Molecular genetics and phenotypic assessment of foxtail millet (Setaria italica (L.) P. Beauv.) landraces revealed remarkable variability of morpho-physiological, yield, and yield-related traits.

Foxtail millet (Setaria italica (L.) P. Beauv.) is highly valued for nutritional traits, stress tolerance and sustainability in resource-poor dryland agriculture. However, the low productivity of this crop in semi-arid regions of Southern India, is further threatened by climate stress. Landraces are valuable genetic resources, regionally adapted in form of novel alleles that are responsible for cope up the adverse conditions used by local farmers. In recent years, there is an erosion of genetic diversity. We have hypothesized that plant genetic resources collected from the semi-arid climatic zone would serve as a source of novel alleles for the development of climate resilience foxtail millet lines with enhanced yield. Keeping in view, there is an urgent need for conservation of genetic resources. To explore the genetic diversity, to identify superior genotypes and novel alleles, we collected a heterogeneous mixture of foxtail millet landraces from farmer fields. In an extensive multi-year study, we developed twenty genetically fixed foxtail millet landraces by single seed descent method. These landraces characterized along with four released cultivars with agro-morphological, physiological, yield and yield-related traits assessed genetic diversity and population structure. The landraces showed significant diversity in all the studied traits. We identified landraces S3G5, Red, Black and S1C1 that showed outstanding grain yield with earlier flowering, and maturity as compared to released cultivars. Diversity analysis using 67 simple sequence repeat microsatellite and other markers detected 127 alleles including 11 rare alleles, averaging 1.89 alleles per locus, expected heterozygosity of 0.26 and an average polymorphism information content of 0.23, collectively indicating a moderate genetic diversity in the landrace populations. Euclidean Ward's clustering, based on the molecular markers, principal coordinate analysis and structure analysis concordantly distinguished the genotypes into two to three sub-populations. A significant phenotypic and genotypic diversity observed in the landraces indicates a diverse gene pool that can be utilized for sustainable foxtail millet crop improvement.

5M approach to decipher starch-lipid interaction in minor millets.

KEY MESSAGE: The 5M approach can be applied to understand genetic complexity underlying nutritional traits of minor millets. It will help to systematically identify genomic regions/candidate genes imprinting metabolite profiles.

Existence of genetic lineages within Asian genotype of Taenia solium-Genetic characterization based on mitochondrial and ribosomal DNA markers.

Taenia solium cysticercosis is a potentially eradicable neglected zoonotic disease with public health importance. The genetic lineages of T. solium in Asia and Africa/America are distinct and the genetic composition of the parasite was found to influence the clinical symptoms in patients with cysticercosis. In the present study, the Cysticerci collected from pigs of two southern states of India (Karnataka and Andhra Pradesh) were genetically characterized based on mitochondrial (COX 1 and Cyt b) and ribosomal (ITS-1 and TBR) DNA markers. The study confirms the existence of two mitochondrial lineages of the parasite as Asian and African/American. Cytochrome oxidase 1 (COX 1) based analysis revealed the existence of two sub-lineages of the parasite within the Asian lineage based on the polymorphism at 994 position as 994A/G. In India, both the sub-lineages were identified and genetic divergence among different Indian isolates was evident. Further, the sequence analysis of Cytochrome B (Cyt b) revealed the existence of six sub-lineages of T. solium in India as 69T/69G, 97A/97G as well as 264T/264C. The analysis of nucleotide sequence of large subunit ribosomal DNA (TBR) revealed the existence of two sub-lineages in India based on the deletion of a nucleotide at 624th position. The cysts collected in the present study were more closely related to those of China and Indonesia than with other Indian isolates. Further, the sequence analysis did not indicate the presence of Taenia asiatica in the examined pigs and African/American lineages of T. solium. The results of the present study help to better understand the genetic diversity of T. solium in India.

Advancements in molecular marker technologies and their applications in diversity studies.

