Effects of micronutrients on bulb growth, yield and quality of local and high yielding onion (Allium cepa L.) cultivars in Bangladesh

Micronutrients have important functions on onion production. An experiment was conducted at the Landscape section and Laboratory of the Department of Horticulture, Bangladesh Agricultural University, Mymensingh during the period from October, 2017 to March, 2018 to investigate the effects of micronutrients on bulb growth, yield and quality of local and high yielding (HY) onion cultivars in Bangladesh. The experiment comprised three onion cultivars viz., Taherpuri (local), BARI Piaz 1 (HY) and BARI Piaz 4 (HY), and five micronutrients viz., Control (no micronutrient), Boron (B) @ 0.2 g/plot, Zinc (Zn) @ 0.5 g/plot, Copper (Cu) @ 0.2 g/plot and B+Zn+Cu @ (0.2+0.5+0.2 g/plot). The two-factor experiment was laid out in randomized complete block design with three replications. Results revealed that onion cultivars and micronutrients had significant influence on the parameters studied. BARI Piaz 4 along with the application of B+Zn+Cu @ 0.2+0.5+0.2 g/plot produced the highest bulb size, increased plant height, number of leaves, fresh weight of bulb, per cent dry matter content of bulbs and bulb yield compared to other onion cultivars and micronutrient treatments. The highest bulb yield (16.07 t/ha) was recorded in B+Zn+Cu, while the lowest bulb yield (8.92 t/ha) was found from control. Highest gross yield of onion (20.67 t/ha) was recorded from BARI Piaz 4 with B+Zn+Cu @ 0.2+0.5+0.2 g/plot. Therefore, it can be concluded that combined treatment of BARI Piaz 4 and B+Zn+Cu @ @ 0.2+0.5+0.2 g/plot was found to be better in respect of bulb growth and yield, and Taherpuri for quality of onion

Genetic regulation of daylength adaptation and bulb formation in onion (Allium cepa L.).

Genetic studies aimed at onion improvement have been limited because of outcrossing, high heterozygosity and a very large genome size with a high level of repetitive DNA. Onion bulb initiation is photoperiod-dependent, which places a significant barrier to adapting new varieties for growth at different latitudes. In comparison to photoperiodic regulation of flowering, relatively little is known about genetic regulation of the bulbing process. This project aims to test the hypothesis that the genetic regulation of bulb formation in response to daylength is analogous to the daylength regulation of flowering and to identify genes involved in daylength adaptation in onion. A comprehensive set of developmental, diurnal and spatial mRNA and quantitative expression experiments were carried out to investigate the bulbing response. Bulbing ratios were used to measure the bulbing response of onion plants and the reversibility of the bulbing process under long day (LD) and short day (SD) conditions. RNA-Seq analysis provided a large number of differentially expressed transcripts in onion in response to daylength. Five FT and three COL genes were identified in onion including two novel COL sequences. AcFT1 was expressed in LD, which might induce bulb formation, while AcFT4 was expressed in SD, which might inhibit bulb formation. AcFT5 and AcFT6 were expressed in LD and might also be involved in bulb formation itself. FKF1, GI and COL2 showed good diurnal expression patterns consistent with photoperiod sensing and regulation of FT1. All FT genes exhibited different diurnal expression patterns peaking at different times of the day. FKF1, COL2, COL3, FT1, FT4, LFY and GA3ox1 genes showed distinctive patterns of tissue specific expression in onion. FT genes did not show any variation in expression that would account for the difference in critical daylength between the LD and SD varieties of onio

Temporal and spatial expression of Arabidopsis gene homologs control daylength adaptation and bulb formation in onion (Allium cepa L.)

Genetic studies aimed at onion improvement have been limited because of high heterozygosity, a very large genome size with a high level of repetitive DNA and a biennial life cycle. Onion bulb initiation is daylength-dependent, which places a significant barrier to adapting new varieties for growth at different latitudes. Compared to the photoperiodic regulation of flowering, relatively little is known about genetic regulation of the bulbing process. This study aims to identify the role of gene sequences involved in daylength-regulated bulb formation and tissue specific expression of onion. A comprehensive set of developmental and spatial quantitative mRNA expression experiments were carried out to investigate expression of onion FLOWERING LOCUS T (AcFT), LEAFY (AcLFY) and GIBBERELLIN-3 OXIDASE (GA3ox1) during the bulbing response. Bulbing ratios were used to measure the response of onion plants under long day (LD) and short day (SD) conditions. AcFT1 was expressed in LD, which induces bulb formation, while AcFT4 was expressed in SD, which inhibits bulb formation. AcFT5 and AcFT6 were expressed in LD and might also be involved in bulb formation itself. All AcFT, AcLFY and GA3ox1 genes showed distinctive patterns of tissue specific expression in onion, with AcFT genes found primarily in the sites of perception in the leaf and LFY in the basal tissues, the site of response. The results are consistent with AcFT1 expression being the signal for LD-induced bulb initiation and AcFT4, being involved in suppressing bulbing in SD

