncle length, and grain yield but negatively with culm length and PBT. A total of 528 microsatellite alleles were detected, with 11.0 alleles per locus, revealing the presence of high polymorphism. Genetically, four subpopulations were detected based on structure analysis. In the germplasm, high levels of gene flow (Nm = 1.51) and gene diversity (HE= 0.83) were found. Among the subpopulations, we discovered high levels of inbreeding (FIS= 0.92) and moderate genetic differentiation (FST= 0.14). High polymorphism information content (0.806) along with a high level of molecular variance among genotypes (79%) was detected. A large number of multiple alleles were detected in numerous landrace accessions, revealing the presence of heterogeneity and heterozygotes in the landrace germplasm. The results of the present study are vital for the utilization of landrace diversity in the genetic improvement programs designed for rice quality improvement and consumer preference. We need to characterize aromatic rice landrace accessions conserved in global genebanks to assess their variability, genetic structure, and population differentiation.Molecular and phenotypic characterization revealed a high variance among the genotypes but low variance within genotype and among the subpopulations.We found moderate genetic differentiation with high gene flow between accessions of four subpopulations of aromatic rice landraces.Landraces that displayed huge genetic diversity both at phenotypic and molecular levels could be exploited for rice improvement.

Crop wild relatives (CWRs) are vital sources of variation for genetic improvement, but their populations are few in genebanks, eroded in natural habitats and inadequately characterized. With a view to explore genetic diversity in CWRs of AA genome rice (Oryza sativaL.) species in India, we analyzed 96 accessions of 10 Oryzaspecies by using 17 quantitative traits and 45 microsatellite markers. The morpho-quantitative traits revealed a high extent of phenotypic variation in the germplasm. Diversity index (H′) revealed a high level of within-species variability in O. nivara(H′ = 1.09) and O. rufipogon(H′ = 1.12). Principal component (PC) analysis explained 79.22% variance with five PCs. Among the traits related to phenology, morphology, and yield, days to heading showed strong positive association with days to 50% flowering (r= 0.99). However, filled grains per panicle revealed positive association with spikelet fertility (0.71) but negative with awn length (− 0.58) and panicle bearing tillers (− 0.39). Cluster analysis grouped all the accessions into three major clusters. Microsatellite analysis revealed 676 alleles with 15.02 alleles per locus. High polymorphism information content (PIC = 0.83) and Shannon’s information index (I = 2.31) indicated a high level of genetic variation in the CWRs. Structure analysis revealed four subpopulations; first and second subpopulations comprised only of O. nivaraaccessions, while the third subpopulation included both O. nivaraand O. rufipogonaccessions. Population statistics revealed a moderate level of genetic differentiation (FST= 0.14), high gene diversity (HE= 0.87), and high gene flow (Nm = 1.53) among the subpopulations. We found a high level of molecular variance among the genotypes (70%) and low among populations (11%) and within genotypes (19%). The high level of molecular and morphological variability detected in the germplasm of CWRs could be utilized for the improvement of cultivated rice.

The use of untapped plant genetic resources of wheat (Triticumspp.) can enhance its productivity. In the present study, we characterized 22,416 accessions of three different species of wheat conserved in the Indian National Genebank using 23 qualitative and 12 quantitative traits to develop a core set. These accessions were highly diverse on the basis of range, coefficient of variation, and Shannon–Weaver diversity index. Initial grouping was done on the bases of species and origin, and thereafter, agromorphological data were used to develop core sets for each species group using the heuristic approach with PowerCore. Finally, a composite core set was constituted comprising 2,226 accessions, which included 1,779 accessions of bread wheat (T. aestivumL.), 394 of durum wheat [T. turgidumL. subsp. durum(Desf.) van Slageren], and 53 of emmer wheat [T. dicocconSchrank; syn. T. turgidumL. subsp. dicoccon(Schrank) Thell]. The core set was validated under field conditions. Also, the coincidence rate of range (CR) (bread wheat, 85.78%; durum wheat, 87.52%; and emmer wheat, 95.34%) and variable rate of the coefficient of variation (VR) (bread wheat, 174.9%; durum wheat, 136.5%; and emmer wheat, 105.81%) were more than the threshold values of 80 and 100%, respectively. The phenotypic correlations among different traits attributable to coadapted gene complexes and total variation shown by principal components in the entire set were also mostly preserved in the core set. The composite wheat core and the trait‐specific germplasm sets identified would serve as valuable resources for global wheat improvement programs.

Isolates of Trichodermaspp. collected from Pleurotus ostreatusand P. eryngiibeds, which included loosened substrate compactness and development of green colour, were grouped into three species. The occurrence of different species of Trichodermawas as T.cf. virens(70.8%), T. longibrachiatum(16.7%) and T. harzianum(12.5%). The conidia of Trichodermaspp. were ellipsoidal, obovoid and phialides were bowling pins, lageniform and the length of phialides was 3.5~10.0 × 1.3~3.3 μm. Phialides of T.cf. virensand T. harzianumwere tending clustered, but it was solitary disposition in T. longibrachiatum. T.cf. virenswas characterized by predominantly effuse conidiation, sparingly branched, and fertile to the apex and it was penicillate type. RAPD analysis could detect variability amongst three different species of Trichodermausing two newly designed URP-primers. However, intra-specific variation could not be detected in all the isolates except for rDNA sequence data classified Trichodermaisolates into three distinct groups representing three species. The profiles of rDNA sequences of isolates representing a species showed high similarity in T.cf. virensand T. harzianum.However, there was a variation in rDNA sequences of isolates representing T. longibrachiatum.The results of present study reveals that molecular techniques of RAPD and rDNA sequencing can greatly aid in classification based on morphology and precise identification of fast evolving species of Trichoderma.