Interaction effect of seedling age and different doses of GA3 on growth and yield of tomato (Lycopersicon esculentum Mill.)

An experiment was conducted in the Horticultural Farm of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka-1207 during the period from October 2010 to March 2011 to find out the effect of GA3 and seedling age on the growth and yield of tomato. The experiment was laid out in randomized complete block design (RCBD) with three replications. The experiment consisted of four concentration of GA3 such as control G0 = no GA3, G1= 75 ppm GA3, G2 = 100 ppm GA3 and G3 =125 ppm GA3; three different seedling ages such as S1= 20 days, S2 = 25 days and S3 = 30 days old seedling. All parameter varied significantly at different concentration of GA3 in different DAT. The combined effect of G3S3 (125 ppm GA3 with 30 days old seedling) gave the maximum yield (90.28 t ha-1), on the other hand combined effect of G0S1 (no GA3 with 20 days old seedling) gave the minimum yield (59.83 t ha-1). The maximum yield (2.79 kg) plant-1 was recorded from treatment combination of G3S3 and the minimum yield (1.20 kg) was recorded from treatment combination G0S1. The maximum yield (32.47 kg) plot-1 was recorded from treatment combination G3S3 and the minimum yield (21.52 kg) plot-1 was recorded from treatment combination G0S1. The maximum yield (90.28 t ha-1) was recorded from treatment combination of G3S3 and the minimum yield (59.83 t ha-1) was recorded from treatment combination of G0S1. Therefore, 125 ppm GA3 with 30 days old seedling was found suitable combination for tomato production

Field blue straggler stars: Discovery of white dwarf companions to blue metal-poor stars using UVIT/AstroSat

Blue metal-poor (BMP) stars are the main-sequence stars that appear bluer and more luminous than normal turn-off stars of metal-poor globular clusters. They are believed to be either field blue straggler stars (FBSS) formed via post-mass transfer mechanism or accreted from dwarf satellite galaxies of the Milky Way. A significant fraction of BMP stars are discovered to be potential binaries. We observed 27 BMP stars using UVIT/\textit{AstroSat} in two FUV filters, F148W and F169M. We report the discovery of white dwarf (WD) companions of 12 BMP stars for the first time. The WD companions have estimated temperatures T$_{eff}$ $\sim$10500 $-$ 18250 K, and masses 0.17 M$_{\odot}$ $-$ 0.8 M$_{\odot}$. Based on [Fe/H] and space velocity, we group the 12 BMP/FBSS stars as the thick disk (5) and halo (5), whereas two stars appear to be in-between. All the 5 thick disk BMP/FBSS have extremely low-mass (M $<$ 0.2 M$_{\odot}$) WDs as companions, whereas the 5 halo BMP/FBSS have low (0.2 M$_{\odot}$ $<$ M $<$ 0.4 M$_{\odot}$), normal (0.4 M$_{\odot}$ $<$ M $<$ 0.6M$_{\odot}$), and high mass (M $>$ 0.6 M$_{\odot}$) WD companions. Our analysis suggests that at least $\sim$44 $\%$ of BMP stars are FBSS, and these stars hold the key to understand the details of mass transfer, binary properties, and chemical enrichment among the FBSS

Nutritional composition and bioactive compounds of mini watermelon genotypes in Bangladesh