Morphological and Morphometrical Study of Umbilical Cord of Newborn Babies

out during January to December 1998 at Bangabandhu Sheikh Mujib Medical University, Dhaka to expand the knowledge of gross anatomy of the umbilical cord of Bangladesh. The length of the cords were irrespective of sex ranged from 28 to 93 cm with a mean (±SD) of 55.6 (±10.78). The length of the umbilical cords of males were significantly longer than female (P\u3c0.001). The diameter of the cords irrespective of sex were varied from 1 to 1.9 cm with a mean (±SD) of 1.45±0.31 cm. The mean circumference length percentage ratio index of umbilical cord was 8.31. Thirty-three (66%) cords were inserted eccentrically, all being paracentral in position. The rest were inserted centrally. False knots were more frequent (47; 94%). Only one (2%) showed a true knot in addition of false knot. In 2(4%) cases cord had not any true or false knot. It is concluded that the gross morphological and morphometrical features of the umbilical cord in Bangladesh appear to be similar to those described in western literature

Psychiatric Morbidity in Psoriasis and Vitiligo in Two Tertiary Hospitals in Bangladesh

Background: Many of the established skin diseases give rise to psychiatric disorders notably psoriasis and vitiligo. In Bangladesh, no study has yet been reported on psychiatric morbidity among psoriasis and vitiligo patients. Objectives: The objective of the study was to see the psychiatric morbidities in two chronic skin diseases, psoriasis and vitiligo, in Bangladesh. Methods: This was a cross sectional, analytical and comparative study. It was conducted to see whether psychiatric morbidity was higher among patients with psoriasis than that of vitiligo. Specific types of psychiatric disorders were identified by consultant psychiatrist assigned as per criteria of (Diagnostic and Statistical Manual for Mental and Behavioural Disorders-Fourth Edition)DSM-IV among 50 patients with psoriasis and same number of patients with vitiligo and were compared. Study places were the Departments of Dermatology and Venereology, Bangabandhu Sheikh Mujib Medical University (BSMMU) and Dhaka Medical College Hospital (DMCH) in Dhaka city. Results: Among the two dermatological conditions, psychiatric disorders were found 25 (50%) in psoriatic patients and 12 (24%) that in vitiligo patients. The proportion of major depressive disorders (MDD) was higher among psoriasis patients 15(30.0%) compared to vitiligo patients 04(8.0%). However, no statistical difference was found between two groups of patients in terms of anxiety disorders (8% in psoriasis and 12% in vitiligo patients). In patients with psoriasis, MDD was found highest (30.0%) followed by anxiety disorders (8.0%), adjustment disorder (4.0%) and somatoform disorder not otherwise specified (2.0%). Whereas, among the vitiligo patients, anxiety disorder was found highest (12.0%) followed by MDD (8.0%). The Present study showed significant association of psychiatric morbidities in these two dermatological diseases (psoriasis and vitiligo) with the variables of the study population. Conclusion: It has been found in Bangladesh that the psychiatric morbidity is higher among the patients with psoriasis than vitiligo. Key words: Psoriasis; Vitiligo; Psychiatric morbidity DOI: http://dx.doi.org/10.3329/bsmmuj.v4i2.8636 BSMMU J 2011; 4(2):88-9

Histomorphological Study of Umbilical Cord on 50 Bangladeshi

Microscopic study was done on 50 human umbilical cords in the Department of Anatomy, during January to December 1998 at Bangabandhu Sheikh Mujib Medical University, Dhaka. The basic structure of the umbilical cord was observed. The covering of umbilical cord varied on two sides. The side overlying the umbilical vein was covered by simple epithelium and that overlying the umbilical arteries was covered by multilayer epithelium. Presence of internal elastic lamina of umbilical arteries was found in 18% and in the veins was in 70% cases. Remnant of allantois was found in 28% cases

Effects of non-chemical treatments on postharvest diseases, shelf life and quality of papaya under two different maturity stages

