M. M. Haque

Genetic variability in flooding tolerance of mungbean (Vigna radiata L. Wilczek) genotypes

The study was an exploratory in nature conducted using a large number of mungbean (Vigna radiata L. Wilczek) genotypes of diverse growth habit and adaptive characters. Soil flooding induced changes in eleven morpho-physiological characters of one-week old seedlings of 530 mungbean genotypes was compared in the study. The first and second principal components (PC) of principal component analysis (PCA) results accounted for 58 and 14%, respectively of the total variations of mungbean genotypes. The variation for first PC was composed mainly of relative dry weight (DW) of shoot and leaf as well as total DW. The second PC distinguished the genotypes that produced larger root system. There were seven clusters distinguished in the cluster analysis. The genotypes in cluster 4 and 6 performed better in respect of relative total DW and relative root DW, respectively and hence having flooding tolerance. The genotypes in clusters 7 and 1 performed very poorly and those of under clusters 3, 2 and 5 were moderate to poor. D2 analysis indicated that the clusters differed significantly from each other. Discriminant function analysis (DFA) reaffirmed that more than 90% of the genotypes were correctly assigned to clusters. Both PCA and DFA confirmed that the relative total DW followed by shoot and leaf DW as well as leaf area were the major discriminatory variables and the root : shoot ratio and root DW were the secondary important variables to distinguish genotypes into groups. In this study, multivariate analyses were used in identifying the mungbean genotypes of desirable traits for flooding tolerance.

Assessment of genetic divergence in salt tolerance of soybean (Glycine max L.) genotypes

A large number of soybean (Glycine max L.) genotypes of diverse growth habit and adaptive characters were used in the experiment. Soil salinity-induced changes in nine morpho-physiological characters of 30-day-old seedlings of 170 soybean genotypes were compared in the study. The first and second principal components (PC) of principal component analysis (PCA) results accounted for 97 and 2.5%, respectively, of the total variations of soybean genotypes. The variation for the first PC was composed mainly of relative total dry weight (DW), relative shoot dry weight, as well as petiole dry weight. There were four clusters distinguished in the cluster analysis. The genotypes in cluster IV performed better in respect to relative total dry weight and relative shoot dry weight and hence having salt tolerance. The genotypes clusters III performed very poorly and those of clusters II and I were moderate to poor. D2 analysis indicated that the clusters differed significantly from each other. Discriminant function analysis (DFA) again asserts strongly that more than 92% of the genotypes were correctly assigned to clusters. Both PCA and DFA confirmed that the relative total DW followed by shoot and petiole DW were the major discriminatory variables, and the root DW were the secondary important variables to distinguish genotypes into groups. In this study, multivariate analyses were used in identifying the soybean genotypes of desirable traits for salt tolerance.

Genotypic variability in plant water status of French bean under drought stress

Seven genotypes of French bean (Phaseolus vulgaris L.) were evaluated under semi-controlled conditions at the Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh to analyze genotypic variability in leaf water status under water stress. The plants were grown under two moisture regimes, viz. 80% field capacity (FC) and 50% FC throughout the growing season. The genotypes showed significant variation in water relation traits. Genotypes BB24 and BB43 maintained higher relative water content (RWC), but lower turgid weight/dry weight ratio (TW/DW) and water uptake capacity (WUC). When drought susceptibility index (DSI) among the genotypes was considered, BB24 was found the most tolerant to drought and BB04 was the most susceptible one. A close positive relationship between leaf TW/DW and DSI under drought was recorded (R2 = 0.627). Leaf TW/DW was decreased considerably due to water stress by 10% in genotype BB24 followed by BB43 (13%), and both BARI bushbean-2 and BB04 (19%). Stomatal aperture and whole plant transpiration rate were found minimal in the BB24 and BB43 compared to that of BB04 and BARI bushbean-2. Considering these water relation traits, genotypes BB24 and BB43 may be considered as relatively tolerant to tissue dehydration. The study also revealed that the TW/DW, WUC, stomatal aperture, and whole plant transpiration rate was negatively and significantly associated with yield; however, the RWC was positively correlated with yield under water stress conditions.