Given the present rising trends in changing lifestyle and consumption patterns, watermelon production has shifted from big to small-sized fruits having desirable quality attributes. Hence, analyses of fruit quality traits of mini watermelon are crucial to develop improved cultivars with enhanced nutritional compositions, consumer-preferred traits and extended storage life. In this context, fruit morphological and nutritional attributes of five mini watermelon genotypes namely BARI watermelon 1 (W1), BARI watermelon 2 (W2), L-32468 (W3), L-32236 (W4) and L-32394 (W5) were evaluated to appraise promising genotypes with better fruit quality. The evaluated genotypes expressed different levels of diversity for fruit physical qualitative traits including differences in shape, rind and flesh color and texture. The study also revealed significant variability among the genotypes regarding all observed fruit morphological and nutritional aspects as well as bioactive compounds. Among the studied genotypes, W1 stood out with the highest TSS as well as rind vitamin C and total phenolic content accompanied by higher fruit weight and thick rind. On the other hand, W3 genotype was featured with higher amount of \b{eta} carotene, total phenolic and flavonoid content in its flesh along with rind enriched with \b{eta} carotene and minerals. However, comparatively higher amount of sugar and total flavonoid content was recorded in the rind of W5 genotype. Therefore, W1 and W3 could be exploited for table purpose and using in breeding program to develop mini watermelon cultivars with more attractive fruits in terms of quality acceptance and nutritional value in Bangladesh. Furthermore, rind of BARI watermelon 1 and L-32394 could be considered as the potential cheap source of bioactive compounds to be used for dietary and industrial purpose which would decrease the solid waste in the environment.Comment: 22 pages, 6 tables, 3 figure

GlobULeS. IV. UVIT/AstroSat detection of extremely low mass white dwarf companions to blue straggler stars in NGC 362

We report the discovery of extremely low mass white dwarfs (ELM WDs) as a companion of blue straggler stars (BSSs) in the Galactic globular cluster NGC 362 using images from AstroSat's Ultra Violet Imaging Telescope (UVIT). Spectral energy distributions (SEDs) for 26 far-UV (FUV) bright member BSSs are created using data from the UVIT, the UltraViolet and Optical Telescope (UVOT), Gaia EDR3, and the 2.2 m ESO/MPI telescope. A single SED is fitted to 14 BSSs, whereas double-SED fits revealed ELM WDs as binary companions in 12 of the 26 BSSs studied. The effective temperature, radius, luminosity, and mass of the 12 ELM WDs are found to have a range of Teff = 9750−18,000 K, R = 0.1−0.4 R⊙, L = 0.4−3.3 L⊙, and M = 0.16−0.20 M⊙. These suggest that 12 BSSs are post-mass-transfer systems formed through the case A/B mass transfer pathway. To the best of our knowledge, this is the first finding of ELM WDs as companions to BSSs in globular clusters. This cluster is known to have a binary BSS sequence, and the 12 binary and 14 single BSSs (as classified by the SEDs) follow the mass transfer and collisional sequence of BSSs in the color–magnitude diagram. The cooling ages of nine of the ELM WDs are found to be younger than 500 Myr. Though the binary BSSs may have formed during the core collapse (∼200 Myr) or as part of the dynamical evolution of the cluster, they provide new insights on the dynamics of this cluster

Globular Cluster UVIT legacy Survey (GlobUleS) III. Omega Centauri in Far-Ultraviolet

We present the first comprehensive study of the most massive globular cluster Omega Centauri in the far-ultraviolet (FUV) extending from the center to ~ 28% of the tidal radius using the Ultraviolet Imaging Telescope aboard AstroSat. A comparison of the FUV-optical color-magnitude diagrams with available canonical models reveals that the horizontal branch (HB) stars bluer than the knee (hHBs) and the white dwarfs (WDs) are fainter in the FUV by ~ 0.5 mag than model predictions. They are also fainter than their counterparts in M13, another massive cluster. We simulated HB with at least five subpopulations, including three He-rich populations with a substantial He enrichment of Y up to 0.43 dex, to reproduce the observed FUV distribution. We find the He-rich younger subpopulations to be radially more segregated than the He-normal older ones, suggesting an in-situ enrichment from older generations. The Omega Cen hHBs span the same effective temperature range as their M13 counterparts, but some have smaller radii and lower luminosities. This may suggest that a fraction of Omega Cen hHBs are less massive than those of M13, similar to the result derived from earlier spectroscopic studies of outer extreme HB stars. The WDs in Omega Cen and M13 have similar luminosity-radius-effective temperature parameters, and 0.44 - 0.46 M$_\odot$ He-core WD model tracks evolving from progenitors with Y = 0.4 dex are found to fit the majority of these. This study provides constraints on the formation models of Omega Cen based on the estimated range in age, [Fe/H] and Y (in particular), for the HB stars.Comment: Accepted for publication in ApJL; 13 pages, 5 figures, 1 tabl