Crop improvement is a continuous effort, since some 10,000 years ago when primitive man made the transition from hunting and foraging to domestication and crop cultivation. Since then, man-made interventions have changed the entire scenario of crop evolution, by means of genetic alterations of plants and animals made to satisfy man's needs. The process of domestication has led to dramatic changes in their appearance, quality and productivity that have contributed substantially to global food security. The tremendous decline in cultivable land, freshwater, and increasing risk of biotic and abiotic stress demand immediate attention on crop improvement to cope with the higher demand of ∼ 40% of the food by 2020. Therefore, plant genetic variation plays a key role in plant breeding for its improvement. Most of the genetic variations useful for crop improvement have been deposited and maintained in seed gene banks across the world; they need to be brought into the mainstream of breeding lines. Recent advances and progress made in molecular markers have been substantial tools for deeper insights of genetics, and greatly complemented breeding strategies. Integration of the next-generation sequencing (NGS) technologies with precise phenotyping, association mapping, proteome and metabolome studies has increased the chances of finding candidate genes and their allelic variants controlling a trait of interest. Further, these functional markers (FMMs), genotype-by-sequencing and association mapping methodologies have opened new avenues for identification of novel genetic resources (lines) that can facilitate accelerated crop breeding programs for increased yield, high nutritional quality, and tolerance to a variety of abiotic and biotic stresses. The details of popular molecular markers, advancement in the technologies and strategies for crop diversity studies and their application in crop breeding programs are presented here.

Salacia mulbarica leaf extract mediated synthesis of silver nanoparticles for antibacterial and ct-DNA damage via releasing of reactive oxygen species.

In this examination, we researched the advantages of DNA fragmentation and metallic nanoparticles well-appointed with biomolecules. A novel interpretation of DNA damage by Silver Nano-Clusters (AgNCs) which were developed by the utilization of green synthesis method was demonstrated. The green synthesis of AgNCs was accomplished by utilizing the leaf extract of Salacia mulbarica (SM). The preparation of SM-AgNCs was developed by estimating surface plasmon resonance peak around 449 nm by using a UV-Visible spectrophotometer. The effect of phytochemicals in SM leaf extract on the development of stable SM-AgNCs was confirmed by FTIR spectroscopy. The size of the fabricated SM-AgNCs was estimated by dynamic light scattering and zeta-sizer analysis and the morphology of the SM-AgNCs was examined by transmission electron microscopy. The presence of clusters of Ag particles in the prepared SM-AgNCs was recognized by energy dispersion X-ray analysis. The results show that saponins, phytosterols, and phenolic compounds present in plant extract may play a great part in developing the SM-AgNCs in their specialized particles. The succeeded SM-AgNCs shows incredible anti-bacterial action towards Escherichia coli and Bacillus subtilis. In-light of the antibacterial study, these SM-AgNCs were analyzed with calf thymus-DNA and found significant damage to the strand of thymus-DNA.

Increased Catalase Activity and Maintenance of Photosystem II Distinguishes High-Yield Mutants From Low-Yield Mutants of Rice var. Nagina22 Under Low-Phosphorus Stress.

An upland rice variety, Nagina22 (N22) and its 137 ethyl methanesulfonate (EMS)-induced mutants, along with a sensitive variety, Jaya, was screened both in low phosphorus (P) field (Olsen P 1.8) and in normal field (Olsen P 24) during dry season. Based on the grain yield (YLD) of plants in normal field and plants in low P field, 27 gain of function (high-YLD represented as hy) and 9 loss of function (low-YLD represented as ly) mutants were selected and compared with N22 for physiological and genotyping studies. In low P field, hy mutants showed higher P concentration in roots, leaves, grains, and in the whole plant than in ly mutants at harvest. In low P conditions, F v/F m and qN were 24% higher in hy mutants than in ly mutants. In comparison with ly mutants, the superoxide dismutase (SOD) activity in the roots and leaves of hy mutants in low P fields was 9% and 41% higher at the vegetative stage, respectively, but 51% and 14% lower in the roots and leaves at the reproductive stage, respectively. However, in comparison with ly mutants, the catalase (CAT) activity in the roots and leaves of hy mutants in low P fields was 35% higher at the vegetative stage and 15% and 17% higher at the reproductive stage, respectively. Similarly, hy mutants in low P field showed 20% and 80% higher peroxidase (POD) activity in the roots and leaves at the vegetative stage, respectively, but showed 14% and 16% lower POD activity at the reproductive stage in the roots and leaves, respectively. Marker trait association analysis using 48 simple sequence repeat (SSR) markers and 10 Pup1 gene markers showed that RM3648 and RM451 in chromosome 4 were significantly associated with grain YLD, tiller number (TN), SOD, and POD activities in both the roots and leaves in low P conditions only. Similarly, RM3334 and RM6300 in chromosome 5 were associated with CAT activity in leaves in low P conditions. Notably, grain YLD was positively and significantly correlated with CAT activity in the roots and shoots, F v/F m and qN in low P conditions, and the shoots' P concentration and qN in normal conditions. Furthermore, CAT activity in shoots was positively and significantly correlated with TN in both low P and normal conditions. Thus, chromosomal regions and physiological traits that have a role in imparting tolerance to low P in the field were identified.