Identification of QTNs Associated With Flowering Time, Maturity, and Plant Height Traits in Linum usitatissimum L. Using Genome-Wide Association Study.

Early flowering, maturity, and plant height are important traits for linseed to fit in rice fallows, for rainfed agriculture, and for economically viable cultivation. Here, Multi-Locus Genome-Wide Association Study (ML-GWAS) was undertaken in an association mapping panel of 131 accessions, genotyped using 68,925 SNPs identified by genotyping by sequencing approach. Phenotypic evaluation data of five environments comprising 3 years and two locations were used. GWAS was performed for three flowering time traits including days to 5%, 50%, and 95% flowering, days to maturity, and plant height by employing five ML-GWAS methods: FASTmrEMMA, FASTmrMLM, ISIS EM-BLASSO, mrMLM, and pLARmEB. A total of 335 unique QTNs have been identified for five traits across five environments. 109 QTNs were stable as observed in ≥2 methods and/or environments, explaining up to 36.6% phenotypic variance. For three flowering time traits, days to maturity, and plant height, 53, 30, and 27 stable QTNs, respectively, were identified. Candidate genes having roles in flower, pollen, embryo, seed and fruit development, and xylem/phloem histogenesis have been identified. Gene expression of candidate genes for flowering and plant height were studied using transcriptome of an early maturing variety Sharda (IC0523807). The present study unravels QTNs/candidate genes underlying complex flowering, days to maturity, and plant height traits in linseed.

Genetic diversity analysis of fungal pathogen Bipolaris sorghicola infecting Sorghum bicolor in India.

Bipolaris sorghicola (Lefebvre and Sherwin) is a well known and economically important seed-borne pathogen with the specific species of sorghum (Sorghum bicolor [L] Moench) as host. Thirty-two strains were obtained from different geographical area of sorghum growing places in India. Molecular characterization using three marker systems i.e., universal rice primers (URP), inter simple sequence repeat (ISSR) and random amplified polymorphic DNA (RAPD) was carried out. Molecular marker work revealed differences along with geographical origin clustering of various B. sorghicola strains which could not be revealed through conventional method of characterization. Out of 13 URPs, 20 ISSR and 50 RAPD primers screened, 8 primers each from URP and ISSR, and 10 primers from RAPD marker were found to result in reproducible banding pattern. One hundred per cent of polymorphic bands was recorded in all three molecular markers. Total number of bands was recorded 1986 with average of 248.25 in URP marker, and 2026 bands with average of 253.25 in ISSR marker and 2158 bands with average of 215.80 in RAPD markers. Maximum heterozygosity (Hn) was revealed by URP 17R (0.40), ISSR 10 (0.41) and RAPD marker OPC-5 (0.34). The polymorphism information content (PIC) values ranged between 5.89 to 8.28 in URP, 4.57 to 8.79 in ISSR and 4.44 to 9.64 in RAPD marker profiles. Maximum cophenetic correlation was found in URP (r = 0.910) followed by ISSR (r = 0.904) and RAPD (r = 0.870). The combined analysis of all three marker systems showed high cophenetic correlation (r = 0.911), which indicated a very good fit of the data for genetic diversity analysis. To best of our knowledge, this is a first report of genetic characterization of B. sorghicola. Hence, combined use of three marker systems would be more sensitive and reliable in characterizing genetic variability in B. sorghicola strains.

Modern spectroscopic technique in the characterization of biosensitive macrocyclic Schiff base ligand and its complexes: inhibitory activity against plantpathogenic fungi.

Complexes of the type [M(L)Cl2], where M = Co(II), Ni(II) and Cu(II) have been synthesized with a macrocyclic Schiff base ligand (1,4,5,7,10,11,12,15-octaaza,5,11,16,18-tetraphenyl, 3,4,12,13-tetramethyl cyclo-octadecane) derived from Schiff base (obtained by the condensation of 4-aminoantipyrine and dibenzoyl methane) and ethylenediamine. The ligand was characterized on the basis of elemental analysis, IR, (1)H NMR, EI Mass and molecular modeling studies while the complexes were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, IR, electronic and EPR spectral studies. All the complexes are non-electrolyte in nature. The covalency factor (ß) and coefficient factor (α) suggest the covalent nature of the complexes. The ligand and its metal complexes have shown antifungal activity with their LD50 values determined by probit analysis against two economically important fungal plant pathogens i.e. Macrophomina phaseolina and Fusarium solani.