Crop Protection to Outsmart Climate Change for Food Security & Environmental Conservation

Pearl millet is an important source of energy and nutrition for millions of people in the drylands of sub-Saharan Africa and South Asia. Recently, blast, also known as leaf spot, caused by Magnaporthe grisea (Anamorph: Pyricularia grisea) has emerged as a serious threat to pearl millet cultivation causing substantial yield loss. Seeds tend to contain several storage proteins, some have an inhibitory action against plant pathogens. The present study aimed to identify the defense proteins in seed extrudes of ten pearl millet blast differential lines and investigate their protective effect against growth of Pyricularia grisea (Pg 45, Patancheru isolate). The biochemical observations of seed extrudes revealed the presence of plant defense linked hydrolytic enzymes chitinases (12-18 units/ml), β-1,3 glucanases (16-48 units/mg protein) as well as cysteine protease inhibitors (57-123 PI units/mg protein) among the tested lines. The pre-treatment of P. grisea media with respective line seed extrudes resulted in significant reduction (22-40%; p<0.001) of fungal radial growth and fungal dry weight (20-77%; p<0.001). The effective concentration for the 50% fungal growth inhibition (EC50) was identified as 400 and 600 μg/ml for resistant lines IP 21187 and ICMR 06444, respectively. Further, the seed extrudes were able to significantly retard the spore germination (by 18 h) and initial growth (by 48 h) of Pg 45 by 24-83%. These findings suggest that the identified proteins are playing synergistic role in pearl millet defense against blast pathogen, Pg 45 and provide the basis to explore the novel biological control strategies in plant defense

Efficacy of seed defense proteins in biofortified pearl millet lines against blast and downy mildew

Pearl millet is a nutritious and climate-resilient dryland cereal crop. The present study was conducted to identify the defense proteins in seed extrudes of 25 biofortified (Fe and Zn) inbred lines, and investigate their efficacy against blast (isolates Pg 45, Pg 138, and Pg 186) and downy mildew (isolates Sg 409, Sg 445, and Sg 576) diseases. The study revealed the presence of cysteine protease inhibitors (4.3–58.5 units/mg) as well as pathogenesis-related (PR) hydrolases including chitinases (5.3–16.3 units/ml), β-1,3-glucanases (7.3–32.9 units/mg), and cellulases (0.19–4.11 units/mg) in the test lines. The activity levels of cystatins and PR hydrolases in the pearl millet lines were in relative consistency with the resistance levels observed in the greenhouse screenings against blast and downy mildew diseases. Furthermore, antifungal screenings of seed proteins against blast pathogen exhibited a significant reduction in radial growth of Pg 138 (57%) followed by Pg 186 (13%) and Pg 45 (10%). Spectrophotometric assays ( A595) exhibited significant retardation in spore germination and initial growth (48 h) of Pg 45 (53.8–87.3%) followed by Pg 186 (19.2–61.3%) and Pg 138 (1.5–36.7%). Furthermore, seed proteins of biofortified lines efficiently reduced the downy mildew disease incidence in greenhouse screenings by seed treatments of susceptible pearl millet lines ICMP 451 (0.6–36% against Sg 409; 32–61% against Sg 576) and 7042R (14–80% against Sg 445). The results of this study will provide insight into the biochemical basis of resistance in pearl millet against foliar blast and downy mildew diseases, and to exploit novel strategies for breeding for disease resistance

Stability and rheological study on carbon-based nanofluids

In this study, an organic derived nanofluid has been developed from bio-origin resources. Carbon nanopowder (CNP) is obtained from derived rice husk and was prepared via a simple two-steps thermal process with minimum energy (low temperature and reaction time) using solar assisted plasma furnace. Nanofluids comprised of CNP and EG/water binary mixture has been prepared at various concentration such as 0.02 – 0.10 vol% of CNP. Flow curve of nanofluids showed that at minimum inclusion of CNP improved the stress of the fluid significantly. More to the addition, dynamic viscosity measure possesses that addition of CNP stabilized the properties of the fluid compared to virgin base fluid. Moreover, the stability results showed that the nanofluids stabilized starting from 1 week onwards as evidenced by UV-Visible spectrophotometer analysis. Furthermore, little to no precipitate noticed even after 8 weeks. This work offers greener approach for nanofluids which organic derived and environmentally friendly (very low percentage of nanoparticle, 0.02 vol%