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Maize (Zea mays L.) is one of the important cereal crops in the world and is the third largest grown cereal crop in India. Field surveys conducted in 2013-15 recorded stalk rot incidence of 28–35% in southern states of India. The typical symptoms were observed after pollination with the drying of the lower leaves and eventually entire plant wilted prematurely, lower internodes turned in to grey-green color and stalks are hollow and weak leading to the lodging of the plant. Stalk rot associated pathogen was isolated on PDA medium. Out of 219 Fusarium isolates, 19 were distinct and the fungal colonies on PDA medium showed the development of pale brown to dark brown pigment. Macro conidia were produced in orange sporodochia from monophialides on branched conidiophores with apical cells tapered and elongated. Chlamydospores were solitary and intercalary. All 19 isolates were morphologically identical, and a representative isolate was used for molecular identification. The ITS rDNA and TEF gene were amplified and sequenced using ITS1/ITS4, TEF1/TEF2primer pairs. The nBLAST search and phylogenetic analysis confirmed that the pathogen was Fusarium equiseti. Pathogenicity tests conducted on 50-day-old maize plants by injecting conidial suspension of F. equiseti produced typical stalk rot symptoms after 15 days of post-inoculation and the pathogen's identity was confirmed by cultural and morphological features after re-isolation. Association of F. equiseti as the causal agent of sheath rot of maize was reported from China. The association of F. equiseti with stalk rot of maize is the first report in India.

Inter simple sequence repeat (ISSR) markers were used to estimate genetic diversity among 21 samples of Acorus calamus , an endangered medicinal herb from South and North East India. Out of 100 primers screened 14 generated distinct and reproducible DNA fragments. Using these primers, 103 discernible DNA fragments were generated of which 53 (51.5%) were polymorphic and remaining 50 (48.5%) were monomorphic. The amplified PCR fragment size ranged from 450 to 2250 bp. Nei’s genetic diversity ( h ) and Shannon’s index ( I ) among the population were estimated as 0.2005 and 0.2946 respectively. Value for total genotype diversity among population ( H T ) was 0.1893 while within population diversity ( H S ) was found to be 0.0834. The mean coefficient of gene differentiation ( G ST ) was as high as 0.5595 and the gene flow ( N m) was found to be 0.3937; both indicated rapid genetic differentiation among the populations of A. calamus . Analysis of molecular variance (AMOVA) indicated that 43% was attributable to among-populations diversity and the rest (57%) to differences within populations. The UPGMA dendrogram based on Ward’s minimum variance algorithm showed a high level genetic divergence between the populations from South and North Eastern India (∼119 linkage distance) which explains the existence of two geographically distinct populations.