Electron impact secondary electron emissions from atomic and molecular solid targets

Synopsis The Sternglass theory [Sternglass, Phys. Rev. 108, (1957) 1] for fast-ion-induced secondary electron emission, which is proportional to the stopping powers, has been modified to calculate the electron impact secondary electron yield from both elemental and compound targets with atomic number Z = 4 92 for incident energy range 5 10 5   i E eV. This modification includes the use of a realistic stopping power expression that involves calcula-

Electron impact L and M-subshell ionization cross sections for atoms (14 ≤ Z ≤ 92) including the relativistic effects

Synopsis Electron impact inner-subshell (L and M) ionization cross sections for various atoms (14≤ Z ≤92) are calculated and compared with experimental and other theoretical results. The electron impact ionization cross sections (EIICS) are needed in various fields ranging from biological to chemical, plasma to astrophysics, and laser to medical physics. At energies above the breakup threshold the scattering in a three-body system remains a most challenging quantum mechanical problem. For simpler targets, like H and He, there are few accurate calculations available but for many electron targets it is rather disappointing. Experimental data for the K-shell ionization are rife; they are, however, limited for both the L-shell and M-shell but their subshell data [1] are practically zero. On the other hand the huge demands for EIICS in applications cannot be fulfilled easily by generating a database either by experimental or by quantal studies. So resorts are made to fulfill this void by using simple–to-use models that must yield accurate results. In this study we report few such models that are capable of describing reasonably the experimental data for a wide range of atomic targets over a wider energy domain. Two easy-to-implement models, namely XMCN [1,2] and XMUIBED [1], are presented here; the former modifies the DM relativistic factor of the MCN model with a Z-dependent factor, while the latter replaces the Bethe part of the BED model by a simple two-parameter Born term. Both the XMCN and XMUIBED models, however, generate reliable EIICS quickly. Our results in Fig. 1 are compared with the experimental data and found good agreements for Land M-subshell.

Varietal Evaluation of Potato Microtuber and Plantlet in Seed Tuber Production

Diamant, Asterix, and Granola varieties differed significantly in foliage coverage, plant height, and yield. They produced lower graded minituber (67.62%, 78.16% ha−1, and 66.27% of Asterix, Granola, and Diamant varieties, resp.) as per seed rule of the National Seed Board of Bangladesh, while foliage coverage (74.38%) was the maximum in Diamant. Microtuber in field condition showed the maximum survivability, plant height, foliage coverage, number of stems plant−1, and SPAD value as well as yield of minituber compared to plantlet. On the contrary, microtuber derived plants of the three varieties gave the maximum yield (20.49 t ha−1, 19.12 t/ha−1, and 19.98 t ha−1 of Asterix, Granola, and Diamant varieties, resp.) and it was the minimum in plants of plantlets derived from all varieties (9.50 t ha−1, 7.88 t ha−1, and 9.70 t ha−1 of Asterix, Granola, and Diamant varieties, resp.). Microtuber derived plants produced a minimum percentage of <28 mm size of minituber compared to plantlet derived plants in case of all varieties.

Correlation of Serum T4, T3 and TSH Levels with Radioiodine Thyroid Uptakes

In total, 240 studies including serum T4, T3, TSH and thyroid uptake at 2 and 24 hrs were performed in 48 Bangladeshi adult individuals (52% female and 48% male). The aim of the present study was to make a correlation between thyroid serum levels and radioiodine thyroid uptake values of same individuals. Serum T4 and T3 were assessed with commercially available radioimmunoassay kits and TSH with a highly sensitive immunoradiometric assay kits (Beijing Atom Hightech Co. Ltd., China). The uptake study was consisted of oral administration of 6 – 10 μCi of 131 I as sodium-iodide. Correlation coefficients (r) were calculated and tested for statistical significance. Radioiodine thyroid uptake values measured in this study show a statistically significant positive correlation with T4 and T3 levels and negative correlation with serum TSH levels. The present results were also compared with the experimental data available in literature and found to be in fairly good agreement.

Synthesis and Characterization with Antimicrobial activity of Cu(II), Ni(II) and Zn(II) metal complexes of Schiff base derived from o-aminophenol/ethylenediamine and Cinnamaldehyde

Transition metal complexes of Co(II), Cu(II), Ni(II) and Zn(II) Containing Bidentate Schiff base, derived from the condensation of ethylenediamine/o-aminophenol and cinnamaldehyde were synthesized and characterized by IR, UV-Vis., and some physical measurements. IR spectral studies show the binding sites of the Schiff base ligand with the metal ion. Molar conductance data and magnetic susceptibility measurements give evidence for monomeric and electrolytic nature of the complexes. The complexes have been found to have moderate antimicrobial activity against the tested bacteria.