Papaya is a climacteric fruit and highly perishable in nature, which trigger ethylene production and hence, its consumption period is very short after harvesting. The experiment was conducted at the Laboratories of the Departments of Horticulture and Agricultural Chemistry, Bangladesh Agricultural University; and Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh during the period from March to June 2018 to study the effect of non-chemical treatments on postharvest diseases, shelf life and quality of papaya under two different maturity stages. The two-factor experiment consisted of two maturity stages viz. (i) Maturity stage 1 (M1: mature green colour) and (ii) Maturity stage 2 (M2: 0-10% yellowing); and six non-chemical treatments viz. (i) Control (T0), (ii) Hot water treatment @ 50�C for 10 minutes (T1), (iii) Gamma irradiation @ 0.08 kGy for 10 minutes (T2), (iv) Chitosan coating @ 2% (T3), (iv) Hot water + gamma irradiation (T4), and (vi) Hot water + chitosan coating (T5). The experiment was conducted in a completely randomized design (CRD) with 3 replications. The combined effect of maturity stages and non-chemical treatments were significant on all the parameters studied viz. external colour, weight loss, pulp to peel ratio, pulp pH, total soluble solids (TSS), disease incidence and severity, and shelf life of papaya. The papaya fruits under combined treatment of hot water plus gamma irradiation showed better appearance and external colour than the others at both maturity stages. The maximum weight loss was recorded in M1T0 (17.96%) followed by M2T0 (16.58%) while the minimum was found in M1T5 (3.69) followed by M2T5 (3.91). The highest pulp to peel ratio was observed in M1T4 (3.82) followed by M1T5 (3.78), while the lowest (3.00) was recorded in control under both maturity stages. The highest pulp pH was observed in M2T4 (6.15) followed by M2T5 (6.07) while the lowest was found in M2T0 (4.83) followed by M1T0 (5.05). The maximum disease incidence and severity were recorded (100%) in M1T0 and M2T0, whereas the minimum disease incidence (81%) and severity (12.36%) was found in M1T4. The longest shelf life (16.50 days) was obtained in M1T4 followed by M2T4 (15.25 days) and the shortest shelf life (8.65 days) was observed in M2T0 followed by M1T0 (9.25 days). Thus, hot water plus gamma irradiation followed by hot water plus chitosan coating under both maturity stages could be used to significantly reduce postharvest fungal infection, extend shelf life and improve quality of papaya

Effect of corm size and growth regulators on growth, flowering and quality of gladiolus (Gladiolus grandiflorus L.)

Gladiolus is the 8th most important in the world cut flower trade grown for its elegant attractive spikes and good keeping quality. However, the farmers in Bangladesh have limited access to the scientific cultivation of this crop, and yield and quality production of flower is low compared to other gladiolus growing countries in the world. Growth regulating chemicals have been reported to be very effective in manipulating growth and flowering of gladiolus. Therefore, an experiment was conducted at the Landscaping section of the Department of Horticulture, Bangladesh Agricultural University, Mymensingh, during the period from October 2017 to April 2018 to study the effect of corm size and growth regulators on growth, flowering and quality of gladiolus (Gladiolus grandiflorus L.). The experiment consisted of two corm sizes viz., 3-4 and 4-5 cm, and two growth regulators viz., GA3 @ 250, 500 and 750 ppm, and NAA @ 100, 200 and 300 ppm along with water as control. The two-factor experiment was laid out in a randomised complete block design with three replications. The results revealed that the corm size and growth regulators at different concentrations significantly affected various growth, floral and quality traits of gladiolus. The highest plant height, maximum number of leaves per plant, longest leaf length, maximum number of florets per spike, longest spike and rachis length were observed in 4-5 cm sized corms and GA3 @ 750 ppm, compared to rest of the treatments. Earliness in flower initiation and maximum duration of flower was observed in 4-5 cm sized corms and GA3 @ 500 ppm. Significant variations among the treatment combinations were observed for all the parameters studied. The treatment combination of 4-5 cm sized corms and GA3 @ 750 ppm was found to be best in respect of growth, floral and quality characters of gladiolus. [Fundam Appl Agric 2018; 3(3.000): 596-601

Diurnal expression of Arabidopsis gene homologs during daylength-regulated bulb formation in onion (Allium cepa L.)

Bulb initiation in long-day onion is regulated at the physiological level in a similar way to the photoperiodic regulation of flowering in Arabidopsis. This study establishes in onion, the diurnal time-course expression, in onion, of key genes particularly linked to circadian regulation in Arabidopsis. The long-day onion variety ‘Renate’ and the short-day (SD) onion variety ‘Hojem’ were used for these experiments. Onion plants were grown under natural LD conditions in the Phytobiology Glasshouse and immediately after bulbing they were transferred to two SANYO 2279 controlled environment cabinets for 10 d providing constant LD (16 h photoperiod including 8 h fluorescent followed by 8 h incandescent light) and constant short days (8 h photoperiod with fluorescent light). Five FLOWERING LOCUS T (FT) and three CONSTANS-LIKE (COL) genes were identified in onion, including two novel COL sequences through RNA-Seq analysis. The new AcCOL2 shows a diurnal pattern of expression similar to Arabidopsis CONSTANS (CO). Allium cepa FLAVIN-BINDING, KELCH REPEAT, F-BOX PROTEIN 1 (AcFKF1), Allium cepa GIGANTEA (AcGI) and AcCOL2 showed good diurnal expression patterns consistent with photoperiod sensing and regulation of AcFT1. All FT genes exhibited different diurnal expression patterns peaking at different times of the day. Notably, AcFT1 was expressed in the later part of the day which is very similar to the expression of Arabidopsis FT, while AcFT4 was expressed late in the night and the early morning in both Renate and Hojem varieties of onion, with the caveat that, AcFT4 is under less stringent daylength control in Hojem than in Renate. The timing of the peaks and expression pattern in both Renate F1 and Hojem suggest that AcFT5 may be under circadian or diurnal regulation under LD conditions and AcFT6 might not be circadian or diurnally regulated. These findings will help to understand the basis of the difference between responses of onions adapted to different latitudes, which is important for developing new varieties